# Atlas milling machine power feed



## b.dygger (Oct 11, 2014)

Has anyone made a replacement MF-7  large scope, MF-8 small scope (table feed shaft) and MF-26 yoke? 
I recently purchased an Atlas Milling machine with serial number between 005466 and 008123 (identified from manual as the serial number plate is missing). The MF-26 yoke is broken and the shaft (scope) is missing. I've 




had no luck trying to find replacements parts, so I considering making them. I'm hoping someone else has done this and perhaps has a drawing/design for the parts in question.


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## Terrywerm (Oct 11, 2014)

I have made telescoping shafts for packaging machinery in the past. Typically the torque load on them is not too high, much like I would expect for your mill. I do not have any drawings, but I will do my best to describe what I did.

The universal joints were purchased from McMaster-Carr here:  http://www.mcmaster.com/#universal-joints/=u3t03s

Telescoping shafts are not too hard to make. I typically made them from square tubing with machined stub ends welded in for the u-joints to attach to. 

For very short shafts, I made the entire shaft. The inner shaft was made from 1/2" round stock, and had a 1/8" hole near the end for a roll pin.  The outer shaft was 3/4" OD with a slightly over 1/2" bore. DOM tubing of the right size could be used too, if you wish. I then milled two slots in the side of the outer shaft, 5/32" wide, running along the length of the shaft, but directly opposite from each other. Slide the inner shaft into the outer shaft, then line up the hole in the inner shaft with the two slots in the outer. Press a 1/8" x 3/4" roll pin into the inner shaft.  Now attach your u-joints and you are done.


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## John Hasler (Oct 11, 2014)

Note that the joints must be properly phased to get constant velocity at the output end.

http://www.engineersedge.com/power_transmission/universal-joint-design-calculations.htm


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## b.dygger (Oct 11, 2014)

I want to thank both you for your help. 
Bill


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## Terrywerm (Oct 11, 2014)

You are most welcome. Let us know if you have further questions.


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## wa5cab (Oct 12, 2014)

*b.dygger*,

I took a look, but the only drawing for parts of the drive shaft that I found is for MF-27.  And it wouldn't help as MF-27 is made from MF-26.  The only dimension on it is for the wrist pin holes, .2500"/.2505".


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## b.dygger (Oct 13, 2014)

I appreciate the info, and your efforts to help, thank you.


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## Earl (Oct 22, 2014)

Here is some info on the yoke.


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## LJP (Oct 22, 2014)

I made the MF 26 yoke and other repairs to my Atlas Mill. The repairs are shown in this thread. I traded the Atlas Mill for a horizontal Hardinge, I do not have measurements, sorry.


http://www.hobby-machinist.com/showthread.php/22832-Atlas-Hor-Vert-Mill


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## b.dygger (Oct 23, 2014)

Thank you Earl, this will be a big help. This is going to be one of my first 'machine' projects in over thirty years. Having recently retired from a non-manufacturing job  I'm looking forward to re-kindling my love of metal working machine projects.


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## Earl (Oct 23, 2014)

two of those yoke pieces and the block that goes in the middle are made of steel.   The other yoke piece (an original) is pot metal.  The steel pieces were made by the previous owner of the mill.  If I need a yoke,  I will just need to drill that center block and put pins in it to hold it all together.  let me know if you need any more photos or dimensions.

Earl


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## b.dygger (Dec 3, 2014)

Hi Earl and thank you for responding to this thread. I thought I had a found a guy with a parts machine but it it turned out to be a shaper not a milling machine. So I'm back to making my own yoke and shaft assembly. Any dimensions and photo you can provide of the shaft assembly will be helpful. The pictures of the yoke you made will be very helpful and thank you once again for your assisstance.
Best regards , Bill



Earl said:


> two of those yoke pieces and the block that goes in the middle are made of steel.   The other yoke piece (an original) is pot metal.  The steel pieces were made by the previous owner of the mill.  If I need a yoke,  I will just need to drill that center block and put pins in it to hold it all together.  let me know if you need any more photos or dimensions.
> 
> Earl


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## ogberi (Dec 3, 2014)

I believe I have the shafts and yoke in question.  I'll dig through my shop in the next day or two and see if I can find 'em.  I'll take measurements and pics when I locate them.


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## b.dygger (Dec 3, 2014)

Thank you that will be very helpful.



ogberi said:


> I believe I have the shafts and yoke in question.  I'll dig through my shop in the next day or two and see if I can find 'em.  I'll take measurements and pics when I locate them.


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## ogberi (Dec 3, 2014)

Okay, I did find them.  Then I got distracted by machining my QCTP for my little Taig. 

But I did get a whole bunch 'o pictures, and took measurements first.   Tell ya what.  If you can provide dimensions and pictures of the assembly that goes under the table, I'd greatly appreciate it. Mine is busted, and I got to cast or machine another housing.   

Anyway, here's my measurements. Mostly with a caliper, though some with a ruler. 

The telescoping part is two round shafts, one nested in the other. A pressed dimple rides in a slot, providing drive. 

The big (outermost) shaft : 

6.25" long, .75" in diameter.  The fork is machined into the end of the shaft, and the arms are 1" long. 

The small shaft is .5" in diameter, 6.25" long (my best guesstimate by shoving a piece of wire down the outer shaft and comparing the exposed vs hidden lengths).   The end of the small shaft goes into a U joint half, secured with a pin. 

The slot in the small shaft is .125" wide, and can safely go the entire length of the shaft.  I'm guesstimating it's .125 deep, based on the "around .125" depth I measured at various points.  

The U joints have a .5" cube as the wobbling part,not sure about the pin (it's mushroomed out, and I'm too lazy at the moment to grind it and drive one out to measure). 

The U joint on the small shaft is pinned to the shaft.  The OD of the joints measures .87", the "base" the arms sprout from is .27" thick, and the arms are .75" long (from the top of the base to the end of the arm).  I would surmise they're a tiny bit more than .5" between them, so the U joint works smoothly. 

The big part of the shaft has the arms machined into the end of it, if that helps. 

Lastly, the included photos show the phasing of the U joints.  Yeah, I know it's a mess. It's broken, and I haven't even bothered with it in 7 years.  

Don't be afraid to ask me for more measurements or pictures.  It only takes a moment, and I can usually wrangle some shop time when I get home from work. 

Here's the tool porn:















Hope it helps, and I would truly appreciate some pictures of the housing (the second picture shows mine is broken).  I'd *love* power feed on my MFC, even if it's a DC motor driven jobber.


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## b.dygger (Dec 5, 2014)

Thank you for posting the pictures and additional info, it will be very helpful. It will take me a few days to get back to my shop as I am trying to finish up several client projects from my day job. But as soon as I can I will take that housing off and get pictures for you. Feel free to email me directly b.dygger@gmail.com.
Best regards
Bill


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## b.dygger (Dec 12, 2014)

Hi sorry for the delay in responding, it's always  hectic at this time of year. I'm trying to close my office and finally retire, this job is the last hold-out. I will try and get back in my shop and get pictures and measurements as soon as I get caught up. 
Best regards and Merry Christmas to all,
Bill



ogberi said:


> Okay, I did find them.  Then I got distracted by machining my QCTP for my little Taig.
> 
> But I did get a whole bunch 'o pictures, and took measurements first.   Tell ya what.  If you can provide dimensions and pictures of the assembly that goes under the table, I'd greatly appreciate it. Mine is busted, and I got to cast or machine another housing.
> 
> ...


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