How Are Slotted Keyways Squared Off?

[T Bredehoft]

Or you could use a Woodruf cutter, it plunges into nearly half it's diameter, leaving nearly squared corners. They appear square at the surface but are cut the full radius of the cutter.

 

[jpfabricator]

Cracks, and electricity love sharp edges. By introducing more square edges into a shaft, you increase the possibility of a crack forming.
Therefore squaring off the slot may be doing more harm than good.
If for some reason the ramp or radius will be undesirable due to astetic reasons, then hide everyting under the keyed accessories with a woodruff key.


Sent from somewhere in East Texas Jake Parker

 

[Riaan]

Or you could use a Woodruf cutter, it plunges into nearly half it's diameter, leaving nearly squared corners. They appear square at the surface but are cut the full radius of the cutter.

My n00b brain is finding that hard to visualize!

 

[Tony Wells]

A Woodruff cutter would leave what you have drawn, basically the same as a plain milling cutter, albeit with a smaller radius at the end.

Yes, EDM is Electrical Discharge Machining, akin to ECM, Electro-Chemical Machining where the normally insulating oil used in EDM is replace with an acid, typically. It can be very aggressive.

 

[Bill Gruby]

Use a small end mill of the correct size to get the bottom flat and then use a corner chisel like gunsmiths do to get square corners.

"Billy G"

 

[Riaan]

Thanks guys! My curiosity has finally been satisfied!

(and I'll admit that I am.. what's the word... gratified that my inability to fathom a way to machine it wasn't grounded in COMPLETE stupidity. )

This forum is great!

 

[chips&more]

End mill it, then plunge broach it with a square shaped broach. Stay away from the bottom because you will have chip build up. Then carefully remove that chip build up at the bottom with a chisel/graver.

 

[Bill Gruby]

Stupidity is a word in the dictionary. It should be left there. It is not one of our favorite words here. If needed we will answer the same question as often as necessary on this Forum until the answer is understood by all members.

"Billy G"

 

[RJSakowski]

I would cut the keyway with an end mill. If the key need to fill the complete slot, round the end of the key. Grizzly actually did that on the input shaft to the gear box and rounded one end of the key on the G0602. Unfortunately, some doofus put the key in backwards and used a hammer to make it fit, resulting in a split spacer and bunged up shaft.

Many years ago, before I had a mill, I had to cut a 1/4 keyway in a 1-1/2" shaft. I made a chisel from a broken pulley tap and hand cut the keyway. Never again! However, if a square end were required, cut the keyway with an end mill and clean up the corners with a chisel. Woodworkers have been doing that for centuries.

Bob

 

[Franko]

I can't imagine a client that would pay a machinist what it would take to cut such a slot, or any reason to cut one other than to show off.

The slot would be more practically built, rather than cut, by welding or braising a semi-circular plug at the rounded end of the milled slot. A similar plug would be relatively simple to fill a ramped end cut by slotting saw.