I have two Nema 34 steppers on the x axis (rack and pinion drive), running Mach3. the feedrate is 200 ipm, acceleration is 8. Never stalls at this rate during jogging, machining or rapids. However, on pressing the feed hold button one or both of the motors stall. Also, the motors stall on activating the Stop button. This stalling occurs when it changes direction, not before a direction change. Is there a way to change the feedhold settings to match those during jogging in terms of acceleration?
Thanks for your replies.

There are no settings to alter with regard to FeedHold as it simply looks at your Acceleration settings in Motor Tuning and stops the motors with respect to that. Pressing Stop whilst in motion will however cause lost steps in most cases.
If you wish to attach your xml I will look at it to see if there are any issues , also say what revision of Mach you are using.
Hood

                                            
I'm on my way to solve the problem.  It seems that the resonance was in equilibrium with the tangential curve of electron backfiring.  The positrons combined with the neutrons and created a white matter that nullified the dark matter and henceforth created a inertial curve within the time and space dimensions, leaving a solitary, three phase voltage centrifugal curvature.  I have now understood after lots of days in and days out, I have finally concluded everything came out from nothing.  To state briefly, my CNC evolved.  Hopefully you too can correlate between the time and space pulse direction and create matter out of your CNCs.  Today my friends, don't take it lightly, try the hockey puck  yourselves.

                                           "THAT WAS SIMPLY FUN, REAL SOLUTION FOLLOWS"

I placed a heavy hockey puck (around 10 oz) on the rear shaft of the motor.  Made sure that there was equal space between the puck and the body of the motor.  Since then, the motors don't stall on feedhold.  I'll try to update in the coming days.  Thanks Hood for the quick reply.  I switched from my custom profile to the default MachMill profile.   But found no difference.  Hence I tried the hockey puck damper.

I'm on my way to solve the problem.  It seems that the resonance was in equilibrium with the tangential curve of electron backfiring.  The positrons combined with the neutrons and created a white matter that nullified the dark matter and henceforth created a inertial curve within the time and space dimensions, leaving a solitary, three phase voltage centrifugal curvature.  I have now understood after lots of days in and days out, I have finally concluded everything came out from nothing.  To state briefly, my CNC evolved.  Hopefully you too can correlate between the time and space pulse direction and create matter out of your CNCs.  Today my friends, don't take it lightly, try the hockey puck  yourselves.

What reference source did that come from?

RICH

There's a long thread on building dampers at CNC Zone. Some have found that just pressing a hocky puck on the rear shaft eliminates resonance.
I have "rattle" type dampers on my router. It would be nearly unusable without them.