#emc | Logs for 2005-10-10

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[00:00:11] <les> well you are at the right place...i'm a commercial user/machine designer
[00:00:29] <les> router or mill?
[00:00:41] <cnc_wright> It's a Jet JVM 830 mill
[00:01:01] <les> let me hunt up a picture
[00:02:04] <cnc_wright> www.matronics.com/cnc2/ is a jvm 830
[00:02:23] <les> and I see you are on the wiki...so am I
[00:02:53] <cnc_wright> I put myself in there a year ago and then fizzled out...
[00:03:57] <les> ok got a picture.
[00:04:01] <les> nice.
[00:04:14] <les> what is the travel?
[00:04:15] <K`zan> So much for the live cd. Funny though EMC would run on the hosed CD but on this one it fails to connect, might be that I don't have a driver attached.
[00:04:34] <K`zan> Play with it more later.
[00:05:31] <cnc_wright> That mill is not mine. I emailed the owner and he didn't upgrade to ballscrews. I think the travel is approx 27x10 or so.
[00:06:20] <les> ok so 20-25 mm screw
[00:06:51] <cnc_wright> I was thinking of get screw stock and machineing my own ends. Not sure about dealing with the heat treat and I'm have machined anything since high school (1988)
[00:07:36] <les> Well, I machine ballscrew ends fully hardenend
[00:07:42] <les> but it's slow
[00:08:11] <les> one trick is to grind off most of the case with a hand angle grinder
[00:08:20] <cnc_wright> I have a 13x40 lathe and a little bit of tooling. Not sure about feeds-n-speeds.
[00:08:22] <les> the middle is softer
[00:08:37] <cnc_wright> That's a good tip...Thanks.
[00:09:18] <les> cemented carbide, lots of coolant slow with light feeds
[00:09:30] <les> a tool post grinder helps.
[00:09:48] <cnc_wright> I do have some carbide insert tools...cemented is better for this application?
[00:10:37] <cnc_wright> I don't have a tool post grinder...yet.
[00:10:49] <les> yes because they rapidly dull due to interupted cuts in rc60 hardend steel. You can keep a diamond file handy to renew the edge
[00:11:39] <les> once the cut is continuous things get better
[00:11:44] <cnc_wright> See what a little experiance will do!....I have much to learn.
[00:12:20] <les> and the core is usually rc30-40....so you can single point cut threads easily
[00:12:50] <les> one caution: on many screws the lands are not a good mechanical datum
[00:13:12] <les> so collets might not work well
[00:13:56] <les> sometimes have to use a 4 jaw and indicate the raceway while in threading mode...matching the pitch of the screw
[00:14:57] <cnc_wright> I have a 4-jaw. Another good tip...I need to index all my work off of the grooves...which are the whole point of a ball screw in the first place.
[00:15:10] <les> right
[00:15:48] <les> many rolled screws have an uncontrolled burr on the lands
[00:16:02] <cnc_wright> Some of the ballscrew vendors have different end machine designs. I was going to go with two angular bearings.
[00:16:03] <les> ground too unless it's removed
[00:16:21] <les> that is what I use
[00:16:35] <les> db configured 40 degree angulars
[00:16:41] <les> preloaded
[00:16:49] <les> to 5% dynamic
[00:17:19] <les> it's tight lathe work...tenths matter.
[00:18:01] <cnc_wright> Probably beyond my skill level at this point. Perhaps I can buy them machined.
[00:18:18] <les> you can hone stuff to size with sandpaper if you don't have a grinder
[00:18:29] <cnc_wright> What do you do for the other end of the screw?
[00:18:30] <les> make stuff about .001 oversize
[00:19:05] <les> My last ones are fixed-fixed...double angulars on both ends
[00:19:21] <les> but the are very long
[00:19:43] <les> for you a floating deep groove will be fine on one end.
[00:21:00] <cnc_wright> Do you recommend any different brands/sources for screw stock?
[00:21:14] <les> ball or acme?
[00:21:21] <cnc_wright> Ball.
[00:21:35] <les> I use HIWIN.
[00:21:55] <les> very good quality, low price
[00:22:48] <cnc_wright> I think I looked at those a while back. Rockford & THK were the only names I could remember right now though.
[00:23:02] <cnc_wright> I need to go do some research again.
[00:23:07] <les> HIWIN is often half the price
[00:23:21] <les> look at ABBA too
[00:23:30] <les> although I have not tried them
[00:24:33] <cnc_wright> I was planning to go with ground screws and pre-loaded nuts.
[00:24:59] <les> ok. good choice but of course expensive.
[00:25:44] <les> Hiwin sells an oversize ball preloaded precision rolled that is very good
[00:26:18] <les> last quote I got was 2.5 meterx25mm with 2 nuts for $400
[00:26:41] <cnc_wright> hmmm.
[00:26:42] <les> they are shipped in that way, then choped for mill retrofit
[00:26:48] <les> or fit
[00:27:05] <les> they were oem for bridgeport cnc!
[00:27:30] <les> 5 TPI
[00:27:37] <cnc_wright> They should be long enough for mine then. Mine is a little smaller.
[00:27:42] <les> e300 .002"
[00:27:50] <les> but mine mapped out much better
[00:28:04] <les> no play.
[00:28:45] <cnc_wright> 5 tpi is what my current acme screws are.
[00:28:52] <les> they are 5% of max dynamic load preloaded
[00:29:24] <les> sounds good ...they are a little big at 25mm...but the price is hard to beat
[00:30:04] <les> 4140 chrome moly steel
[00:30:28] <cnc_wright> I had planned to make my ball screws "the same" as my acme ones so I could swap them in and put the handles back on.
[00:30:52] <cnc_wright> I need the mill to make the parts to hole my servos. Kind of a catch-22.
[00:30:58] <les> well that's just the ends right?
[00:31:07] <cnc_wright> yes
[00:31:28] <les> so no problem...turn em down to whatever you want
[00:31:39] <les> as long as there is room for the nut
[00:31:53] <cnc_wright> That's my current unknown.
[00:32:06] <cnc_wright> I have no idea what the yoke looks like in this machine.
[00:32:28] <les> just have to have a look I guess
[00:33:13] <cnc_wright> Are there any tricks to removing a mill table?
[00:33:39] <jmk_away> an engine hoist to hold it up
[00:33:44] <jmk_away> jmk_away is now known as jmkasunich
[00:33:51] <les> heh...I'll tell you soon...mine is about ready for a rescrape
[00:34:04] <les> some kind of hoist
[00:34:44] <jmkasunich> use T-nuts and clamps to allow you to attach the hoist above the center of gravity without straps or anything underneath the table to get in the way
[00:34:47] <cnc_wright> I have an eninge lift that folds up. It might fit through the door ;-)
[00:34:55] <les> although the jet might not be that heavy
[00:35:14] <jmkasunich> at least 150-200 lbs I bet
[00:35:17] <les> two people might easily take it off
[00:35:46] <les> well kinda easily
[00:35:48] <jmkasunich> the advantage of a hoist is control - you don't have that "get the damned thing off (or on) before I drop it" factor
[00:35:56] <les> yup
[00:36:19] <cnc_wright> You have to "slide" it all the way off one end don't you?
[00:36:30] <jmkasunich> I've done some machinery moving (1600 lb lathe, 1800 lb mill, comletely disassmbled and reassembled the mill) and I perfer to do it by myself
[00:36:47] <jmkasunich> that forces me to use hoists and such instead of brute force, forces me to plan things out ahead
[00:37:02] <les> heh I moved that whole shop from chicago
[00:37:02] <jmkasunich> yes, slides off
[00:37:14] <les> I don't ever ever want to do that again
[00:37:30] <jmkasunich> I did mine one at a time, with months between each one ;-)
[00:38:01] <jmkasunich> for the mill table, you probably need to remove the handle and dial and such from one or both ends, then remove at least one end bracket
[00:38:05] <les> mine took 2 overloaded 24 foot trucks...the biggest I could rent
[00:38:13] <jmkasunich> probably better to do both end brackets
[00:38:23] <jmkasunich> thn the table slides off, leaving the screw behind
[00:38:35] <jmkasunich> don't drop the table on the screw (that's why you need the hoist)
[00:39:05] <cnc_wright> The plan seems simple enough. The execution...we'll see.
[00:39:31] <jmkasunich> take notes when disassembling so you remember later
[00:39:45] <les> I have a lot of machines coming in so I have to deal with a bit of rigging
[00:39:54] <cnc_wright> It's time for me to take the nike approach and "just do it"
[00:40:05] <jmkasunich> some previous owner of my mill put the X leadscrew bearings together with both angular contact bearings facing the same way
[00:40:26] <cnc_wright> That doesn't do much good.
[00:40:29] <les> got bucket forks for the light stuff...forlift from the apple packing house down the street for the rest
[00:40:46] <les> forklift
[00:40:47] <jmkasunich> result: next heavy cut popped the bearings out of their ways (force was applied to the "weak side" of the bearings
[00:40:55] <les> eww
[00:41:00] <jmkasunich> yeah
[00:41:36] <jmkasunich> this mill is a horiz/vert combo, in horiz mode it sometimes needs heavy feeds
[00:41:44] <jmkasunich> so the feed mechanism is strong
[00:41:53] <cnc_wright> I have an escalera stair climbing hand truck for moving pinball machines. It has a forklift attachment that would be perfect for sliding the table on to.
[00:42:24] <jmkasunich> they interlock the feed with the spindle, cause otherwise if the spindle stops the feed will break tools, or bend the horizontal arbor (1") or worse
[00:43:03] <jmkasunich> better to lift from above if you can
[00:43:11] <jmkasunich> do you have a clamp and t-nut set?
[00:43:22] <les> I'm ready for a second mill. I was toying with a used vmc, but I fear if it didn't have a high speed spindle it would be useless for production
[00:43:25] <jmkasunich> lower forks onto table, clamp them down ;-)
[00:43:31] <les> and not needed for prototypes
[00:43:44] <cnc_wright> That's what I was just thinking.
[00:45:27] <cnc_wright> I'll have to come at it from the side though. Should still work. The hand truck is rated for 1500 lbs. I just have to be mindful of my CG.
[00:45:50] <Imperator_> night guys
[00:46:00] <cnc_wright> I can lower the knee all the way down. That might help a bit.
[00:46:12] <les> For engineering prototype work I think an emc converted bridgeport boss would be fine.
[00:46:35] <les> yeah I lower the table and rotate the head upside down to move...
[00:47:29] <cnc_wright> This is great. You have given me all kinds of ideas that I just wasn't coming up with before.
[00:47:41] <icee> so, when designing a microstepper
[00:47:46] <icee> how important is equal torque between steps?
