Seems to run nice at 40ipm http://electronicsam.com/images/emco/EMCOThreading.JPG
video soon... On 7/9/2013 11:34 AM, sam sokolik wrote: > ok - some cool news I think. So - with the switch on the interface > board set to off (non step/dir mode) the control signals are 4 phase > drive. (seems to be unipolar). pins 2 through 5 control one axis - 6 > through 9 control the other. I hacked a hal file to setup stepgen to > output 4 phase (patterns 5 through 10). > > First tried pattern 9 (Unipolar Half Step) because the scale was setup > for that. > the performance was the same. 20ipm max and would probably have to back > that off... > > Second was pattern 10 (Bipolar Half Step) I know - not likely - and it > wasn't. Didn't like it. > > Third was pattern 5 (Unipolar Full Step) I halved the axis scales also. > similar performance.. 20ipm max. (and sound so far was pretty crappy) > > fourth was pattern 6 (Unipolar Full Step (two windings on)) > Holy crap. That sounds nice. maxed out at 30ipm and didn't try any > faster. Full stepping is .00054ish per step. Workable for sure. > > That is what the original control/software maxed out at. I will try > faster when I get a chance. > > That is totally usable with linuxcnc - no mods to the control. I need > to hook up the index and 100ppr and try some threading! > > One thing to try is - I think I can put the interface board back into > step/dir and full step. I don't know what pattern it does though. > > sam (happy dancing..) > > > > On 7/8/2013 7:13 AM, sam sokolik wrote: >> We got a few of these lathes from a local school. they are cute little >> cnc lathes. >> The technology is pretty old though. The steppers are 72 steps per rev. >> >> I found this >> http://www.maxton.com/ebay/emco/EMCO%20Compact%205PC%20Conversion%20to%20Mach3.pdf >> >> which talks about converting to mach. They remove the octal latch and >> jump through it. >> I wanted to see if I could get linuxcnc to drive the board without >> hacking the latch out. >> >> this is what I have found/figured out >> >> I think this is correct.. (this is with switch 1 on the interface board >> set to >> 'on' which puts the board into step/dir) >> >> x step pin 2 >> x dir pin 3 >> z step pin 4 >> z dir pin 5 >> index pin 12 >> estop pin 11 >> 100 ppr sensor pin 10 >> 74ls374 enable pin 14 >> 74ls374 clock pin 1 >> >> I setup linuxcnc to send a pulse at every base period for the 'clock' >> that latched the outputs of the chip. (thanks Jeff E for the idea) this >> is using the >> 'reset' option of the printer port that allows for a cycle within each >> base period >> the same feature that makes 'double step' work. This allows me to >> 'latch' the >> 74ls374 each base period with the current step/dir pattern. It seems to >> work >> >> Now it took me a bit of tinkering to figure out that I didn't read the >> above article >> well enough to notice that you needed to set a switch to put the emco >> interface >> board into step/dir mode. During this time I was flipping bits on the >> printer port >> to try to figure out why it wasn't working. I think by default the >> interface is setup >> as phase drive. (4 phases per stepper) as I think I was flipping all 8 >> data bits on >> the printer port and was getting stepper clunking. >> >> Well - the performace of these drives/steppers are pretty poor. (assuming >> I have the timing right - and I didn't get too much time to play with >> it.) In the >> above article they talk about around 20ipm is about max. That is what I was >> seeing - plus there is a weird interaction when you run both axis at once. >> (they get quite a bit noisier for some reason). Now it could be that I >> don't quite >> have the timing correct - like maybe the step/dir needs to be inverted or >> or something - I will play with it more. >> >> I would also like to switch it back to non-step/dir mode. (phase drive >> maybe?) >> because there might be a reason the original software used it.. (better >> performance?) plus I think I have the original software and would like >> to try >> it out also. (need to setup a pure dos machine to test) >> >> lathe >> http://www.electronicsam.com/images/emco/emcoclose.JPG >> interface/drive >> http://www.electronicsam.com/images/emco/interfaceanddrive.JPG >> >> sam >> >> >> >> >> >> >> >> >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by Windows: >> >> Build for Windows Store. >> >> http://p.sf.net/sfu/windows-dev2dev >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > ------------------------------------------------------------------------------ > See everything from the browser to the database with AppDynamics > Get end-to-end visibility with application monitoring from AppDynamics > Isolate bottlenecks and diagnose root cause in seconds. > Start your free trial of AppDynamics Pro today! > http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. 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