What is the maximum CNC bit length can shapeoko pro accommodate?
A number of factors come into play.
Size of the bit. Thinner bits will deflect. Thicker bits will cause deflections of the router as well as the āZā plate. I expect chatter will play into this also as the bit cuts.
Small cuts will alleviate some of these issues, thus possibly dulling the bit as it doesnāt have a chance to cool with no chip load.
So I didnāt give you a number, there are a number of factors involved. The material you are cutting, speed, depth, desired finish, and more are beyond my thoughts right now.
Cutting deep can cause issues is all I am saying. Others will chime in and give some insight.
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Not a real answer here butā¦ It will depend on the thickness of your material, the Z travel amount, the depth you will be cutting, the retract height you have designed in your project, the cutting length of the bit you are using, how deep in the router you set your bit and possibly the clamp height you have.
Anthony
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I have successfully cut 1.5" thick treated pine with a bit that has a 1.5" cutting length. If you have enough stick out from a router bit that has a 1" cutting length you could cut thicker wood than 1" but sometimes the shank of the router bit is slightly larger than the spirals of the cutting part of the bit and will burn the top of the cuts where the shank rubs on the wood. So if possible get cutting length of the bit to match the material you are cutting.
The further a bit sticks out from the router the more the run out of the bit is. So the less precise your router will cut the further out the bit sticks due to a lot of reasons. The router bearings run out, the collet runout, the bit runout and the bit wobble in the collet due to all of the above situations. So there is no theoretical limit but there is a practical limit of about 1.5" of cutting depth. You can purchase 2 inch or longer cutting lengths but they are impractical for a Shapeoko.
My machine is a Shapeoko 3 with HDZ and Dewalt 611 router.
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That being said, and rather sage adviceā¦
Purely mathematical, donāt do this. But if you raise your Z axis to the top, then raise your router as high as it will safely go in the spindle mount, then measure the distance from the tool gauge point (the bottom edge of the collet nut) to the table. Then subtract your stock thickness and retract height. (See, it depends on the job). But in theory that will be your (current) longest tool.
I have a 3/8" x 4", 1 3/4" flute, and a 1/2" x 5", 3" flute end mill that I will use for unique situations. I ābabyā them, and I donāt use the entire flute length for any given cut. The machine/spindle just arenāt powerful enough to get carried away.
Good rule of thumb is to use the shortest possible tool you can. Less wobble, less runout, less deflectionā¦ On a lot of operations on my setup sheets, I will include the shortest tool length and measure the tool stickout as I put it in the collet. Or I will put sharpie marks on the longer tools.
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I like your idea of subtraction of stock, the need of long bit is really for specific application since itās not practical due to deflection and wobble as you said. sometimes i need to cut 1.5-2 in deep for custom ashtray jobs which is why i need this type of long router bit.
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