Diamond bits on plywood - vibrations

I was cutting some wood and plywood with 1 flute simple bit and it was working fine.

Some time ago I found that people prefer Diamond Bits for the plywood because they produce more clear cuts on the top. I tried a couple of bits (3.17, 2.4, and 2.1) but comparing to 1 flute 3.17 I am getting serious vibrations.

Do you have any quess what is the reason and what am I doing wrong?

My build is quite stiff, every single bearing is really tightened. But on these bits I am having very serious vibrations. The top of the part is better (no hair), but the cut itself is having slight wobble. (on the screenshot below left was cut by 1 flute, and right ones is Diamond 2.1mm)

[attachment file=46075]

Sorry no luck to embed the video from YouTube - Video shows sound I get. Some resonance?


Is the diamond bit a 2 flute? I think you just need to slow down your RPM’s, or cut deeper per pass.

Do you have a link to the bit, I’m not sure what it is.

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Ryan, so sorry, due to some reason thought these are called diamond bits, but these are CORN type bits!

Here is the lot: https://www.banggood.com/10pcs-11_522_53mm-Carbide-End-Mill-Cutter-PCB-Drill-Bits-p-1090388.html?rmmds=myorder

Just noticed that price is a bit…mmm… cheap, even for chinese made)) But the geometry looks fine

Do you think what you said above could be right for these bits?


P.S. I think I had around 10 000 RPM, and 1.5mm depth that time

Those are drill bits, best for pushing down into wood and not so good for pushing sideways.

Hmm… Are you sure you are looking at the right link? (or you’re referring to the name Chinese decided to give to the goods?)

They do not look like a drill ones. I’ve heard they are used for the brittle materials like PCB, Carbon, and Plywood




I wouldn’t use those for plywood, they’re really made for pcb(fiberglass) or carbon fiber panels. The ones you linked to will gum up with wood and glue. Plain old 1 or 2 flute endmills work best for plywood. Plywood really is a shitty material to cut no matter what though. The glues they use are really hard on the end mills.

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Thanks guys,

Seems like I will forget about these, and will contunue to deal with 1 flutes… (and sleep well)