A QCTP question, or two

I mentioned earlier that I had bought a pack of 5 Soba holders from Chronos currently on offer quite cheap. I had only tried one so checked the others. All are 'tight' compared tot the old ones but one perversely only goes onto the boring tool position of the block and jams on the other side. Haven't worked out quite why but it shows there may be differences between the two clamping slugs. Must now do some measuring as per Phil's operation.

Hi Bazyle,

Well, well...

I was going to order a pack of 5 myself, fully expecting to fettle them as described above, looks like the linisher set-up will get some more use.

The 2 Soba holders I have (from a different source) are very well finished apart from a little edge breaking required on the tool slot.

Let me know how you get on - on my tool-post (Bison T00a) the difference between no clamp/tight as you describe, and nicely clamped is about 0.035 inch difference in the depth of the slot. Someone mentioned that a tolerance of 0.005 inch would be acceptable around a mean value for the tool-post. One holder which differs by 0.007 from the Bison clamps up very well, so I have left that be. Note: all my additional holders, except the one mentioned above, needed metal removed, I found none too loose.

I simply compared a well fitting holder (Bison original) to each clone holder to establish what had to be removed to make it fit.

Regards

Phil

Edited By CotswoldsPhil on 30/12/2015 14:05:50

A final bit of information (for those not bored silly) about the dimensions of the Bison QCTP and compatible holders.

I decided (for reasons unknown) to rest an original Bison holder on 6 mm bars (instead of 1/4 inch as previous) to locate the bottom (working-face) of the t-slot relative to the V's. Working in metric, to my surprise, I got exactly 3.00 mm; is this a coincidence or designed?

Phil