Help Cutting circles TM2 router

[John999]

Hi
I am routing circles 4.75" diameter from 3mm alum sheet and can't get them perfectly round.
Max revs, 2 cuts at 2" per min.
I have edited the cutting g code to over 200 points.
The circle diameter is accurate in the X axis but the Y axis is down 3/32".
Any ideas?
Thanks
John
Designs 05

[MoparJon]

I don't know if this will help you or not, here is a link to a file on Torchmate's web site dealing with circle problems; might give you a few things to try, if you have not already:

Poor Circular Cutting Solutions

Best of luck!

-Jon-

[John999]

Thanks for that Jon
That was usefull.
My accuarcy is now within 1/16" on the 4.75" on the Y axis. X axis perfect.

There is also a concentric circle 5/8" dia cut inside the 4.75" circle. This has come out with flats top and bottom of the Y axis.

John

[Mike@Torchmate]

Thanks for that Jon
That was usefull.
My accuarcy is now within 1/16" on the 4.75" on the Y axis. X axis perfect.

There is also a concentric circle 5/8" dia cut inside the 4.75" circle. This has come out with flats top and bottom of the Y axis.

John

I would ensure that the gear ratio's are set correctly by running a gantry axis test, after checking for mechanical backlash or slippage. If there are flat spots to a circle it is likely that when a certain axis is changing direction, the motor is spinning but due to either a loose set screw or mechanical backlash the motors motion isn't being transferred to the gear rack.

The Gantry axis test can be found here:

Gantry Axis Test

[John999]

Thanks for that Mike
Accuracy now within 12 thou x to y
John