Super-B Not Cutting Round Circles

[Shibbychris]

Hello All,

I inherited a 4x4 Super-B in my welding class, and have little experience. The machine cuts straight lines wonderfully, but for the life of me, I cannot get it to cut a round circle of any size. I have slowed it down, sped it up, gotten the cut height closer, and further away, and tried multiple materials and thicknesses. The attached picture shows 1/8" aluminum, with (what is supposed to be) a 3" od and 2" id. The "donut" came right out of the Dynatorch software, so I don't believe it to be an issue with the program itself, but seems more mechanical in nature, as the X and Y movements just don't appear harmonious. Any advice would be greatly appreciated.

Thanks,
Chris

IMG_0833.jpg

[ROKCRLER]

@CNCSASRUSS might be able to shed some light on your issues, hes the new owner of the Super-Bee tables.

[robertspark]

check your drive mechanisms on each axis (pinions / pulley's / grub screws etc).... looks like something loose creating backlash to me on the inner circle at least looking at the z motion (left to right shunt). the outer one is more difficult to work out as that looks like the y axis being loose (up and down shunt in the photo)....

check you don't have backlash settings set as well or set incorrectly to over or under compensate..... as that may be the software.

start with the mechanical and check carriages are secure on rails too.... all drive it's are tight etc and then look at the software backlash settings and finally the post processor to see you are not using one with backlash compensation or the wrong settings set for bAcklash.

on an older table something may be worn too..... so you may need to add backlash compensation or replace worn pinions....

[acourtjester]

What I see is a drive system problem. if you look at the image you can see each time the motor transition direction. As the table moves around the circle cut, it reaches a point where each motor changes direction. At that point if the drive is sloppy you will see a bump. These are always shown in opposite sides of the circle and you can tell which drive is faulty by looking at which motor is reversing directions at that point.

aaacuts.JPG

[weldguy]

Definitely looks like a loose gear or pulley on one of your drive motors. May just need to tighten a setscrew to fix this one.