Makita RT0700C collet cone

I have 1/4" router bits but my Makita router RT0700CX2 sold with metric collet (6mm)
At ebay you can find 1/4" collet but for unreasonable price
So I try to make collet by myself
unfortunately unsuccessful because:

1. PLA plastic to weak and collet broke
2. printed parts misaligned inside chuck
3. scad/stl sizes (specialiy for internal size) and sliced model (Slic3r 1.1.7) are mismatch

any way work is done
don`t try to repeat it :)
I find what ER11 collets works good (about 0.1 mm tolerance) and will try for ER16 later

=====Update for MTAM86
single collet with inside diameter exactly 6.0 mm