New to me MFB

[omni_dilletante]

I have been looking for an Atlas Horizontal mill for some time. One showed up on Craigslist this weekend and I picked it up last night. It is an MFB and I think it shows potential.

I don't think I have seen a chain drive on any of these. Is this normal?

It is missing the table feed lever and throw out yoke (Part numbers: MF-16, MI-63, MF-15). I figure these are exceedingly rare. So far Google has not lead me to a description of how to fabricate these. Found a couple of drawings on the Atlas Yahoo group. I would appreciate hearing from anyone that has done this. (Or does anyone have one near Portland Oregon that would let me measure it and take some pictures?)

Hope to post more pictures after I take it apart, clean it up and move it to the basement.

 

[wa5cab]

Omni-,

No, chain drive is definitely not normal. That makes it a 4-speed machine. It originally had a 2-step pulley on the spindle and the countershaft and 8 speeds. M1-79CX and M1-80B.

Robert D.

 

[cjtoombs]

Early ones had a 4 speed change pulley on the spindle, they were 16 speeds. Your machine is early; it doesn't have the provisions for the outboard brace. I don't know when the outboard brace was introduced in relation to the pulley changes, so I can't say for sure whether yours came with the 4 or 2 pulley setup. Someone must have been planning on doing some heavy duty cutting with that chain drive. One problem with the 2 pulley setup was that the belt was hard to source, so that may be why this one was modded. I expect that provisions for back gear were also removed when doing the chain drive, so you may only have 2 speeds on that mill. There are always parts on eBay for these, though most are asking three arms and a leg for them. If you are patient, you can wait and the parts you need will come up on auction with a low starting bid. They don't tend to go that high if you can catch them like that. I bought several small parts including a 1" arbor and a new overarm support reasonably like that. What size arbor and tools did you wind up with? Nice that it came with that many cutters.

PS. I have modeled the 4 speed change pulley as well as the other spindle parts, if you have a way to view them. They are not complete, as I did not bother with some of the details, but they should get you in the ballpark.

 

[omni_dilletante]

Wa5cab - The chain drive has two sprockets, I assume they provide the same ratios as the original. What I don't like about it is that it is noisy.

The back gear is present and in good shape. The back gear was engaged when I got it and I managed with some effort to disengage. Now that I think about it I need to see if the chain conversion allows me to not use the back gear. That would be a bummer.

cjtoombs - I would like to see your pulley/spindle mods.

 

[VSAncona]

Nice find. You got the vise with it -- that's a big plus.

I think the outboard brace first appeared around 1947-48, so your machine pre-dates that.

Seems like a few of these machines have popped up on this board lately.

 

[omni_dilletante]

I think the outboard brace first appeared around 1947-48, so your machine pre-dates that.

I am curious what it would take to add the outboard brace. Is it a matter of changing the Cross Slide Screw MI-36 for a MI-66, the Cross Slide Screw Bearing MI-33 for a MI-67 and the Arbor Support MI-8 for MI-60? Or is there more to it?

 

[cjtoombs]

I am curious what it would take to add the outboard brace. Is it a matter of changing the Cross Slide Screw MI-36 for a MI-66, the Cross Slide Screw Bearing MI-33 for a MI-67 and the Arbor Support MI-8 for MI-60? Or is there more to it?

I think that is the only difference. I have thought about just machining a tapered clamp that would go on the current tapered cross slide screw bearing and fabricating the rest of the parts. It's a low priority project, though.

 

[VSAncona]

I am curious what it would take to add the outboard brace. Is it a matter of changing the Cross Slide Screw MI-36 for a MI-66, the Cross Slide Screw Bearing MI-33 for a MI-67 and the Arbor Support MI-8 for MI-60? Or is there more to it?

That's the way I understand it as well. My mill is an MFC, so I haven't had to do to make the swap. But I've read threads on other forums from people who have done it.

 

[wa5cab]

Atlas built 12 models of horizontal mills, M1 through MHC. They first appeared in the 1941 catalog (probably printed late 1940) as the 16-speed (4-step spindle pulley) M1, MF and MH. In the 1943 catalogs, they are still called M1, MF and MH but are 12-speed (3-step pulley). Atlas later retroactively renamed these M1A, MFA and MHA but the "A" does not appear on nameplates so they are only identifiable by serial number. The M1B, MFB and MHB came out in 1945 and are 8-speed machines with 2-step pulleys. The M1C, MFC and MHC appear around (or by) 1948 and are also 8-speed. To date, no one has turned up a 1942, 1944 or 1947 catalog, so the exact transition dates are a little iffy.

Although there are several other parts that are different, the only significant difference between the B and C models is the outboard stay or bar (and the lack of overarm guard that adding it required). Of course, the cross feed screw and bearing changed as well but only because adding the bar required lengthening them slightly.

Robert D.

 

[VSAncona]

The M1C, MFC and MHC appear around (or by) 1948 and are also 8-speed. To date, no one has turned up a 1942, 1944 or 1947 catalog, so the exact transition dates are a little iffy.

I haven't seen any catalogs from those years either, but the parts lists can help us narrow it down a little. The Milling Machine Bulletin (MMB-2) parts price list shows the MFB model and is dated January 1947. The revised parts list showing the MFC model (MMB-3) is dated March 1948. So it's probably safe to say that the MFC was introduced in early 1948.