[00:48:12] <icee> I'm thinking about driving with current amounts that are like.. (0,1), (.4,1), (1,1), (1,.4), (1,0)
[00:48:37] <icee> the torque at (0,1) is obviously (1/root(2)), or 71%, and at the next step it's 76% or so
[00:48:38] <jmkasunich> the ideal currents are points on a sine/cosine wave
[00:48:48] <icee> yah, I know that
[00:48:54] <jmkasunich> that would give you constant torq
[00:48:57] <jmkasunich> ok
[00:49:20] <jmkasunich> I see, you're asking how bad will it be if you approximate
[00:49:21] <icee> Rather than using a DAC per channel, I have in my current design two comparators per channel, and 2 global dacs
[00:49:24] <icee> and multiplex
[00:49:42] <icee> Some of the data sheets, like the L6228, for quarter stepping just do very naive things-- full current or half current
[00:49:51] <les> I'm a servo type so not sure...but I am using stepper on a paint robot....inherently explosion resistant
[00:50:35] <jmkasunich> trying to understand what you mean by 2 comps/chan and 2 global dacs
[00:50:51] <icee> jmkasunich: well, rather than having a DAC that i modulate for the stepping
[00:50:59] <jmkasunich> you have a micro or something? (you can build a simple microstepper drive without a micro or dacs)
[00:51:02] <icee> I have 2 DACs on the board that produce preset voltages that correspond to certian current levels
[00:51:10] <icee> I'm using a CPLD
[00:51:41] <icee> anyways, I compare the current on each phase to both the DACs, and feed the result to the CPLD
[00:51:54] <icee> a mux in there picks which current level I want per channel depending on the stepping sequence
[00:51:56] <jmkasunich> so trying to do as much as possible in the digital realm
[00:52:08] <jmkasunich> * jmkasunich is analog oriented
[00:52:37] <icee> Trying to avoid a lot of DACs for microstepping. Those two DAC outputs are shared for all 4 phases on my board
[00:53:01] <jmkasunich> why use DACs at all then, just use a couple of fixed resistor dividers
[00:53:14] <icee> That's what I probably will do initially
[00:53:30] <icee> But i'm putting down footprint for a SPI DAC and a SPI connector in
[00:54:14] <icee> I like the idea of software programmability of current levels, but I'll need another board to actually speak the SPI and do smart things with it
[00:54:26] <icee> (like lower current levels on inactivity, etc)
[00:54:55] <jmkasunich> can I suggest sticking with one comparator per winding, and using a crude resistive "DAC"?
[00:55:08] <icee> there's no microstepping then
[00:55:18] <jmkasunich> ie, 2 or 3 digital outputs, with resistors connected to them.
[00:55:37] <jmkasunich> the resistors all join at one node, and that is the reference for the comparator
[00:55:41] <icee> oh, i see.
[00:55:50] <jmkasunich> if all outs are hi, maxV, if all low, minV
[00:56:06] <jmkasunich> the resistors can be 1K, 2K, and 4K, gives you a crude 3 bit DAC
[00:56:11] <icee> Yah, I had thought about that or a parallel DAC
[00:56:26] <icee> I mean, most dacs are exactly what you describe, with input buffers and an output amplifier
[00:56:38] <jmkasunich> you could actually use custom resistor values, to get the exact voltages you want for sine/cosine
[00:57:03] <jmkasunich> for instance, 45deg = 0.707, you can choose resistors so that a particular bit pattern gives you that
[00:57:10] <icee> * icee nods
[00:57:14] <icee> it would increase my component count though
[00:57:19] <icee> and wouldn't be software programmable for current levels
[00:57:31] <jmkasunich> true
[00:57:48] <jmkasunich> the component count issue depends on your goals
[00:58:10] <jmkasunich> I'd rather have a bunch of $0.005 resistors than one $2.00 DAC
[00:58:43] <jmkasunich> how many microsteps per full step are you aiming for?
[00:59:06] <icee> I guess what I'm asking is-- what is better-- microstepping with imprecise angles and precise torques.. microstepping with varying torques and precise step sizes, or not microstepping at all
[00:59:09] <icee> 4
[00:59:31] <icee> i'm pretty sure the imprecise angles is a no-no
[00:59:51] <cradek> half stepping sure is easy
[00:59:56] <jmkasunich> its a vector thing - the two are related
[01:00:12] <icee> cradek: yah, but with half stepping the naive way you have nonuniform torques too
[01:00:25] <icee> you're alternating between 71% and 100% torque
[01:00:44] <jmkasunich> torque is proportional to the magnitude of the current vector times the angular displacement between that vector and the rotor position
[01:01:07] <jmkasunich> so changing either the magnitude or the spacing will result in torque ripple
[01:01:20] <icee> jmkasunich: you also need to factor in rotor inertia
[01:01:32] <jmkasunich> not really
[01:02:40] <jmkasunich> the reaction of the rotor to the torque ripple wil be affected by rotor intertia (actually by total inertia), but the actual ripple won't be
[01:03:11] <icee> i guess what i'm trying to ask is.. what real world performance problems can I expect from varying torque? I figure it must not be that bad, because the stupid half stepping drivers are doing this even worse than I am
[01:03:29] <jmkasunich> well the main reason to go to microstepping is for smoothness
[01:03:45] <jmkasunich> halfstep is smoother than full, and micro is smoother than half
[01:04:19] <jmkasunich> as speed goes up, it's the roughness of full or half step drives that make them start to lose steps
[01:04:54] <jmkasunich> the real-world impact of roughness depends very much on your application
[01:05:08] <icee> * icee nods
[01:05:09] <icee> that's helpful
[01:05:24] <icee> my initial application is to run a some 200 oz-in steppers on a mini mill
[01:05:48] <icee> but I hope to eventually use the same board to drive a full size mill, and my brother in law has interest in using it for a plasma cutter
[01:05:59] <icee> feed rates and accelerations in all of these applications are not likely to be too extreme
[01:06:05] <jmkasunich> you're building the drives because you want to? (because if you just want drives, it's very hard to beat the commercial stuff with a homebrew drive)
[01:06:22] <icee> mostly because I want to, yah.
[01:06:46] <les> seems like you would enjoy servos...
[01:06:47] <icee> It'll be a lot cheaper before opportunity cost is figured in.. but since it's something i enjoy i don't think opportunity cost really matters
[01:07:16] <jmkasunich> (I do power electronics for a living, I have dozens or hundreds of power mosfets laying around, and for me it still makes more sense to use Xylotex (for small motors) or Gecko (for big ones)
[01:07:59] <icee> yah, I know about economies of scale, and the benefits of using a proven design.
[01:08:05] <les> it's like scraping machines...can't justify it for business...so when I do it i'm "off"
[01:08:53] <jmkasunich> its not just scale - especially if you are a digital only guy, you will fry some FETs before you're done, and/or have nasty problems with electrical noise
[01:09:12] <jmkasunich> so you better double or triple the material cost for your first couple drives
[01:09:15] <icee> jmkasunich: well, I've designed DC-DC converters before-- similar space.
[01:09:25] <jmkasunich> OK, didn't know that
[01:09:45] <icee> not so much back EMF, but.. i'm using IRFI1310N's with nice body diodes etc
[01:10:15] <jmkasunich> * jmkasunich googles that part
[01:10:19] <les> reminds me...am I going to get all manner of rfi from that vfd?
[01:10:36] <jmkasunich> depends on how you define "all manner"
[01:10:43] <les> should I clean it up with some inductors?
[01:10:51] <jmkasunich> enough to totally fsck up AM radio reception, yes
[01:11:13] <les> before it is laying next to the encoder wires etc in the conduit
[01:11:14] <jmkasunich> enough to fsck up a computer in a decent case, probably not
[01:11:30] <jmkasunich> don't run encoder and motor wires in the same conduit
[01:11:43] <les> oh the servo amps pretty much trash any radio reception
[01:12:23] <les> jmk I pretty much have to as set up...but all encoders are diff shielded twisted pair
[01:12:24] <jmkasunich> I've used off-the-shelf RFI filters (corcom or similar) to clean up VFDs as far as radio goes
[01:12:53] <jmkasunich> much of the radio stuff is radiated from the power lines, so filtering at power input helps a lot
[01:13:12] <jmkasunich> can you get shielded 3-conductor cable for the motor leads?
[01:13:18] <les> I know they don't like capacitive reactance on the outputs...how about some small inductors?
[01:13:32] <jmkasunich> dunno
[01:13:37] <les> yeah I will shield the motor if I can find the wire
[01:13:47] <jmkasunich> they have to not saturate at peak motor current
[01:14:01] <jmkasunich> means they're not neccessarily as small as you might like
[01:14:21] <jmkasunich> and anytime you have L plus (stray) C you tend to have ringing too
[01:14:51] <les> motor has plenty of L already
[01:15:13] <jmkasunich> exactly - lots of L, such that it doesn't resonate with a few nF of stray C
[01:15:25] <icee> Here's another minor issue I'm having, btw
[01:15:31] <jmkasunich> put a few uH between the drive and the motor leads and things will be different
[01:15:37] <icee> How do I know what voltage I can drive a stepper with?
[01:15:50] <les> I see
[01:15:52] <icee> I know stepper voltage is specified based on winding resistance, and that if i'm controlling the current that doesn't matter
[01:15:56] <jmkasunich> that is a function of the motor, and the PWM frequency
[01:15:56] <icee> but things cant still arc internally, etc
[01:16:04] <jmkasunich> need to keep the PWM ripple down
[01:16:34] <icee> yah, I know about the ripple currents and all. it would just make me feel better to know 'the coil in the motor won't arc < 30V'
[01:16:36] <jmkasunich> ripple current is proportional to DC supply volts, and inverse to PWM freq and motor inductance
[01:17:02] <jmkasunich> I seriously doubt arcing is a concern until you get well over 100V
[01:17:07] <icee> you get what I'm saying, right? Even if the motor inductance is a billion henries, there's some voltage that if you give it to the motor instantaneously where it'll arc
[01:17:41] <jmkasunich> yeah, I understand, I just don't think arcing is a concern at such low voltages
[01:17:46] <les> L di/dt?
[01:18:25] <icee> OK. It'd make me feel better if it was specified tho
[01:18:27] <jmkasunich> in this case, it is more like di/dT = V/L, V is determined by the DC supply (clamped by the freewheel diodes)
[01:18:55] <jmkasunich> if you are interrupting the current thru an inductor with a switch or something then you have to worry about nasty V spikes
[01:19:14] <jmkasunich> but with a FET bridge, they are clamped
[01:19:36] <icee> yup. power flows from ground to vcc or ground to ground when the high side is off
[01:20:30] <jmkasunich> make sure the loop from low fet to high fet to power supply cap and back to ground at the low fet is low inductance
[01:21:10] <icee> yah. I'm considering having planes.
[01:21:23] <les> I put transorbs on my servo amps, because estop disconnects the motors and shorts them. Copley said the frewheel diodes couls handle it though.
[01:21:33] <les> freewheel
[01:22:18] <jmkasunich> icee: how much current/voltage are you using anyway?
[01:23:29] <icee> jmkasunich: 2.8A/phase initially. But I've designed the board to tolerate up to 8A/phase
[01:23:39] <jmkasunich> those look like some pretty hefty FETs, more gecko sized than xylotex sized
[01:23:49] <jmkasunich> (xylotex is 2.5A/phase I think)
[01:24:46] <icee> because of DAC, comparator, etc errors and the magnitude of the ripple, I figure I have about 100-200mA of absolute current error
[01:25:17] <jmkasunich> you are sensing current with a resistor in the source lead?
[01:25:49] <icee> with a resistor on the ground side
[01:25:59] <icee> big TO-220.. .3 ohm I think
[01:26:29] <jmkasunich> ouch
[01:26:34] <jmkasunich> .3 ohm is pretty high
[01:26:44] <jmkasunich> 10x the on resistance of the FETs
[01:27:05] <icee> yah. it's a tradeoff between the offset voltages/DAC errors and the resistance value
[01:27:25] <jmkasunich> at 8A, you'll have 2.4V and 19 watts in the resistor
[01:27:28] <icee> actually, it's .1 ohms
[01:27:34] <jmkasunich> better
[01:27:37] <icee> .1 ohms 10W is how I have it specified
[01:27:44] <jmkasunich> still kinda hi
[01:27:58] <icee> partial duty cycle on those 6W, too
[01:28:31] <icee> (i leave the low side turned on and only modulate the high side.. so things should flow directly from fet to fet without appreciable current across the resistor when 'off'
[01:28:53] <jmkasunich> yeah
[01:29:01] <jmkasunich> what are you using for high-side drivers?
