Kress ATC

[Jonathan]

next time
, give it a try in a furnace of some description, and dont forget, bright red first time and blue the next and im sure you will be very pleased with the results..

Rick

I've done it before and been pleased with the results - I think this was just a funny grade of steel. The fire was plenty hot enough to get the pieces bright red.

[m_c]

My idea uses a similar set-up to the rapid changer for locking, however doesn't use a constant taper. It uses a small taper to maximise locking force at the locking point, but to avoid needing an excessively long taper, the taper changes into a recess to allow the ball to drop away for release clearance.
Then to avoid needing as much force to ensure a good release, you have a set of balls above the pull stud that are pushed by one moving taper, into another stationary taper to force the holder down.

The tapers are designed such that the release taper doesn't contact the release balls until the locking ball taper has moved away from the balls. Sketches show it would need a taller pull stud than normal to allow room for the two tapers. I'll tidy up my sketches later and scan them in. I'd put them in CAD, but I'll probably not use that option, and I still need to build a router!

Personally, I think a scaled down INT/CAT/BT ATC would be a better option. Mount it to the side of whatever motor you have, and drive it by a belt/gears. It would increase weight a good bit, but you'd have a tried and tested system, with lots of clamping force, and less balancing problems.

[i2i]

one of these to add to the end of an existing R8 or int 30 spindle would be worth making. With a smaller toolholder it could be made to fit inside a fair bit of the existing taper and use the collar as the ejecting face.

[m_c]

My idea sketch is attached. Red hatched bit slides, blue hatched bit is the holder.

Some issues I can think of (in no particular order)-
*)If going for the full ATC route, due to the spring travel needed, a small air cylinder might not be able to provide enough force to release the holder. Could be solved by using a larger diameter, however at what point does diameter become an issue? Alternative, although more bulky option would be an external cylinder with lever mechanism (this would eliminate issue of needing rotating air seals)
*) Lots of bits would need hardened, ground and polished.


Attachment 6954



i2i, if you've got a spindle with a drawbar, there are plenty of ATC options about. Having a hole through the spindle opens up lots of options.