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What to check on a Bridgeport before buy

manoweb

Plastic
Joined
Sep 13, 2018
Hello, long story short, somebody is willing to sell their Bridgeport with DRO. I used to be good with shapers, lathes and mills back in the day, but now I haven't touched one in 25 years. Recently I picked up TIG welding as a hobby and with that comes... need for more :)

Problem is, even if I used to be good with metalworking, right now I am not sure what I should do to check out the machine and see if I want to proceed with buying it. I really want it, and I think they might be willing to give me a good deal, but I need to move fast - sorry if I rushed here, created an account, and posted this as my first post. I promise I will fill out all the stuff :)

In short, what should I do to evaluate how good the machine is? They will give me some time to use it but I need to come up with a checklist or something similar...

Thank you
 
Hey I just realized there is a specific forum for machine inspection. I should have probably posted there. Hopefully the admin will do what is right.
 
There is plenty on the subject with a simple google search

Yeah when I wrote that I was about to catch a plane, before it took off I loaded around 8 different forums and pages to read among which, the one you referenced (that honestly is quite interesting but not very practical)
 
Where are you located and how much are they asking for mill?

Los Angeles California and I believe someone said $1800. I know it has DRO but I do not know what machine that is, how old, if any tooling is included... I'll try to get more info tomorrow but I might just have to show up at some point and see.
 
Pictures of it?
Step pulley or vari speed head?
Table Size?
Backlash on X and Y?
Table rock?

I know that I had commented on a thread regarding this exact stuff. But I cant seem to find it.

Search this forum though, this has been hashed out a dozen times.

Jon
 
First of all, if you've been out of machining for 25 years, you probably don't have the equipment or knowhow to do a very through inspection.

Before you buy, check out the serial number so that you know the age of the mill. The head means nothing, the machine serial number is on the top of the knee, in front of the Y feed handle.

Pictures do help a bunch.

As far as the DRO, if it doesn't work, it's worth it's weight in scrap. Old DROs can be very problematic.

Does the machine come with:
A vise? A Kurt is the most desirable with a BP or anything else that doesn't "pull down" be the least.
Drill chuck? A decent drill chuck and arbor will set you back $hundreds.
Boring head? Not always needed, but when you do, there's very few substitutions.
Collets? Kinda hard to hold endmills without them.
Rotary table?
Dividing head?

There's a whole bunch of stuff that you'll need like a good indicator, indicol, parallels. You'll have at least double the cost of the mill in ancilary equipment and cutters before your done. This isn't a cheap hobbie.
JR
 
Thanks for the advice, I'll try to go there today or tomorrow. As far as I know everything works, including the DRO, but we will see.
 
And... in fact I will go tomorrow, a week later, to see it. I got some more info in the meanwhile:
2HP motor of the "main" head
0.5HP motor on the... secondary head behind? I am not even sure why, how one would use it.
Mitutuyo DRO
No tooling, vise, nothing, this comes out of a larger machine shop that is all CNC now and whatever.
 
And... in fact I will go tomorrow, a week later, to see it. I got some more info in the meanwhile:
2HP motor of the "main" head
0.5HP motor on the... secondary head behind? I am not even sure why, how one would use it.
Mitutuyo DRO
No tooling, vise, nothing, this comes out of a larger machine shop that is all CNC now and whatever.


Pass along the info if you don’t get it I’m in the market for one
 
Sounds like it may have a shaping head on it (the small motor behind). Also Pretty sure with the 2 hp motor is a v/s unit. There is one thing you need to consider that’s not related directly to the mill. Do you have the correct power to run it? It may be set up for 440 volt which is no big deal, it can be coveted back to 220 easily. The motor will also be 3 phase. Around here, if in reasonable shape, $1800 would be a bargain! Recently there was a rusted up peace of crap that sold for that!
 
Is there a way to post pictures from a cell phone? Traveling from the airport now and I cannot use a regular PC.

Also, the serial number above the knee seems to be BR250912 - what info can I get from this?
 
Yeah I see. Is there any advantage in having a more "modern" machine compared to a much earlier one?

Shared album - Alessio Sangalli - Google Photos
The one above should be a video of the machine running before we opened the motor assembly

Imgur: The magic of the Internet

Has a bunch of images that show pretty much what was inside the motor/varispeed assembly (not sure about the terminology here but pics should make it clear). We rotated the head 90deg to extract the motor, and when doing so some oil started to slowly leak (see one of the pics). Is that a bad sign?
 
As long as you are in there replace the VS belt and plastic pulley bushings if needed. Oil leak normal with the head tilted BPs normally dribble as most of the spindle lube is total lose anyway. Newer is better given equal wear ,most of those had chrome ways as I recall.
 
Do I need to replace the whole thing:

136 - Adjustable Motor Vari-Disc Assembly, 2 HP

Or is it possible to get the bushing only? May I stress the fact I intend to get a VFD anyway, not sure it makes a difference (for my understanding, I would need to "lock" the mechanical speed in place). I think I saw also some sort of rebuild kit for the head, with new belts bearings etc but now I cannot find it anymore.

Understanding the effort and the price of the required parts will help me make the right choice :)
 
You might be able to replace just the bushings. if you call and talk to Barry, Nathan, or Heather they can tell you exactly what you can/cant get and replace on its own.

It will be best if you have the head apart when you call though.

Jon
H&W Machine Repair
 








 
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