Upgrading pr control box

[jseiler]

My memory was off. I think the archive was saying that the max out of a PR box was 4000-7000 pps (depending on good communications).

Checking this thread, 25000 should be right. Mike R. is 99.9% right about these things.


http://www.talkshopbot.com/forum/messages/26/18313.html

Right now, I believe my old pr box runs in half step mode. So 1 revolution has 400 steps and each revolution is .2" or .0005" resolution. This is more than good enough, I think.

I like the idea of buying a prt box because it does give me an upgrade path to 4g instead of my original plan of going Mach/gecko straightaway. I really like shopbot control language a lot.

Have you seen mariss F.'s announcement about PID/feedback steppers he's working on? He mentioned it on cnczone. 40% more torque, no lost steps, all while maintaining 3 axis synchronization. I hope shopbot comes up with a version 5 or 4g+ version when mariss releases.

John

[jseiler]

My plans have changed for the time being. I really need to figure out 1/4, 1/2 and full step adjustments.

I am taking ownership of a k2cnc kt-1414 (14"x14") frame that I want to connect the prt box up to. I got the prt box working with the keling motors I have with the unit values set up appropriate to the k2 (.1" lead, so 10 turns of the screws/inch of travel). I connected up the motors in bipolar half coil (using only the a a/ and b and b/ coils) to keep the current requirements down while keeping the inductance reasonable (1/2 of the series bipolar and twice the parralell). Is it wiser to use only half the rated current in parallel bipolar to get the lower inductance or is it better to use half coil and run full rated current?

So...anyone have a clue how to set the jumpers on the prt board to get 1/2 or full step instead of 1/4 step? I can't find this anywhere in the manual, but it alludes the to the possibility. I'd like the option of the additional speed considering the 10:1 ratio on those k2 standard screws.

John