Cutting CNC Dovetails

1

Has anyone tried making dovetails with the M4? I see a lot of finger joints with cnc projects, but rarely dovetails. I understand that finger joints are easier, but I would think dovetails would be doable with only a switch to a dovetail bit. The tails (i.e., the part that looks like a trapezoid on the board face and rectangle on the end grain) could be cut with a standard bit since it is just cutting out a trapezoid shape. The pins (i.e., the part that looks like a trapezoid on the end grain) could either be cut with a dovetail bit for best accuracy (this would cut the pins with the wider side of the pin down against the spoilboard) or could possibly be done with a standard bit that steps down and inward along the dovetail angle (this would cut the pins with the wider side of the pin pointing up towards the M4).

In my head, it seems to work. Has anyone tried in practice?

2

the problem is that a bit cannot cut a sharp corner, it will be rounded with the
same radius as the bit. so you cannot cut the sharp trapizoid

for cutting the pins, you would have to provide a way for the dovetail bit to
get down to the starting depth without the sled tipping. This would mean that
you need a slot between your workpiece and some support for the sled.

This is why there are a lot of cnc joints that are similar to dovetails, but
they are all rounded in some way.

David Lang

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3

I know that a cnc cannot get sharp corners, but it can get close enough that taking off 1/16" by hand shouldn’t be very difficult. As for the plunge depth with a dovetail bit, that doesn’t seem to be very difficult to overcome either.