Lost Steps in X Axis Mach3 after Stop?

I was cutting a v-carve outline of a quilt block for my wife. I realized I had forgotten to secure the lower left clamp where the touch plate had been used. I hit the Stop button in Mach3, secured the clamp and restarted the program from the start since it hadn't cut very much. When it restarted i had lost about -.030" in X axis. This made the v-groove for part of the project almost twice as wide. My question is:
1. By hitting stop did I lose steps in the x-axis?
2. Should I have hit Feed Hold, then Stop or just the Emergency Stop?
3. What is the best practice for stopping and then restarting in that situation? I had written down the X,Y G54 coordinates at the start, but didn't recheck them.

FYI, I am running an 2 year old Avid Pro4848 with Nema34 and their integrated electronics kit.

Any thoughts would be appreciated. Thanks

I don't run M3 but usually the E stop is for emergencies only. I always try to hit the feed hold or pause button and the program always starts where it left off.

But if he restarted after re-zero it should be ok. No re-zero then backlash in the system, yes Pause should just restart without issues. That is one reason I went to Mach4 was the little things in Mach3 that should work fine but don't.

I've had that happen a couple of times when I hit the E-stop instead of Feed Hold. Once I corrected my error I restarted without homing XY and redoing Z zero and it shows in the cut. It's quite a shock to the system to hit the brakes that hard and it will show every time.

David

I think it just cuts power to the drives and it coasts to a stop. And feed hold takes waaaaayyyyyyy too long to activate. M4 is supposed to have that fixed.

Worse when the x-box (or whatever, I ain't a kid anymore) times out and you're running disconnected and have to go to the PC and mouse.

Give me an 'industrial' control, or give me ... nothing, I guess.

Mine doesn't coast on the E-stop or Feed Hold but with Feed Hold I don't have to re-home and set Z zero again. The E-stop is an abrupt 'clunk' when the button is pushed and it happens NOW, no coasting at all. I guess some systems are different but I know how mine reacts to the E-stop.

David

Quote:

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Originally Posted by mark gaylo

I was cutting a v-carve outline of a quilt block for my wife. I realized I had forgotten to secure the lower left clamp where the touch plate had been used. I hit the Stop button in Mach3, secured the clamp and restarted the program from the start since it hadn't cut very much. When it restarted i had lost about -.030" in X axis. This made the v-groove for part of the project almost twice as wide. My question is:
1. By hitting stop did I lose steps in the x-axis?

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Yes - you most likely lost steps.

Quote:

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Originally Posted by mark gaylo

2. Should I have hit Feed Hold, then Stop or just the Emergency Stop?

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Feed Hold

Quote:

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Originally Posted by mark gaylo

3. What is the best practice for stopping and then restarting in that situation? I had written down the X,Y G54 coordinates at the start, but didn't recheck them.

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Assuming that your material did not move, then theoretically had you hit Feed Hold you could have resumed running your program from the location it stopped. If there is any chance that the material has shifted (moved) then the best practice would be to Rewind back to the beginning of your program and re-zero your x and y axes to your original program zero location on the part.

Quote:

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Originally Posted by mark gaylo

FYI, I am running an 2 year old Avid Pro4848 with Nema34 and their integrated electronics kit.

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I am also running the CNC Router Parts/Avid Pro4848/Nema34 machine with air cooled spindle. Some folks seem to poo-poo Mach3, but I am quite pleased with the results I achieve with my setup.
David

It's been a couple years now, but I think you can jog after feed hold to clear or check whatever, and restarting will return it to where you left off.

But dont go and check that out in the middle of something important. I might have it mistaken with another control.

Here is what happens with a E Stop with Mach3, there is a buffer of un used gcode. When you restart without taking that in consideration bad things happen.