Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Jammerm on March 12, 2014, 01:27:21 PM
-
Is there a reason why, when I run longer g-codes, my steppers lose a few steps or go completely out of whack. One cut I did on a wheel started out very well and then lost about 20 steps on both the x and y axis. I re-tuned the motors and it seemed to help. Cut the whole wheel in a rough code and then started the finish code. About half way through, it dropped down about 2mm on the z axis. I caught it pretty quick and I think I can repair it. Is this bad steppers or poor tuning?
Would there be a better section in the forum for this type of question? Feel free to move it. :)
-
Probably poor tuning or even the micro step value is causing resonance.
Is everything mechanically in order. Gibs are too tight?
Did you hear the steppers stall or squeal when running the code?
Was it running well prior and this is a new problem? Or are you just getting started?
-
Small error in steps per unit and small backlash can add up over a lot of axis moves and thus seems like loosing some steps or small
inaccuracy.
Completely out of wack can be due to incorrect vel or accel settings for the motors and work your doing. Additionaly inadequate motor torque can cause lost steps when making very small axis moves like what one would find in 3d machining.
RICH
-
I'm basically just getting started. Been playing with it mostly and just got some complicated codes to try out. This one has over 150,000 lines of code. The problem occurred about 3 hours in. I'm still having a little trouble with the e-stop tripping for no reason.
-
The Estop tripping is likely a debounce setting being too low or a ground issue. Have you applied any debounce (not index debounce). Maybe both.
It is complicated in the beginning (and even now in the not so beginning).
-
On large files, it is advisable to turn off the tool path display. Some problems as you report can occur otherwise.
John Champlain
-
I was having a lot of trouble with the ground so I beefed it up pretty well. I didn't know there was a debounce setting, I'll have to look and find it. And, how would I turn off the tool path display?
-
Diagnostics page.
Russ
:)
-
I didn't know there was a debounce setting, I'll have to look and find it.
Config. / General Config.
Upper right corner.
Russ
:)
-
What kind of setting should I try for the debounce?
Thanks to everyone for your help.
-
Usually you want the Debounce Interval as low as possible, preferrably 0.
If you need to use it the norm is to start at around 2000 and work your way down.
Hood
-
The debounce values are in 40 microsecond intervals 40/100,000,000ths of a second. Even a value of 2000 as Hood suggests is requiring the signal be present for 2000 x 40us=80000/1,000,000,000ths of a second or 8/10,000ths of a second. Most of our machines (hobbyist) dont move very far in that short amount of time even in rapids.
-
Hey Fastest1 - you might want to give your keyboard a quick clean - I think your zero key is sticking a tad. ;D
-
Hey Fastest1 - you might want to give your keyboard a quick clean - I think your zero key is sticking a tad. ;D
:D :D
Might need to up the debounce a bit ;D
Good one Ian,
Russ
:)
-
only 3 decimals! :-( I remember there was a time before the internet when you could have argued if you were wrong. Kind of hard with it in print and uneditable.
Russ, fortunately my 0 value is still the same ;-)
-
I thought I said denounce.