Tool holder too high

[kyler]

Welllll..... I bought a cheap Chinese wedge type QCTP. I got the T-nut cut down to fit my Logan and installed it on the lathe. When I bought it I also bought a 1/2" Carbide Indexable Lathe Tool Set because the slot size was 1/2" and I assumed thinking thicker is better.

So, I finally got it all mounted up tonight and adjusted a holder as far down as it would go and DAGNABIT... it is still about a 64th too high! :angry:

I think I know the answer but I'll ask anyway.

I need to buy a set of 3/8" holders, right?

 

[pdentrem]

You could use 3/8" shank tooling but you already have 1/2" you could chuck up the holders in the lathe and remove a bit over the 1/64th that you are too high on your HIGHEST tool. Or you could deepen the tool slot by the same amount if there is enough metal under the tool.

3 ideas in less than 2 posts!

 

[kyler]

You could use 3/8" shank tooling but you already have 1/2" you could chuck up the holders in the lathe and remove a bit over the 1/64th that you are too high on your HIGHEST tool. Or you could deepen the tool slot by the same amount if there is enough metal under the tool.

3 ideas in less than 2 posts!

Since I don't have a mill (I paid a local shop to make the t-nut), this sounds like a good idea - but I'm not picturing how this would work.

Are you saying put the tool holder in my 4-jaw chuck and in essence, face cut an 1/8" off the bottom of the holder?

 

[ScrapMetal]

Why not just put an end mill in the lathe, install your new (too high) tool holder, and machine the bottom of the slot? Hope that made sense. -Ron

 

[Tony Wells]

I think he meant to mill not the bottom of the holder, but the bottom of the slot. There should be full access to the entire slot. Should work, then all 1/2" toolholders would work. Modify the block.

 

[Tony Wells]

Same here. I keep a few spare set screws of longer and shorter length to keep from having to put so much torque on the socket to split it. I have done that, and it's a pain to deal with, especially if it's not a screw on the end where you can get vise-grips or a pipe wrench on it.

Not that I advocate milling the bottom of the slot, as it does sacrifice a little rigidity, but sometimes it's the easy way out. I have one that won't turn loose with the QCTP if I have the tool clamped up pretty tight because it flexes. Aggravating when I forget and use it on a heavy tool. I try to use it on light, small tooling.

 

[kyler]

I wouldn't take off an eighth if it's only a sixty-fourth too high. Take just 1/32" off. If you were close to me I'd do it for you in about 10 minutes. I had to do this for some holders I bought.

I have a Dorian CA size QCTP on the 16x40 lathe. The Dorian brand holders need no alteration to get 1" shank tool holders on center. The quality import tool holder blocks I bought from Jeff @ Tools4Cheap.net are just about 2mm too thick between the bottom of the block and the bottom of the tool shank slot, so I mill .100" off those.

Please tell me you didn't buy a set of those cheap Chinese toolholders with 6 holders and a few bits of crappy triangular-shaped faux-carbide. If you did, try to return them before you use them. I'll be happy to help you get one or two holders and some inserts to replace them that will actually work quite well rather than cause heartache and frustration.

I bought these through Jeff and since he is well regarded here, I assumed that even being Chinese there were okay. I'll PM you.

 

[pdentrem]

Since I don't have a mill (I paid a local shop to make the t-nut), this sounds like a good idea - but I'm not picturing how this would work.

Are you saying put the tool holder in my 4-jaw chuck and in essence, face cut an 1/8" off the bottom of the holder?

Yes you face off the bottom of the tool holder.

 

[4R8]

Looks like a mighty fine job to me Paddy, Kyler ought to be wrapped!

Now that's what a "machinist community" is all about. Excellent.

 

[kyler]

WOHOO! :biggrin:

Can't begin to say how grateful I am!