New Lathe Chuck keys

[oaklandish]

Factory lathe chuck keys suck. Even on a top of the line Bison 6 jaw. I am sure many here have encountered these token keys. They are too small, too short, have too much play, come included with auto loosening handles and smash your knuckles clearances from the lath headstock and chuck bodies. Plus they are ugly. I made some new ones...



Before heat treating.

 

[oaklandish]

I decided that I did not want to deal with set screws coming loose any longer so I opted to try my hand at heat shrink fitting. The handle is tapered from the center to one side so that it is about two thou larger than the reamed key body.
View attachment IMG_7910 2.MOV

 

[oaklandish]

Heated up until the straw color roughly matched the color indicating a sufficient heat to expand the key by about 2.5 thou. I had about 8 seconds to get it to fit and land on center.
View attachment IMG_7911.mov

 

[oaklandish]

Hardening the head of the key. I quenched in water as that what I had available.
View attachment IMG_7909.mov

 

[oaklandish]

After tempering it for a bit it still seems to hold its hardness and is definitely not brittle. I whacked it with a hammer and the hammer shivered... but I did not get a video of that.

View attachment IMG_7917.mov

 

[oaklandish]

I made one for the lathe spindle and 4 jaw chuck that are the same size, and one for the 6 jaw which is unfortunately a different size.

 

[oaklandish]

The chuck keys are about 7" high and about 10.5" long on the handle. They fit snug and feel awesome. Just enough clearance for anything I can imagine fitting on the lathe and give enough leverage to get everything snug with a very controlled level of exertion.
View attachment IMG_7918.mov

 

[oaklandish]

Here is an in-progress video of the fit of the key for the 4 jaw chuck
View attachment IMG_8074reduced2.mp4
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