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Round Ram Bridgeport Advice

kubiack

Aluminum
Joined
Feb 18, 2008
Location
Texas
I am looking at buying a round-ram Bridgeport mill and am seeking advice before purchase. I am on the fence about buying this machine or holding out for a mill with a dovetail-ram. We have never had any heavy industry here and so machining equipment is few and far between. This mill is in pretty good shape with a small amount of ware in the x axis ways and feeds but nothing I can’t live with. It comes with has a J head, a shaping head, and factory power feed and the price is reasonable for this area.

What are the drawbacks of buying a round-ram instead of a dovetail-ram. I would imagine it would be a little less ridged and can not take as heavy a cut. I mostly do forge work so the mill will be used for repairing forging equipment, making dies, and tooling. The mill will not get regular uses so I don’t think I will be missing out to much by not having the dovetail-ram. Any input or opinions would be welcomed.
 
I have one of each and my biggest gripe are riser blocks for round rams are RARE ! That's half the reason I got a dovetail machine as I needed more head space with RT with a chuck mounted on it. They also have smaller tables as a rule 32" or 36" . Shaper head if it has the tooling in a nice addition.
 
The more I research about the round-ram the more I am convinced I would be better off with a Series 1 machine. I called a few Bridgeport parts suppliers and they have everything for a Series 1 but only some of the parts for the round-ram. It also appears machine specific accessories such as riser blocks are pretty much nonexistent. This mill is a lot better than the one I have now but it will have to be a temporary machine until I find what I really want. Machines are pretty rare here so it may be a while before I find a good Series 1. I made him an offer that I know I can get my money back on when I sell it, just have to wait and see if he takes it.

He did not have the shaping head attached to the machine and I was able to buy it for a very reasonable price.
 
J-head round rams are pretty good. I have one, like it, and would say its very comparable to its taller brothers on a rigidity basis because you lose the nod knuckle which stiffens the turret/ram/head assembly quite a bit. These machines came with the standard 42" table and the larger knee, unless special ordered with the smaller table (not sure what rule John is thinking of). Im also a big fan of the shorter base as its much easier to move IMO.

The reason many complain about the round ram mills is because most of them (the early models) were produced with the smaller M heads which were lower powered (1/2 hp) and had a nod knuckle that was prone to flexing under heavy cuts. Taken for what it was intended to be, a small mill that was very versatile, the M headed round rams were good mills, but using one for roughing large parts out wouldnt be fun, tho even the Series I mills arent all that stiff.

Regardless, I wouldnt worry much about accessories or parts for the base outside of power feed and a good DRO. Items such as feed screws, handles, dials, knee bevel gears etc are interchangeable and common. Personally, I also wouldnt add riser blocks as they only make light machines even less rigid. If you really need the height, larger (better) machines without the Bport name/price/following typically sell for less. If you do decide to go that route, you could always machine your own if you couldnt buy them (most are shop made anyway it seems).
 
I've got a Round Ram BP built around 1954. It's in suprisingly good condition and works great. While I haven't needed any parts for the ram, as mentioned earlier all other parts are interchangeable.

I'm in the process of stripping about 5 layers of paint off it so I can repaint.
 
I also have a r ram jhead and IME it's solid and cuts great. My only gripe is when indicating the head the ram bolts on one side sometimes tilt the head while tightening. However, I have found to tighten them slowly, a little on each at a time and it will stay put.
 
[First Post]

I, too, have recently acquired a round-ram J-head; mine has a 110V 3/4 HP motor.

It's a bit rusty, but not too bad. Humid here in Houston, y'know...

I have been very careful not to mess with cranks and so forth until I get it cleaned up and lubed, which calls for the questions-

1. Is there a preferred way to remove light rust, e.g., from the back of the ram and the top of the ways (?) that guide the knee?
2. I know those 'zerks' aren't for grease; what kind of oiler do they use, and where do you get one?
3. How far down should I tear it if I want to make stuff now and possibly 'restore' it later?​

I really like the Art Deco aura of this machine.

