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Author Topic: Weird, Z axis randomly increasing travel. Causing deeper cuts  (Read 3385 times)

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Weird, Z axis randomly increasing travel. Causing deeper cuts
« on: January 18, 2011, 03:52:51 PM »
So I went to do some .005 " engravings today which I have done everyday for 5 years, and after just a couple commands to lift Z and lower back to .005 it started to cut deeper, then on the next engraving letter deeper still until it was below the flutes on the ball cutter and the cutter snapped.

I took down my Z servo and air blasted the encoder. I ran a Z test bringing from 0 to 1 back to 0, 20 times in a row and it never lost accuracy.

I then did a hard restart on the PC and when I went to fire up Mach3 it gave me an error and instead of showing me an error code it just gave me a blank gray window where moch3 should have been. I clicked close and got a Mach3 has suffered an error message. I restarted mach3 again and it was fine.

I ran my engraving program and everything was fine except a couple engravings in the middle of the program where clearly not as deeply cut as the rest.


Does this sound like a signal interference problem or a software problem?

I'm hesitant to run the program again out of fear of loosing more cutting bits and material stock.

Offline Hood

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Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #1 on: January 18, 2011, 07:30:50 PM »
Could be anything really, could be axis sticking slightly on the way up, depends on the following error of your drives whether that would cause an issue or not.

Could be something interfering with the pulses, noise, possibly other software etc.


Mach not starting properly would suggest a software issue though, may be worthwhile renaming  the Mach folder to something like OldMach3  and re-installing Mach to the default Mach3 . Once installed you can copy over xml etc from the old folder

Could also be computer hardware problems, HDD dying or memory issues.

Not much help I am afraid :(

Hood

Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #2 on: January 22, 2011, 12:23:50 PM »
Hi,

I have some problem with all axes, if I test, for example Z axe for movement to 10 mm, wen return to 0 is stop to 0.01 and wen go to 10 mm is stop to 10.001 mm, and again return to 0, is stop to 0.02 and again to 10.002 ..................and so on. No accuracy.

I use UHU servo, and when I tested with uhu tuning software, accuracy is OK, for example wen I use G command to move Z axe, is move and go back without lose position for hundred times, but with mach3 lose position.

Any suggestion.

Tanks.
       
P.S. I tried and with EMC2 but result is the same.
« Last Edit: January 22, 2011, 12:28:44 PM by morarudnl »
Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #3 on: January 22, 2011, 12:54:35 PM »
I found the solution to the problem I was having and it turned out to be multiple problems all happening at the same time.
First, I just swapped computers so the mach3 set up was not right and I had the acceleration set to high. This was causing over travel on the down cut.
Second, the mounting bolts on my Z axis servo motor over the years got stressed and came loose. That was my fault for using crappy bolts from home depot.
and last problem was the counter balance of the milling head was not right to begin with, and thats why the acceleration speed needed to be lower in the first place.

When I set all this up 5 years ago I ended up forgetting about all the micky mouse fixes I put into place and they all came back to bite me all at the same time.

Offline Hood

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Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #4 on: January 22, 2011, 02:09:52 PM »
Hi,

I have some problem with all axes, if I test, for example Z axe for movement to 10 mm, wen return to 0 is stop to 0.01 and wen go to 10 mm is stop to 10.001 mm, and again return to 0, is stop to 0.02 and again to 10.002 ..................and so on. No accuracy.

I use UHU servo, and when I tested with uhu tuning software, accuracy is OK, for example wen I use G command to move Z axe, is move and go back without lose position for hundred times, but with mach3 lose position.

Any suggestion.

Tanks.
       
P.S. I tried and with EMC2 but result is the same.

Try setting the active state of the Dir output to the opposite of what you have now.




I found the solution to the problem I was having and it turned out to be multiple problems all happening at the same time.
First, I just swapped computers so the mach3 set up was not right and I had the acceleration set to high. This was causing over travel on the down cut.
Second, the mounting bolts on my Z axis servo motor over the years got stressed and came loose. That was my fault for using crappy bolts from home depot.
and last problem was the counter balance of the milling head was not right to begin with, and thats why the acceleration speed needed to be lower in the first place.

When I set all this up 5 years ago I ended up forgetting about all the micky mouse fixes I put into place and they all came back to bite me all at the same time.

Good to hear you got things sorted :)

Hood
Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #5 on: January 27, 2011, 02:50:43 PM »
Hi,

Tanks Hood, I was misunderstood, mach3 loos steps,  if I command to go 10 mm my motor  moves 9.98 mm and when return to 0 move to 0.02 and so on adding up errors.

With uhu.exe software, with G command, if command 1000 steps or more and return to 0, my motor return without errors.
Today I change my old computer (1.2Ghz) with AMD dual core (5Ghz) but some problems remain.

Tanks.
   

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Re: Weird, Z axis randomly increasing travel. Causing deeper cuts
« Reply #6 on: January 27, 2011, 05:00:05 PM »
Try changing the active state of your Dir pins
Hood