Boring bar sleeve made - Thanks!!

M

mwestcott

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I recently posted questions on boring bars and holders, and received tremendous help and advice from mikey and others. After a great phone conversation with Dave (mmcmdl) I purchased a couple of carbide bars from him. As recommended, I got an Aloris AXA boring bar holder, which is far better than the one I had from the cheap set. I made a bar sleeve as best I understood it be done, bored and then reamed the hole (another first). I don't have a mill, so the slots were done with a hacksaw. I made it long enough so the bar shank would be fully supported always. I've used it on a couple of small projects and it seemed to work well. I attached a couple of photos to ensure I really did this correctly. I didn't have any steel stock large enough, so I made it from aluminum. Is that sufficiently stiff, or will I be happier making another from steel?

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I need to make some of those for the Micro 100 boring bars.
Sweet. I'll need to add a register for alignment.
Well done
 
Nice sleeve, should last forever.

One thing, not trying to be picky. The small slit you made on the outside should be on the inside, across from the full slit, about half the wall thickness deep. The idea is to have somewhat even compression on both sides of the inner bore, especially with harder materials than aluminum or thicker walled bores. Again, though, nothing wrong with yours in this application.
 
The outside slit is in the flange, which is an excellent idea, regardless of whether one also adds a cut in the ID.
 
Good job there, Sir!

Personally, I would also make the expansion slit opposite the through slit a bit deeper. The wall thickness from the bottom of my expansion slits to the bore is only about 1/16" thick. Mine are just 12L14 mild steel and they have stayed round and un-cracked for what must be over 20 years now.

I also applaud your choice of the AXA-4D. It is an excellent boring bar holder and will serve you well. With the right sleeves, it will handle any bar you have up to 3/4" OD and it will hold them solidly.
 
I am still a bit confused on the slit opposite the full contraction slit. Should it be an expansion slit on the outside of the sleeve, as I did here, or should be on the inside of the sleeve, with a corresponding expansion slit in only the flange? Or does is make a difference with material and/or size of the bar?
 
Slitting the flange, like you did, prevents that from influencing the clamping action. While you could continue that into the barrel OD, there would be no clamping at the ID, just increased flexibility near your full slit. So it would be better to slit the ID partially through the barrel, allowing some clamping action as the barrel pivots on the uncut OD of the barrel.

Even better, I would think, is to cut through the barrel but not for its entire length, starting from alternating ends for multiple slits.

Edit: like this https://www.hschmidt.com/product/stainless-steel-expanding-collet-sleeves-58-converts-12-58/
 
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The slit doesn't matter as it is a boring bar . ;)
 
Also , if you want to get fancy ..............................bore the sleeve off center to the OD . This will give you a very fine height control by rotating the sleeve . :)
 
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