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Author Topic: Crooked Cuts?  (Read 5657 times)

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Crooked Cuts?
« on: August 01, 2010, 12:44:12 AM »
Hello All,

I recently picked up an old Phoenix GS cnc router.  I have no past experience and spent the first week just getting the thing running.  I cut the roadrunner first and it looked pretty good.  I then wanted to cut out something in 3d and loaded in a file.  On this file the X axis cut horribly crooked.  The whole picture shifted farther and farther to the right to the point where a 90 degree angle was at nearly 45.

I believe I have a problem with the motor as it's probably really old and it makes a nasty screaching noise.  All of the motors make more noise than I think they should, but I have no reference to know if that is normal or not.  The X axis motor is easily the loudest though and I figure before I go throwing money at a problem I know nothing about I should at least ask first!

So anybody have any thoughts for me?  Thanks!

Offline Hood

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Re: Crooked Cuts?
« Reply #1 on: August 01, 2010, 01:53:19 AM »
Sounds like your motors are stalling and loosing steps. Reduce your Velocity and acceleration in motor tuning by half and see if it helps.
Hood

Offline Tweakie.CNC

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Re: Crooked Cuts?
« Reply #2 on: August 01, 2010, 06:08:43 AM »
Erikgolson,

If it's the GS... made by Magnum Technologies then I think it will have servo motors (which I know nothing about).

Can you establish if your machine is servo or stepper motor driven ?.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Crooked Cuts?
« Reply #3 on: August 01, 2010, 01:34:42 PM »
Hello guys, thanks for the replys!

@Hood- I'm trying that as we speak.  After the first couple of lines it appears to still be drifting.

@Tweakie- Yes, it is made by Magnum Technologies!  I've done a bit of looking around and couldn't really find any information on them.  If you could point me in that direction it would be great as I have no documentation for this thing whatsoever.  I had to dissect it a bit to figure out what was what and to get the thing running.  It appears the original mainboard has been replaced with a SoundLogic unit with some other small board soldered to it to connect the original stepper drivers.  I inquired with a motor retailer and was told that my motor is  "7 amp 8 wire motor nema 34, 5" long single shaft, 200 steps per revolution, about 900 oz-in"

Another problem I'm encountering is that Mach doesn't communicate with my machine properly after it has been shut down after the initial setup.  When I refire everything my controller doesn't operate the axis properly and everything seems to just go haywire, like the Z axis will change itself to go up instead of down. 

Offline Hood

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Re: Crooked Cuts?
« Reply #4 on: August 01, 2010, 06:23:43 PM »
Can you attach your xml please.
Hood
Re: Crooked Cuts?
« Reply #5 on: August 01, 2010, 06:48:57 PM »
ok, here you go
Re: Crooked Cuts?
« Reply #6 on: August 01, 2010, 06:51:18 PM »
I also swapped the inputs for the x and y axis to check the y motor as well and it does the same thing.  :(
Re: Crooked Cuts?
« Reply #7 on: August 02, 2010, 04:30:14 PM »
I'm going to try replacing all of the motors to see if I get better results.  The stepper drivers are the original centroid drivers from the early 90's.  Other than size, does anyone know of any benefits to upgrading them to say some gecko G201X's?

Offline Hood

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Re: Crooked Cuts?
« Reply #8 on: August 02, 2010, 04:37:35 PM »
You said "I also swapped the inputs for the x and y axis to check the y motor as well and it does the same thing" what exactly did you swap and are you meaning the Y now misbehaved and the X was now ok?
Hood
Re: Crooked Cuts?
« Reply #9 on: August 02, 2010, 05:07:26 PM »
With the design I was cutting out, the router travels back and forth on the X axis.  I couldn't tell if the Y axis was off as well, or if it was just the X axis.  So in mach I changed the input pins between the two motors so the design would have the router travel back and forth on the Y axis.