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johngoodrich
22-09-2011, 10:25 PM
i was cutting a sample 3d part today just trying things out, roughed it out fine, changed tool and then started finishing. after a few cuts router basically lost position but the motors did not stall, it was as if it missed a couple of lines and then moved on. not sure what happened. anyone got any ideas

John S
22-09-2011, 11:10 PM
Trying to go too fast ?
What do you have acceleration and velocity set to ?
Also who breakout board are you using ?

johngoodrich
22-09-2011, 11:14 PM
its a routout cnc breakout board. velocity set to 2000mm/min max. accellleration is set to about 0.25 seconds. the rest of the progrm ran fine it was just this one bit that did it so i don 't think the velocity/acceleration is a problem hopefully

johngoodrich
22-09-2011, 11:15 PM
feed in the program was 1500mm/min

John S
22-09-2011, 11:49 PM
Velocity and feed sound reasonable but acceleration sounds very high, might not be able to have time to move, try increasing the time.

Jonathan
22-09-2011, 11:59 PM
One way to see if it's going to stall is run something like this:

G61
G0 X0 Y0
G0 X100 Y100
G0 X0 Y0
G0 X100 Y100
G0 X0 Y0
G0 X100 Y100
G0 X0 Y0
G0 X100 Y100
etc...

Doing that clearly moves X and Y at maximum feed, then reverses ... so if the acceleration is wrong that's quite likely to stall it. My machine used to stall if I ran that code at 8m/min, then I changed the computer to a better one and it'll do that at 15m/min without stalling.

John S
23-09-2011, 12:58 AM
Best to put a G21 on the top line in case he's from the States :lol:

Jonathan
23-09-2011, 01:02 AM
Best to put a G21 on the top line in case he's from the States :lol:

Nah, that'd be his own fault for using silly units and not having limit switches!

John S
23-09-2011, 02:07 AM
LOL !!:wink:

johngoodrich
23-09-2011, 07:31 PM
npe i'm from uk, cornwall and i do have limits so it won't matter any way. i'll try turning the accelleration down a little.thanks