On 1/19/2016 3:33 AM, Gene Heskett wrote: > 2 optos in series because the BoB you bought is also an isolated version, > _will_ hurt you. Particularly if using a PWM output for spindle speed > control, you _WILL_ have to get rid of it if you want anything that even > resembles linear speeds so the PID can control it right. > Cheers, Gene Heskett
That's what the Pico stepper control board I bought is for. Still sitting on the big box bolted to the side of my Acra mill. It has linear scales on X and Y and a 127 count rotary encoder on the Z ball screw. I do have 1600 oz/in steppers mounted in place of the more massive 14 volt DC motors that had tachometers. According to the specs for both, the steppers have higher torque than the DC motors did at their peak RPM, and the steppers are rated to run at even higher RPM than the DC motors. On paper the steppers appear stronger. I did a test hookup on the X axis and fiddled around jogging it back and forth In Mach 3. It moved plenty quick, faster than I've seen on Youtube demos of old Anilam Crusader M systems. The proof will be in the <S>pudding</S> milling. Anilam had no problems 26 years ago doing closed loop with linear scales and DC motors only reporting back their RPM. Don't see why it should be difficult to do with steppers. I kept the 2:1 belt reduction on all axes. Spent yesterday shifting stuff around in the shop to be able to get back to work on the 13" LeBlond lathe. I also now have to take apart and inspect the Z-axis servo on my PLM2000. Buying an old space saver Hyster with some brake issues. I said let's check out the brakes first. Nooo. Dad wants to use the new toy to move heavy stuff, right now, including my CNC mill. Well it got knocked over and the Z motor housing now resembles a crumple zone on one corner. :( However it IS on the sturdy table I have been wanting to move it to so I could actually use it to Do Stuff. Turns out the "brake issue" was no brake fluid, at all. Zilch. Zero. Also got to have fun with rollers and large steel prybars to move a B&S #2 surface grinder and a Hardinge DV59 split bed lathe. Two more fix up projects. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
