Quote Originally Posted by Ricardoco View Post
Magic, i do wonder why nobody has made a larger unit for a little more money, say er20 or er32.

I suspect it's got a lot to do with holding force, balance and liability.
Reading the bit in that manual about bearing/seal replacement, states that if the seals have failed that bad that the holder won't release, then you can pull them out by pulling with 220N of force on the holder. With so little force, I doubt they're using a self locking taper (it takes a lot more than that to release even a MT1 taper!), which means they must be relying on friction to transmit drive. Even an INT/BT/CAT taper takes a good bit of force to knock out.
Also with so little holding force, it won't be able to withstand much force before the holder starts to get pulled out when in use, which is probably why that style doesn't exist for larger spindles.

I would like to see one of the ATCs dismantled, to see how the pull stud mechanism works, and how they've sprung it.

Although having seen a close-up of the tool holders pull stud, it's given me an idea on something that may work in a compact format while still providing a high pull out force...