Bridgeport mill back in service

[Morgan1952]

Hello everyone,
Fairly new to the forum. So I thought I would post a project that I have been working on. I won't call it a restoration but rather a refresh on a 1981 Bridgeport mill.
The History is simple Last July I found a Bridgeport that I thought had some potential at a auction online and I got it for a very good price. The mill looked pretty sad and was pretty dirty. It came with a Lyman Mk 4 power feed on X axis. (non working). when it arrived the handle was broke off the left side which is where the power feed was mounted. It turns out that the handle broke where it attached to the leadscrew. Fortunately the lead screw was not damaged and just removed the power feed since it already had several components missing. Wired it up and tested the actual Machine functions. I started cleaning as first order of business. The head was really quite and I checked the runout on the spindle and it was way better then I thought it would be. It only has a couple tenth's at most for runout. So before making any real chips I decided to tear the machine apart and clean everything to prevent anymore damage too the machine. I also decided that the head was not in any need of tearing it apart at this time just needed some cleaning.
The first Picture is the mill as I received it.

Actually this is before it shipped to me but it didn't get any better in transit.
I started cleaning it and after a few hours of cleaning and inspecting I decided that I needed to take it apart to clean the ways and oiling system.

it actually was cleaning up pretty good but I couldn't get to everything the way I wanted to.


I did check several other things before I took it apart, like backlash in the screws, how tight the table, slide and knee was along with the table across the full screw.
I didn't have anyway of lifting the heavy parts off the machine so I improvised by building a wooden gantry to assist with a ratchet hoist.
It worked and was pretty stable.
I will break this post up into parts to keep it from getting to long.

Have a good day

 

[Morgan1952]

After I got it torn down I found most of the oil ports were somewhat restricted or completely plugged so I am glad I took it apart.
the oil system was in pretty bad shape and all of the oil meters were also plugged. The ways were in better shape than I had hoped.
So for now I'm not going to be reworking them, mostly just a good cleaning and repair what is needed. The Ram was stuck I could not get it to move, then the handle on to move the ram broke off. With some oil and wrench I was finally able to get it off.
After cleaning everything up I made the decision that while it was apart I should just go ahead and paint it. First thought was to just and the existing paint and use it as the base for the new paint. That got me in trouble with the better half. My shop is in the garage which is also were my wife parts her dark Blue care. She didn't like it when she came out and found it had turned a light shade of grey. Note to self, move the wife's car before sanding!!!!
After I had the base sanded for a couple of days I notice darker spots showing up in the base and also some cracks. I noticed a wide crack in the radius at the base below the ways for the knee. After digging into the cracks I stuck oil. Lots of oil. I then knew my plans had to change, I decided to just go ahead and strip it back to raw casting to make sure I got rid of all the oil.

This is the base completely stripped.
Then I decided to level the casting out like they did when it was new so the next step was the wonderful body filler.
Body filler is so much fun, put it on take it off, put it on take it off, repeat, and repeat.

After going over every part It was time to clean and prep for paint. Cleaned with Windex, rubbing alcohol, and acetone. Built a makeshift paint booth to contain the over spray.



First two coats, I used dark grey epoxy primmer.
The next two coats grey 2K urethane primmer.

The last two coats I used Acrylic enamel with hardener.

The total painting process was over a four or five day period.
The Acrylic enamel was the worst.
Next step is to start the reassembly.

See you on the next post
Have a great day

 

[Morgan1952]

Now for the reassembly,

Putting it back together was a lot more fun then taking it apart.
I did a final cleaning of the way's and made sure to put way oil on before reassembling.

It is starting to look like a mill again.

For the oil system I replaced all the lines and some of the fluid meters.

I cleaned the head and polished the gear housing, but I did not rebuild it. it was already in very good running shape. I did replace the quill feed handle, the clock spring the quill reverse trip lever and the key to the quill feed handle. If I need to get into the head in the future I will tear it apart and repaint the housing the same way I did the rest of the mill.
Some additional items I did while I had the mill apart are as follows.
I split the lead screw nuts, When I took the machine apart I had .022 backlash on the X axis, it now has .003 backlash and easy to turn throughout the movement of the table. On the Y axis I started a about .025 and now at .010. I haven't attempted to take anymore out at this time.
I put the nut on the screw on the ends in the same orientation as they are in the mill and separated the two halves of the nut's, measured the distance between them and then moved to the middle of the screw and did the same thing the deference was about .005 on both the X axis and the Y axis screws.
I hope you enjoy my project.

Best regards

 

[hman]

VERY good looking refurbish/restoration! You're doing a thorough job.

 

[Morgan1952]

Thanks hman,
I appreciate the comments.

Best Regards

 

[NegativeK]

That's an impressive repaint! And you make it sound so easy, even though I'm sure it wasn't.

 

[Morgan1952]

Thanks for the nice comment NegativeK. You are correct, it took a lot of work but I am happy with the end results.

Best Regards

​