Atlas milling machine arbor bushing?

[BGHansen]

I'm making a road trip tomorrow to pick up a decent (at list from the photos) Atlas MFC. It's missing the arbor, tools4cheap has a 7/8" one for a reasonable price. Arbor spacers are plentiful on eBay. I have some 1" cutters which naturally won't fit on the 7/8" arbor. Has anyone ever made a bushing of sorts to use larger hole tooling on smaller arbors?

I'm thinking I should be able to take a piece of 1" OD, 7/8" ID tubing and mill a keyway slot through it. This would slip on the 7/8" arbor. I'd use 1" ID arbor spacers on either side of the 1" ID cutter, they'd just go beyond the 1" bushing so the balance of 7/8" spacers wouldn't "mash" the bushing. Seem plausible?

I also thought about turning a piece of 1 1/4" or 1 1/2" CRS about 1" long, bore out a 7/8" hole. Run a broach through it for the keyway. Then turn a shoulder on it 7/8" diameter and a depth just a few thousandths shy of the cutter thickness. Use regular 7/8" arbor spacers to hold the cutter against my sleeve. Seem like that would work too?

Curious if anyone has come up with a good solution. Not to belabor it, but I also thought about buying a MT2 end mill holder, probably 3/4" ID (from tools4cheap). Then use a piece of 1" CRS, turn one end to 3/4" to fit in the end mill holder, machine the other end to accept the clamp nut and fit in the support arm bushing. Naturally will need a keyway milled in also.

Thanks in advance for any help!

 

[wa5cab]

BG,

I think it's a bad idea which you will probably come to regret. For one thing, you have to have a slip fit between the bushing and the arbor plus between the bushing and the cutter. So you have just doubled the slop. For another, the length of the bushings will sooner or later turn out not to work with something you are in a hurry to do. For another, unless you make a bunch of bushings, one day you will be short one. If you have too many 1" bore cutters to scrap or can't find someone who will swap 7/8" ones with you, buy a 1" arbor. There is at least one guy on eBay who has been selling 7/8", 1" and I think 1-1/4" arbors for the Atlas MF...MFC for a long time.

Robert D.

 

[Restorer]

For many years I used a bushing. Problem is, if it slips things get stuck in a hurry.

When the cutter stops rotating and the feed keeps going the power feed can be broken.
Mine got real tight a few times but didn't break.

I made another arbor 1 inch, with a keyway, no problems since.

See my post "Tools you can make for the Atlas Mill".

Restorer

 

[BGHansen]

Thanks for the tips! I just got home with my "new" mill. It's an MFB in pretty decent shape. It's missing the knob on the RH side of the table, handle on the Z height wheel and the kick-out table detail. Figure those parts are relatively easy to make. Needs a new main drive belt too, figure on going with a link belt. Harbor Freight has them for $25 for a 5 foot length. I'm going to mount it to a roll-around tool box. I know stability is key to quality work so I'll come up with some sort of cam legs to set the cabinet after it's rolled into position. Oh, the draw bar is missing the hex on the end, another easy correction as I have some 5/8" hex steel stock.

 

[cjtoombs]

If you are patient, you can find them on Ebay. I wound up getting a 1 inch (mine came with a 7/8) for a reasonable price. You can also find 7/8 cutters on ebay as well, but they will likely be dull, so unless you have a way to sharpen them, that may not be the way to go. I got the shell mill holders from toolsforcheap, I tried one out, it worked fine. Enjoy your new purchase.