Chamfering mills are for chamfering! The problem with using one to make a V-groove is that the tip of the tool has just about zero cutting speed, so it will be ploughing rather than cutting. Even if you don't break the tip it will likely leave a poor finish. Tilt the block, or at least use a slitting saw to cut a deep groove first so that the tip of the chamfering cutter isn't cutting. Look at a V-block, there's normally a slot at the bottom of the V.

Andrew

You could possibly rough out the Vee with a series of steps done with decreasing diameter milling cutters finishing with say a 3mm one to put the groove into the bottom on the vee much like the saw would. Followed by a pass with your chamfer tool to cut the corners off the steps.

Not tried it but another option may be to grind a little off the end of a chamfer cutter so that the edge will have some peripheral speed, this would leave a slight flat at the bottom of your Vee which could have a 3mm slot milled in or depending on what is going into the Vee you could knock the corner off of that.

What are you cutting ? Might get away with a wood router Vee tool if it is aluminium.

This may be of use, though not sure if you really need one now that you have the mill.

Edited By JasonB on 03/06/2018 20:18:29

I bet this will upset a few, essentially gluing bits of steel!

Sometime ago, I wanted a steel block with a big 90 degree endmilled slot, or at least someone else' design called for such, to which I thought bugger that. I cut a 5mm plate of steel same footprint as block, cut off 2 pieces of thick steel angle of a suitable size web and mounted them side by side with the edges on the 5mm plate. Elicited them in place. Robbie done! I should add that the resulting V was to serve as a guide for toolgrinding so the Loctite was not put under any great stress so would not let go.

The 90 degrees is not a requirement – the only thing is it needs to be symetrical. For anything square that you might want to drill in it (if a 90 degree V) you should have some relief at the bottom of the groove, so you might just as well add it at the start.

There are other ways of fabricating the part. Depends on the size of it, really.

More info on Drill Mills here for anyone interested.

**LINK**

And cutting speeds

**LINK**

A Drill Mill is not the same as a Spotting Drill by the way.

Stuff like this does come up on eBay from time to time at a good price and very handy to have if you can get one.

If you want to cut something softer than steel you could try this.

**LINK**

Having the tooling this is what I would use. A left hand and a right hand 45° cutter mounted back to back on a mandrel. If you had lots of these grooves to cut some used 90° or 45° cutters would be worth looking out for.

Martin C

This picture shows the difference between the cutters. The two on the left are Spotting drills, the one in the middle is a Drill mill and the one on the right is a Chamfering mill.