Out with the wobbly standard router collet and in with the refined, low TIR
(Total Indicated Runout) ER collet. I know what you're thinking... What is runout?
Have you ever inserted a bit into a drill incorrectly at an angle? That bit would
have an incredibly high runout (wobble agressively). However, the runout that is
important here is not even visible with the naked eye. If there is a significant
runout, then bores will be slightly larger, fine etching grooves will be wider than
expected, tiny end mills will break easily, and the router bearings would wear faster.
Here are collets specially made for the Porter Cable routers so you will have pin-point
accuracy. These collets are rated at 0.0004" TIR Precision Grade. Now, you can have
the precision at a low cost that is typically found in expensive spindles.
Porter Cable and Bosch Collets, Nuts and Kits
Specifications: Steel (SUJ 2), H.R.C. 45-52, surface Roughness: Ra 0.5um, internal
hole by boring machine, and degree of concentricity exceeds the DIN standard. 100%
examined. Pictured accessories are for the Porter Cable router.
Benefits: Low noise operation, longer tool life, more accurate cutting and higher
kerf fidelity, and compatible with carbide microtools.