Finally Time for Some Work on The Bridgeport

projectnut

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Well, my machine is now in its 52nd year and its age is starting to show a bit. The head is starting to rattle in low speed, and the X leadscrew has seen better days. This machine was apparently equipped with a factory power feed when new, but somewhere along the way it was removed. When I purchased it the machine lacked the manual mounting plate, bearing assembly and crank on the right end of the table. It also had a short X leadscrew to accommodate the original power feed.

No problem. I picked up the missing parts at a local used equipment dealer for $15.00. I made an extension for the lard screw and started making chips. A couple years later I decided to move the machine from the garage to the basement. I disassembled it and hauled the pieces through the house it down the stairs to the basement. At this point I realized it still had the original split nut for the X axis. On reassembly I split the nut and reinstalled it. At the time I was able to get the backlash down to .005" which is within factory specs. Twenty some years later the backlash is up to .020". I'm sure I can adjust it one more time, but with the short leadscrew i think it's time to bite the bullet and replace it. I should also be able to gain an additional 2" of movement with the longer leadscrew.

As long as I'm taking things apart, I might as well refresh the refresh the head. I've contacted H&W, and they have all the parts I need in stock. They have however gone up in price considerably since I last checked. Before the pandemic the upper head kit, the leadscrew and nuts could be purchased for just over $400.00. Today they cost just shy of $800.00. They also suggested I replace the Y axis nuts since they are the originals. With only .010" backlash they didn't think it would be necessary to replace the leadscrew.

I know others have taken on this task in the past, but the latest posts I can find on the subject are pre pandemic. For those that have done the job how much time did it take? I see H&W has videos on the subjects, but these are professionals with all the proper tools close at hand, and years of experience. This will be my first rebuild/refresh. I do have all the tools I believe are necessary and many years of machine design and building experience. However, it's been a long time since I've taken on something like this. Any input would be appreciated.
 
The first place to look with a noisy variable speed head is the motor pulley. The plastic bushings and key wear in the moving side of the pulley and then the pulley rattles around. I just went through this with a Willis mill. New bushings and key eliminated the rattle in the head.
 
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