I decided a fair few years back that I wanted to make use of the Tormach TTS system on my Mini Mill.
To that end I purchased a few items from Tormach whilst I was in the USA on holiday back in 2014, including the R8 TTS adapter collet (part #50568).
At the time this was $23.75 (£15.00), although it appears to have nearly doubled in price in the last 6 years and is now $39.95 (£26.00).
Novakon now also sell an ATC/QTC R8 collet for a much friendlier price of $12.00 (£7.70).
Tormach also make a MT3 taper version of this collet the TTS Collet MT3 (part #30251) listed at $31.95 (£21.00) at present.
The R8 TTS adapter collet is basically a 3/4″ R8 collet that has had the nose shortened slightly so that it sticks out less from the spindle.
Any quick change tooling system needs to be able to release and secure a tool quickly, and not all tapers are suitable for this.
Morse tapers are too shallow a taper to release easily for fast tool changes and are prone to sticking which is why the R8 system was developed, although even this system is less than ideal for a tool changer, which is why most automated mills use quite sharp tapers such as BT or ISO with pull studs on the top.
The TTS system relies on the ability of a MT3 or R8 collet, when pushed from the rear of the collet, to relax its hold on a parallel 3/4″ shaft, enough for gravity to drop the tool holder.
The reason I picked the TTS system is because it is an easy retro fit to my Mini Mill that requires no modification (just purchase the appropriate R8 or MT3 adapter) and has decent array of holders available, from Tormach, as well as several aftermarket suppliers at reasonable prices. It is also relatively simple to machine some of your own holders.
One of the upgrades I want to make to my Sieg SX2 Mini Mill is a power drawbar that will make changing tools much faster, this is an upgrade I can make use of with or without the CNC conversion.
The power drawbar design is based on a design by DJ Bird as part of his CNC conversion, plans for his power drawbar are available here.
My version differs slightly as I am not fabricating the air cylinder, since I purchased a new surplus Fabco AA-521-X 1/4″ stroke air cylinder on Ebay back in 2014 for $14.66 with $23.88 shipping and import duty (about £25.00), these retail for around $85.00 (£55.00).
Here is the power drawbar modelled in Fusion 360
and a section through the middle
