# End Mill Holders for Atlas MFC



## JPMacG (Apr 23, 2021)

I have been less than happy with running end mills in the MT2 spindle socket of my MFC.  The MT2 lacks rigidity, nomatter whether the end mill is installed directly in a collet or used in an MT2 holder.  So I got the idea of making my own end mill holders that would screw onto the spindle.


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## JPMacG (Apr 23, 2021)

In order to minimize runout I bored the holders in situ on the MFC, then reamed them to final diameter on the lathe.


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## JPMacG (Apr 23, 2021)

Each holder is about 2.3" long - a nice compromise between collets, which tend to be too short for most milling operations and an end mill holder, which tends to be too long.


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## Ulma Doctor (Apr 23, 2021)

Nice work, they are sure to serve you very well!
the most accurate way to bore the holders is on the machine!!! nice touch


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## VSAncona (May 4, 2021)

Beautiful job! I really like your design. I just made an end mill holder for my MFC based on the original Atlas design and I agree with you that they can be too long for some situations. Here is a video of my efforts:


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## wa5cab (May 4, 2021)

The complaint about the Atlas 2MT holder with the four sleeve reducers is that it is too short.

All of the standard commercial holders that I have (and that I do not recall the source of) are about the same effective length as the custom made set or maybe are a little shorter but every %$#@ one of them is the Tanged instead of Draw Bar type.  As I have said numerous times before, never ever use a milling cutter holder loaded with anything other than a drill bit that is not secured in the spindle with a Draw Bar.


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## VSAncona (May 4, 2021)

Atlas made two different lengths of 2MT holders. The short one is number M6-945 (top one in photo) and was sold with a draw bar for use with the 6” Atlas lathe. The longer holder, number M1-577 (middle one in photo) was sold specifically for the milling machine and uses the same draw bar as the horizontal cutter arbors. In addition to the extended reach needed for the horizontal mill, it‘s also long enough to hold double-ended end mills. The holder at the bottom of the photo is a Polish-made Bison brand 2MT holder, also with a threaded end for a draw bar. It’s entirely too large for the tiny Atlas.


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## VSAncona (May 4, 2021)

Where did you get boring bar you used for the small dia, holders? I wanted to bore mine, but didn‘t have a small enough boring bar.


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## JPMacG (May 4, 2021)

It was in a set of boring bars from Little Machine Shop.  https://littlemachineshop.com/products/product_view.php?ProductID=2682&category=

The bar is not as rigid as I would like.  I took lots of spring passes and it was difficult to control the diameter to better than a few mils.  I used a reamer to get the final diameter - back on the lathe.


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## JPMacG (May 4, 2021)

Your YouTube video is excellent.  Thank you for publishing it.   I just subscribed to your channel.


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## wa5cab (May 5, 2021)

CORRECTION TO Post #7 above:

I'm also not certain as to what the top 2MT arbor is or who made it but it isn't an Atlas 945.  My guess is that it was originally an Atlas M1-577 that someone shortened in order to use it with a 6" lathe, as it sorta looks like the one in the M6-945 kit.

The Atlas 945 kit is a set-screw type 1/2" shank diameter cutter holder set consisting of an arbor somewhat similar to the M1-577 (except that the taper is 3MT and the large diameter end is shorter), a 3/8"-16 draw bar and hand wheel, and a thrust bearing/spacer to support and center-up the hand wheel end of the draw bar.  The 2MT version for the 618 and other 6" lathes is M6-945.  The M1-577 and both of the other arbors directly take a 1/2" shank diameter milling cutter.  There is an Atlas 563E 1/2" OD reducing bushing set with ID's of 7/16", 3/8", 5/16 and 1/4" for smaller shank diameter cutters.

NOTE:  Never ever use a Weldon style (those with a flat ground on one side) milling cutter with any of the reducing bushings unless you carefully rotate the cutter so that its flat is on the other side of the bushing from the set screw.


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## VSAncona (May 5, 2021)

You’re right, Robert. The holder on top is for the 6” lathe. At one time I had the holders and draw bars for both the 10” and 6” lathes, but must have gotten rid of the 945. I edited my post above.


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## wa5cab (May 5, 2021)

OK.


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## JPMacG (Dec 3, 2021)

I'm bringing this old thread back up because I now have done a few projects with the end mill holders.  They are working very well.  Their length and rigidity are a significant improvement over my Morse taper collet and end-mill holder.   They really improve the usability of the mill.  I previously had avoided using end mills because I was not satisified with their perofrmance, but now I favor end mills over arbor cutters. 

Machining the spindle socket and getting the registry diameter just right was a time-consuming hassle,  but well worth it in hindsight.  I encourage other MFC owners to go his route.


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## Winegrower (Dec 3, 2021)

Here’s a question for horizontal mill operators:   I have a small cute Sheldon horizontal mill, but I have never considered or really even thought of using an end mill in it.   Is there any operation with end mills where one would prefer a horizontal mill over a vertical mill?


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## JPMacG (Dec 3, 2021)

One example of when a horizontal with an end mill is handy:  I restore vintage radios and electronic test equipment as a hobby.  This usually involves replacing the old 2-wire power cord with a modern IEC power connector.  To install the IEC connector I have to mill a rectangular hole in the back of the equipment chassis.  The horizontal mill is great for this because the radio/equipment chassis can sit on its feet on the mill table while I mill the hole.  A vertical mill would require that the equipment be placed on its front panel, which usually has knobs, dials and meters.

But in general, I think a vertical mill is more useful than a horizontal with an end mill.


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## matthewsx (Dec 3, 2021)

I have a new to me Hardinge BB4 which is even smaller than the Atlas. I've got a nearly complete set of collets so I can hold most any endmill I want. Any tips/tricks for operating these small horizontal machines?

John


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## VSAncona (Dec 4, 2021)

Did you single-point thread these? I may try making one. They look like they would be really rigid.


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## JPMacG (Dec 5, 2021)

Yes, I single point threaded them, 1"x10.   It was slow going as I used a small threading tool that lacked rigidity.   I cut an internal relief groove at the end of the thread prior to threading.


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