Actually, the up front cost for the TTS system is fairly low. You need a modified R8 MT collet and one of the ER collet chucks. I modified a Lyndex 3/4" R8 collet in situ in my RF30 mill using s small grinding wheel. The TTS ER20 collet chuck can be found on eBay for less than $20. That gets you to the same point as the spindle mounted collet chuck. The advantage is that the TTS collet chuck can be removed from the spindle and replaced without losing your offset accuracy. Adding more TTS collet chuck increases versatility in that you can have a lineup of tools needed for a particular project. I currently have 30 various collet chucks, end mill holder, drill chucks, etc. but it is definitely not required. Much the sam as having quick change tool holders for the lathe. You can get by with just a couple of different styles. Having more is just a convenience.
