Hello All,

Looking for some help here.
I have just finished a major mechanical upgrade to my CNC router which has operated well since 2017 when I built it.  I am using Mach3 and Windows 7 Pro, 32 bit (SP-1), 4 gig ram, AMD A4 3.8 GHz processor along with a UC100 and a PMDX-122 BOB as always with no problems.  One of the changes I made with this upgrade was to go to micro stepping.  I use Automation Direct drivers and 4 wire bi-polar 34 frame 3 stack motors.  One on the Z and X and two on the Y.  Always ran them at the 400 Smooth setting with no problems other than noisier at low speeds than I would like.  I have them set up now at 5000 steps per revolution and all is well as far as movement and scaling is concerned. 
My problem is that no mater what I do I cannot get more than 51 IPM velocity. The motors are direct coupled to the ballscrews so 25,000 steps per inch is what I need and it works fine. The scaling is dead nuts on the money.  I have tried various kernel speeds to no avail.  If I type in 100 IPM and save it then run the motors there is no increase in speed and in the motor tuning window the velocity is cut back to 50-51.  The machine runs great but I can't get any more speed out of it.  The other thing I have discovered is that I cannot get the Driver Test to open.  I click on it and nothing happens.  I have only used it once back when I first built the machine and it worked fine.  ?
This velocity thing has me puzzled so I'm hoping someone on here way smarter than me can show me the light. Something is limiting the ability to increase the velocity but I have not been able to find it. 

Thanks,
Old Mike

What frequency do you have the UC100 set to, you may need to up it.

Thank you Graham.  It took me forever to find where to change the UC-100 frequency but when I finally did that was exactly what the problem was.  Thank you so much for your help.

Old Mike