[01:29:29] <icee> I have 2mV of offset error in the comparator and 10mV of error from the DAC (conservatively)
[01:29:55] <jmkasunich> don't forget tens of mV (or more) of ground bounce
[01:30:00] <icee> I'm using the 1310N for all 4 legs, and driving it with an ir2304
[01:30:10] <jmkasunich> hundreds of mV if you aren't carefull about layout
[01:30:46] <icee> jmksaunich: I have a monostable so I don't sample the comparator for a microsecond or two after I turn thigns on
[01:31:21] <jmkasunich> that's good - cause you'll have diode recovery current spikes
[01:33:01] <jmkasunich> I'd still recommend resistor "DACs" instead of dual comparators
[01:33:29] <jmkasunich> fast, sensitive comparators are gonna have a higher cost and higher component count than the resistive dacs
[01:33:45] <jmkasunich> figure at least a bypass cap and a couple resistors per comparator
[01:33:58] <jmkasunich> plus the comparator itself
[01:34:33] <jmkasunich> is the monostable a timer inside the CPLD, or a physical circuit?
[01:34:42] <icee> it's a timer, yah.
[01:34:51] <jmkasunich> ok, so more-or-less free
[01:34:55] <icee> I'm a little scared of what happens if the clock should go away
[01:35:03] <jmkasunich> poof
[01:35:29] <icee> yah, pretty much.
[01:35:38] <jmkasunich> you are gonna have the CPLD drive the IR2304 directly
[01:35:50] <jmkasunich> (four CPLD outputs driving 4 FETS)
[01:35:57] <icee> most of the time the clock going away isn't so bad
[01:35:59] <icee> jmka: yah
[01:36:10] <icee> but going away during that 'ignore the comparator' timespan is very bad
[01:36:22] <icee> if you want to see, btw
[01:36:22] <icee> http://lyle.org/~mlyle/stepperboard.pdf
[01:36:28] <jmkasunich> make sure the power up and power down states of the CPLD outputs are "FET OFF" ;-)
[01:37:02] <icee> hehe, yah
[01:37:26] <jmkasunich> I don't see a cap on VGATE
[01:37:26] <icee> this is slightly out of date btw, it's before i moved the stepper state machine into the cpld
[01:37:44] <icee> lower right of the power page
[01:38:06] <jmkasunich> duh
[01:38:30] <jmkasunich> I'm accustomed to the output caps of a supply being drawn at the supply, even if smaller bypass caps are all gathered at the bottom
[01:38:38] <jmkasunich> needed to maximize the window
[01:39:01] <jmkasunich> LM2675 is one of those "simple switchers", right?
[01:39:16] <icee> Yah. It's my first time using one of the national parts
[01:39:18] <jmkasunich> shouldn't the FB pin be connected to the output?
[01:39:21] <icee> But it seems to be pretty nice
[01:39:28] <icee> haha
[01:39:33] <icee> thank you.
[01:39:42] <jmkasunich> I've used parts in that family, dunno if it was this one or not
[01:39:58] <icee> Reminder to self: changing net names around and not doing it everywhere is bad.
[01:40:20] <jmkasunich> built a switcher for a VFD (day job)... 300-1200VDC in, +24, -24 and +15 out, 200W total
[01:40:42] <jmkasunich> used the simple switchers to derive additional voltages, + and - 12 from the + and - 24
[01:41:18] <icee> jmka: I've used mostly the linear parts. But uh, the Linear data sheets lie heavily and the parts are expensive
[01:41:18] <jmkasunich> Vgate is for the gate drivers, about 10-12V, right?
[01:41:23] <icee> yah
[01:41:35] <jmkasunich> Vcc is logic supply, 5V?
[01:41:38] <icee> 12V, minus whatever decay in the charge pump and a diode drop
[01:41:39] <icee> yah
[01:41:46] <jmkasunich> and Vstep is the main motor power
[01:41:57] <icee> yup.
[01:42:30] <jmkasunich> ack....
[01:42:49] <jmkasunich> I hate it when people send signals flying thru the ether (personal gripe)
[01:43:08] <jmkasunich> looking at page 4, "where is the reference voltage coming from, I just see a cap"
[01:43:25] <jmkasunich> I prefer to draw the lines whenever possible ;-)
[01:43:25] <icee> hehe.. yah.. net naming can be bad.
[01:43:32] <icee> but so can pages of maze
[01:43:44] <jmkasunich> true
[01:43:59] <jmkasunich> but many circuits can be layed out so the signals flow, rather than just being a maze
[01:45:41] <jmkasunich> I would scale the DAC outputs... at 8A, you'll have 0.8V at the comparator input
[01:46:03] <jmkasunich> I suspect the DAC output goes 0-5V, so you'll only be using 16% of the DAC range
[01:46:28] <icee> yah.. i could give it a lower Vref
[01:46:33] <icee> the DAC, that is
[01:46:50] <icee> though because of the structure of the output amplifier, etc, that won't give me 5x the resolution
[01:46:51] <jmkasunich> no, put a 4.7K/1.0K voltage divider on the DAC output
[01:47:05] <icee> why not just change the dac's reference?
[01:47:16] <jmkasunich> let the DAC continue to swing 5V, minimizes the effect of DAC errors
[01:47:17] <icee> that way it's nice and low impedance still
[01:47:53] <icee> yah.. I'll consider doing something about it
[01:48:04] <jmkasunich> it's a tradeoff
[01:48:20] <jmkasunich> the DAC probably has low DC output Z, but for high frequencies not so good
[01:48:29] <jmkasunich> rely on the caps at the comparator inputs for low Z
[01:48:41] <icee> I need to simulate that, btw
[01:48:47] <icee> the caps out at a distance from the DAC
[01:48:50] <icee> to make sure it doesn't oscillate
[01:49:18] <jmkasunich> the resistor divider would do a nice job of decoupling the DAC from the cap
[01:49:27] <icee> yah, good point.
[01:49:35] <jmkasunich> I'd make the caps much bigger too, unless you specifically need fast changes in threshold
[01:49:48] <icee> * icee nods
[01:50:02] <icee> they're just small to lower the amount of loading on the DAC. if I divide it or otherwise terminate it they can become bigger
[01:50:05] <jmkasunich> 0.1uF with a 4.7K/1K voltage divider gives 100uS time constant, that should be fast enough
[01:50:37] <jmkasunich> another thing - I seem to recall LMx39 comparators as being pretty slow (several microseconds)
[01:51:22] <jmkasunich> but I'm a little rusty there
[01:51:33] <jmkasunich> I recall using LM311s or similar when we needed speed
[01:52:01] <icee> 1.3 us for a 100mV input step, 5mV overdrive typical
[01:52:13] <jmkasunich> is that fast enough for your application?
[01:52:31] <jmkasunich> how fast is your PWM gonna be?
[01:52:39] <icee> I think so; the offtime is a fixed 100us
[01:52:55] <icee> and the ontime is a minimum 1-2 us
[01:52:59] <jmkasunich> so less than 10KHz PWM?
[01:53:09] <icee> yah
[01:53:15] <jmkasunich> gonna have a lot of ripple current, and audible noise
[01:53:28] <jmkasunich> most drives I'm aware of use 20KHz or so
[01:54:09] <icee> well,i can turn down the offtime just by resynthesizing the cpld
[01:54:28] <jmkasunich> why fixed off time? easier to do in the CPLD as opposed to conventional PWM?
[01:55:13] <jmkasunich> unless I misunderstand, you mean that the period = 100uS plus whatever time it takes the current to rise to the comparator trip point
[01:55:20] <jmkasunich> so the frequency is current dependent
[01:55:37] <jmkasunich> and each bridge will be running at a different (and changing) frequency
[01:55:56] <icee> yah, easy to do, and it's what the ST micro chips I used as a reference do
[01:56:06] <jmkasunich> huh
[01:56:11] <jmkasunich> hmmmm, I mean
[01:56:16] <icee> I could also count the time on and adjust the offtime
[01:56:24] <jmkasunich> simpler yet:
[01:56:28] <icee> I have lots of extra gates
[01:56:46] <jmkasunich> turn all windings on at the same time (say every 50uS, or every 100uS)
[01:56:48] <icee> actually, i can just run the off time counter
[01:56:58] <jmkasunich> at that time start a blanking timer for a uS or two
[01:57:11] <jmkasunich> afterwards, start monitoring the comparators and turn off when you hit threshold
[01:57:34] <jmkasunich> that means one global timer for overall period, one global blanking timer
[01:57:51] <icee> It'd save lots of gates to do that, but it'd make the input ripple currents a lot worse
[01:58:03] <jmkasunich> and it ensures that you aren't turning one bridge on while another is sampling the comparator
[01:58:25] <jmkasunich> (which increases the risk of noise tripping the comp)
[01:58:49] <icee> hm. yah, makes sense.
[01:58:50] <jmkasunich> caps are your friend as far as input ripple goes
[01:59:52] <jmkasunich> you want caps local to each bridge
[02:00:04] <jmkasunich> from the bottom of the sense resistor to the top of each high side FET
[02:00:35] <icee> yah.. i was planning on a couple 470uF's plus a 0.1uF ceramic local to each
[02:00:37] <jmkasunich> ideally the bottoms of both sense resistors are physically close together, and that is the "star ground" point, where the power and control ckts meet
[02:00:59] <jmkasunich> comparators should be as close as possible to that point
[02:01:08] <icee> is it better to do that than to just have a plane and keep all the ground very very low impedance?
[02:01:14] <jmkasunich> VREF bypass caps also close to that point
[02:01:24] <jmkasunich> you want a plane too ;-)
[02:01:30] <icee> I'm wary of dividing up power and signal grounds despite it being a common practice
[02:02:02] <Jacky^> bedtime *_*
[02:02:09] <jmkasunich> night jacky
[02:02:10] <Jacky^> g night all
[02:03:33] <jmkasunich> you don't really have to divide it up
[02:03:47] <jmkasunich> just make sure that power currents don't flow thru the control part of the plane
[02:04:10] <icee> yah, that i'm careful about.
[02:04:14] <jmkasunich> damn, this is where I really wish we were both looking at the same piece of paper and I had a pencil
[02:04:46] <icee> I'll feed in power inbetween the logic and steppers, and put the capacitors inbetween
[02:04:50] <jmkasunich> assume that the two sense resistors enter the ground plane near the center of the board
[02:05:21] <jmkasunich> put the comparators, and the vref bypass caps to the right of center, with the caps as close to the sense resistors as possible
[02:05:37] <jmkasunich> put the power bypass caps to the left of center, again as close to the sense resistors as possible
[02:05:42] <jmkasunich> feed power in from the left
[02:06:19] <jmkasunich> you using 2 or 4 layers for your PCB?
[02:06:25] <icee> i'm thinking 4
[02:06:34] <jmkasunich> good ;-)
[02:06:47] <icee> split power plane, ground plane, and ground pours on top and bottom where possible
[02:06:53] <jmkasunich> yes
[02:07:08] <jmkasunich> power plane is VCC on the control side of the board, VSTEP on the power side
[02:07:28] <icee> yah. maybe a little island of vgate, too
[02:07:53] <icee> though the currents there are not very significant.
