GS750 Plus Closure problem

gg markers

New Member
Hello all, and thank you in advance for any help.

My plotter started being unable to make perfect circles. They come out sort of oblong and don't close properly. I've went through all of the troubleshooting in the manual; x,y,theta adjustments... everthing has been cleaned and oiled, but no change. I'm running omega 4.0 software.

Thoughts?
 

Fred Weiss

Merchant Member
How old is the plotter?

When you say you've checked the theta adjustments, that needs some clarification.

  • Have you checked that the Theta belt has the recommended amount of tension?
  • Have you checked that the Theta belt has all its teeth?
  • Have you checked that the Theta belt is positioning the blade in its correct home position when you turn on the power to the plotter?
Do the out of shape circles happen in any particular spot or anywhere?

What degree blade are you using and have you tried replacing the blade with a new one? Are the cut edges clean and smooth?
 

Fred Weiss

Merchant Member
You might want to check Post #16 in this thread for directions on setting the home position for a Gerber plotter with a tangential blade. The method isn't any different for a 30" plotter than the 15" one I was discussing in that post.
 

gg markers

New Member
Thank you so much for the quick reply! I'm not sure what the correct tension is, but I tried loosening it a bit and tightening it a bit but, no change. I also replaced the blade and the blade holder. I'm using a 45 degree blade to cut sand blast stencil.

The belt is missing a tooth... I removed it and tried to replace it, but the new belt I have is way too tight. I had to force it on and it wouldn't allow the blade to turn, so I put the old one back on. You think I have the wrong belt? Any ideas on where I can buy parts for this beast?
 

Fred Weiss

Merchant Member
Thank you so much for the quick reply! I'm not sure what the correct tension is, but I tried loosening it a bit and tightening it a bit but, no change. I also replaced the blade and the blade holder. I'm using a 45 degree blade to cut sand blast stencil.

The belt is missing a tooth... I removed it and tried to replace it, but the new belt I have is way too tight. I had to force it on and it wouldn't allow the blade to turn, so I put the old one back on. You think I have the wrong belt? Any ideas on where I can buy parts for this beast?

You should be able to order the belt from any Gerber distributor or direct from Gerber. Be sure you specify the model of the plotter since there are different length belts for different plotter models. You can also order theta belts from a third party provider named The Plotter Doctor. My understanding is that he also provides a pretty good set of instructions with it.
 

Tony Teveris

New Member
In GspPlot using the Plotter / Printer Select dialog turn off the "Smart Start Point" feature. Does this make any difference?
 

gg markers

New Member
I tried turning that feature off, but it didn't make a difference. I took the whole assembly apart and I've ordered a new theta belt and the z cam is cracked so I ordered a new cam as well.

FYI it's WAY cheaper to order straight from Gerber than from Plotter Doctor.

Thanks everyone for their input and I'll let you know if my replacement parts fix the problem :::fingers crossed:::
 
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