Head removal tool

[emolson]

I've got a bridgeport-like mill with broken swivel, planning to remove the head to check the gear/worm.

Done that once before with engine hoist/muscle, but I've seen descriptions/videos of a tool made by welding a collet to a base that bolts to the table which seems like much easier way to go.

However, this machine doesn't use R8 but a fairly expensive quick change collet, and I also don't have a welder on hand so I'm considering something a bit different.

The outside of the spindle measures about 3 3/8", I'm thinking I can use a hole saw to drill a bunch of squares of plywood, then laminate them with glue/screws, with the bottom few layers a bit larger to bolt down to the table. Seems like it would be at least as stable since it's a larger diameter and will hold it over a length of 6" or so. Anything I'm missing or does this seem like a reasonable plan?

 

[jccaclimber]

Plausible, maybe even reasonable, but definitely don’t try to retract the quill!
In the past I’ve seen it done with a large rod up the center as well, but I don’t know how that would do with your QC setup.
I’ve personally done it by securing a piece of 3/4” round stock in the vise and chucking to that. You do need that piece of stock to be *very* well secured, particularly in the sideways tilt direction. I had it passing through a piece of 1.5” x 6” long square stock and welded in, but a v-slot cut into a bar might do just as well.

 

[mchasal]

Does your collet have a 3/4" capacity? The one H&W makes is just a 3/4" rod, so as long as you can grab that with the collet it should work just as it does with an R8 spindle. It's pretty reasonable at $50: Mill Head Removal Post - H & W Machine Repair

 

[emolson]

Does your collet have a 3/4" capacity? The one H&W makes is just a 3/4" rod, so as long as you can grab that with the collet it should work just as it does with an R8 spindle. It's pretty reasonable at $50: Mill Head Removal Post - H & W Machine Repair

Thanks, I ended up just pulling it with engine hoist again but I'll have to look into that for reassembly.

For anyone considering this in the future, I tried with a stack of 6x6" 3/4" plywood squares, but it was flexing a lot once the weight of the head started being on it, so I lost my nerve.