I'm keepin' it!

mwi
 
How old is this machine? The early Bridgeports had knees which were only 9 inches wide rather than the newer ones with 12 inch knees. The smaller knee machines were somewhat lighter being only 1500 lbs rather than 1900 for the 12 inch knee ones. My old Bridgeport literature indicates that the J heads were available for the 9 inch knee. It appears when Bridgeport introduced the dovetail-ram, the knees were 12 inch.
 
S/N 8745

Spent the last little while as a drill press, evidently; can't get the taper to let go. I oiled it up good and'll let it set tomorrow...

Also need to shim the quill lock screw.

I noticed my coolant seems to keep rust of the ways of my lathe, so I sprayed it all over the shiny bits of the comatose mill.
How old is this machine? The early Bridgeports had knees which were only 9 inches wide rather than the newer ones with 12 inch knees. The smaller knee machines were somewhat lighter being only 1500 lbs rather than 1900 for the 12 inch knee ones. My old Bridgeport literature indicates that the J heads were available for the 9 inch knee. It appears when Bridgeport introduced the dovetail-ram, the knees were 12 inch.
 
How old is this machine? The early Bridgeports had knees which were only 9 inches wide rather than the newer ones with 12 inch knees. The smaller knee machines were somewhat lighter being only 1500 lbs rather than 1900 for the 12 inch knee ones. My old Bridgeport literature indicates that the J heads were available for the 9 inch knee. It appears when Bridgeport introduced the dovetail-ram, the knees were 12 inch.

Not true. 9 inch knees were available for quite some time. I owned an early one. Early v rams still had the round ram base with the bolts coming from underneath.
 
[Refer to this thread.]

Well, the gentleman who sold me this mill insinuated it had a R8 taper, which it turns out not to have. It is an M-head with a Morse-2 taper. Caveat emptor.

I was leery of banging away on a tool intended for precision, so I used the "heat-n-beat" method: I heated the drill chuck end of the taper with a mapp gas torch tapped the thing from the side, quenched it, [repeat 1x], then used a palm nailer on the end of a piece of all thread. After about 90 seconds it let go. Mushroomed the all thread pretty good. Inspecting the old piece, it was slightly corroded on each end of the taper. The bamboozle-er reportedly used the mill as a drill press for fifteen years, and judging from the stuck-ness of the collet, he probably wasn't making that one up. The little thing seems pretty tight overall, so I remain hopeful it'll mill.

I have an ER25 MT2 collet set from my little lathe I am going to use.

EDIT: Forgot to re-mention the penetrating oil down the drawbar hole overnight.
 
How old is this machine? The early Bridgeports had knees which were only 9 inches wide rather than the newer ones with 12 inch knees. The smaller knee machines were somewhat lighter being only 1500 lbs rather than 1900 for the 12 inch knee ones. My old Bridgeport literature indicates that the J heads were available for the 9 inch knee. It appears when Bridgeport introduced the dovetail-ram, the knees were 12 inch.

The 12 inch knees were available long before the dovetail ram came about in 1956.


1. Is there a preferred way to remove light rust, e.g., from the back of the ram and the top of the ways (?) that guide the knee?
2. I know those 'zerks' aren't for grease; what kind of oiler do they use, and where do you get one?
3. How far down should I tear it if I want to make stuff now and possibly 'restore' it later?[/INDENT]

1. I prefer a green scotchbrite pad and WD40 for cleaning. Serious nasty-ness = substitute brake parts cleaner.
2. Use the search feature on this site. There are quite a few threads detailing converting a grease gun to oil. You can also buy a regular oil gun for these from McMaster or any of the other usual sources.
3. I would at the very least disassemble the top part of the head direclty below the belt cover and clean the crap out, followed by pulling the table to clean the knee out (usually serious chips in the knee elevating gears) and cleaning out the ways. Both of these will also give you a chance to check/clean all of the oil passages throughout the machine. None of its rocket science, just be careful taking it apart and dont force anything. Once you know how its done you will be surprised how quickly you can have these machines apart the 2nd or 22nd time.
 
The 12 inch knees were available long before the dovetail ram came about in 1956.

