Any Bridgeport gurus?

[Mike B]

Sorry to be a bit shy, but are there any Bridgeport Mill experts able to give me a shout? Looking at my first mill and could do with someone taking a look at a lead I have. If anyone else has any useful pointers on buying, please feel free to respond here.

sorry for the scant detail but I don’t want to advertise it here for someone else to buy.

 

[Seadog]

Did you mean Any Bridgeport Gurus? Change the title.

 

[Mike B]

Did you mean Any Bridgeport Gurus? Change the title.

I did, phone autocorrected it! Unable to change the title sadly!

 

[Seadog]

Use the Report button and a Moderator will edit it.

 

[Mike B]

Use the Report button and a Moderator will edit it.

The mods work fast! Thanks moderator team and Seadog, meanwhile anyone got any tips on buying?

 

[The Artilleryman]

Not a guru, but an owner. Main things are table surface, smoothness of travel x & y, no movement if you try to twist the table (lock y then check x and visa versa), smoothness of speed change on vary head, if it has an original feed motor - does it work (the speed pot can be changed if it's not very linear in speed adjustment) motors for these are very, very expensive.

Hope this helps.

 

[Fastdruid]

I don't know Bridgeports, apart from because they're a well known "name" they're frequently overpriced for their condition. That's not to say they're not good machines. They are but it's easy to pay over the odds for them.

In general the same applies for any s/h mill (or lathe).

1) What overall condition is it in? Has it been loved in a home workshop, show queen that's pretty but horrible mechanically or abused to within an inch of its life and is only good for scrap?
2) Does everything work?
3) Is it missing parts (either taken off or "essential" like feed gears)? Ensure it has the _correct_ draw bars for example.
4) Is it the model you _want_, particularly with Bridgeports there are many different options, as they were fitted with a variety of different "heads".
5) What tooling does it take? In the case of the Bridgeport R8 is probably the preference but they came with a variety, 2MT, 7B&S or B-3 for the earlier heads which are rather less useful these days.
6) Is there any freeplay in the spindle/quill or anywhere else there shouldn't be. Obviously you're not going to detect 0.001mm of play but don't be scared to give things a good yank. If there is any detectable by hand play for most parts I'd walk away.

Beyond that you have things that can to a certain extent be worked round.
1) How scarred is the table?
2) What is the backlash on the axis?
3) Does everything turn and move nicely with no grinding, graunching or other horrible noises.
4) What condition are the ways in?
5) What power does it need (and if you have that at home)?

Finally, what tooling does it come with? It's easy to spend many times the initial purchase price of a lathe/mill on tooling and work holding. A machine that comes with a load in the first place can be well worth it.

 

[slim_boy_fat]

I don’t want to advertise it here for someone else to buy.

I don't recall any examples on the forum of gazumping when a Member has sought advice on a tool/machine, they're a good bunch and above stooping to that . Good luck with the purchase/search.

 

[pressbrake1]

You’re too far away from me

Head noise , variable speed heads can suffer
Long bed machines can get slack and some bow

Check quill feed
As there’s no fancy knees with feed gearboxes they’re not such a mine field
Again the head is simple just make sure both speed ranges work and don’t slip

 

[brightspark]

I don't recall any examples on the forum of gazumping when a Member has sought advice on a tool/machine, they're a good bunch and above stooping to that . Good luck with the purchase/search.

you wouldn't know if they did look how many members are on here and how many hundred none members they are

 

[ronan]

On the vari-speed heads the sheaves are bushed with plastic so they can slide on the motor shaft. If the bushes are worn they can make a lot of noise. If the spindle bearings are knackered, they are easy to change and not silly money if you shop around. Parts can be an issue, there was a crowd in Bristol i was trying to buy parts from and they were a nightmare so i didn't bother anymore. There is a machine tool dealers in Liverpool who are better.

 

[slim_boy_fat]

you wouldn't know if they did look how many members are on here and how many hundred none members they are

Aye, I suppose so - that's just me giving folk the benefit of the doubt.

 

[pressbrake1]

Aye, I suppose so - that's just me giving folk the benefit of the doubt.

There’s a difference between members and lurkers

 

[roofman]

There’s a difference between members and lurkers

Yea talking of... I asked a question i think last week about voltage on a SAF mig, was watching it for a few days on blagbay and dropped my guard and posted a pic of the specs on the welders plate on the rear of machine which identified it....next morning the listing was pulled Going to be more careful in future to outwit the rats of the internet

 

[Mr Fro]

All I can say is go and have a look of you can.

Get it up and running and have a listen for any noise. Also check for play and such as mentioned earlier.

When I was shopping for mine last year, I found a few where the owner had adjusted the gibs to take out the slack in the middle but they were chuffing tight at the ends of the travel.

They're getting long in the tooth now and, though relatively simple, the power traverse circuits can cause the feeds to run slowly. This isn't a huge problem because they can be updated (I've done mine as the Erskine board popped).

Just remember they are old and expect some wear and play. There will always be another one come up and it's definitely worth doing the miles to see it in the flesh.

 

[mr_splatter]

I have a J head Bridgeport. I stayed away from the vari speed model as it is more complex. Mine also has a much simpler table motor without the electronics which I prefered. I converted it from 3 phase to single with two VFDs which was easy and worked nicely. Things I found on mine which are worth looking for

- Grease used instead of oil for the lubrication - seems to be a common mistake
- Teeth missing on the head adjustment - not a big issue for me because once set I don't adjust but having moved it twice I support the head so as not to damage any more teeth
- Stuck dovetail to adjust the head movement front and back. These can get stuck because I guess they are rarely adjusted. Took some work to loosen
- Broken quill spring. Mine has always been broken and I haven't got round to replacing yet but don't think it is too difficult
- Damage to knobs or castings - I have a bit of a casting knocked off before I bought it. I have the piece and tried to reattach with JB Weld but it didn't work but its only cosmetic

Apart from these mine is fine. Other things I have seen/heard of that are worth checking including items mentioned above..
- Bent x axis leadscrew - worth trying all the leadscrews for smoothness. Make sure they haven't loosened the gibs too much to get full travel. Give the table a good yank, there should be no play
- Backlash is inevitable and not really an issue so I would not be worried unless it is really excessive
- Galled taper - put your finger in (switched off!) and check it is smooth in there - As mentioned there are a variety of tapers used but I think R8 is the most common
- Smooth z axis and handle present

Also do you get anything with it like a machine vice. Mine came with one which was also dowelled to the table. That was worth £100 in itself

Good Luck!

 

[Fastdruid]

- Grease used instead of oil for the lubrication - seems to be a common mistake

This is a very very common issue on many machines. You get the "it looks like a grease nipple, so I'll use grease". This then means you end up with the oxymoron of a regularly "lubed" machine being starved of lube! On my Harrison there are portions where the oil is designed to "drip" down, it obviously doesn't when you use grease!

Equally the grease retains chips etc and forms a grinding paste rather than flushing things "off". In general I'd suggest if anyone has ever used grease on it to dismantle and clean it _all_ out. Which can be fun when the parts are 30Kg+!

For example, this was the nasty rancid grease I flushed out of the oil ports on my Harrison. Just horrible.