# My Atlas 618 milling attachment



## trlvn (Mar 9, 2019)

Hey!  I made diy milling attachment!!

I don't have a mill and acquiring one is not in the cards for the foreseeable future.  But then I ran across Harold Hall's amazing website and the idea of using an angle plate to enable the compound to move a vise in the vertical direction.  So I did that:






Since I'm a newbie, there were a couple of missteps and a piece that had to be remade.  I already had the vise which had 3/8-24 mounting holes on the bottom.  I had to add an extra set of mounting holes to get a better range of travel. 

Here's a sort of 'exploded' diagram:






I know this isn't a real mill.  I know I'm not going to be taking heavy cuts and I plan to mostly use it with aluminum and brass.  Hopefully it will work OK for that.

It isn't hard to set up or tear down.  Two allen keys are all that is necessary to mount it.  A 1-2-3 block in the vise helps to get it pretty square to the spindle.  I need to buy proper end mill holders.  I see Shars has some morse taper mount holders for $12 USD per size.  I'm going to order 3.

All in all, this has been a fun project.  Hopefully I'll get some use out of it.  First thing I want to try is a carriage stop.

Craig


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## PeterT (Mar 9, 2019)

Good for you. Parts look great. Making things & learning is all part of the fun IMO.


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## RobinHood (Mar 9, 2019)

Great work on your milling attachment. That will serve you well.

Have you considered getting MT3 collets instead of the dedicated endmill holders? (I think your spindle nose is MT3?). It would allow you to “choke up” your endmills (and work pieces / drills / other cutters) much closer to your spindle bearing and thus you would have better rigidity. They are available in sets like this: https://littlemachineshop.com/products/product_view.php?ProductID=1615 (no affiliation)


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## trlvn (Mar 9, 2019)

RobinHood said:


> Great work on your milling attachment. That will serve you well.
> 
> Have you considered getting MT3 collets instead of the dedicated endmill holders? (I think your spindle nose is MT3?). It would allow you to “choke up” your endmills (and work pieces / drills / other cutters) much closer to your spindle bearing and thus you would have better rigidity. They are available in sets like this: https://littlemachineshop.com/products/product_view.php?ProductID=1615 (no affiliation)


I looked at those but Shars has morse taper end mill holders on for a really attractive price:

https://www.shars.com/precision-end-mill-tool-holder-morse-taper-2-3-8

I like the idea of a set screw to make sure that the end mill doesn't get drawn out of the holder.

Craig


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## Tom O (Mar 9, 2019)

Nice! Half the fun is figuring out the holding and fixturing of parts!


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## DPittman (Mar 9, 2019)

Good job!  I too made myself a milling attachment for my 10x22 lathe and with careful setup and very light cuts I can do some basic milling.  While I hope to someday have real milling machine, I sure am glad I have my little attachment for now!  I had a 618 lathe also and always wanted one of the factory made milling attachments but was always astounded what they seem to sell for on eBay.


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## YYCHM (Mar 9, 2019)

Dumb question here but..... does 618 stand for 6" swing and 18" between centers?  I tried googling Atlas 618 and didn't come up with anything defining the machine size.  What size motor is on your machine?

The stuff you're turning out on that machine looks very good.  I'm doubting your newbie claim


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## trlvn (Mar 10, 2019)

YYCHobbyMachinist said:


> Dumb question here but..... does 618 stand for 6" swing and 18" between centers?  I tried googling Atlas 618 and didn't come up with anything defining the machine size.  What size motor is on your machine?
> 
> The stuff you're turning out on that machine looks very good.  I'm doubting your newbie claim


Oh I'm a newbie alright!  If you squint at the photo, you can see two extra holes on the face of the angle plate. I carefully worked out how to attach it to another angle plate and attach that to the compound so I could bore the 1.25" recess needed to mount it on the boss.  Only when I got it mounted did I realize that moving the piece with the cross-slide would let me bore a rounded rectangle--not a larger diameter.  Duh. 

After a bunch of head-scratching, I came up with this:





You can faintly see the marks where the bore is to go.  Before actually boring, I switched to a shorter bolt so the head wasn't sticking out so much.  (Which meant another trip to Cdn Tire!)  There are two tapped holes in the edge of the faceplate and that side is bolted onto the faceplate.  To support the other side, the round piece is tapped on both sides.  One side is bolted to the face plate.  On the other side, the bolt runs...through a clearance hole in the work piece, then a nut and then threaded into the support.  The nut let me fine-adjust the face of the work piece to run fairly true.  The additional piece on the left is just a counterweight to make it a little less lopsided! 

I was pretty nervous when I started up the lathe...even at 55 rpm!  Honestly, it ran pretty well.  I think I had it up to 500 rpm for drilling the initial holes.

BTW, I had planned to take more pictures but my hands were completely black from the cast iron work.

Craig
PS if you look at the lathe bed below the work piece, you can see where the previous owner 'made room' for turning something just a little bit bigger!  I didn't need that this time...but you can see my lathe has had a hard life.


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## DPittman (Mar 10, 2019)

YYCHobbyMachinist said:


> Dumb question here but..... does 618 stand for 6" swing and 18" between centers?  I tried googling Atlas 618 and didn't come up with anything defining the machine size.  What size motor is on your machine?
> 
> The stuff you're turning out on that machine looks very good.  I'm doubting your newbie claim


Yes you're exactly right, 618 means 6" swing and 18" between centres.


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