Boring with an Atlas Milling Machine

[JPMacG]

I'd like to know the options for boring using my Atlas MFC mill. Can a boring head be fitted on the spindle somehow? I suspect that I would run out of room in the Y direction. What are you all doing?

 

[A618fan2]

Yes, it can be done. I've not done it, but Atlas called for a special arbor fitted with an inserted cutter to be used for boring. I've never seen one though. There's a very short paragraph and one illustration (page 4, para 6) in the October 1962 MMB-5 edition Atlas mill instructions that addresses boring with the mill. I did a quick search for one of Sam Brown's Atlas mill articles (he wrote for Popular Mechanics for decades) hoping he covered it but couldn't find one. My Google-fu skills are fading....maybe someone else will be able to find something more detailed.

John

 

[Ulma Doctor]

if you can find or make a simple MT2 boring head.
you'll want it threaded for use with a drawbar, otherwise the boring head could be ejected under strain

 

[machPete99]

I am not familiar with the Atlas but if it is an MT2 spindl there are MT2 adapters for Criterion style heads.

 

[wa5cab]

It does.

 

[cjtoombs]

Due to the short y travel of the Atlas and general lack of room, you might think about a "lathe" style boring bar. This would look a lot like a horizontal milling arbor except it wouldn't need the treads or keyway and would have a through hole with a tool that could be adjusted in our out to vary the bore size. Of course, this wouldn't work for blind holes, but something simmilar without the arbor support could be done for that. I think it would be hard to do much with a boring head and MT2 adapter due to the lack of space, but it might be possible. Good luck.

 

[JPMacG]

Thank you everyone. This is all very helpful. And yes, my concern is the lack of space in the Y direction versus the length that a conventional boring head would require.

The Atlas user's manual shows the boring arbor like CJToombs described. That may be a good option. I think setting the tool length to get the desired bore diameter might be a challenge, and the arbor would limit the minimum bore to something like 1 inch.

 

[cjtoombs]

Thank you everyone. This is all very helpful. And yes, my concern is the lack of space in the Y direction versus the length that a conventional boring head would require.

The Atlas user's manual shows the boring arbor like CJToombs described. That may be a good option. I think setting the tool length to get the desired bore diameter might be a challenge, and the arbor would limit the minimum bore to something like 1 inch.

Yes, it does seem a bit limiting, but back in the day other boring could be done on the lathe (good hobby lathes had a t slot table for that purpose). I've never done it before, but from what I've seen most of the lathe boring bars like I described used a setscrew to advance the tool bit in a controled fashion, and if you offset the setscrew (or used a wedge with the setscrew in the end) you could use a micrometer to measure the tool height so that you could more easliy hit the right size bore.

 

[JPMacG]

I'm bringing back this old thread for an update... I decided to try a conventional boring head on the MFC. It is a 2" import that I found on eBay for a good price. I made an adapter so that it could mount directly on the threads of the spindle, with part of the spindle nested within the head. This saves maybe two inches compared to mounting it using the Morse taper. I'll see how it works out.

 

[34_40]

That's a pretty good idea JPmacG.
I don't know how I missed this thread.?.? When I started reading this I was thinking you might be able to use end mills
mounted in an arbor ( or is that a mandrel???) But your idea is way better than mine!! LOL.