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.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
My first Bridgeport
- Thread starter Petrolero
- Start date
You've seen this before but now here's the worm gear - it will not turn.
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
- Joined
- Oct 14, 2013
- Messages
- 979
It looks like it sheared at the step; no surprise, that's a big stress concentrator. Not evil, just stupid
Sent from my SM-G892A using Tapatalk
Sent from my SM-G892A using Tapatalk
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.
- Joined
- Oct 14, 2013
- Messages
- 979
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.
Sent from my SM-G892A using Tapatalk
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.
Sent from my SM-G892A using Tapatalk
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.
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.