Milling a woodruff key slot into a crankshaft

[Dave1]

Any engine builders out there have a suggestion as how to mill a woodruff key slot key slot into a crankshaft to install the crankshaft gear?
My project involves installing a Chevy crank into a T block, so the front of the crankshaft have been modified, part of the modification involves cutting a new key slot to accept the crank gear.
I have a Bridgeport style milling machine with a verticle spindle, and a woodruff keyway cutter on hand.

I was able to establish the location of the key slot in relation to number one crank throw.

The problem is, I cannot find an secure way of clamping the front of the crank in the vise, this crankshaft weighs about 25 lbs, I don’t think it’s a great idea to the majority of the crankshaft unsupported,…. it seems that I am asking for something terrible to happen.

Dave

[RecklessKelly]

If the end of the shaft is center drilled, you could hold it with a dead center and support it with a V block.

[Jerry VanOoteghem]

Just a couple of matched V-blocks should do it. You might also think of clamping a block against the end of the crankshaft so, if the cutter grabs, it won't move the crankshaft laterally.

[Dave1]

Thanks fellas, will try that tomorrow

[Kevin Pharis]

As I recall the key is inline with the rod throws. Suggest you clamp rod journals over 123 blocks to ensure clocking, then shim up and clamp the snout for support.

Would be easier to mill a flat bottom slot for a square key… but getting the rod throws inline would be much more difficult

[EliasRay]

That’s an exciting project, Dave! Using V-blocks with strap clamps or a custom jig might help stabilize the crankshaft securely.

[J and M Machine]

Like this. You just have to indicate it.