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
