How far out can a bit go?

Is there a certain distance a bit should protrude from the collet? Inventable bits have the little collar but I’ve purchased ones that have a longer overall length and longer cut.
My main query for this is if I have it too far in, the router will hit the dust shoe. If it’s too far out I’m sure there’s some lateral equation which means it could snap high up.


Here is a video on the subject from Mark Linsday

I must say however that I leave just a bit more bit sticking out than he recommends because I dont want to touch material with the collet on some cuts where there is a lip I might touch.

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Pretty good video.
The v bit depth is interesting, I put the bit as far in as possible (don’t know why) and this may explain why some lettering isnt carved that smooth.

It looks like I’ve been fixing the bit too low down, I’ll try and squeeze it up slightly. It does make it tricky when cutting 10mm (1/64 of an inch) deep and the dust shoe getting in the way.

Many years ago, I was taught by a guy I apprenticed under to insert the bit until it bottomed out, then pull it back up a 1/4" and tighten down the collett. I have never had a bit snap or chatter (unless I was pushing through too fast etc.) ever and I just assumed this was why. He swore that was the perfect depth to have it into the router. Of course, this is in regards to using the router as you normally would - not mounted in a CNC machine. YMMV.

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You put it in as far as it will go without bottoming out and or clamping on the flutes.

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