Hello..

My router have 6mm and 8mm collet. That's fine. But for drilling PCB (on old cnc I use dremel) I need 1/8 collet. So I grab some stell piece and put into the lathe. After aprox 20 minutes I have brand new 1/8 collet. As I don't have reamer the hole is just drilled with 3.2mm drill bit, and as I don't have slitting saw (I use hacksaw) I just wonder how much runout that thing have. So I put dial indicator to contact shank and I turned by hand spindle. ... ... The nedle on dial indicator does move It indicates 0.05mm TIR (0.002") Not so bad. But near unusable. After that "just for sake" I put original 6mm collet into spindle and measure that. (nuts) There was 0.1mm TIR!! (0.004") So I checkt 8mm too.. Litlle better than mine 0.04mm TIR. So all collet are crap! I'm just litle checking and investigate and found that 8mm (and probably other too) collet have different TIR if I lose and little turn it inside spindle. So that forward me to think that spindle tapper is bad. But don't have instriment to measure it. I remember one user on this forum (can't remember) have same problem with ruter runout.

Does somebody measure TIR on routers? And how to improve that.

Slavko

p.s.
Photos show all 3 collet's