[02:08:09] <jmkasunich> I wouldn't bother with ground pours on the power side, I'd just make the traces from high source to low drain, and from low drain to Rsense as wide as possible
[02:08:26] <jmkasunich> minimze the inductance in that loop
[02:08:38] <icee> well, pours are easy to do and improve EMI
[02:08:57] <icee> I'll guard ring the comparators, too
[02:09:28] <jmkasunich> the uninterrupted plane is far better than a pour
[02:09:40] <jmkasunich> I would use pours for MT1, MT2 and SENSE
[02:10:19] <jmkasunich> I'm visualizing a line down the middle of the board
[02:10:43] <jmkasunich> on the left, the FETs, power terminals, and motor terms
[02:10:58] <jmkasunich> straddling the center line are the IR2304 drivers
[02:11:02] <jmkasunich> on the right is all the control
[02:11:33] <icee> for sense I was thinking, instead of a pour, to use coaxial routing
[02:11:34] <jmkasunich> left of the line, the outside layers are pours of MT1, MT2 and SENSE, the plane is VSTEP
[02:11:51] <icee> i can run a fat trace, and put a ground box all around the trace
[02:12:25] <jmkasunich> traces on the sides are much less effective than traces under or above
[02:13:11] <icee> well, there'll be plane under. nothing above, though
[02:13:17] <jmkasunich> the part from Q15 source to R5 to Q16 source should be wide, short, and above an un-interrupted ground plane
[02:13:47] <icee> yup
[02:13:56] <jmkasunich> the part going to the comparators can be a skinny trace going off into the control section, it should be attached near the top of R5, not near Q16 as on the schematic
[02:14:14] <icee> yah
[02:14:16] <icee> kelvin sensing
[02:14:31] <jmkasunich> floods around the skinny part are usefull (floods in the entire control section are usefull, just not so much in the power section)
[02:15:30] <jmkasunich> doing something like this in 2 layers would be a challange
[02:16:01] <icee> yah, i got that idea when i did some calculation on the ripple currents etc
[02:16:06] <icee> and figured out that i needed inch wide traces
[02:16:50] <jmkasunich> question - is the LM239 good for input signals that approach it's negative supply?
[02:17:14] <jmkasunich> don't have a data sheet handy, and most of my work with comparators is wiith dual supplies, so it's not an issue for me
[02:18:53] <icee> the bounce etc i can expect is well within the absolute maximum ratings
[02:19:05] <icee> whether there's any weird behavior with stuff saturating when it goes below vss, i don't know
[02:19:18] <jmkasunich> the saturation issue is what I was talking about
[02:19:37] <jmkasunich> some comparators actually reverse their output state when you go below the rail
[02:19:54] <icee> it's unspecified
[02:22:01] <jmkasunich> pg 15 of the data sheet shows a simplified schematic of the LM239
[02:22:15] <jmkasunich> going more than one diode drop below ground would be a bad thing
[02:22:29] <jmkasunich> dunno about simply going down to ground
[02:22:47] <icee> hm. maybe i should just give up and buy a xylotex board :P
[02:24:15] <jmkasunich> it's ok... the input common mode range goes down to zero
[02:24:57] <icee> yah.
[02:24:57] <jmkasunich> on the high side you aren't allowed to get higher than 1.5V below the supply, but that won't be an issue for you
[02:26:56] <jmkasunich> hmmm... just thought of another way to address the VREF issue that avoids needing two comparators
[02:27:04] <Jymmm> I'm making a sign and it skipped steps (0.90")... How can i "reset" the position w/o mucking with it's "current position" ?
[02:27:47] <icee> jmka: how's that?
[02:28:10] <jmkasunich> dual 4 to 1 analog mux
[02:28:43] <icee> yah, but why bother? using a quad comparator for 2 phases is cheap
[02:29:03] <jmkasunich> yeah, the more I think about it the more I tend to agree
[02:29:14] <jmkasunich> the only prob is that you only have two levels
[02:29:21] <jmkasunich> hard to get precise microsteps that way
[02:29:41] <jmkasunich> I'm trying to figure out a way to get more precise levels (and more of them) cheaply
[02:30:13] <icee> well, I could just get a proper DAC per phase
[02:30:37] <jmkasunich> gets pricey (and for serial dacs, slow, or complicated, or both)
[02:31:06] <jmkasunich> the idea of using only 1 for all windings is good...
[02:31:35] <jmkasunich> the idea of only changing it when you want to power down or reduce current is also good
[02:31:52] <jmkasunich> just wish you could have more thresholds scaled from that one DAC output
[02:32:14] <icee> so there's a big need for more than quarterstepping, eh?
[02:32:25] <jmkasunich> thats what I was thinking with the mux - DAC drives a divider string, MUX selects which tap of the string feeds the comparators
[02:32:33] <jmkasunich> depends on your applications
[02:32:39] <jmkasunich> some work fine with full steps
[02:32:48] <jmkasunich> Xylotex uses 1/8 steps
[02:32:54] <jmkasunich> gecko uses 1/10
[02:33:58] <jmkasunich> if you're gonna go to the trouble of building a drive, might as well build a high class one
[02:34:42] <icee> Maybe I should just buy the xylotex board for now, and then build one for my full sized machines
[02:35:04] <jmkasunich> if your current needs only go up to a couple amps, that makes a lot of sense
[02:35:27] <icee> is the xylotex stuff robust?
[02:35:32] <jmkasunich> Xylotex does everything in one chip (practical at that power level) and you can't possibly beat that in cost or performance with a discrete design
[02:36:07] <jmkasunich> pretty much so - none of these drives (including Geckos or your design) will survive direct shorts on the outputs and other such abuse
[02:36:28] <jmkasunich> I have a xylotex 3-axis board, I've used it for testing and such for a couple years
[02:36:35] <icee> * icee nods
[02:36:37] <icee> running how much current?
[02:36:55] <jmkasunich> 1 to 1.5A
[02:36:59] <icee> It puzzles me a bit that they're selling 2.5A drives and bundling them with 2.8A steppers
[02:37:01] <jmkasunich> they are adjustable
[02:37:16] <icee> and I don't know what chips they're using, but if it's the ST micro parts, etc, I'd be wary of really running them at 2.5A
[02:37:25] <jmkasunich> 2.5A into a 2.8A stepper you don't lose much torque
[02:37:33] <jmkasunich> they need a fan at full current
[02:37:43] <jmkasunich> I don't use a fan on mine because they're only part load
[02:38:03] <jmkasunich> I did manage to kill mine shortly after I got it, but it was my fault
[02:38:27] <jmkasunich> one of the output traces runs close to a mounting hole, I used a screw with an oversize head, and it shorted the trace to grouhd
[02:38:29] <icee> jmka: thank you for all your help with this.. it's been very useful.
[02:38:30] <jmkasunich> ground
[02:38:45] <icee> I think I'll still build something.. but it might make sense to get a xylotex board to have something to play around with. it's certainly cheap enough
[02:39:08] <jmkasunich> yeah, then you can concentrate on a high performance high power drive for the one you design
[02:43:24] <jmkasunich> I realize I've been pretty nit-picky, sorry about that. In my day job I work on things that run hundreds of volts and hundreds of amps, so I tend to be obsessive about noise and layout issues and such
[02:43:42] <jmkasunich> much of what I was talking about might be overkill for something at this power level
[02:47:35] <icee> jmka: oh, it's understandable
[02:47:48] <icee> and you found a big bug with the dc-dc converter, too, which I owe you big for :)
[02:48:48] <jmkasunich> fresh eyes always helps... I dunno how many times I've overlooked the same mistake, then somebody else looks and it jumps out at them
[02:49:39] <icee> that one would have been tough to fix dead-bug style.. and it would have smoked pretty much everything as vgate climbed up close to vstep
[02:50:08] <les> jmk: you really ought to give up this day job thing and start a business. Starving, the rolling in money, then starving again is fun!
[02:50:32] <jmkasunich> rolling in money is nice, but starving isn't
[02:50:41] <les> heh
[02:52:07] <jmkasunich> lately the thought has crossed my mind more than once (especially when dealing with big company beaurocracy), but I know it would require intense commitment - I prefer to be able to spend my nights doing other things (like EMC)
[02:52:54] <les> Well business has to be something that's fun...then you just play all day.
[02:53:08] <jmkasunich> the "business" part of it would not be fun
[02:53:20] <jmkasunich> the "looking for customers" part especially
[02:53:44] <les> Although I must admit I am getting stressed out some...too much "play"?
[02:55:51] <les> But it sure beats corporate beaurocracy
[02:56:45] <les> at least I am getting stressed out over making things rather than posturing, politics, and other bs
[03:28:57] <jmkasunich> goodnight all
[04:24:24] <Jymmm> First.... Y axis skips .90". Ok, I get that "mostly" aligned back up. Then I'm cleaning up aroudn the table and the power supply unplugs from the computer. SIGH
[08:38:58] <an0n> morning all
[09:55:59] <Jacky^> hi
[09:56:20] <Jacky^> who is Aaaarrrg ?? O_O
[09:56:57] <an0n> no idea
[09:57:11] <Jacky^> hey an0n
[09:57:34] <an0n> what's up?
[09:58:00] <Jacky^> just waking up .. *_*
[09:58:11] <an0n> *jealous*
[09:58:50] <Jacky^> this morning i will go to the postal office to get a card (hope is good for international payment...)
[09:58:55] <Jacky^> an0n: hehe
[09:59:17] <Jacky^> i need to buy some gecko ..
[09:59:28] <an0n> :)
[09:59:49] <Jacky^> you ?
[09:59:58] <Jacky^> solved the electronic issue ?
[10:00:02] <an0n> maybe
[10:00:06] <an0n> I havent tried it yet
[10:00:13] <Jacky^> good
[10:03:18] <an0n> maybe after work today
[10:03:38] <Jacky^> :-)
[10:35:40] <K`zan> Night all.
[12:39:50] <Jacky^> hello
[13:07:07] <Jacky^> les: you around ?
[13:08:48] <Jacky^> i'm losting in the abba catalog :\
[14:40:31] <les> I'm around now
[14:40:41] <Jacky^> hey les
[14:40:47] <Jacky^> g mornig :)
[14:40:58] <les> hi jacky. An office day for me.
[14:41:16] <Jacky^> i need some help.. when you can ..
[14:41:17] <les> Writing boring engineering reports
[14:41:23] <les> go ahead
[14:41:26] <Jacky^> mmhh .. yeah
[14:41:32] <Jacky^> ok
[14:41:41] <Jacky^> whan youve a little of time
[14:41:52] <Jacky^> i want to order the slides from abba
[14:42:11] <Jacky^> but i dont know wich type
[14:42:12] <les> yes...
[14:42:47] <les> ok. explain a little again about the machine capabilities you want
[14:43:10] <Jacky^> 1x1 mt wood cnc machine
[14:43:15] <Jacky^> we talked ..
[14:43:23] <Jacky^> slides 15 or 20 mm
[14:43:37] <Jacky^> but i dont know which model
[14:43:58] <Jacky^> also wich lenght
[14:44:05] <les> let me bring the abba site up
[14:44:10] <Jacky^> thnaks
[14:44:19] <Jacky^> if youve not time now
[14:44:30] <Jacky^> we can see later , dont worry
[14:45:10] <Jacky^> this morning i got a visa card from postal office .. i think its ok for online payment
[14:45:34] <Jacky^> so, i'm starting buy
[14:47:01] <Jacky^> im looking at some self lubrificant model, but im not sure ..
[14:48:00] <les> ok let's see...
