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Need input on Bridgeport way wear

BuffDan

Aluminum
Joined
Apr 6, 2005
Location
WNY
I'm considering a auction Bridgeport, and would like feedback on the knee way wear. The rest of the machine is fine, table great, head quiet, some tweaking needed. Thanks!
I'm retired, so I mainly do machining for friends, myself.. So I dont need .0005 accuracy
 

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The flat knee ways were chrome plated and it's about worn thru. I looks like the are worn pretty even surprisingly. Most times they are worn in the middle and not on the ends. The shop who has it must have machined wide parts and on the rear of the Y ways. As they look the worse. I would bet the dovetail ways are as bad. If your only going to need .001 or .002" tolerance the and only use it for an hour or two a week the machine should be OK.. If you buy it take off the table and saddle, replacing the BiJur metering units, new way wipers, tighten the feed nuts, stone the ways and adjust the gibs up. 1/2 moon flaking is approx. .002" before it is flash chromed and the chrome is almost worn thru.
 
Thanks.. I will bid low. Shame, as the table is pristine, the head is very quiet, the dial backlash is roughly .013,
 
I'd be hard to pass on this mill if it was me, too. I've run mills much worse than this in my past. I agree with Richards thoughts, too. Go for it!
 
that would be a dream on my BP. i have an olderr non chrome knee and the guy before me filled it with grease. it was a huge upgrade from a mini mill but i can tell you if i need tight specs ill be looking to have all the ways recut and table peened.
 
with respect to Richard, I don’t understand how .003-.005” of wear on a knee surface, translates to any loss in tolerance on a part. Only sense I can make of this implication is that, if the way surface is worn unevenly, and this one doesn’t seem to be, you wouldn’t be able to compensate for wear with the gib. So in that case, the axes would become loose in the most worn areas. My feeling is that the result wouldn’t necessarily be dimensional, but rather in surface finish (Which I guess could effect a dimension).

my mill is old and worn, but even, and I was able to reduce backlash to around .005”, not that backlash equals tolerance.

I must be missing something.

edit: reread Richard’s post and this is basically what he said. Never mind. I was never here :)
 
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Well I didnt go for it.. It went for $4300 (Fees and taxes included) Wasnt the right one for me.
 
Just for a point of reference: I bought my mill with very little wear for $500 in south jersey. It's a 1967 step pulley machine. Had no frills or tooling but was almost 100% complete. (missing quill handle, fine adjust wheel) and needed routine maintenance.

If this helps, I asked my son to skip school that day. We towed a low u-haul trailer behind our F150, and I brought a lot of tools, an automotive floor jack, and a HF engine hoist. We disassembled the mill in place until all we had left was the column. Took about 4 or 5 hours. We had the 1.5 ton engine hoist whose base legs weren't wide enough to straddle the column. That was the only real difficulty. Had I sprung for the heavier duty engine hoist, that would have worked better.

Note: We didn't do a complete disassembly, only broke the mill into manageable components. I was unable to move the ram for example. I pulled the motor, separated the drive pull covers from the head, removed the head, and then took off the ram and turret as a single component. Really wasn't that heavy as I recall. Only slight issue is that we used a lifting eye, which, because I couldn't move the ram, wasn't near the center of gravity.

Other trick I used was, I brought lifting eyes that threaded into tee nuts in the table slots. I had a bit of chain and made a bridle so that we could remove the table. Again, not being able to get the engine hoist under the mill, we slid the table off onto a rubbermaid cart (that I brought for the purpose) then grabbed the table from there.

In retrospect, fork lifts etc are all the best way to move these. I suspect part of the reason this went so cheap was because the seller didn't want to assist with the move and buyers couldn't/wouldn't do what my son and I did.

Lessons learned:
1) Picking up the column is tricky without an engine hoist or gantry crane that can straddle the base. If we had that, we could have knocked several hours off the move.

2) We did borrow cribbing to support the column. We kinda just tipped the column back and forth, slipping in 2X lumber until the base was high enough to clear the engine hoist's legs. I had some big crow bars which helped.

3) Sliding the mill on the trailer was our last hurdle. I needed a come along. Fortunately, my high schooler was a varsity defensive lineman/rugby player who just pushed the 800lb column across the steel trailer bed. Not sure what I would have done without him.
 

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If my father asked me to skip school for a day, I would say that I am behind in school now.
Then he would say, how about I give you a day of tutoring in your weakest subjects.
Then I would say, let's move another mill tomorrow. All we have to do is invert the head (with motor) and lower the table.
 
For some reason quite nice looking Bridgeports have the knee ways trashed ......some look like people used them as anvils or mixed chemicals on them from the rust.......doesnt anyone notice the ways are not cleaned or lubricated ,they just use the machine as "the last guy left it"
 
I really think that either the bijur stopped working, or they stopped using it. I activated it twice when I was there ,and didnt see any lube. :( Really, all the equipment there was well used. They had a Taiwanese mill with horrible sounding bearings, Not sure how they could use it without hearing protection. Apparently the shop owner was quite elderly and must have just let the equipment deteriorate.
 
I’m sure no one missed the point, but just in case:
A series 1 Bridgeport weighs just under 2000lbs. That really requires a forklift to move properly.

If the seller can’t/won’t help you load it, that really lowers the price and number of potential customers.

That’s why I have a really nice mill in good shape that I paid $500 for. It was lucky, but not just luck. The seller just wanted the mill gone and didn’t want to spend any time or effort getting rid of it. (no judgement, btw)

One really can disassemble a mill, virtually anywhere, and almost hand carry out the pieces. I did it with a reluctant teenager. (He’s great but not interested in my milling machine, or almost anything I do).
 
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There are a bunch of mills for sale by me. Just saw one on fb marketplace in Betlin NJ thats the exact situation I described with my mill in my posts above. Asking price is $1000. Looks like it has a short table, old 2 axis DRO and maybe x-axis power feed.

”BRIDGEPORT MILLING MACHINE buyer has to pick up it’s heavy your going to need a trailer and come along and rollers that’s what it’s so cheap ok ✅

If you are a PM member in good standing, and need help or tech support, I’m about an hours drive from this mill. My son is now 23 and lives near this mill. He would probably be willing to do some heavy lifting for a couple bucks. Little Adam is 6’6“ probably 275. Fork lift not required.
 
Maybe there is something I don't know but I have moved lots of BPs and I have never taken one apart to do it.
I too have moved a lot of B-ports and clones.
You flip the head sideways to make it easier.
BUT .. 4 bolts and that top comes off so not as tippy.
Done the toolmaker size with a "cherry picker".. engine hoist. Forklift certainly nicer but not as much fun.
A guy brought me two 2500 lb surface grinders for cnc refit. Liftgate truck which is fine since I do not have a forklift now but he freaked out during the unload move.
He was really stressed which was amusing but at the same time I do understand.
 








 
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