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Some notes about my Bridgeport Series 1 base referbish

Randalthor

Aluminum
Joined
Mar 7, 2018
Location
Kansas City
I finally finished the referb on the base of a Bridgeport I bought a couple months ago. I already went through the head and posted some notes in this thread.

http://www.practicalmachinist.com/v...efurbish-progress-plus-some-questions-348351/

I'm not an expert for sure, but perhaps someone new can gain a few ideas, should they choose to do a base referb.

I ended up taking everything apart including removing the knee. I didn't repaint anything (I don't have the equipment to do that) plus my mission was not to really improve the look (although that would have been a nice bonus) rather to improve functionality. In disassembly and reassembly, I again relied heavily on a sort of "Service Manual" -Guide to Renovating the Bridgeport, by ILION.

I also again used a lot of plastic sandwich bags and labeled everything on disassembly, and took lots of pictures.

I was extra careful in removing and replacing the heavy parts because someone warned you can easily bump the ways with the heavy parts and create a raised burr on the ways.

I didn't have an engine hoist, so I threw together a hoist out of some scrap scaffolding and used some come-alongs to lift some of the heavy parts.

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I ended up having to replace all the bearings in the base, which takes a press. I had a press with a small travel, but needed one with a larger travel for some of the shafts/bearings in this mill, so again a threw together a frame with more travel from scrap steel. I just used wood blocks to get the right height to press bearings out/in, and a bottle jack.

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I think this mill sat idle for possibly a couple decades in storage, so there was some light surface rust on some of the interfaces, for example, the ram dovetails and the turret. I removed those and removed the light surface rust with fine steel wool, lubed the turret with super lube Teflon grease, ram with way oil, and put them back together.

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The ram wouldn't go back all the way. It stopped just as the end of the ram dovetails hit the end of the turret dovetails. It turns out, at some point something had hit the end of the ram dovetails hard enough to bugger the end. I could see where the dovetails were interfering with one other, right at the end. I stoned the high points out, so that the ram could continue back smoothly. Someone had broken the handle to move the ram (probably trying to get it all the way back, when the end of the dovetail was buggered, so I had to drill and remove the broken off piece before I could install a new handle.

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I'll continue in next post.
 
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I removed the table with a couple saw horses, removed the saddle and then the knee with my hoist. The knee had sat in one place so long there was rust. I cleaned the ways on the column, but you can see where the left way was still stained where the knee sat for so many years. I couldn't scrub the stain off. It felt perfectly smooth and no rust, and the flaking was fully intact, so I left the stain.

The knee on the same side actually looked worse.

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But the rust was actually worse than it looked and came out easily. Fortunately, there wasn't any pitting.

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I lightly stoned the ways before putting everything back together. There were a couple high spots on the saddle that I stoned out, as I recall.

There were many oil passages plugged, so I got the chance to give those a good cleaning. It took a lot of time to clean all the parts. Almost 50 years of grime.

I started out intending to replace all the bearings in the X axis, but when I had the screw out, I noticed it had about .010 wear in the middle of the screw, so I bought a new one. I asked Barry at H&W if I should get new brass nuts with it, and he suggested I should. I decided to keep the Y axis screw, as it only had .003 wear in the middle, but did replace those nuts as well (per Barry's advice)

I discovered the new nuts didn't have the holes for the one shot oiler, so I had to measure very carefully and drill them. I placed one of the holes face up here for the pic.

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You'll notice that the cast iron dog bone (which holds the brass nuts)has a hole in the top to allow manual oiling from the little hole in the table above. I decided I didn't want to leave the hole in the dog bone open, since the one shot oiler oils both screws, and it's just another hole to allow for dirt/filings to get in there. So I plugged that hole by drilling and tapping with a 5/16" tap and made a special screw so that it would sit flush with the top of the dog bone, and not interfere with the table above. I made the screw by altering a bolt, with a bench grinder and a dremel tool. Perhaps someday I'll have a mill to make things like that. :rolleyes5:

There was one of the one shot metering units about plugged, so I replaced it. I replaced quite a few of the one shot plastic lines. A couple looked like they had some spots which were damaged a little, but mostly, they were sooo short, it was hard to get them back on after removing them to check the metering units. Seriously, the factory had those things on so short, you couldn't get the compression nuts (hooked to the hoses) back on the metering units. I ended up putting most of the hoses on new and using a heat gun to bend them how I wanted.

