My first Bridgeport

Ypu should plug those two holes in the back of the knee while you have access! They let chips in to the gearing!

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Too late - the knee is back on. I can see the utility, however, of plugging the gap at the rear of the knee -that should prevent most chips from entering. Sort of like the way wiper but wider.
 
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You've seen this before but now here's the worm gear - it will not turn.

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This is the best I could do with the cell phone camera- Looks like this is deliberate sabotage as both the main shaft and retaining ring have been also milled down so there's no way to get them out.

Any suggestions, or do I just not understand what I am looking at. It's plain the shaft that runs this worm gear is broken off and subsequently turned down.

Thanks!
Mike
 
Remove that set screw, it holds the shaft in. You may need to drill and tap the end of the broken shaft for a stud, you could use a nut and sleeve or a slide hammer to pull it out
 
It looks like it sheared at the step; no surprise, that's a big stress concentrator. Not evil, just stupid

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Remove that set screw, it holds the shaft in. You may need to drill and tap the end of the broken shaft for a stud, you could use a nut and sleeve or a slide hammer to pull it out
Firstram-

Setscrew is out - the worm gear will not turn at all unless I use a chisel and hammer to get it to turn slightly, so it's jammed in there.
I agree, I'm going to have to drill and tap the broken stud to get it out- I'll probably take it to a machine shop where they can set it up in a Bridgeport mill and do it the right way... I tried briefly to hand-drill it but no luck.
 
Can you turn a guide sleeve that fits in the bigger hole? I think you need to drill and tap the shaft to hook up a slide hammer for pulling the broken shaft.

Can a Bridgeport owner confirm how the worm attaches to its shaft?

One other semi-crazy thought: you could run a carbide tipped oscillating saw between the worm and the casting to cut off the far end of the shaft! Then slide the worm to close the saw cut, clamp, and repeat on the other end (if needed). Once you have the worm out, you would need to add a shim washer to make up the saw kerf.

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Can you turn a guide sleeve that fits in the bigger hole? I think you need to drill and tap the shaft to hook up a slide hammer for pulling the broken shaft.

Can a Bridgeport owner confirm how the worm attaches to its shaft?
According to the diagram, its fitted with a woodruff key to keep shaft and worm bound together.
I'd turn a guide sleeve if I had a lathe- need the Bridgeport to fix the Bridgeport...

I'm off to a machine shop with it this morning- I'll pay someone with the right tools to do it properly.
One other semi-crazy thought: you could run a carbide tipped oscillating saw between the worm and the casting to cut off the far end of the shaft! Then slide the worm to close the saw cut, clamp, and repeat on the other end (if needed). Once you have the worm out, you would need to add a shim washer to make up the saw kerf.

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Sometimes it’s just easier. Sort of like going out to dinner.
Found a willing machinist in a neighboring town (40 minutes away) who will do precisely what has been recommended- set up on a Bridgeport mill- indicate in the hole where the adjustment bolt should be - drill and tap for a sturdy bolt to go down in - use prybars or other appropriate instruments to pull out the broken shaft like a bad tooth...

He says to call him back on Friday and he should have it finished. Meanwhile, new parts inbound from H&W - and I have a few days to clean up all the innards of the Quill Housing.
 
That’s a good call; it will be great to have it taken care of. Cleaning and reassembling everything in the quill housing is a substantial task. It took me at least a few days.
 
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