Thanks for the pictures. That helps a lot.
Hmm looks like I might have to cut my boss down I think. If I bored out the bottom hole on the QCTP it would pretty much wipe out that entire threaded portion on the bottom.
Only problem now is I need a tool post in the lathe to machine down the boss but cant because the piece with the boss on it will be in the lathe chuck
Also if I machine the boss down to 16mm to fit inside the QCTP it would be very thin in the walls as the hole in the boss where the original bolt sticks out of is 14mm. So the cast boss would only have 1mm thick walls left ?
I am not real sure what to do now? I didn't want to remove the boss completely as I think it would add a lot of support to the tool post. And I would also like the option of being able to go back to the original tool post if need bee.
Any ideas ?