Even though it didn't need it, I replaced the one shot hose which goes through the knee. In a video, Barry suggested to leave some extra length of hose in the knee in case that hose gets damaged. That way, one can just cut some hose off and pull the slack hose out from inside the knee. That seemed like a good idea to me, so that's what I did. I made sure the extra hose inside the knee wouldn't rub against anything (like the screw)

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The one shot lube pump was an old Dropsa. It was leaking oil out of the stem. I took it apart and was hoping it just had a simple Oring seal there, but it was a special seal. I tried to get a new seal, but no luck. I ended up replacing the whole unit with a Bijur pump.

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Continued in next post
 
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The top fitting of the new Bijur pump didn't exactly fit the connecting fitting, so I had to rob one fitting off the old Dropsa pump.

Someone had put some makeshift bolt to adjust the screw backlash for the table, so that was another of the many parts I had to replace. If you look carefully, you can see it in this pic (along with all the grime I later cleaned out).

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I also replaced the 2 stacked bearings for the cross feed.

When I got down to disassembling the knee, the guide book said to just remove that bearing, take it apart, clean it and repack with fresh grease. The bearing felt loose and had all kinds of trash inside it. Once again I made a call to Barry, and he said if I'm that far down replace the bearing, so I did. He also made me aware there is a special bushing which goes with the bearing, which was made into in the original bearing (and not able to be removed). So the bushing has to be bought separately. Here's the old bearing with the bushing "made" into the bearing.

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Here's the new bearing with the bushing I had to press into the bearing.

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I also asked Barry if I should replace the brass nut for the knee, he said those things almost never wear out and to keep the original, if it looked OK. Mine looked fine, so I kept that.

At this point I had pretty much decided to replace all the bearings, like I did with the head, so I replaced the two bearings on the drive shaft for the knee.

Here it is with the gear on the end before I pulled it out. Even with all the grime, the gears didn't show any wear. More parts to clean. I went through about 7 gal of diesel fuel in cleaning parts.

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Here it is out of the machine. The two bearings on the ends are identical (only one can be seen in this pic)

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Continued in next post.
 
When I finally started putting everything back together, I noticed the cross feed gib didn't have much adjustment left, so I decided to shim the gib. I checked the slope of the gib and the amount I needed to back the gib up, so I ordered a .005 sheet of shim stock. It turns out that was too thick. After shimming the gib, it was so far out I couldn't get the aluminum cover for the felt wipers on.

This is really a poor design of Bridgeport, imo. The cross feed gib only has about 3/8 of adjustment before it hits either one of the felt wiper covers. I may yet try to get some thinner shim stock, or not shim that gib at all. It doesn't have to be shimmed right now, so I may wait.

I did use the .005 shim stock to shim the table gib. It seemed to be about the perfect thickness for that job. Here is the gib about flush with the saddle, which I've heard is supposed to be ideal. I watched one of the many H&W videos which shows how to do this. They show using a nifty pair of industrial duty shears to cut the shim stock, but I just used a cheap pair of Chinese kitchen shears, when my wife wasn't looking.

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I also noticed the cross feed dial rubbed just a little bit against the bearing retainer. Someone had shimmed the dial out on the table feed, so I decided to shim the dial out a little bit on the cross feed. I ended up using the .005 shim stock to make a little washer. It worked perfect.

I had to remove the woodruff key off the Y screw to get my little dial shim on, and that key lived up to the reputation of many woodruff keys. It wouldn't budge. I tried all the usual tricks, punch, sidecutters, etc. and it was going no where.

I saw an interesting idea on youtube. I cut a slot in a scrap piece of steel, laid that piece of scrap on the shaft so as the slot in the scrap fit like a glove along side the key. Then welded the piece of scrap to the key. The scrap protects the shaft from weld jumping on the shaft, and protects the shaft against heat, but allows the key to get red hot.

Used PB Blaster before then welded the scrap and key together. Waited for the key to cool, then tapped on the piece of scrap from the backside. The woodruff key finally surrendered. Here it is beside the y screw.

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Here is the flip side where I used a hand grinder to cut out a little bevel to make it easier to weld.

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I finally got all the dials, table, etc. back on. It was time to put the head back on.

