FET-3 Rev B Drive Timing

I've got a FET-3 board from Stepperworld.com and everything seems to be working pretty well, but I need to get the drive timing dialed in. I didn't see an entry for the FET-3 or the FET-4 (which is basically a 4-axis version of the FET-3) on the timing Wiki page (wiki.linuxcnc.org/cgi-bin/wiki.pl?Stepper_Drive_Timing). I also suspect that my "Rev B" version of the board was originally based on a stepper IC and is now a PIC, which may have changed the timing from the original.

There was a discussion over at CNCZone.com on getting the FET-3 to work, but there was never any resolution. I was wondering if anyone here has gotten the FET-3 timings worked out. It would save me quite a bit of time experimenting.

The CNC Zone discussion:
www.cnczone.com/forums/emc_linux_enhance...fet3_controller.html

Thanks,

Jeremy

Thanks for the response John. It took me awhile to get things to the point where I could respond.

I did email This email address is being protected from spambots. You need JavaScript enabled to view it. back in late January and have not heard anything back.

Based on the stepper diagnostic link you gave me, I was able to get the machine running well. The accuracy and repeatability are very good.

Before I submit the FET-3 controller timings for the wiki I have another question though. It doesn't seem to matter what I set the "Direction Hold" and "Direction Setup" values to in the "Basic machine information" Stepconf screen (attached image). They can both be 100 ns or 4000ns and it doesn't seem to make a difference.



In the "Tweaking Software Step Generation" document below, it mentions that with "normal stepping (no direction change), the increased dirhold value has no effect". Does that mean that the "Direction Setup" value won't have any effect either?

wiki.linuxcnc.org/cgi-bin/wiki.pl?Tweaki...ftwareStepGeneration

Thanks again John. I'll leave them at 4k then.

I appreciate the help.

Jeremy