QCTP repeatability

[Huub Buis]

How can a locked 4 way post be quick change? Photos?

I made this video some time ago but had no time to edit it. I think it will give an Idea on how I do it.
You can use a 2 or 4 way tool post. You than can (un)lock the tools by releasing 2 bolts half a turn

 

[martik777]

I have an Aloris BXA wedge. Vertical repeatability is +/- .001 Horizontal is about the same.

My piston offshore AXA with offshore holders repeats +/- .002 horizontal and +/- .001 vertical.


Dorian makes an Aloris - type tool post with 4 holding positions, so it is both 4-way *and* quick change.
You can see it here:

Yikes: about $5,000 in Canada with 2 holders

 

[Dabbler]

Yikes: about $5,000 in Canada with 2 holders

yeah. out of my range. Possibly my big lathe and all its tooling might be worth that much.

 

[mksj]

JBOLT did a comprehensive review on QCTP holders, repeatability and comparison between different holders. The repeatability was 0.0005" worse case, and in many cases much less. This will depend on the type/quality of QCTP holder, as the wedge type are felt to repeat more consistently. I will use several tool offsets, dropping in different holders, I have seen no difference in the diameter cuts that I can detect within a few ten thousandth. I do use a Dorian BXA quick change tool post. Even if your height in your tool post is off by say 0.001" the diameter cut effects will be minimal.

Qctp Holder Review Part 1

I have read a lot of discussions on the pros and cons of QCTP holders from various manufacturers but never a head to head comparison so I collected four of the commonly used BXA-1 holders for review. I have had inexpensive import QCTP's and more recently a new Aloris QCTP . Just from an...

www.hobby-machinist.com

Qctp Holder Review Part 2

I'm still waiting on the steel but I was able to do the aluminum test cuts. The process was use the same insert and insert tool in each of the tool holders. The stick-out of the tool was set to the same dimension for each holder. The material was set to the same 2" stick-out from the jaws of...

www.hobby-machinist.com