[14:48:24] <les> 15mm BR series
[14:48:37] <les> lowest precision grade will be fine
[14:48:44] <les> light preload
[14:48:46] <Jacky^> i think so
[14:49:11] <les> length need to be axis travel + bearing spacing
[14:49:35] <Jacky^> yeah ..
[14:50:33] <Jacky^> im looking here: http://test.machinesources.com/e-catalog/e/abba/
[14:50:34] <les> understand the these are not structural....they must be bolted to a stiff straight surface
[14:50:46] <an0n> hello
[14:50:56] <Jacky^> hi an0n
[14:50:58] <les> hi anon
[14:51:15] <an0n> les: do you know how to fight stiction in huydralic systems?
[14:51:22] <an0n> friction/stiction..
[14:51:23] <Jacky^> uhm ..
[14:51:32] <les> now...what bearing spacing are you thinking of?
[14:51:39] <Jacky^> les i dont what they mean with 'preload' ..
[14:51:51] <Jacky^> know*
[14:52:04] <les> anon: florocarbon o-rings...
[14:52:08] <an0n> preload bearing-> |<--SPRING-->| <- bearing
[14:52:19] <les> jacky...ok i'll explain preload
[14:52:21] <an0n> err ballnut..
[14:52:21] <an0n> ;)
[14:52:32] <Jacky^> les: i was thinking 1x1mt of working area..
[14:52:55] <an0n> les: how much of friction does that take care of?
[14:53:59] <les> preload is an interference fit...i.e. the bearing is smaller than the rail slightly and is forced on...so there is no play even with forces on the rail
[14:54:28] <Jacky^> understood ..
[14:54:31] <les> anon: I just figure teflon like materials typically have a lot less stiction
[14:54:40] <les> VITON comes to mind
[14:54:47] <an0n> ah, wont help too much in that case..
[14:55:45] <les> the valve stem seals in one of my cars was viton...it was very slick
[14:56:08] <an0n> why isnt there seals pre-made in it?
[14:56:13] <les> even though the o-ring tends to wipe off lubricant film
[14:56:47] <les> well I think lots of viton orings are made
[14:57:02] <an0n> that's probably what's there..
[14:57:06] <an0n> I dont have the material specs..
[14:57:07] <les> jacky: moving gantry or moving table?
[14:57:13] <an0n> but it sticks too much
[14:57:26] <les> viton is usually green...
[14:58:04] <Jacky^> les: no idea about gantry :/
[14:58:29] <les> Well, I would suggest moving table anyway
[14:58:32] <an0n> we are thinking of replacing the cylinders with slides off a huydralic pack.. instead
[14:59:12] <Jacky^> les .. you know .. i need a machine that can work all day ..
[14:59:19] <les> I would imagine reducing seal preload will help too..until it leaks!
[14:59:32] <an0n> ah, cant have any leaks..
[14:59:39] <les> I understand jacky
[14:59:39] <an0n> they are precision ground..
[14:59:53] <an0n> and leakage is minimal
[14:59:59] <an0n> but so if friction also..
[15:00:24] <les> yes the hydraulics on my new tractor does not leak a drop
[15:00:41] <Jacky^> les: moving gantry should be better.. i suppose
[15:00:44] <Jacky^> right ?
[15:01:06] <an0n> cant really compare this to a tractor :/
[15:01:30] <les> Moving gantry has some advantages....but it is much harder to build and much more expensive
[15:01:51] <les> Moving table is easier...does not require twin screws
[15:01:56] <les> but it's bigger
[15:02:31] <Jacky^> i prefer moving gantry
[15:02:42] <an0n> les: how close can you get the fit with a toolpost grinder?
[15:03:01] <les> for you, one meter travel moving table will require about 2 meter rails
[15:03:06] <Jacky^> no problem about build it.. my cousyn have 3 lathe ..
[15:03:15] <Jacky^> smallest medium big
[15:03:17] <Jacky^> ;)
[15:03:31] <les> anon: I can do .002 mm with care
[15:03:41] <Jacky^> so.. moving gantry should be better
[15:03:56] <an0n> I wonder how close I'd end up at..
[15:04:16] <les> twin screws....
[15:04:38] <les> anon: depends on how good your lathe is
[15:04:44] <an0n> les: trying to decide if it would be possible to manufacture the parts instead of taking them off a huydralic pack..
[15:04:49] <les> you can always hone the last bit
[15:04:58] <Jacky^> les: what twin screen ?
[15:05:37] <les> gantries usually require two syncronized ballscrews...one on each side
[15:05:43] <Jacky^> its not a prob
[15:05:53] <Jacky^> just let me now what i need
[15:06:17] <les> ok lets do moving gantry twin screw...like my machine
[15:06:52] <Jacky^> les: .. i'm annoyng you
[15:07:01] <les> bearing spacing for x will need to be about....300 mm
[15:07:05] <Jacky^> but, dou you have some photos ?
[15:07:19] <les> yes..
[15:07:19] <Jacky^> to see summary assemblement
[15:07:23] <Jacky^> great
[15:07:31] <les> getting a link
[15:07:36] <Jacky^> ok
[15:08:17] <Jacky^> be patience ..
[15:08:29] <les> http://www.lmwatts.com/cnc.html
[15:09:03] <les> anon, I am having to hone little ultrasonic resonators
[15:09:27] <Jacky^> les: well
[15:09:40] <Jacky^> assuming a machine like that then
[15:09:49] <Jacky^> of course with my sizes ..
[15:09:55] <les> a 2 mm rod slides and turns in a 1.902 hole...
[15:10:04] <les> no problem with honing
[15:10:50] <Jacky^> ok ..
[15:11:03] <les> ok jacky 300 mm spacing...so your travel plus spacing plus ends....
[15:11:16] <Jacky^> yeah
[15:11:22] <les> equal about 1.5 meter rail lenghth
[15:11:36] <Jacky^> right
[15:12:00] <Jacky^> so i can get 1 mt work area
[15:12:15] <Jacky^> if i understand well
[15:12:17] <les> ballscrews can be shorter...just travel plus ends
[15:12:37] <Jacky^> yeah
[15:13:24] <Jacky^> ok les ..
[15:13:27] <les> so 1.5 will have a little left over...1.25 could squeak by
[15:13:56] <Jacky^> ok..
[15:13:59] <Jacky^> wait ..
[15:14:14] <Jacky^> now i try to plain all
[15:14:27] <Jacky^> with the help of my cousin
[15:14:27] <les> it's good to make travel a little bigger than 1 meter anyway if you want to machine all of a 1 meter workpiece
[15:14:41] <les> ok
[15:14:50] <Jacky^> right
[15:15:03] <Jacky^> i will show all to you before to buy ..
[15:15:09] <les> ok
[15:15:32] <Jacky^> at the end i will send you a big spaghetti package :)
[15:15:34] <Jacky^> ok ..
[15:15:39] <Jacky^> thanks ;)
[15:16:11] <Jacky^> ah ..
[15:16:28] <les> anon:
[15:16:31] <les> http://news.thomasnet.com/fullstory/20965/1303
[15:16:54] <Jacky^> les: gecko 340 should be ok for 250 servos motor
[15:16:59] <Jacky^> right ?
[15:17:14] <les> 250 oz in?
[15:17:30] <an0n> les: will a oil film make that tight?
[15:17:37] <les> yes it would be fine
[15:17:50] <Jacky^> ok
[15:17:55] <an0n> hm, maybe I should get some high precision bearings and machine a toolpost grinder.
[15:17:56] <Jacky^> thanks
[15:18:08] <les> yw
[15:18:41] <les> yes I have two tp grinders...they both use class 9 bearings
[15:18:53] <les> themac j-40 and j45...
[15:18:56] <les> link...
[15:19:04] <an0n> I think I've seen them before
[15:19:46] <les> http://www.aegis-ceramics.co.uk/themac.htm
[15:20:01] <les> unfortunately they cost several thousand dollars
[15:20:41] <an0n> yep :(
[15:21:10] <les> some pop up on ebay from time to time
[15:21:23] <les> dumore is another good brand
[15:21:26] <an0n> hm ok
[15:21:41] <an0n> too bad ebay & shipping means insane $$
[15:22:01] <les> and yeah you can make one....doing a class 9 spindle would be funn
[15:22:06] <an0n> hehe
[15:22:22] <les> everything must be .002 mm accurate
[15:22:23] <les> heh
[15:22:43] <les> and perfectly balanced
[15:22:53] <an0n> well, I guesss that's out of the question ;)
[15:22:53] <les> mine runs at 40,000 rpm
[15:23:02] <an0n> if you breathe at any part it's misaligned
[15:23:19] <les> you really have to watch temperatures
[15:23:26] <an0n> if you do that kind of work :D
[15:23:32] <les> ha
[15:23:45] <an0n> http://www.blocket.se/view/6129678.htm?caller=nbl_s&l=0&c=1&city=11
[15:23:54] <an0n> 500$
[15:24:10] <les> anyway...for occaisional use...just hone bores and shafts with sandpaper
[15:24:41] <an0n> I might be better having somone edm the hole and grind the shaft..
[15:26:17] <an0n> :)
[15:26:28] <an0n> * an0n is a toolfreak
[15:26:36] <les> so am I
[15:26:44] <an0n> I cant help wanting to have a cylindrical grinder/surface grinder
[15:26:46] <an0n> and a edm..
[15:27:05] <an0n> it's not like I have any serious production with machine tools..
[15:27:14] <an0n> but, I still want a edm ;)
[15:27:46] <les> but when you need one you need one...my surface grinder is one of the least used tools...but I must have it there
[15:28:04] <an0n> I hate to be unable to machine stuff..
[15:28:10] <an0n> tool steel ;)
[15:28:18] <les> yeah
[15:28:42] <an0n> I could run it 24/7 to make parts..
[15:28:56] <an0n> milling some stuff isnt possible
[15:29:00] <an0n> not with my resources..
[15:29:15] <les> well abasic shop with screw cutting lathe, tool post grinder, surface grinder, mill, bandsaw, and welder...
[15:29:24] <les> and you can make most anything
[15:29:33] <Jacky^> les: how much the difference of cost between 15-20 mm rails ?
[15:29:40] <Jacky^> dou you remember ?
[15:29:52] <Jacky^> is it convenient 20 mm maybe ?
[15:29:56] <les> jacky they are probably almost the same price
[15:30:03] <les> 20 is fine
[15:30:10] <an0n> les: still, a edm is a nice tool ;)
[15:30:12] <Jacky^> thanks
[15:30:23] <an0n> you could machine your cutters from solid carbide ;)
[15:30:37] <an0n> *fzzzt*
[15:30:42] <les> edm is handy...esp wire
[15:31:17] <an0n> yep
[15:31:21] <les> I sharpen a lot of carbide with diamond
[15:31:37] <an0n> I were just kidding ;)
[15:31:42] <an0n> but, with a edm you could
[15:31:56] <les> Too bad I have an office day...would rather be working on mounting the new spindle
[15:39:30] <les> jacky, read my post here...it's about ganties
[15:39:33] <les> http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/
[15:39:43] <Jacky^> les: sure, thanks
[15:39:54] <Jacky^> i'm translating .. :/
[15:40:08] <Jacky^> i will disturb you after .. if i can
[15:40:11] <an0n> I need to pull the gearbox apart so I can check on getting new bearings..
[15:40:15] <an0n> or order them rather
[15:41:01] <les> bad bearings?
[15:41:22] <an0n> yeah, chineese crap..
