Green Tractor Talk banner

1 - 19 of 19 Posts

·
Registered
Joined
·
284 Posts
Discussion Starter #1 (Edited)
I finally got my Bridgeport Mill finished. It took me a lot longer than I intended but I'm happy with it. It's a 54 year old machine but it's showing normal wear according to my rebuild book. I purchased this mill from a local machine shop. I replaced quite a few parts in the quill assembly and upper unit which included new bushings, bearings, two new shafts and missing quill feed parts. The X and Y lead screw nuts were also replaced. The X axis lead screw is in great shape, but the Y axis lead screw is worn in the center because it wasn't getting any lube due to the grease clogged passages. I'm going to replace that in the very near future. I completely tore the whole mill down to its basic pieces and cleaned everything up and repainted as I did with my lathe. You would think that a machine shop would know that the alemite fittings are intended for oil and not grease but this mill had been greased and all of the way passages were clogged with grease. The precision bearings in the quill are in good shape thankfully because they are quite expensive. Although this machine has fewer parts than my South Bend Lathe it was harder to do because everything is SO heavy. I purchased a hydraulic lift table (1000 lb capacity) from Harbor Freight to help in addition to my 2 ton engine hoist. The lift table was very handy.

I'm controlling this mill with another TECO FM50 VFD which turns my single phase 220V to 3 phase 220V. I've also included a POT to vary the speed and included an Emergency Stop Button in the pushbutton station you can see in the photos.

I haven't used the mill yet but I'm going to in the near future. I just purchased a new R8 collet set today and a collet rack to attach to the mill. I got a few old collets when I bought the mill along with 6" machinist vise. It's not a Kurt vise but I think it's going to be okay. I'll have to wait and see. I cleaned it up also and repainted it and it looks pretty good.

Still to come is a DRO for the X/Y axis. Have to pay the real estate property taxes first. :banghead:

DSCN1033.JPG

DSCN1035.JPG


Didn't see the dust/dirt on this when I took the photo. :unknown:

DSCN1036.JPG

DSCN1037.JPG

DSCN1038.JPG

The Forward/Off/Reverse switch used to be on the side of the motor cover where you see the new aluminum junction box I fabricated in order to fill in the large hole that was left.

DSCN1041.JPG
 

·
Administrator
Joined
·
17,311 Posts
Wow Jim, great job!

Makes mine look like crap...thanks:laugh:
 

·
Super Moderator
Joined
·
7,914 Posts
Jim,

She's a real beauty. Good luck with it!

Frank
 

·
Registered
Joined
·
1,965 Posts
Hiya,

I have just the vise for you, an original full size Bridgeport, turns and moves easy with no errant mill marks but some good patina from sitting unused for years. Needs a chainfall to pick up or you'll throw your back out.

Tom
 

·
Administrator
Joined
·
20,363 Posts
Wow! :bigbeer: Having a variable speed drive is super nice. :thumbup1gif:



Makes mine look, well, I don't have one. :cray::lol:
 

·
Premium Member
Joined
·
14,131 Posts
That is one pretty machine. Nice job.
 

·
Registered
Joined
·
503 Posts
You did an amazing job on the Bridgeport mill. It looks like you took a lot of pride in doing it and it shows. My First is a copy and looks like crap right now. A real original Bridgeport would have been my goal.
 

·
Registered
Joined
·
498 Posts
Oh so nice... Wish I had one.
Haven't found the right deal yet.
 

·
Registered
Joined
·
395 Posts
I am all kinds of jealous! That thing looks awesome! Great work!

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
3,687 Posts
I am all kinds of jealous! That thing looks awesome! Great work!

Sent from my SM-G920V using Tapatalk
I am jealous,,, TOO!! Want to share some hints on the cleanup??

My drill press could use some effort,,,,


OR, you could come visit,,, for a week!! :bigthumb:
 

·
Premium Member
Joined
·
6,593 Posts
:good2::thumbup1gif::good2::thumbup1gif::good2::thumbup1gif::good2::thumbup1gif::good2::thumbup1gif:
 

·
Registered
Joined
·
284 Posts
Discussion Starter #14
I am jealous,,, TOO!! Want to share some hints on the cleanup??

