Runaway axis

[Superone]

Hi,

I purchased the Mach3 CNC Kit With 3-Axis DC Servo Drive & PLC. I have been using this system for about a year with great results. The system functions very smoothly and accurately with speeds that I could never achieve with my previous "stepper motor" system. However, I have been battling a runaway motor problem since the beginning. This "runaway motor" problem only happens during a manual jogging event. I do not have the pulse generator, so I use the keyboard in order to jog my machine around. What happens is, lets say that I am finding the edge of my part and I slowly bump the edge finder close to the part. At some point, absolutely randomly and this has occurred on all three axes now, I will bump the jog button on the keyboard in the direction that I want the tool to move and that motor will just keep going in that direction. This has caused slow crashes and is especially worrisome in the z direction when the tool gets pushed into the wood or plastic that I am going to be cutting. The only way to stop this action is to hit the Emergency Stop. This has also caused my "zero" to be lost or slightly off. Please help. Any Ideas what may be causing this issue?? I am running my system with Win XP.

Thanks
Richard

[Superone]

Anyone else have this issue???