Newbie with a question on a mill

[Orphanbrg]

Hello everyone,

This is a partial reprint of my Say Hello post up in the newbie section.

I've been looking at a 1948 Bridgeport Round Ram M Head mill a local guy is selling from a deceased relative. The mill looks to be in good shape with a reasonable amount of light surface rust from 3 years of inactivity. Backlash is running between .0010 - .0015" at the center of X & Y travel but unfortunately, I couldn't get a feel for the end of travel because the mill is hemmed in with other equipment. From the lack of tooling found I can only assume that the previous owner used it primarily as a drill press.

There are a couple of issues with the mill however. One being that the previous owner was an electrician's nightmare from the look of the wiring in the shop. As of yet, I have no way of powering the mill up and with the motor cover missing somewhere in the piles of unnamed junk, I've got no way of knowing what voltage and amp draw it is. It is one of the smaller pancake style motors which I assume is 1/2 hp and it turns freely running a flat belt step pulley. The other issue is that it is either missing the drawbar or, if Bridgeport made one, a solid spindle. The top of the spindle ends with the typical spline with about 3/4" worth of thread and nothing else. Photos I've been able to find suggest a nut over these threads with the drawbar passing thru. There is a Jacob's chuck in the mill and is in there solid. On last inspection, I didn't think to climb up to see if the spindle was hollow, assuming that they were all hollow and the drawbar was missing also leaving me to guess whether it's a MT2 or B&S7 taper. Any ideas?

Since I have very little headspace in my basement, less than 7', this little mill will fit perfect. I contacted both H&W Machinery and CE Wood Machinery and inquired about value and based on their recommendations, the owner and I have agreed to a price of $500 for the mill and large vise already attached. What is everyone's thoughts on that?

Thanks

 

[markba633csi]

Those round ram Bridgies don't get as much love as the later ones but I like them. For bang for the buck they can't be beat. The motor would most likely be a 3-phase unit but you can buy a vfd for about 100$ that will run it from your 220 volt service. Static phase converters are even cheaper (essentially a capacitor in a box) and give 2/3 of the motor power in exchange for simplicity and low cost.
You can replace the drawbar or even make one yourself, I wouldn't be too concerned. If there is a chuck in it there should be a drawbar.
And no matter what taper it has you can find tooling for it.
How long is the table? I prefer the shorter ones like 32" or 36" but 42" was the most common I think
-Mark

 

[rabler]

You will only see the drawbar if the quill is raised completely. Was it possible that the quill was extended when you looked at it? A chuck being held in the spindle would seem to indicate there is indeed a drawbar. Drawbars are fairly easy to replace, in a pinch you could probably use a piece of allthread.

 

[Orphanbrg]

When you look at the M Head parts schematic below the only thing showing is part # 43, no retaining nut, no drawbar. When I move the quill up to the limit, nothing pokes out of the spindle above the retaining nut threads. My concern is that the Jacob's chuck is rusted in.

Although I didn't measure it, I'd say it's a 36" table

 

[rabler]

Part number 38 & 39?

If the chuck is rusted in, dump some penetrating oil into the spindle center and let it sit for a day or two. Then use some sort of rod to drive it out.

 

[Janderso]

Backlash is running between .0010 - .0015" at the center of X & Y travel

Welcome to the forum!
Lots of help here.
I think you meant to say, .010" to .015" backlash or am I misreading your point?

 

[benmychree]

I had a M head that I used on a horizontal mill, it was a #7 B&S taper and did have a drawbar, it used a nut that screwed onto the top of the spline shaft, and it seems to me that the drawbar was captive under the nut so that the drawbar could be used to eject the tool in the spindle without hammering on the drawbar end. all this was about at least 30 years ago, so the details are a bit fuzzy, I sold the head after I got a real vertical mill.
I see that the parts diagram clearly shows that arrangement.

 

[benmychree]

I add that my M head had vee pulleys, not flat pulleys that you describe.

 

[Orphanbrg]

Rabler,

Part 38 & 39 are missing, only part 43 is present. I'll try the penetrating oil the next time I'm out there.

Janderso,

You are correct .010-.015. Not enough coffee!

 

[rabler]

Off topic-
Looks like I passed through your neck of the woods yesterday coming back from Dayton.