Router Bits and collet help

Hello all,

Been away from my Maslow CNC for some months now and getting back into the swing of things, IE: update the firmware, ground control, and buying new hardware.

When I first started using my Maslow I had a bunch of problems. Someone suggested switching to single flute bits and that has been the fix. However, I just purchased some 6mm single flute bits thinking they would work in the 1/4" collet but it won’t tighten enough.

I tried to research this and ended up more lost then when I started.

IS there a collet that will work in the Rigid router that will allow me to use these 6mm single flute bits?

Is shimming these bits a bad idea if there is no collet available?


I haven’t tried it, but this one should work.


Since we are running the routers at lowest RPM and feed rates, I’m not sure how relevant something I read with smaller/faster/more RMP cnc-machines is. I will dump it anyway.
For other than Maslow cnc’s the recommendation was to only use reducers as a temporary solution.
I guess it’s not a to big issue if all your stuff is cleaned. Still a collet

has double the slots to clamp your tool ‘straight/not out-of-balance’ than a reducer can do.
The concerns in the article addressed the longevity of the first bearing in the router from bit side.


be very nervous about shimming, if you are even slightly out of balance, the
high power of the router can result in a LOT of vibration and force.

in general, a 1/4" collet (6.35mm) will not clamp down to 6mm

I expect that it’s going to be more expensive to find a collet that will fit the
router and handle metric bits than it would be to just replace the bits.

David Lang



6mm bits are much easier to find and much cheaper then 1/4" bits.
while you are at it you might as well get a reducer to 4mm and 3.175mm as those come in handy

just get a reducer they are less then $5 direct from china and about double that on ebay

as far as shimming, I have tried and it wont’ work. I have used aluminum tape and it works for 5 minutes and then you break a bit or worse. not worth even trying. .

Crap I just bought 12 6mm bits!

$4.39 12.7mm (1/2) to 6mm and 12.7mm to 8mm Amazon