Woodruff cutter making

[RobWilson]

Hi Chaps 

Pete's post got me thinking of when I needed an odd size woodruff cutter to cut the key seat in my CUB lathe cross slide lead screw I was making , I actually though I had this base covered 
as I have a good selection of said cutters ,but there is always one you dont have . So being Sunday as well I set about making one from the end of a drill bit .

The drill bit . 



The MT shanks are soft enough to turn and are  HSS  , so a quick zip with a zip disc and off came the hard fluted part . 



I gave the centre a quick clean up to remove the rust and crud .




Then slapped it in the Boxford lathe for a spin . 

Ruffed the shank down .



Finished to size , ready to cut some relief.

 


Parting off .



Spun round in the chuck , cutter od turned to finish size and some relief on the outer face being put on .  I used magic marker to see were I was at as I did not want the 
cutter to end up to narrow . 




Job still in the chuck , chuck removed from lathe and fit to dividing head . 



Teeth cut .




Cutting edge relief . 



Sorted . 




Now to harden it ( not the correct way to treat HSS ) I just heated it up cherry ,held it for a minute and stuck it into a bucket of water . 



I did not have a TCG at the time so a few strokes with a wet stone and off I went . 




Job done 




Rob

[EdK]

Nice use of an old, rusty drill bit.

Ed

[Roadracer_Al]

Well done! Looks like the 30* cutter in the horizontal makes that job pretty straight-forward. I've made similar cutters but the 90* end mill or slitting saw always makes the cutter fragile or have few teeth.

Hmmm... I could send a thick slitting saw out to be re-ground with a 30* bevel!

[RobWilson]

(09-11-2015, 11:27 AM)Roadracer_Al Wrote: Well done!  Looks like the 30* cutter in the horizontal makes that job pretty straight-forward.  

Well spotted, it is a 30 deg cutter , I have used dovetail cutters in the vertical mill as well , I always fine it fun messing on making ones own cutters . I have quite a collection of home shop cutters . 


Rob

[Highpower]

(09-11-2015, 10:37 AM)EdK Wrote: Nice use of an old, rusty drill bit.  

Ed

Note to self: Don't throw away any rusted, broken, chipped or dull cutting tools anymore.  

Rob, it must be nice to have a lathe that can handle that much stick-out on a turning tool and not chatter like mad. You are a miracle worker when it comes to getting great finishes on parts.  

[krv3000]

a job well dun rob

[PixMan]

Interesting, I always thought drill shanks were too soft for use as cutting tools (and the flutes too hard to do anything without a grinding wheel.) I learned yet another new thing! Thanks Rob!

I would have gone through the expense of buying a cutter on eBay, then wait. There's a million of them there, but an awful time figuring sizes if the seller doesn't give the actual measurements because the American numbering system is a weird three digit thing that changed in the mid 20th century. If the seller says it's a "604" you may not know if its the old or new number. I should just get a 30º milling cutter and make them!

[RobWilson]

Hi Ken ,

 I did have a quick look on Ebay , but the key size is one of those odd ball sized ones  ,I have most of the common sizes but not that one ,so at the time I think the only one was a used one on Ebay ,in dubious condition  and as you say would the size have been listed correctly   . First time for me using a 3MT HSS drill shank to make a cutting tool from ,bit of an experiment, I normally use drill rod /silver steel , It turned lovely , next time I would use my heat treat oven and a TCG when I get the latter repaired lol so it looks a bit more pro . 

But it dose show what can be done with old worn out tooling , a drill bit like that could be picked up here at a car boot sale for coppers / cents . Just food for thought . 



Rob

[DaveH]

When I was an apprentice a couple of years ago   we went around the Dormer Drill factory in Sheffield (UK). The main drill body was HSS and the shank was med/high carbon steel the two blanks were butt welded together. Although the shank is softer than HSS it is hardened slightly at the factory, and because it is a med/high carbon steel it is possible to harden it.
Which is what Rob did.
 
DaveH

[RobWilson]

Never new that Dave , always thought the hole drill bit was  HSS , learned something new today    


Rob