60* TCMT Dovetail Cutter

[SteveJustSteve]

This is the first cutter I've ever made and while there's certainly room for improvement, it does function properly and has already modified many free hardened steel KDK tool holders to fit my CXA tool post. I used a TCMT 432 rather than an insert with more relief angle only because a friend had given quite a few of them. The downside to this was in order to achieve adequate clearance w/o grinding more into the inserts I had to push the cutting edge slightly in front of the center line of the cutter. To my knowledge (which is very limited so feel free to educate me) the only disadvantage of doing this is that the cutter has more of a negative rake so it needs more horsepower to run it. Luckily I have a 4HP Series II BP
It seems to leave a good finish though it does seem to hit pretty hard even with two cutting edges. Let me know what you think.

I had zero luck embedding a video so if you care to see and hear it in action here the G+ link
Feedback/advise is always appreciated Thanks
https://photos.app.goo.gl/zSt0CKwDHAJP5tcS2

[tonyfoale]

Steve,

By coincidence I was doing exactly the same 2 days ago.

[SteveJustSteve]

That's awesome. I don't think I've ever seen a dovetail cutter with the insert orientated like that, where did you get that idea? It looks like you may have had to use quite a bit negative rake rake to obtain enough relief, is that right?

[DIYer]

Thanks SteveJustSteve! We've added your Dovetail Cutter to our Machining category,
as well as to your builder page: SteveJustSteve's Homemade Tools. Your receipt:

Dovetail Cutter by SteveJustSteve

tags: dovetail, cutter

[tonyfoale]

That's awesome. I don't think I've ever seen a dovetail cutter with the insert orientated like that, where did you get that idea? It looks like you may have had to use quite a bit negative rake rake to obtain enough relief, is that right?

The side rake is negative but the front rake is positive. These pix. show the side rake and clearance. Both are excessive but there isn't much room to work with using two inserts. This cutter was originally for a job which needed a small size. The geometry could be made better with a single insert. As they say, the proof is in the eating and it works fine. I must look for some inserts with built in rake.
Yours is larger which gives more scope for juggling the geometry.

[olderdan]

This is a well used (battered) one that I made long ago, it has a hardened shank with hand filed clamp pads, I only use it for roughing on tough material, being a cheapskate I use any worn out T/C tips that will fit and sharpen them on my Tiplap.
It is just over 20mm over the tips and I must have tried to copy the geometry from a commercial one, its performance is reasonable, and it does save the HSS cutters from a hard time.

[tonyfoale]

Alan,

Am I being thick, but how do you cut dovetails with that?
Like you I often grind inserts, sometimes to change geometry and sometimes to extend their life.

[olderdan]

Sorry Tony
It's me being thick, I missed the fact that I was replying to a dovetail cutter post and should have done it as a new post.

[tonyfoale]

Sorry Tony
It's me being thick, I missed the fact that I was replying to a dovetail cutter post and should have done it as a new post.

i should have realised that. I probably shot my reply off too soon.

[old_toolmaker]

Very nice workmanship! Well done!