1. I prefer a green scotchbrite pad and WD40 for cleaning. Serious nasty-ness = substitute brake parts cleaner.
2. Use the search feature on this site. There are quite a few threads detailing converting a grease gun to oil. You can also buy a regular oil gun for these from McMaster or any of the other usual sources.
3. I would at the very least disassemble the top part of the head direclty below the belt cover and clean the crap out, followed by pulling the table to clean the knee out (usually serious chips in the knee elevating gears) and cleaning out the ways. Both of these will also give you a chance to check/clean all of the oil passages throughout the machine. None of its rocket science, just be careful taking it apart and dont force anything. Once you know how its done you will be surprised how quickly you can have these machines apart the 2nd or 22nd time.

I decided to try PB Blaster which was recommended by the guy at O'Reilly... Man! You can actually see the iron oxide changing color! I also picked up some kind of purple degreaser, which wrinkles the 'new' paint but seems to leave the old paint alone. I'll be getting some rubber gloves for that part.

After that post, I did exactly what you recommended, CWB, and then picked up a grease gun, which I filled with automatic transmission fluid to pump through those zerks. After finishing the cleanup process, I'll go find the proper oil and use that.

Since this thing was just a fancy drill press for 15 years (reportedly), I think I'll act on your suggested tear-down after I have studied the prints.

Thanks, CWB!
 
I've had a round ram M head machine down to nuts and bolts. The head is really simple with a few gotchas well documented here. Read some of the M head posts by guys like Jim Rozen. The knee, saddle and table are virtually identical to a V ram machine. At least the machine is a Morse 2, mine is a Brown and Sharpe No 7 which is very close to MT2 and easily confused. Fortunately I have two sets of B&S collets for it and simply use straight shank tooling, but mostly its been used as a drill press since I do have a J head machine.
 
<snip> Read some of the M head posts by guys like Jim Rozen. <snip>

Yes, Mike, they are de rigueur if they can be found. Let's collect them all up here, OK?

More good threads:

My Bridgeport Round-Ram
M-head.
M head rebuilder
High Speed M head
flood damaged M head (shows a tool to remove the star-shaped nut)


My humble cast iron castoff came out of a "professional" shop in the sense that the old fellow was making odd-ball screws and nuts on contract (near this place: Space City Screw). But he didn't know very much about mills, evidently - The oil ways are full of grease. (OMG!)

I got this thing mostly for the learning experience and to help me stay grounded (I am a design engineer, not a machinist). I am making a small lot of fixture parts right now, and then I'm going to look beneath the T-slots, so to speak. Probably put that in a separate thread linked back here.

Thanks, everyone for your friendly, helpful web presence/presents!
 
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Knee stuck - gib jammed

I UPS'd out my little lot of fixture parts today and decided to do some maintenance on the old thing. I was after two things in particular:

1. I wanted to de-grease the oil-ways.
2. I wanted to see if I could help the ~3/4 turn of backlash on the long table.

The backlash thing was a particular nuisance because when I turned the crank the table would start to move after about a half turn, then stop for another half a turn, and then start moving again. It felt like the feed nut was moving back and forth in its hootenanny.

I started dis-assembly and de-greasing in a pretty normal way until I encountered the knee gib screw. It was rust encrusted, so I PB blasted it and sat back awhile. While sitting back, I began to wonder, "I wonder if there're any tricks to this knee gib thang?" So, while PB blaster was doing its thing I came inside and did mine, turning up the above linked thread.

YIKES!

So, I cranked the knee up all the way (table, saddle, and so forth already removed) and started loosening the knee gib screw. Sure enough, it wanted to 'hang up' after turning freely a couple of turns. So, I turned it out until I got resistance and cranked down the knee a wee bit. Hallelujah! The gib stayed put while the knee moved down! I repeated the procedure until the screw came out and then pull Mr. gib out for a PB blaster tub soak.

Oh, and the longitudinal slop factor was assignable to an improperly installed nut. More on that later, but I found what I expected based on a separate meander through old BP threads.

Howard Chappelle reportedly said that the most important tool for building a fair sailboat was a comfortable chair. That one stuck with me...
 
The most important thing I've learned since I started working on machine tools? Patience.

I like making progress but I've learned sometimes you just need to put the tools down and walk away. Sometimes its overnight or the next weekend sometimes you just need to get a cold drink and start in again.
 








 
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