Cutting thick materials - shank diameter vs bit size

Just getting started with using the Carvey here, sorry if I am missing something…

Let’s say I have a thick(ish) MDF board (20 mm = 0.8") that I want mill out some shapes from, and make holes in.
Using a 1/16" bit, with a 1/8" shank. I.e. the lower, “cutting part” of the bit is thinner than the shank.
Let’s assume the length of the bit’s cutting part is “L”. For the bit in question, L is smaller than the 20 mm material thickness.

What happens if I try to cut through the board, i.e. the full 20 mm?
The first few tool passes will be fine, but at some point the thicker, upper part of the bit will interfere/push against with the already cut path… right?

I can’t see a way for Easel to know what L is (unless there is a way to specify this, which I cannot find), which would mean that the value L is the upper limit for how deep cuts I can make (at least with bits where the cutting part of the bit is smaller than the shank.


I haven’t used Carvey but in Easel you set total cut depth equal or shallower than the “L” as you call it.
Easel do not account for bit/shank diameters, straight bit or V-bits.

If you want to go deeper the neck (transition between shank and tip) will crash /rub the material and most likely cause the router to loose steps. You can mill a wider top channel in order to prevent the neck from hitting uncut material, but not all designs accommodate this workaround.

A common practice it so go as 1/4" or so into the material, then rough cut it with a bandsaw or similar, then carve the remaining materials off using a router/flush trim bit.

Right - cut depth can be easily set.
My question is really what happens if I set a depth that is bigger than L… Guess I will most likely break the bit.
Won’t try :slight_smile:

You replied while I was adding to my first reply :slight_smile:

Depending on the material: Going deep may break the bit / or cause the machine to loose steps due to increased friction.

You may have to do it two sided which complicates things. You’ve got a 1/16" cutout and you’re going to try to put a 1/8" object in it…it’ll probably break the bit and/or ruin the workpiece.

Yeah I only have a single bit right now, a bunch more are on order.
Doing as a two-pass cut will work too, making a slightly wider hole to begin with, then drilling the final hole through the workpiece using the desired diameter.

For now I solved the whole thing by using a much thinner workpiece - with great result. Nice!