V-Carve Pocketing Problem

[mklafehn]

I am using an evaluation version of V-Carve and in particular the OPEN sign file that is provided by Vectric. Anyway, the program is terrific and does a great job, however after the sign was finished I noticed small round machine marks in the pocketed section. These are caused from the router plunging. Where the router is moving, no marks.

I was using an Onsrud 52-910 bit (1/4" upcut spiral) and my Z speed was .5 ips. I am cutting into 3/4" clear pine.

Is there a strategy to eliminate these marks? I was thinking about a 1/4" bullnose, but don't know how that would work. I did try a straight end mill bit and it was about the same, maybe a little worse.

I have included a photo for review. Any suggestions would be appreciated.


4836

[rcnewcomb]

We found that a downcut spiral bit eliminated or at least reduced this. Try something from the Onsrud 57 series like a 57-910.

[mklafehn]

Thanks Randy!

I just happen to have a 57-910, so I will give it a try.

Did you ever try a roundnose or covebox bit?

I can get one as small as 1/8" and I was thinking since it has a nice rounded end it wouldn't give the round circles that are caused by the pin point end of the bit biting into the wood as the router plunges.

Thoughts...

[gerald_d]

Mike, I am assuming those are dips and not bumps, otherwise you would have sanded them out...

Your z appears to be overshooting on a plunge. You should check that the z-axis is well tuned to eliminate backlash or freeplay.

You could also change the z speed and decel ramp to get a smoother stop.

We sometimes manually edit the file so that a pocket is done with a single plunge, or even plunge on a gentle incline.

.....but you only noticed them after finishing the sign, so they could be bumps after all. Typical if a bit is hard to plunge and it actually lifts the gantry a bit.