[15:41:36] <an0n> replacing them with SKF counterparts
[15:42:01] <an0n> the bad skf bearings are better then the good chineese ones
[15:42:04] <an0n> ;)
[15:42:25] <les> I have seen plenty of good chinese bearings...but I have alo seen used bearings or used grease used in new chinese tools
[15:43:16] <an0n> well, skf is good :)
[15:43:20] <les> yup
[15:43:25] <an0n> and it's the easiest thing to get..
[15:43:31] <an0n> since we sell skf at work ;)
[15:43:36] <les> heh
[15:43:54] <an0n> I wonder if I should buy bearings for 10krpm..
[15:44:10] <les> for the mini mill?
[15:44:15] <an0n> not a minimill..
[15:44:30] <an0n> benchtop...
[15:44:35] <les> ok
[15:44:41] <les> I remember now
[15:45:25] <les> most greased bearings around that size will be good to 10k
[15:45:41] <les> 200-400 size
[15:45:53] <an0n> hm, trying to acheive 10k/rpm silently ;)
[15:46:02] <an0n> I want want my machine walking around
[15:46:11] <les> 6200 is the most used bearing in the world I think
[15:46:20] <les> might be some in the gearbox
[15:46:25] <an0n> yeah probably
[15:46:25] <les> good to 12k
[15:46:31] <an0n> the gearbox is going away also..
[15:46:54] <an0n> geared 1:3
[15:47:01] <an0n> ett staticly..
[15:47:02] <les> spur gears at 10k might not be happy
[15:47:07] <an0n> yep
[15:47:29] <an0n> I am mostly aiming to machine alu..
[15:47:54] <an0n> 5kw and 10k/rpm
[15:47:56] <an0n> should make some chips
[15:48:01] <les> My new spindle is rated for high speed machining of al
[15:48:12] <les> specs say "with caution"
[15:48:19] <les> avoiding end loads
[15:48:21] <an0n> even though the 5kw is at 2800rpm..
[15:48:40] <les> I reach 4 kw at 18000
[15:48:41] <an0n> but it should be plenty anyway..
[15:48:52] <les> 18000 to 24000 constant power
[15:49:01] <les> below 18000 constant torque
[15:49:14] <an0n> :)
[15:49:23] <an0n> but I dont think I need to gear that much
[15:49:36] <an0n> I can reach 6000rpm with the VFD I am going to buy..
[15:49:40] <les> heh...no...
[15:50:15] <les> I don't think I will do much aluminum with this...it costs a lot and I don't want to damage it
[15:50:20] <an0n> yeah
[15:50:25] <an0n> the motor I am going to buy is cheap..
[15:50:32] <les> new bearings/balance is $800
[15:50:44] <an0n> like 350$
[15:51:11] <les> sounds ok
[15:51:12] <an0n> so I can afford to change it..
[15:51:45] <les> does your mill use tapered roller spindle bearings?
[15:51:54] <an0n> yes
[15:52:08] <les> those generally run at under 5k
[15:52:12] <les> rpm
[15:52:41] <les> beyond that 40 degree angulars are used
[15:53:07] <les> the colombo has db 15 degree angulars at the nose
[15:53:07] <an0n> I'll give SKF the specs when I order..
[15:53:19] <les> hence the low end load spec
[15:53:21] <an0n> so they can match my bearings for me..
[15:53:22] <an0n> :)
[15:53:29] <an0n> that's probably the easiest way to do it
[15:53:33] <les> yeah
[15:53:41] <an0n> at 2800rpm I'll have 5kw..
[15:53:51] <les> well...I have to order a vfd today
[15:53:57] <les> I will call them now
[15:54:12] <an0n> :)
[15:54:49] <an0n> 10000/(2800*2)=1,7
[15:55:11] <an0n> 5/1,7=2.9kw
[15:55:30] <an0n> maybe dropping one when I overdrive it to that speed..
[15:55:41] <an0n> should be plenty of both torque and speed for al..
[16:11:44] <Yuga> hey all
[16:11:46] <Yuga> hey les
[16:12:14] <Jacky^> Yuga: heyyyyyyyyyy
[16:12:21] <Yuga> hey Jacky^
[16:12:26] <Jacky^> :)))))
[16:12:43] <Jacky^> where have you been all this time ??
[16:12:52] <Yuga> was picking my nose
[16:13:04] <Jacky^> uhm
[16:13:12] <Yuga> not realy. was busy forming a mold for a speaker box i am building
[16:16:45] <Jacky^> wow
[16:16:47] <Jacky^> :)
[16:16:52] <Jacky^> tried focal ?
[16:17:03] <Yuga> focal?
[16:17:08] <Jacky^> yes
[16:17:13] <Yuga> whats that?
[16:17:15] <Jacky^> dynaudio ?
[16:17:28] <Jacky^> always on rcf are u playng ?
[16:17:57] <Yuga> it's a Bill Fitzmaurice designed box
[16:18:06] <Yuga> it's quite the bugger to build
[16:18:25] <Jacky^> :P
[16:18:40] <Yuga> the thing is that i need like 4 of these boxes
[16:18:55] <Yuga> and i didnt feel like shaping them all out of wood
[16:19:22] <Yuga> so i made a fibre glass mold, poured it full of cement, and now i have my final mold :)
[16:19:46] <Yuga> abit over kill... but the mold is going to last for ever :P
[16:20:03] <an0n> hm, how is the sound of fibreglass?
[16:20:28] <Yuga> should be better than wood considering it's dencer
[16:20:42] <an0n> hm, are you sure?
[16:20:47] <an0n> *curious*
[16:21:04] <Yuga> yes... it's solid... far more solid that the same thickness wood
[16:21:27] <an0n> how thick are you making them?
[16:21:30] <Yuga> and the more solid the box the better the sound
[16:21:42] <Yuga> it's going to be about 6mm thick
[16:21:43] <an0n> yep
[16:22:06] <Yuga> trying to make it the same strength as 20mm ply
[16:22:22] <Yuga> and acording to the fibreglass place... 6 mm will be good :)
[16:22:30] <an0n> nice
[16:22:33] <Yuga> considering they stop bullets with 10mm :)
[16:22:50] <an0n> maybe I should consider it for my car stereo install..
[16:23:06] <Yuga> we made a awsome box out of fibre glass
[16:23:18] <Yuga> for a car
[16:23:25] <Yuga> it has 2x10" speakers in it
[16:23:58] <Yuga> will post the pic's as soon as my server comes back online
[16:24:13] <Yuga> lol.. it's online.. let me find the pic's and post them for you
[16:25:13] <Yuga> do u want me to upload the building process? or just the final product?
[16:28:59] <Yuga> oh well
[16:29:05] <Yuga> seems i am talking to myself
[16:30:33] <rayh> It does
[16:31:21] <Jacky^> hey rayh
[16:31:53] <Jacky^> rayh: question for you
[16:36:36] <Jacky^> rayh: ?
[16:38:12] <Jacky^> rayh: you you have the source doc of Hal for Integrator ? could you send it to my mailbox please ?
[16:38:20] <Jacky^> not pdf ..
[16:40:54] <rayh> I have the Lyx for that. It is in sourceforge
[16:41:09] <rayh> sorry phone dragging my attention away.
[16:41:15] <Jacky^> rayh: good .. np
[16:41:52] <Jacky^> i just wnat to try to translate it in 'IT' .. im note sure but
[16:42:00] <Jacky^> could be funny
[16:42:04] <Jacky^> :)
[16:42:16] <Jacky^> can you give me the url ?
[16:42:44] <rayh> I can dcc the file to you, I think.
[16:42:56] <Jacky^> lets try
[16:43:03] <Jacky^> i'm using nat
[16:43:07] <Jacky^> fw
[16:43:20] <Jacky^> not sure i can receive it ..
[16:43:37] <Jacky^> or
[16:43:45] <Jacky^> you can send it in mailbox
[16:43:54] <Jacky^> [email protected]
[16:44:00] <Jacky^> maybe better ..
[16:44:16] <Jacky^> thanks :)
[16:45:00] <Jacky^> 17:08 DCC SEND from rayh [208.16.249.36 port 1025]: Hal_Introduction.lyx [176kB
[16:45:14] <Jacky^> infact .. im tryng but wont pass..
[16:45:15] <rayh> There is the dcc.
[16:45:38] <Jacky^> :/
[16:46:02] <Jacky^> rayh: can you send it in email please ? [email protected]
[16:47:03] <rayh> On the way to your addy.
[16:47:36] <Jacky^> ok, thank you
[16:47:56] <rayh> It's out of here. Don't know how long it will take to get there.
[16:48:16] <Jacky^> ok
[16:48:29] <rayh> There is a very active LyX user list if you need help with that system.
[16:48:48] <rayh> I could also make a plain text file if that would be better.
[16:49:06] <Jacky^> which format it is ?
[16:50:27] <Jacky^> latex, or openoffice wuold be nice :)
[16:53:46] <rayh> I believe that there is a lyx to latex converter but don't know anything about it.
[16:54:02] <Jacky^> good
[16:54:13] <rayh> let me play here a bit.
[16:54:25] <Jacky^> ok
[16:56:46] <rayh> latex conversion on the way.
[16:57:00] <Jacky^> nice
[16:57:06] <rayh> I thought there was an rtf converter also but I don't see it right now.
[16:57:23] <Jacky^> oh .. dont worry .. its ok
[16:57:39] <Jacky^> thanks
[17:03:02] <rayh> found a latex to rtf converter. will try it.
[17:03:25] <Jacky^> rayh: great,
[17:09:58] <Jacky^> rayh: file received :) thanks
[17:14:32] <rayh> conversion done. will look at with oo.
[17:15:01] <Jacky^> rayh: its ok as is .. np ;)
[17:18:04] <rayh> I've got an open office file here if you want it.
[17:18:18] <ccjoe_> ccjoe_ is now known as ccjoe
[17:18:30] <rayh> It preserves most of the lyx formatting. Chapter headings don't look all that good.
[17:18:35] <Jacky^> rayh: thanks, i'm annoyng you
[17:18:43] <Jacky^> ok
[17:18:49] <rayh> Not at all. It is a challenge
[17:18:54] <Jacky^> :)
[17:20:29] <Jacky^> rayh: ok, 100% received
[17:20:57] <Jacky^> i will try to translate it in italian in the next days
[17:21:24] <Jacky^> then i will send you the return file
[17:21:56] <Jacky^> thanks
[17:22:09] <rayh> The office doc diagrams do not look very good at all.
[17:22:25] <Jacky^> oh .. I know ..
[17:22:32] <Jacky^> its not a prob
[17:22:36] <rayh> I suppose these could be replaced with the real docs.
[17:22:51] <Jacky^> yeah
[17:22:59] <rayh> I'll look forward to the document.
[17:23:12] <Jacky^> but its enough to start
[17:23:21] <Jacky^> ok
[17:25:01] <rayh> the .swx is on the way.
[17:29:21] <Jacky^> rayh: ok
[17:37:40] <Jacky^> rayh: receivedsxw, thanks a lot
[17:38:07] <Jacky^> sxw received*
[17:38:49] <rayh> Wedcome. Glad that you can make use of the info.
[17:39:44] <Jacky^> rayh: :-)
[17:44:51] <rayh> catch you all later.
[18:45:26] <les> blah. I got bored from writing reports and tried running a web telerobot somewhere. It paints on an easel.
[18:46:08] <les> I made a big mess. Dipped my brush too much and had paint running down the paper.
[18:47:17] <Jymmm> Found a pic of les http://pumpkingutter.com/pics/margepump.jpg
[18:47:51] <Jymmm> before morning coffee of course
[18:48:27] <Yuga> hey there les.. u mind if i pm u?
