Thanks Gerry, its a Vortech machine, screw drive, don't know the pitch or the motor off hand and I'm not at the shop currently. When I say 100% speed I'm referring to the 100% setting in Mach when you tab into the jog rate settings etc. When that is set at 90% or less the machine works fine. If you set it at 100% or if you are jogging the machine and use the shift key to jog it at full rate it will lock up.
I can't recall the exact settings for the speed in the confige but it isn't at 100% speed capacity, something down around 80 inches per minute if memory serves me correctly.
When it locks up it isn't stopping dead, sounds like almost like its getting pulsed to go in both directions at the same time. The machine has been running in its current configuration for a year and half with no issues at all until today.
Let me know what else you may need to know.
Thanks
Randy