I'd seen this idea before, so I made a little "mounting peg" to bolt the head down to the table. I made it out of scrap too. The rod is 5/8" to match a 5.8" collet and fastened it in the spindle.

Here it is attached to the table with the head on it. The head is not attached to the base at this point.

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Here is the machine all back together along with the VFD I need to wire before I can power the mill.

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The work lights need some attention. I haven't given them much thought at this point.
 
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I made a few mistakes along the way.

One is that when I had the knee off, I should have backed the stop screw on the knee out more. I didn't think about adjusting it then. The stop screw is in the middle of the knee toward the top in this pic.

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Because I didn't think to adjust that screw when I had the knee off, I had to adjust the corresponding stop screw on the column out further to get a good fit with the stop screw on the knee. It's a long screw, so there are more than enough threads engaging the column, but I didn't like to see any threads showing on the outside. Looks sloppy.

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Another mistake was when I was finally putting the motor on the head (I had taken the motor off the head to lift it up and fasten the head to the table) I got the motor bolted down on the head. It was then I finally took the two bolts out of the motor pulley (the little bolts used to collapse the spring loaded pulley). I'd forgotten you need run the vari-pulley back down to the slowest speed, so the belt collapses the spring loaded pulley some. I pulled the two screws out, and while I was pulling the second one out, the spring caused the little bolt to pull a thread right at the very end of the removal. I don't think it materially affects much, as it just pulled one thread, but it was a dumb mistake.

I made another mistake putting the way covers on. They were cheap import way covers, and the part which goes over the dovetails on the ram wouldn't fit. So I used a hand grinder to grind on the way cover to make it fit. Got a little aggressive, and removed a bit too much material on the left side of the way cover. You can see it doesn't fit perfect like it should.

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I bought the way covers from H&W and interestingly Barry said he hates way covers. He said he cringes every time he goes into a factory and they have him put them on. I asked why . He said in a factory every time he put's them on, it's like the machinists forget about the ways and never sweep them out again. After talking about it further with him I went ahead and ordered the way covers but plan to heed his advice to sweep the ways underneath, understanding way covers aren't bullet proof protection.

I think I'm going to like the table covers because although it's not a good idea to use the table to lay things on, the covers are a good protection if I lay a wrench or something down.

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By far the biggest mistake I made was how much invested in the machine. I originally paid $2300 for the machine and probably have a little north of $4500 in the machine in all the bearings, replacing missing handles/knobs, screw, way covers, VFD, etc. etc. That's too much money for a machine with no DRO or power feeds. But I'm not in the machine belt and Bridgeports are somewhat unusual to find within driving distance here, so it is what it is.

I suspect the expectation is a bit artificial in that most people who report price are the same ones who bought a machine at a super great deal, so it skews the expectation. I just wanted to mention my costs as another data point should anyone expect to purchase a 50 year old machine and go through it replacing worn parts as I did.

Lastly, I just wanted to mention how much clearance is required between the motor and the ceiling. I was worried about this before I bought the mill. Did some reading but couldn't find any exact answers on how much ceiling clearance is needed to tilt the head. I have this in my garage and the ceiling is only 7' tall. I knew the overall height of the mill was shorter than that, but didn't know if the motor would bump the ceiling when tilting the head. I have a little over 2-1/4" head space.

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It turns out that's plenty of head space to tilt the head. It probably clears the ceiling by an inch, maybe more. I know I can't get the drawbar out unless I tilt the head, but I'm glad at least I don't have to remove the motor to do that.
 
Outstanding writeup and detail Randalthor. Thanks for sharing. I keep meaning to order way covers but haven't yet. I wanted the nice pleated ones but man they're expensive. And I don't think you have too much $$ in your machine. Everything is tight and refurbished/rebuilt, and you know so because you've done it yourself. That means a lot. In an area where Bridgeports are hard to come by, that's not a bad price IMO. I had to look a long time for mine and they're fairly common where I live.

As far as DRO, you don't have to buy a brand new expensive DRO or even a cheapie chinese unit (which are also hundreds of $). I have an older Mitutoyo X-Y unit, which is classic quality Japanese. Works perfect, very happy with it. You can pick up good quality used DRO systems on ebay and craigslist. Just gotta be patient and one will fall into your lap at a great price.
 