[18:48:46] <Jymmm> Was making a sign last night... 90 minutes into it the laptop power supply came unplugged =(
[18:48:49] <les> if i have to write any more reports I will look like that
[18:48:57] <Jymmm> les lol
[18:49:14] <Jymmm> http://pumpkingutter.com/
[18:49:16] <les> i was just bored and painting with a web puma telrobot.
[18:49:20] <les> yuga: ok
[18:49:48] <Jymmm> Yuga whispers sweet machining into les ear.
[18:49:56] <Yuga> lol
[18:53:41] <Jymmm> les meant to ask you... are you pinning your workpiece on the table on all four sides? I ask becasue my machine is 24" MAX on top/bottom so if I use 24" material I can only do left/right edges.
[18:53:44] <les> look what a mess I have made:
[18:53:46] <les> http://pumapaint.rwu.edu/
[18:54:20] <Yuga> les. any ideas on the pm?
[18:54:30] <Jymmm> [10:14:15] <les> yuga: ok
[18:55:27] <Yuga> Jymmm... saw that, just getting no reply :)
[18:55:58] <les> yeah you weren't recieving
[18:56:04] <les> I said:
[18:56:10] <les> seal heater vents
[18:56:24] <les> use car interior for cabinet volume
[18:56:35] <les> roll down windows for port
[18:57:21] <les> drivers in door
[18:57:55] <Yuga> ok... so there must be a pannel built behing the drivers seats with the drivers in?
[18:58:02] <les> you know that flutter you get when you open a window at speed
[18:58:10] <les> must be 5-10 hz!!!
[18:58:36] <Yuga> what about it?
[18:58:40] <les> one side of the speaker faces outside...one in
[18:58:52] <les> just think of the car interior as a box!
[18:59:20] <les> comms are a little clow here I think
[18:59:26] <les> slow
[18:59:50] <Yuga> problem is i dont want the speakers to fire out the boot
[19:00:23] <Jymmm> les check it out now - the paint robot
[19:05:59] <les> ha ok
[19:06:11] <les> I can't get on...because you are
[19:06:13] <les> haha
[19:06:15] <Jymmm> there's my artistic taelent for the day
[19:06:22] <les> looking
[19:09:16] <les> jymmm what a nasty mess!
[19:09:24] <Jymmm> what?!
[19:09:36] <les> many try to knock over the easel and throw paint around
[19:09:40] <Jymmm> not like I started with a blank canvas or anything =)
[19:09:46] <les> or hit a PUMA singularity
[19:10:04] <Jymmm> well, that sucks if they abuse it like that.
[19:10:13] <les> oh they love it.
[19:10:22] <les> now...tear the paper off.
[19:10:43] <Jymmm> how?
[19:13:30] <les> I don't know..but people have figured it out. see bloopers
[19:13:43] <les> hey it's movin around. that you?
[19:13:53] <Jymmm> yep
[19:14:03] <les> draw sumething
[19:14:09] <Jymmm> but it's suppose to be yellow =)
[19:14:13] <les> I mean paint
[19:14:25] <Jymmm> ok, let me grab another color
[19:15:25] <les> oh hahaha
[19:18:05] <Jymmm> there a happy face
[19:18:05] <les> new paper please!
[19:18:09] <Jymmm> how?
[19:18:26] <les> uh...they have to change it...
[19:18:31] <les> I guess
[19:18:48] <les> or start a stroke near the edge and the paper comes off
[19:18:49] <les> haha
[19:19:26] <Jymmm> nope
[19:19:29] <les> ow you almost tore it!!!
[19:20:27] <Jymmm> all yours
[19:20:33] <les> heh ok
[20:04:19] <Jacky^> hello Jymmm
[20:04:42] <Jacky^> gnam gnam time ...
[20:04:47] <Jacky^> :D
[20:07:05] <Jymmm> hi Jacky^
[20:12:27] <Jymmm> les 2HP 20K rpm 120IPM 1/4" downcut into 3/4" MDF - how much stepdown can I really do w/o pushing my limit?
[20:34:38] <K`zan> Morning all.
[20:40:01] <alex_joni> hi rayh
[20:41:03] <alex_joni> greetings from sweden
[20:42:27] <alex_joni> ok..going to bed
[20:42:29] <alex_joni> night guys
[20:43:02] <Jymmm> that bum is always sleeping! lol
[20:48:46] <rayh> oops I missed 'em.
[20:49:05] <Jymmm> which one? They're all running back under their ricks!
[20:49:09] <Jymmm> rocks
[20:49:35] <rayh> trying out the new wiki stuff, thanks to alex, paul, steve and matt.
[20:49:58] <Jymmm> I hate wikis.... just a bunch of electronic post-it notes.
[20:50:35] <rayh> "oh running away are ye, come back ere and I'll bite your knee-caps."
[20:50:58] <Jymmm> rayh you said you were goin fishing yesterday... you live near a lake?
[20:51:05] <rayh> They do tend to lack a certain bookishness.
[20:51:27] <rayh> Yes I'm right on a little lake 170 acres.
[20:51:41] <Jymmm> 170 acre lake?!
[20:52:05] <Jymmm> that's a BIG lake! lol
[20:52:05] <an0n> iab
[20:52:16] <rayh> I don't know what the conversion factors are for your measurements.
[20:52:20] <Jymmm> an0n a lil warning next time if you please.
[20:52:35] <an0n> that was the final warning
[20:52:37] <an0n> an0n is now known as anonimasu
[20:52:54] <Jymmm> rayh where is this lake of yours?
[20:52:54] <anonimasu> alex: you bastard! come to lule�!
[20:53:19] <Jymmm> anonimasu oh go make some swiss chocolate or something!
[20:53:40] <anonimasu> Jymmm: he's in the other end of the country
[20:53:50] <Jymmm> anonimasu ah
[20:54:12] <Jymmm> 90 minutes into a sign... the power connector on the laptop falls out last night =(
[20:54:29] <anonimasu> I feel like making parts..
[20:55:13] <rayh> Michigan, UpperPenninsula.
[20:55:32] <Jymmm> rayh ah, ok. never been there.
[20:55:58] <rayh> anytime you want to visit email. We've got spare beds.
[20:56:15] <rayh> where is home for Jymmm?
[20:56:25] <Jymmm> 22" x 18" Harley Davidson sign... was looking great... till the power supply got disconnected
[20:56:46] <Jymmm> rayh 30 minutes south of San Francisco... San Jose, California
[20:56:53] <anonimasu> Jymmm: your first scrap piece?
[20:57:01] <anonimasu> ^_^
[20:57:04] <rayh> Okay. I went to hs in Watsonville.
[20:57:12] <Jymmm> anonimasu : My first table top now.
[20:57:20] <anonimasu> it still feels shit even if you've scrapped 100 ;)
[20:57:23] <rayh> Spent a few growing years in Turlock.
[20:57:38] <anonimasu> Jymmm: nice :)
[20:57:41] <Jymmm> rayh oh wow... Watsonville to Turlock... what no Fresno or Stockton in there?
[20:57:43] <rayh> College in Napa valley
[20:57:58] <rayh> Girl friends in each.
[20:58:08] <Jymmm> rayh musta been some commute =)
[20:58:10] <rayh> Those were the early sixties.
[20:58:37] <rayh> Hey gas at 0.18 made for fairly easy travel.
[20:59:02] <Jymmm> anonimasu yeah, 90 minutes into it, 90 minutes togo. real disapointment
[20:59:11] <Jymmm> rayh try $3.10/gallon now
[20:59:37] <anonimasu> *chews a part of of the table with he's bare teeth*
[20:59:39] <rayh> Yep.
[20:59:41] <Jymmm> and I drive a Expedition too =(
[20:59:56] <rayh> Ouch.
[21:00:11] <Jymmm> anonimasu it's MDF, so you REALLY dont want to do that =)
[21:00:15] <Jymmm> rayh BIG ouch
[21:00:19] <anonimasu> th�s?
[21:00:28] <Jymmm> anonimasu chew the tabletop
[21:00:33] <K`zan> Steppers arrived this morning, a lot bigger than I thought thwy would be :)!
[21:00:34] <anonimasu> nah it's real wood..
[21:00:37] <rayh> I may have to start traveling by thumb again.
[21:00:47] <Jymmm> anonimasu ...and cat urine.
[21:01:08] <Jymmm> rayh better watch it... some real freaks out there... even the females
[21:01:18] <anonimasu> I didnt really know they made mdf out of that
[21:01:27] <K`zan> I resemble that remark :)
[21:01:47] <rayh> I know a bit about those folk from my college years.
[21:01:49] <Jymmm> anonimasu If you look at the MDF glue contents, you'll see what I mean.
[21:01:58] <anonimasu> ah :)
[21:02:48] <Jymmm> rayh no, not those freaks (we have hippies in Santa Cruz), these ones are pissed, escaped from a psycho ward, and out for blood and penises for the mantel!
[21:03:15] <Jymmm> "It places the lotion in the basket"
[21:03:41] <K`zan> Heh, califonrnicate, I have heard they gather fruits and nuts down there LOL
[21:04:07] <Jymmm> K`zan: No Senior... no hable engles
[21:04:12] <K`zan> * K`zan wants a controller NOW :).
[21:04:18] <rayh> met a few of those along the way also.
[21:04:43] <Jymmm> rayh icee live in Morgan Hill
[21:04:49] <K`zan> Heh, heard that also. I grew up with a military family and it was considered MOST *RUDE* to be in another country and expect them to speak your language...
[21:05:18] <Jymmm> What you mean? Spanish is the #1 language in California
[21:05:41] <Jymmm> Now, if they could vote, it be official.
[21:06:45] <K`zan> Because of the average rudeness of those people I refuse to learn spanish...
[21:07:02] <Jymmm> has anyone ever hit 1/16" aluminim with a router bit?
[21:07:07] <Jymmm> rudeness?
[21:07:16] <anonimasu> Jymmm: Yes.
[21:07:25] <Jymmm> anonimasu any damage to the bit?
[21:07:25] <K`zan> I do however enjoy watching the results of yelling "EMIGRATIONE" in places where they gather :).
[21:07:28] <rayh> It does seem to me that they were further between back in the 60s.
[21:07:28] <rayh> someone pointed out that we are only 6 meals away from total anarchy.
[21:07:35] <anonimasu> Jymmm: didnt I tell yoy you were going to be machining alu?
[21:07:38] <anonimasu> err you..
[21:07:49] <anonimasu> Jymmm: no idea, it'll probably work..
[21:09:36] <Jymmm> anonimasu: That's not it... my machien has a 24.5" travel in the Y axis, BUT (big butt)... I can only place a 24" piece of material with no room for dowels, so I was thinking of getting a oiece of 1/16" x 3/4" x 3/4" angle and mounting it under the table as a guide but I didn't want it to muck up the bit if it hits it.
[21:10:43] <Jymmm> I'd grab some plastic angle if needed, but harder to find.
[21:10:45] <anonimasu> oh, well you will be hitting it sooner or later..
[21:11:26] <Jymmm> well shit... now to find some plastic piece that's angled.
[21:11:42] <anonimasu> machine angles?
[21:11:47] <Jymmm> I'd use drywall corner strips, but way too weak.
[21:12:01] <anonimasu> 20x20mm square stock :)
[21:12:03] <Jymmm> anonimasu nah, I want something easily replacable
[21:12:21] <anonimasu> hm, I was thinking make like 10
[21:12:38] <anonimasu> excersise..
