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Maximum Milling Cutter Diameter
- Thread starter Green Frog
- Start date
- Joined
- May 10, 2012
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- 995
The number and range of speeds on the Atlas mill varied over it's production, but as far as I know it had speeds and feeds appropriate for medium to soft steels with a 4" diameter cutter (which, as mentioned earlier, is the largest that will fit and still use the overarm support). My mill is one of the earlier versions that had 16 speeds, later versions came with 12, I believe.
- Joined
- Dec 25, 2011
- Messages
- 10,503
The M1, MF, and MH were 16 Speed. The "A" models were 12 Speed. And the "B" and "C" models were 8-Speed.
Note that AFAIK, none of the "A" models ever had an "A" on the nameplate. Atlas renamed them retroactive when they came out with the "B" models around 1944 or 1945.. According to MMB-5 (parts manual), all M1, MF and MH with Serial Numbers between 1345 and 5465 inclusive are actually M1A, MFA and MHA. However, there was one report of an MF with a serial number in the 900 range that had 12 Speeds. I've been waiting for one with a serial number between about 1000 and 1344 to turn up but so far, nada.
From the specs in various year catalogs, the speed ranges of the three groups are.
Base... 54-3225
A..........61-2860
B & C.. 62-2870
So not much change at the low end.
Note that AFAIK, none of the "A" models ever had an "A" on the nameplate. Atlas renamed them retroactive when they came out with the "B" models around 1944 or 1945.. According to MMB-5 (parts manual), all M1, MF and MH with Serial Numbers between 1345 and 5465 inclusive are actually M1A, MFA and MHA. However, there was one report of an MF with a serial number in the 900 range that had 12 Speeds. I've been waiting for one with a serial number between about 1000 and 1344 to turn up but so far, nada.
From the specs in various year catalogs, the speed ranges of the three groups are.
Base... 54-3225
A..........61-2860
B & C.. 62-2870
So not much change at the low end.
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- Mar 24, 2016
- Messages
- 100
wa5cab, I'm sure the question has come up before, but I'll ask it again to get the information into this thread. Is it possible (and practical) to retrofit my MFC and get 12 or even 16 speeds out of it? Would the parts be hard to find and/or exceedingly expensive and would there be any over riding reason not to do it?
- Joined
- May 10, 2012
- Messages
- 995
You would have to make/acquire the pulleys, but once that hurdle is completed it wouldn't be difficult to install. The 12 speed setup would probably be easier to find. The 12 speed may be easier to find, the 16 speeds were only made from 1941 to 44.wa5cab, I'm sure the question has come up before, but I'll ask it again to get the information into this thread. Is it possible (and practical) to retrofit my MFC and get 12 or even 16 speeds out of it? Would the parts be hard to find and/or exceedingly expensive and would there be any over riding reason not to do it?
- Joined
- Dec 25, 2011
- Messages
- 10,503
Is it possible, yes. Is it practical - that probably depends upon how much money you are willing to throw at it. Just off the top of my head, I would guess that the least expensive solution would be to convert from the 1725 RPM single-speed single-phase motor to a variable speed three-phase motor. The 8-speed system probably has enough range to get around the fact that there is no way that a variable speed motor is going to by itself be able to match the 60:1 speed range of the MF.
There are quite a few differences between the MFC and the MF. However, outside of the spindle and countershaft assemblies the other differences don't matter in terms of which cone pulleys are used on the spindle and countershaft. You should download MMB-5 and compare the part numbers of the parts on those two assemblies to see what has to change. Pretty much the entire countershaft assembly including belt guards is different. On the spindle assembly, the spindle, bearings, bushings and gears are as I recall the same. Just about everything else is different.
The easiest way to find all of the necessary parts would be to buy an M1, MF or MH. But you will probably get stuck with the leftover parts. Otherwise, the parts availability on the 16 Speed and the 12-Speed machines is very poor. The 16-Speed machines were made in 1941 and 1942. The 12-speed machines were made in 1943 and 1944. The two 8-speed models were made from 1945 until 1960. And Sears was a second seller of the MFC (only). Parts availability on the used market of 8-speed parts is relatively poor but much better than that of the earlier machines. Clausing has almost no parts left for any of the mills except for maybe some of the ones that were also used on the 618 lathe and carried over to the mill. Far fewer mills were made than lathes. And their production ceased about 20 years before lathe production ceased.
There are quite a few differences between the MFC and the MF. However, outside of the spindle and countershaft assemblies the other differences don't matter in terms of which cone pulleys are used on the spindle and countershaft. You should download MMB-5 and compare the part numbers of the parts on those two assemblies to see what has to change. Pretty much the entire countershaft assembly including belt guards is different. On the spindle assembly, the spindle, bearings, bushings and gears are as I recall the same. Just about everything else is different.
The easiest way to find all of the necessary parts would be to buy an M1, MF or MH. But you will probably get stuck with the leftover parts. Otherwise, the parts availability on the 16 Speed and the 12-Speed machines is very poor. The 16-Speed machines were made in 1941 and 1942. The 12-speed machines were made in 1943 and 1944. The two 8-speed models were made from 1945 until 1960. And Sears was a second seller of the MFC (only). Parts availability on the used market of 8-speed parts is relatively poor but much better than that of the earlier machines. Clausing has almost no parts left for any of the mills except for maybe some of the ones that were also used on the 618 lathe and carried over to the mill. Far fewer mills were made than lathes. And their production ceased about 20 years before lathe production ceased.