Used mill inspection advice

F

FTlatheworks

Registered
Registered
Joined
Apr 24, 2021
Messages
462
I’m looking at a Bridgeport 2j mill. It’s a 2 hp motor with a 9x42 table. All power feeds work. It comes with Bridgeport vice and 10 collets. There’s 2 of them almost exactly the same. I’m going to inspect it this week. I have never had a mill, only a lathe. I know to check for runout and check the table travel.

I was hoping Someone could explain exactly how to check spindle runout, tram, and anything else I should absolutely do to be as thorough as possible. They want 7k for this mill. It’s in nice shape, but I’m not sure if it’s quite worth that much. Please look at the photos and let me know if that’s reasonable. I will post pics below.

I will have a Browne and sharpe bestest .0005 on a small noga swivel, but I also have a mitutoyo metric dial indicator that measure .01 mm.

Please let me know what I can test with those and if there’s anything else I should have and do when I go to see machine under power.
 

Attachments

  • IMG_9844.png
    IMG_9844.png
    998.9 KB · Views: 47
  • IMG_9843.png
    IMG_9843.png
    889.8 KB · Views: 50
  • IMG_9842.png
    IMG_9842.png
    1,000.5 KB · Views: 50
I would be most concerned with the condition of the ways. The spindle can be rebuilt with new bearings. You might want to check for slop in the quill, however.

This guy has a pretty good video on this subject:

 
machPete99 said:
I would be most concerned with the condition of the ways. The spindle can be rebuilt with new bearings. You might want to check for slop in the quill, however.

This guy has a pretty good video on this subject:

Click to expand...
Thankyou! I’ll watch that .
 
machPete99 said:
There are also some older but very good articles here on buying used lathes and mills:

Lathe Milling machine shaper collet parts

Top Quality Metalworking Machinery and machine tools.
www.mermac.com
Click to expand...
Thank you. I had seen that video a while ago before I was close to buying a mill. I never finished it. That was a good video. I’m going to have to study it. I get nervous when I’m in front of the owners before I have bought machines. I wouldn’t want someone doing anything on my machine before they bought it.
 
I also wouldn't be too worried about checking runout. See if the spindle turns free and smooth. Of course if you can inspect under power listen to how it sounds, you'll know if the bearings are bad.

Looking at the machine in the picture, it has way covers, a hopeful sign the ways aren't too worn, but be sure to check them anyway.
It also looks pretty clean, but only a close up inspection will tell for sure.
There will probably be a fair amount of backlash as the machine has power feed so this shouldn't be a dealbreaker, especially if you plan to add DRO.
 
A quick test would be to snug up (but not fully tighten) the table locks at mid position, then traverse the table (manually) to the extremes. If it gets super tight at the ends that would indicate wear in the middle (which is typically where the wear will be).

You could also do this in the reverse and snug up at the far end then traverse to the middle. Then try to rock the table side to side at the end to check play.

A more elaborate method would be to reset the gibs for minimal play (but still have full travel) and see how bad things are in the middle. But that might need some disassembly of way covers on a bridgeport.
 
Just my opinion and not sure if Kansas is a machine desert , but 7K seems like a lot for the machine . You could probably find a fully rebuilt BP from a good reputable company for that money .
 
The x axis gib is located right above the table lock on the left of the machine . You loosen/tighten with a screwdriver if you choose to check it . I have that identical machine here .
 
Appears to be a clean machine though. At least it looks well cared for
 
You must log in or register to reply here.
Back
Top