[21:12:39] <anonimasu> ;)
[21:12:47] <Jymmm> then I have to store them.... not alot of room in an apartment for storage.
[21:13:03] <anonimasu> oh well, buy them then
[21:13:14] <Jymmm> maybe trim molding
[21:13:32] <Jymmm> if I can find it thin enough
[21:16:23] <Jacky^> tarzan ?
[21:16:30] <Jacky^> jane ??
[21:16:31] <K`zan> Jymmm: Right on the storage problems in an apartment, gotta find someplace to store the copy stand between uses, I need a warehouse :-).
[21:16:38] <Jacky^> :/
[21:16:42] <Jacky^> :\
[21:17:31] <K`zan> * K`zan in driver thrash :-/.
[21:17:44] <K`zan> New steppers are burning a hole in my pocket :).
[21:20:48] <Jymmm> K`zan what size? nems23?
[21:20:51] <Jymmm> nema23
[21:21:50] <Jymmm> K`zan These are what I have... http://www.xylotex.com/StepperMotor.htm
[21:22:47] <K`zan> These are the KP4M4-029s I got to play with, I see more capable ones in my future though :-).
[21:23:15] <K`zan> Thrashing between the xylotex, HobbyCNC and building my own at this point.
[21:24:16] <Jymmm> well, Jacky^ has been building/testing his own for a couple months now.
[21:24:31] <Jymmm> hobbycnc = unipolar, xylotex = bipolar
[21:24:49] <K`zan> http://www.pminmo.com/l297-8/l297-8.htm Look easy enough and with good prices on the chips from Futurelec, attractive.
[21:25:16] <K`zan> I just see unipolar as the better choice at this point ?!?!?
[21:25:33] <K`zan> Still dispelling a lot of ignorance :-/.
[21:26:47] <K`zan> Heh, reading the included paper that came with the steppers, "WE'RE ALL GONNA DIE" they contain LEAD, oh heaven I don't have a permanent guantee of infinite life and health :).
[21:32:08] <cradek> K`zan: bipolar is always best, and the l298 is a bipolar driver...
[21:35:43] <Jymmm> YEAH BABY!!!!!!!!! http://www.professionalplastics.com/cgi-bin/main/co_disp/displ/carfnbr/25/prrfnbr/85429/Micarta-Brass-Bullet-Resistant-Laminate
[21:48:59] <K`zan> cradek: SO much to learn :-(.
[21:49:18] <rayh> Starting emc...
[21:49:19] <rayh> insmod: error inserting '/home/rayh/emcdevelop/test2/rtlib/rtapi.ko': -1 Invalid module format
[21:49:38] <cradek> K`zan: you'll learn a lot building your first driver.
[21:49:48] <rayh> Ahyone know about such an error while trying to start emc2 with bdi 4.29?
[21:50:00] <cradek> K`zan: I don't even know if you can run your 5 wire motor bipolar since the centers of the windings are tied together.
[21:50:00] <K`zan> cradek: Yes, thanks much for your site and helpful comments.
[21:50:35] <K`zan> cradek: Can you use a unipolar as a bipolar if you don't use the commom connection(s) ?
[21:51:24] <K`zan> Uh, never mind, maybe with the 6 wire, but I doubt with the 5 wire ones...
[21:51:38] <K`zan> I think :)
[21:51:39] <cradek> yes you can with 6 wire
[21:51:48] <cradek> I'm not sure what 5 wire will do. I think it might be bad.
[21:52:02] <K`zan> I guess that means that my 5 wire ones are shelf decorations then :-(.
[21:52:16] <cradek> maybe you can open them up and make them 6 or 4 wire
[21:52:29] <K`zan> Heh, one pays for an education one way or the other :-).
[21:53:02] <rayh> remember not to pull the armature out of the magnets.
[21:53:36] <rayh> just pull off the cap nearest where the wires enter.
[21:54:02] <K`zan> * K`zan hauls one out of bag and grabs phillips...
[21:56:13] <jepler> one web page suggests hooking up the center tap in a surprising way, but I think it just gives you a needlessly complicated unipolar drive... "To correctly connect a 5-wire to a bipolar drive, the center tap must be connected to the motor supply." -- http://www.motiongroup.com/steppermotors_basics.shtml
[21:58:54] <K`zan> Wires disappear into the coils...
[21:59:12] <K`zan> Might me a good thing to meter out the leads on one so I have a clue what is what.
[21:59:29] <K`zan> or google for a diagram :-).
[22:01:29] <anonimasu> hm
[22:02:47] <K`zan> Heh, for as "popular" as these steppers are supposed to be there appears to be NO data out thereon them other than people asking for it...
[22:03:39] <anonimasu> dosent the manufacturer have the specs?
[22:04:34] <K`zan> Apparently not, odd for a stepper that has been in goddess only knows how many million floppy drives...
[22:06:18] <jepler> K`zan: xylotex sells these to go with his allegro-based bipolar boards (XS3525/8S-x), do you have documentation explaining how to hook those motors to those boards?
[22:07:09] <jepler> oh, wait, I got confused. Jymmm is the one with the xylotex motors, not you? nevermind.
[22:15:17] <K`zan> jepler: No inforation at all, abs nothing on the japan servo company site either...
[22:17:07] <jepler> K`zan: if your meter can read the low coil resistances, it is easy to find which is the center tap.
[22:18:24] <jepler> then for unipolar it's just a matter of figuring out which order makes it rotate clockwise
[22:19:35] <K`zan> Got the docs on how to do that, working on it now.
[22:20:32] <jepler> I don't know any way to find the correct operating current, though
[22:21:08] <anonimasu> I have japan servo steppers..
[22:21:10] <anonimasu> they work great :9
[22:21:12] <anonimasu> :)
[22:21:14] <jepler> if they're from floppy drives, then a good guess is whatever current +12V gives you.
[22:21:17] <K`zan> jepler: Fortunately they were cheap (<$3) so they were acquired to be educational and maybe even useful :).
[22:21:30] <K`zan> KP4M4-029
[22:21:52] <jepler> this one? http://www.doc.ic.ac.uk/~ih/doc/stepper/kp4m4/
[22:22:04] <jepler> +12v dc, four-phase, unipolar, permanent magnet, 3.6° per step
[22:22:10] <anonimasu> is it salvaged off a floppy?
[22:22:35] <K`zan> Probably, that is the only reference I can find.
[22:22:47] <anonimasu> is it?
[22:24:05] <K`zan> I didn't got them from here: http://www.goldmine-elec-products.com/prodinfo.asp?number=G14781&variation=&aitem=3&mitem=6
[22:26:05] <jepler> tou know, I think I bought some of those
[22:26:13] <jepler> ^tou^you
[22:26:15] <anonimasu> cant they give you the datasheets?
[22:26:30] <jepler> I was going to use it to give my etch-a-sketch finer motion, but I got bored and never did
[22:26:45] <jepler> (it's got 7.5 degree motors now)
[22:27:32] <anonimasu> heh
[22:27:37] <anonimasu> there seems to be plenty of info about it
[22:28:39] <K`zan> Where are you finding this ?!?
[22:29:59] <K`zan> http://www.goldmine-elec-products.com/prodinfo.asp?number=G14781&variation=&aitem=3&mitem=6
[22:30:05] <anonimasu> google..
[22:30:06] <K`zan> OOps
[22:30:14] <K`zan> Got it metered out...
[22:30:21] <ValarQ> hello folks
[22:31:27] <ValarQ> anonimasu: have you heard the news? mr Joni has come to town :)
[22:33:48] <anonimasu> ValarQ: yeah
[22:33:52] <anonimasu> the other end of town ;)
[22:34:41] <ValarQ> yeah, the scary skåneland
[22:36:04] <anonimasu> yeah
[22:36:07] <anonimasu> very scary place :/
[22:37:47] <ValarQ> http://www.spelcenter.com/gbs/index.php
[22:40:00] <anonimasu> lol
[22:40:01] <anonimasu> nice
[22:41:05] <ValarQ> yeah :)
[22:41:26] <anonimasu> hm brb, going out to remove the gearbox off the mill..
[22:41:27] <Jacky^> uhm ...
[22:41:39] <Jacky^> evening
[22:41:42] <anonimasu> need to get it togther I want to make chips as soon as I can
[22:41:43] <anonimasu> again
[22:42:29] <Jacky^> ouch
[22:42:33] <Jacky^> no reply ...
[22:42:55] <ValarQ> Jacky^: sorry, evening
[22:42:59] <Jacky^> anyone here speak engllish well ?
[22:43:05] <Jacky^> english*
[22:43:11] <Jacky^> ValarQ: yes .. :\
[22:43:19] <Jacky^> damn bad english ..
[22:43:24] <Jacky^> let me know ..
[22:43:26] <ValarQ> Jacky^: no, we are no native speakers either :(
[22:43:35] <Jacky^> this morning i send an email:
[22:43:36] <ValarQ> neither...
[22:43:39] <ValarQ> heh
[22:43:42] <Jacky^> ok
[22:43:45] <Jacky^> read..
[22:43:49] <Jacky^> Hello,
[22:43:54] <Jacky^> (sorry for my bad english.. i'm from Italy)
[22:43:59] <Jacky^> I need to buy soon 3 Gecko G340, but i don't have credit card (just bancomat with Cirrus,FastPay,PagoBancomat circuits).
[22:44:04] <Jacky^> Do you accept some alternative payment, like postal office payments ?
[22:44:08] <Jacky^> Is there some Geckodrive affiliate in Europe ?
[22:44:13] <Jacky^> Waiting for your reply I thanks you a lot.
[22:44:16] <Jacky^> Greetings
[22:44:22] <Jacky^> Giacomo Cusato
[22:44:29] <Jacky^> is understanble ?
[22:44:41] <ValarQ> well, its pretty ok
[22:44:42] <Jacky^> what i meant ?
[22:44:50] <Jacky^> well .. no reply ..
[22:44:53] <Jacky^> :/
[22:44:53] <ValarQ> i guess you mean some instead of soon
[22:45:06] <Jacky^> soon = fast ?
[22:45:09] <Jacky^> right ?
[22:45:27] <ValarQ> yeah, but then it's in the wrong order
[22:45:32] <Jacky^> ok..
[22:45:52] <Jacky^> but it should be clean ..
[22:45:54] <ValarQ> "I soon need to buy..." would be more correct
[22:45:55] <Jacky^> i hope
[22:46:11] <Jacky^> thats ok ..
[22:46:24] <Jacky^> that why i wrote: (sorry for my bad english.. i'm from Italy)
[22:46:26] <Jacky^> ..........
[22:46:43] <Jacky^> :(
[22:46:52] <Jacky^> will wait tomorrow ..
[22:46:53] <ValarQ> well, i can still make out what you wan't
[22:47:04] <ValarQ> there shouldn't be too much trouble with that :/
[22:47:06] <Jacky^> i need to know
[22:47:16] <Jacky^> if i can pay with visa card
[22:47:22] <Jacky^> probably yes ..
[22:47:31] <Jacky^> its postal office card
[22:47:37] <Jacky^> but VISA
[22:48:43] <ValarQ> i'm off to bed now, goodnight folks
[22:48:45] <Jacky^> it seem they accept Visa card
[22:48:52] <Jacky^> night ValarQ
[23:47:54] <anonimasu> hm..
[23:48:01] <anonimasu> I didnt get the mill into molecules today
[23:48:08] <anonimasu> I failed on getting a shaft out..
[23:48:12] <anonimasu> ended up making special toold..
[23:48:27] <anonimasu> and I coudlnt find the die.. for the end of the tool ;)