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1/4" collett pulling out of router

2592 Views 4 Replies 3 Participants Last post by  Ausie
Hi. I am new to the forum and having conducted unsuccessful searches have decided to place my question here. I have a Triton 1/2" router with a 1/4" collett. On a number of occasions I have had either the whole 1/4" collett pull out of the router, or have had the cutter pull out of the 1/4" collett. The router at the time is being used on hardwood at the highest or second highest speed. Has occurred with both dovetail and straight cutters. Any ideas?
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Couple of things you should check:
Cleanliness of collets- any debris or burrs could prevent you from tightening down evenly on your bit or collets.

Diameter of bits- some lower cost bits have undersized shanks that are smaller diameters than 1/4 inch. These can prevent collets from tightening properly because they can't go that small.

Use two wrenches to tighten- I always feel more secure tightening a bit with two wrenches (if it is an option) than the spindle lock.

Don't bottom out your bits- Leave a little gap under your bits when tightening them down so the collet and bits can be pulled into the spindle and compressed.

Broken collet- After a few years with my first Porter Cable router, the collet developed a crack and lost its usefullness. Less than $10 to replace.

Don't rule out a manufacturer defect- If you try everything else, contact the manufacturer. Quality manufacturers should be more than happy to help you out.

***SAFETY FIRST*** if you are using that router in a table- when a bit comes loose it comes up out of a table. NEVER put your hand over the path of a bit when plowing a groove or dado.

Just a couple of thoughts, hope they help!
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With a micrometer measure the outside diameter of the bushing with a 1/4" shank in the bushing. The diameter should be .500 anything under will not be held evenly in the 1/2" router collet. The same is true for the 1/4" I.D. of the bushing (.251) I.D. It can be checked by useing guage pins in .001 increments.
The router collet I.D. should check out at about .501. A collets holding and runout are effected by the fit of the parts used.
Thanks for the replies. Both the 1/2" and 1/4" colletts are new. Replaced about a week ago to try and resolve the problem. At least they were replaced under warranty. won't be able to check the measurements until tomorrow. Will keep you informed.

I have just measured the shank on two 1/4" CMT cutters. They each measured 0.2485" diameter. The inside diameter of the 1/4" collet is 0.245" while the outside is 0.4985. The inside diameter of the 1/2" collett is 0.490 and when tightened up this closes to 0.481". More than enough to clamp the 1/4" collet. To tighten the 1/2" collet to 0.481" I really had to apply some pressure. I am starting to wonder if I have not been applying enough pressure. I was always lead to believe that one should just "snug" the collet around the shank. I will have to wait until the weekend to do some more tests. Will post the results.
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