My drill press could use some effort,,,,

My cleanup is fairly simple. Disassemble, soak in Purple Power, rinse and degrease further if needed, then use a coarse cup wheel on the side grinder to remove anything the Purple Power couldn't get, and then soak in Evaporust.

I sandblasted the base, knee, and ram to bare metal. Of course I protected the machined surfaces when I did that. I then used Bondo on the base, knee, and ram along with several coats of high build primer and then painted with a Alkyd Enamel. The Bondo is the most miserable part of the job, but it does come to an end..........................finally!:yahoo:

Of course there's a lot of polishing going on as well.
 

·
Registered
Joined
·
2,843 Posts
You did a fantastic job. I would highly recommend a power (pneumatic) draw bar.
So you installed a variable frequency drive for the head, but left the pulley assembly installed? That is probably a good thing because if you get into some large diameter hole drilling I doubt the vfd would supply adequate torque in a 1-1 ratio at the low rpms used.
I have worked in machining going on 40 years and couldn't count the hours I spent in front of knee mills like this. It's a 1 out of a thousand guy that takes such care with his machine as you.
 

·
Registered
Joined
·
284 Posts
Discussion Starter #17
You did a fantastic job. I would highly recommend a power (pneumatic) draw bar.
So you installed a variable frequency drive for the head, but left the pulley assembly installed? That is probably a good thing because if you get into some large diameter hole drilling I doubt the vfd would supply adequate torque in a 1-1 ratio at the low rpms used.
I have worked in machining going on 40 years and couldn't count the hours I spent in front of knee mills like this. It's a 1 out of a thousand guy that takes such care with his machine as you.
Thank you Jeff, I appreciate your post as I also appreciated the praise received from all others. This is a 54 year old machine that came with a few unwanted surprises. The latest "GOTCHA" came in the form of a high speed rattle. Although I saw the machine powered up in the small machine shop that I purchased it from, I did not hear it in the high gear range of speeds. It's quiet in low range. It didn't take long to narrow the problem down and if I had been smarter I would have found it at the time I looked at the machine. The culprit/s in my case as with a lot of other used Bridgeport Mill owners have found out are the Spindle Pulley Hub and the Splined Gear Hub. Those are the two parts shown in the foreground in the photo. This is what $767 worth of parts looks like! :cry: The smallest of the two which is the Splined Gear Hub is the most expensive item shown at $304 ..........ouch! Fixing one of these machines if not for the faint of heart. Also shown is a new cross feed screw and a new timing belt. A bad timing belt can also be a contributing factor to high speed noise.

20151127_102128.jpg

Here is what the new parts look like. You can see in this next photo the sides of the cogs splined pulley hub are slightly tapered which create a tight and sound coupling when engaged in high gear. As the taper wears the two hubs move closer together until they bottom out.

20151127_101949.jpg

20151127_102022.jpg

You can see the wear in the next photo. The old hubs are on the left and the new on the right. You can see that the new hubs, when engaged are sitting about 1/16" higher. Look just below the second groove from the top.

20151127_121445.jpg

There are also a couple of super precision bearings that the splined gear hub spins in that can be bad and they go for about $100 each. I've seen them listed for over $400 each at some bearing suppliers! My two bearings "seem" okay but I'm not 100% sure. If they are not it can be detrimental to the new hubs.
 

·
Premium Member
Joined
·
6,593 Posts
Keep up the good work Jim. Have you seen my rebuild?
 

·
Registered
Joined
·
284 Posts
Discussion Starter #19
Keep up the good work Jim. Have you seen my rebuild?

from my South Bend Lathe thread post #17 :lol:


Originally Posted by RandyM

Now, that is a bang up job Jim. You can work in my shop anytime. I have a 14 x 40 Logan lathe that is next on my list to do exactly what you have done. If you're interested here is my Bridgeport Rebuild thread. Thank you for posting your project. Have you been out to see the Hobby-Machinist? Check it out, it is a very good forum.




Thanks Randy for the compliment. I've seen your thread on the Bridgeport and can say it's renovations such as yours that inspires me. Nice job on yours. I've seen your photos of your shop in the past and wish I had one that nice! :good2:
 
1 - 19 of 19 Posts
Top