[Krlerma]

I have been lurking for some time and decided to finally post a question. I am making some instrument fingerboards in fusion360. I have all thetoolpaths correct but i am struggling with the final pass. They come out real rough looking and need a whole lot of extra hand work to clean them up. My question is what bit should i use to clean them up to on my final pass? Are there specific brands/sizes you guys might have good luck using? Any advice is greatly appreciated

[Jim Dawson]

The finish may be more of a function of technique, feeds and speeds, rather than the endmill, a bullnose might be helpful, or not. What material? Width of cut? Depth of cut? Direction of cut, climb or conventional? Any cutting fluid?

Some pictures would be helpful

[Krlerma]

Jim,

I'm using a 1/2" ball bit. The feed is 92 in/min. Speed is 1000 ft/min . For the material, I used MDF for my first test and ebony for a second test. I was able to hand scrape the ebony clean so it was not a loss. I am doing a tiny step over of .05" thinking it might clean it up better. I will post pix tomorrow when I'm back in the shop. I would be glad to share my fusion model with you if need.

Thanks again

[Jim Dawson]

Sure, I would be happy to look at you Fusion model. Understanding the shape of the part would be a big help.

[RCaffin]

The odds of getting anything useful from MDF are close to zero, imho.
Try cheap hardwood if you can find some. Second hand building materials are a good source.

The feed is 92 in/min. Speed is 1000 ft/min
?? Speed is 1,000 RPM maybe? That's very slow.

Cheers
Roger

[Krlerma]

So here is the file. I probably have the numbers wrong. I need to preface that this is my first 3d model that i have tried to cnc. I do cabinet parts with it and thats it. Maybe its my fault for trying something new.

Thanks guys

[Jim Dawson]

I looked at the file, I need to think about it for a bit to come up with a plan.

[Krlerma]

I looked at the file, I need to think about it for a bit to come up with a plan.

Thanks

[ger21]

.05" is not a tiny stepover. Try .01-.02" for your stepover.

[Jim Dawson]

After running some simulations, I agree with Gerry, you need less stepover. You can speed the process up a bit by swapping the X and Y axis and that might improve the finish or at least make it easier to final hand finish because the striations would be in the long axis

[ger21]

I didn't look at the file, but I'd definitely be running along the fretboard, with the grain.

[Krlerma]

Thanks guys. Ill look at doing that. What bit do you guys recommend? The same 2 flute corebox bit or is there something else that might work better?

[Jim Dawson]

The corebox bit should work fine if it's nice and sharp. You may have to experiment with feeds and speeds to get the finish you want.

[Krlerma]

I performed some tests today. The thing that made the biggest diference was the stepover. Thanks to all that helped

[bostosh]

I find this place really tuff to compete with.
Seriously think of your time and effort.
They vary in thickness but top and slots are perfect
Buy vs D.I.Y.

Allen Guitars & Luthier Supplies