Tangential Tool Holder

[OrangeAlpine]

Niels, I've been toying with the idea of taking a try at the "smash" style of holder. If I understand, you drilled a hole that cleared the tool bit, which, after springback, made the holding channel .050" too large. I'm thinking of drilling the hole .050" undersize, springing the holder out in order to insert the bit, then smashing. I'll make the holder about 10 mm longer than necessary just in case I fail.

Bill

 

[FarFar]

Hello Bill

You have got the spirit.
I can hardly wait and do not drill and thread the pullig together things before squezin.
And leave at least a couple of mm on all surfaces until after the tough event.
I will sit up holenigth and wait for pictures.
Just like X-mas

 

[OrangeAlpine]

Made the hole .057" underize, worked a sharp cornered 1/4" bit through it. Work is the operative word. Would drive the bit in as far as I could, mash it with a 12 ton press, drive some more (about a mm), then press. There is just too much steel in the tool holder. I can squeeze it only about .020" in a vise. Anyway, the bit has been inserted all the way and expands the holder a couple of thou. It has a date with Mr. Sledge tomorrow. But I don't think there is any way I can squeeze it enough to hold a bit in place.

Oh, the saw kerf is about 1 1/4" long. I would not mind making it longer, but do not want to mess up the holder if this fails.

Bill

 

[OrangeAlpine]

After further thought, I'm going to cut in from the side with a hacksaw, making a hinge. Will start by leaving a 3/8" thick hinge and go from there. That ought to allow for good pressing.

Bill

 

[OrangeAlpine]

As usual, I lied. Started out with a 1/4" long cut. Improvement, but way too stiff. Ended up with a 1/4" thick hinge. The sharp cornered bit is still somewhat difficult to insert, but mill finished Rex AA bits work fine. I think that is what I'll use, I think the rougher surface will improve grip. They say a picture is worth a thousand words, here are a few thousand words:

This is what kept me occupied for a few days before tackling the tangential holder. The "Tee nut" is used stock, the stud is oil hardening 9/16" drill rod, the upper nut and handle are a mystery metal of the stainless pursuasion. All stuff that was laying around.



The tool holder. I made it long enough to be double ended. Any ideas on how to be use the other end?


Need I say "closeup"?

 

[FarFar]

Hello Bill

It is better to make two holders.
If You make a double ender the non active tangential tool bit will harm Your hand or lathe soner or later
Steel is cheap.Medical help not so.

Kind regards

Niels

 

[OrangeAlpine]

Here is the "finished" tool holder.


On first use, it seemed really clunky. Just didn't seem to have enough room. I changed the holder included angle from 90* to 60*. Helped a lot. Peeled .100" off of a piece of mystery metal (that's about all I have) and now my 12" Enco thinks its bad a$$.

While turning the same piece of steel, now turned to .875" with a .562" hole (.313" removed in one pass) I managed to slide the bit down in the holder. Disappointing, but it may be my fault. The clamping screw, 5/16" - 24 is centered vertically in the holder, but the top 3/16" of the holder does not contact the bit. Would holding power be markedly improved if the bolt was lower? How about using two 1/4" - 28 bolts? Would a milled bit channel be better?

Bill

 

[FarFar]

Hello Bill

Make the longitudinal slit longer.Most of Your screw force is wasted..The two screw solution can work but always tigthen the lower one first or You will deform top of tool channel were there is not a lot of material.
My gut feeling is one screw a little below midway and as close to tool as possible.
A milled channel will not make it better as contact area is not the isue.Clamp force is and Your screw try to deform a very stiff holder.Loosen the holder a bit.

Kind regards and let us have more pictures.

Niels

 

[FarFar]

Thank You Mike for the links.

I found another more HillyBilly that might work and be simpler

http://www.youtube.com/watch?v=d9w-P8QAseg

Opening a 3/16 inch round hole to square let us say around an inch high is no big job and it has not to be ultraprecise.Presision comes from a final slight squeze.

 

[oldgascar]

How about making the steel bar a bit longer , drilling the hole for the 1/4" sqare hss tool and then using a 1/4" square broach tu cut the hole to accept the hhs tool and then slice int the pocket. Does this also seem like a good approachto make the tool holder ?

Bob