Odd Shaped Bore Holes

[ALSjosh]

Well, I was finally able to get back to the machine and watch it cut today and with backlash measured and compensated for in CNC12 and the program parameters changed in fusion to allow the G2/G3 moves, the holes got better but I still have a strange flat spot in the upper left of my hole. Please note that the part is upside down so the flat spot you see in the picture in the upper right is really in the upper left when the part is upright. My measured backlash values were the following:

X: .0035
Y: .0005
Z: .0045

[suntravel]

Backlash on X should be fixed, it is too much for round holes.

Uwe

[ShawnM]

My measured backlash values were the following:

X: .0035
Y: .0005
Z: .0045

I think your X and Z backlash values are HUGE. You may need to fix those mechanically.

[suntravel]

You cannot fix an unstable machine frame with loads of backlash with software an expect it will run on high feed rates in metal...

Uwe

[ALSjosh]

I will try to chase down the backlash. The couplers seem good and I don’t see anything in particular with the preload or bearing block. Any ideas where to look? Here is a slow motion video of the X axis

[ALSjosh]

Also, these values were before software compensation. Forgot to add that. Retest after applying software compensation were less than .0005. I know that I still need to fix mechanical backlash though. Just no idea where it’s coming from

[Houseman303]

Would it be a good idea to enable smoothing for this in CNC12?

yes, G64 should always be on when outputting line segments. This is also the case with real processing machines when you work with cam programs. I can force G2/3 output in Solidcam for profile and pocket jobs, but not for adaptive or 3D jobs.

[Houseman303]

Well, I was finally able to get back to the machine and watch it cut today and with backlash measured and compensated for in CNC12 and the program parameters changed in fusion to allow the G2/G3 moves, the holes got better but I still have a strange flat spot in the upper left of my hole. Please note that the part is upside down so the flat spot you see in the picture in the upper right is really in the upper left when the part is upright. My measured backlash values were the following:

X: .0035
Y: .0005
Z: .0045

IMG_8674.JPG

I see processing without compensated finishing. I recommend roughing with allowance and then creating a finishing job with radius compensation for the finish. This reduces the mechanical stress on the machine (stiffness) and improves the quality of your component.

[suntravel]

Would it be a good idea to enable smoothing for this in CNC12?

yes, G64 should always be on when outputting line segments. This is also the case with real processing machines when you work with cam programs. I can force G2/3 output in Solidcam for profile and pocket jobs, but not for adaptive or 3D jobs.

Fusion can output G2/3 on any toolpath and I prefer it over short vector stuff...

Uwe

[ALSjosh]

Uwe- Can you share why Fusion is outputting short vectors on my job? Or is the preview of the gcode in CNC12 just showing line segments and that’s not correct?