Thanks for the kind words Maschine.

I researched some opinions about way covers. I agree the pleated ones (at least the "store-bought" ones) are pretty expensive. Some people didn't like them because the pleated covers themselves were hard to clean (trapped chips in the pleats). I chose the cheapy Chinese covers on this purchase.

I know they will eventually break down with the oil, but I'm thinking/hoping it won't happen for quite a while.

Thanks so much for the tip on the DRO. Had no idea one could get a decent DRO on Ebay/Craigslist. Ebay/Craigslist such a land mine sometimes. I'll start keeping watch.
 
Someone recently posted another refurbish project of a Bridgeport, so I thought I'd post my itemized expenses to this thread. I always tally my cost of what I have in any piece of machinery anyway, so I thought I'd post this one public for the possible benefit of someone. Not looking for confirmation or condemnation, just posting what I have in my machine as a possible data point for someone else.

I had most of the tools to do the work but had to buy a few I noted at the end.

I paid $2300 for the machine, which does not include trailer and pallet jack rental to move it.

I bought most of the materials from H&W and use their item numbers. I ended up buying a very small amount of parts that I didn't end up using. Those are included as well. Here are my costs (rounded) in no particular order.

7 gal of diesel for cleaning parts $17.50
1/2 case of brake cleaner for cleaning parts $18
2 tubes of Super Lube w/ teflon $15
Large bottle of blue locktite $25
2J 1-1/2 rebuild kit (H&W) $275
1030 Quill feed knob $21
1259 Ball end for ram pinion handle $3
1159 Ram pinion handle $14
1145-03 Elevating knee handle $50
Quart way oil $8.50
1137 Collet Alignment screw $8
1021 Quill downfeed handle $28
Quart spindle oil $8.50
1277 motor ball bearing $5
1546-02 motor ball bearing $9
1026 Drawbar (pretty junky drawbar) $22
Lubriplate B-105 $3
1164 Felt washer $17
Book-Guide to renovating 2J machine $26
Shipping $28

1489 Timing pulley clutch sleeve $23
012-0044 screws for drum switch cover $2
1552 cotter pin $0.50
1555 washer $1.50
1127 Brake bearing cap $68.50
two 1574 taper pins for upper housing $2.50
1585 Gear housing plate $22
One gallon way lube $18
Shipping $25.50

1218-0102 roll pin key for motor pulley $6
1218-0080 stationary motor pulley $100
shipping $23

0.005 shim stock $26
two key pins 1183 $2
(ordered some tooling which came on the same order so prorated shipping) $8

two 1178 bearing $48
1227 bearing $67.50
1227-a bearing spacer $37
4' of 5/32 black plastic tubing $4
four B8272 compression sleeve for plastic tubing $2
four B1061 compression sleeve for metal tubing $2
shipping $7

Bijur lubricating pump (from Hardinge) $170
Adapter from Hardinge $6
shipping $19

5/32 bendable copper tube from Ebay $7
B1095 compression nut $1
three B8272 compression nut $1.50
three B1061 compression sleeve $1.50
4' 5/32 plastic tube $4
1178 bearing $24
1601 way wiper kit $10
1098 longitudinal feed screw $285
1110 feed nut retaining screw $8
1150 washer head screw $4
two 1180 keys $7
four 1173 ball bearings $53
1069 longitudinal feed nut $33
1070 cross feed nut $33
1022 protective way covers $62
B1371 compression bushing $1
shipping $40

5/16-24 UNF brass grease zerk (Ebay) $9

Quill fine feed hand wheel (Ebay) $46

Bijur metering unit (Ebay) $14

Yaskawa V1000 VFD (including shipping) $443

Box for VFD (Ebay) $54

Electrical fitting $10

Tools

Needed a new rubber mallet and a couple pry bars $15
Some various cutting wheels and welding rod to build lift, stand, etc. $20
Helicoil kit including drill bit $44
special 2" socket to remove nut from bull gear assembly $16

If my math is right, I spent about $2511.50 in parts and $2300 for the mill for a total cost of about $4800.

I still have a few odds an ends for the electrical left.

I still haven't put the power to it yet because the dang "Quick Start" guide for the Yaskawa VFD is over 200 pages. I'm about 1/2 way through it.
 








 
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