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Rough pickguard Edges from 90 V-Bit
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10106&t=53404		 Page 1 of 1
Author:  Rick Hubka [ Sat Aug 08, 2020 12:32 pm ]
Post subject:  Rough pickguard Edges from 90 V-Bit
Hi
I'm making a few dozen pickguards of different colors and with my CNC all cuts are great except the outer edge bevel with a 90 degree V-Bit. I have tried several different 90 degree-V-Bits with no change. I install all 8 pickguard screws to hold it down.
For straight cuts I use a special plastic cutting bit that works great

Feed Rate 55 inches/min
RPM 7000

Faster RPM starts to melt the material.

I even tried repeating the last cut at the same and faster RPM. Sanding the edges takes a ton of time and is not easy on tight turns.
This image is right next to a screw.
Image

Any advise?

Thanks
Author:  rbuddy [ Sat Aug 08, 2020 3:32 pm ]
Post subject:  Re: Rough pickguard Edges from 90 V-Bit
Is it screwed down flat with 100% support against a spoil board? Looks like the bit is forcing the edge down causing it to bounce or vibrate under the cutter when the cutting edge hits the pick guard.
Author:  Rick Hubka [ Sat Aug 08, 2020 5:12 pm ]
Post subject:  Re: Rough pickguard Edges from 90 V-Bit
You are right. The small screws 2 to 5 inches apart do not provide 100% flat support to the somewhat flexible plastic. I am going to make an aluminum hold down plate. TKS!!!
I did slow down the Feed Rate from 55 to 30 inches/min and it was a small improvement.
I'll post back after making a hold down plate.

Why do all these small simple projects always turn out more complicated? LOL!!!
Author:  Rick Hubka [ Tue Sep 22, 2020 11:15 pm ]
Post subject:  Re: Rough pickguard Edges from 90 V-Bit
Hi Guys.
Sorry for the slow response...
Well... I now have a fairly smooth pickguard edge on my pickguards. I doubt that many people hold down that floppy pickguard material better than me now. :lol:
1/8 inch aluminum plate hold down templates!!! Overkill. Maybe???
Here's a picture.
Image

Thanks
Rick
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