Mystery nut and support bracket on 1976 2j head Bridgeport

[Ridetoeat]

Need some help identifying what I am looking at. I decided to clean and adjust the gibbs and at least look at and try to tighten the nuts all I could get by with and then I came across this nut support deal with no adjuster on the x axis, presumably on both axis. Threads has a lot of wear middle compared to ends. Has someone converted this machine to ball screws. Or. ??? Kinda hard to see but that is an oil line sweeping up and going into the nut in the approx. area where you would look for the nut retainer and adjusting screw. See pic attached. I really want to tighten this machine up, might be looking at both screws and new split nuts with a support.

 

[hwelecrepair]

Without clearer pictures, that is a tough call. Certainly doesnt look like the nuts for a Bridgeport. Looks more (but not exactly) like the nuts on a Sharp. What does the other side of the screw (as in if this is looking at the side of table furthest away from the base, what about the side closer to the base) look like?

Jon

 

[Ridetoeat]

Without clearer pictures, that is a tough call. Certainly doesnt look like the nuts for a Bridgeport. Looks more (but not exactly) like the nuts on a Sharp. What does the other side of the screw (as in if this is looking at the side of table furthest away from the base, what about the side closer to the base) look like?

Jon

Yes hard to photo back in there, On the other side the support has a smaller exiting I.D. and the screw just barely clears as it come out, so it is a pocket arrangement. The baffling part is why would someone switch to a different system that still included ACME thread screws and even more one that requited a different nut support.

 

[pontiac428]

I would expect to find something more like this, below. It looks like you have a slightly different system, but should be just a matter of adjusting the compression nut to accomplish the same thing.

 

[Ridetoeat]

Yes, for sure, I just don't see any way to get back in there to do it. Why would someone do a mod that requires a different bracket, yet still used acme threads ?? Since my backlash is more in the middle vs the ends, I think it is due for screws and nuts both and in my case a bracket. I am looking around.

 

[pontiac428]

I agree with that. New screws and nuts would make the machine nicer to use. You could probably order everything you need to convert to a traditional adjustment system. It's probably time for a call to H&W Machine Repair in Fort Wayne to see what your options are.

Edit: Duh, you've already got Jon's attention on this thread. He's the most qualified to answer your questions.

 

[hwelecrepair]

Ya man, the more I look at it, it looks like a sharp nut, which means someone put a sharp yoke into it.

I am intrigued though, I would love to take it apart and see what was done to it. The knee, it shows a Bridgeport serial number?

@pontiac428 I have to admit I cheat most of the time and ask Barry or Zach about the answers, but this one I knew all on my lonesome.

 

[Ridetoeat]

Yes, it had a Bridgeport knee serial # Seems odd. Will the acme threads on the screws be the same if I get a oem support bracket and a new set of nuts. It's got me wondering if I was to buy all the new parts if I could run into unknowns. Certainly have to disassemble and look at things first. I really think the bracket was swapped, it has a redish primer on it unlike anything else on the machine. I am only assuming the oem bracket is still a bolt in until I look deeper.

 

[hwelecrepair]

I have never tried to thread a Sharp (if that is what you have in there) into a set of Bridgeport nuts. With that being said... the OD of a Sharp lead screw is different then that of a Bridgeport. Best bet is to get your hands on a nut adjusting tool for a Sharp and see if that works for you. I think we got one laying around here we can make a deal on, if you would like.

Jon