QTCP debate

[taiwanluthiers]

Ingenious I love that design. Great job!


Cutting oil is my blood.

It seems no different than a 4 way tool post where each and every tool has the shim glued on so that it always comes to the right height.

 

[Huub Buis]

@Huub Buis I think your tool post is brilliant! Beautifully done!

Clearly you have thought this through completely.

The 'engineer' in me makes me want to make a suggestion - in no way critical of your fine achievement - if you don't mind.

Your changeover can be made even faster if you put a third stud to eliminate the need for rotating the top plate. In that way you are always using the same top plate clamp in the same orientation. It will work well as long as there is only one tool in the tool holder at a time.

I think your suggestion could work. To make sure the top plate rests on 3 points only, the top plate has to be a bit higher (1 mm longer studs that presses the tool) at the tool side. That way, the unused stud is clear from the top plate.
I will try it when making the next tool post.

 

[brino]

@Huub Buis ,

Just when I think I've seen all the tool post options out there (lantern, 4-way, quick-change, Multifix, Norman, Dickson, etc.) you bring something new to the table.

Thanks you for posting and sharing this!

Brian

 

[mickri]

I think that the real deciding issue is do you make your own QCTP or buy any one of the commercial QCTP. Make that decision and go from there. They all have their pluses and minuses. Which is easier to use I think mostly rests on what you get used to.

 

[taiwanluthiers]

I went with the Aloris type CXA tool post. I didn't go with the multifix because I have to buy each individual holders, it's too complicated to machine one yourself.

 

[taiwanluthiers]

I just realized that a 4 way tool post could be dangerous sometimes...

I tried to turn this oversized pawn. I got everything right, and polished. Just as I was about to part the piece off, this happens...



There is another tool inside the 4 way tool post that I did not see at the time, so while I was trying to part the piece off the other tool was quietly cutting into the wood. Then when the tool could no longer cut it, it rips the piece right out of the chuck, taking the parting tool with it, and the insert disappeared.

 

[Dabbler]

That would have happened no matter what tool post you were using.

 

[RJSakowski]

That would have happened no matter what tool post you were using.

Not really. With my QCTP, I can only have one tool holder mounted at a time. I can have a tool holder do double duty br mounting both another tool on the back end but that tool would be facing away from the work.

 

[Dabbler]

Not really.

Ah. I misread the post that the dulling of the tool caused the problem.

In over 40 years of using 4-way tool posts I have not had this problem or anything like it. Properly mounted tools always point away from the work when not in use, so I missed his inference. My bad.

 

[ericc]

I changed my tools to swap them in seconds without compromising the regidity of my lathe. After that I changed my 4 way tool post in a 2 way so I can lock the tool with just one handle.
I will make a decent video of my tool post next year. In the link you find a not complete not edited short video that will show how I do it.
My QCTP

Excellent design! I really like it. It is also pretty forgiving on material and tolerance. I am going to make one or two for my lathe as my extra capacity tool blocks.