Hello all, after tons of research here, cnczone, and elsewhere (thanks everyone!) i seem to have stumbled on a very good set of settings for the mach3 / tb6560 combo....
while not confirmed yet (repeatability using verify after test programs) i have reached speeds last night in excess of 1200 rpm!!!!
mainly through the use of 1/2 step mode on my board combined with checking "enhanced pulsing", and sherline 1/2 step mode; and using settings of 25khz kernal, step and dir's of 2 ea. nano sec's, running a 28 volt psu, and 185 oz~in keline steppers, oh and 25% decay rate, with 100% current (wired bipolar parallel)
using my 1/2 - 13 leadscrew ~ i know i know, too cheap for acme or ballscrews lol, i was able to get my axes over 100 ipm at times and settled on 86ipm as a stable maximum for the time being..... more verifications to follow asap!
anyway, just wanted to share with y'all cuz i know we are struggling with these boards and performance, please comment back, thanks, Bill