i hope this post helps someone.
i got tired of swapping out the mt3 tools on my 1720.
i decided to try and upgrade to a collet system.
none of the vendor out there seem to sell a kit.
i ended up winging it
as i so often do.
so i bought an er32 mt3 m12 cheap collet set off of amazon.
i then bought some m12 thread rod and an m12 nut for the drawbar.
i welded the nut to the bar..the nut is an 18mm serrated flange nut.
here are some pics
runout was .0012
no sure if thats good or not..im a novice..