Help solving a motor problem???

[barmybovine]

Hey guys

I have built 4 picstep V4.0 boards and PMINMO's 4 axis interface. I have all 4 motors up and running using Turbocnc

I have a problem though
I can run all 4 motors fine in both directions at low speed but as I try and crank up the speed they run fine in one direction but as they accelerate in the other direction they loose step and just stop spinning altogether. I have tried various wiring variations to the motor and still no joy.

When I change the axis step from hi to lo in the turbocnc config menu the problem occurs but in the opposite direction to before.

I have a35V supply capable of 20+A and 4 motors drawing 2.8each <7.15K resistors on picstep boards> so I am good to go with the PSU. Also this is on an older laptop, could this be my prob?

I have yet to hook a scope up but it kind of seems to me like maybe I am getting a funky wave form in one direction ????

Any advice would be great

Thanks guys

[barmybovine]

bump

[H500]

Sounds like your laptop port is not putting out enough voltage.