Bad Collet ??? - Solved

Don Baer

Moderator
Staff member
I been having problems with the 1/4 collet. I mill for a few inches and all of a sudden the bit start to come out of the spindle. No matter how tight I get the Nut. This is what I think is the problem.
20200514_113926.jpg
When I stop the spindle the collet nut is loose and the Nut and the bit are very hot. I noticed the collect looks like it's been rubbing this collet is a bout a month old and hasn't seen much use so do I need to order a new one or should I be looking at something else.
 
Last edited:
I think I would be looking for a bur inside the shaft of the router. Is this the only one you are having problems with if so then replace this one
I check the inside all the time and make sure it clean. I don't seem to have problems with the 1/8 and 1/2 inch. This is the original collet that came with the spindle and is Chinese. I am thinking I'll order a new collet and a New Nut just to be safe.
 
I have a couple ideas. First and the least likely, is the bit inserted to the correct depth? I have experienced something like what you describe and it turned out I was not gripping enough of the bit.

Secondly, is the bit bent? I have bent a bit shaft in the past and it was not visibly noticeable but it sure ruined the bit's performance. It was hard to detect until I tried a different bit. Then it was obvious something was wrong. Close examination showed a slight bend it the shaft. I guess I was too heavy handed.
 
I have a couple ideas. First and the least likely, is the bit inserted to the correct depth? I have experienced something like what you describe and it turned out I was not gripping enough of the bit.

Secondly, is the bit bent? I have bent a bit shaft in the past and it was not visibly noticeable but it sure ruined the bit's performance. It was hard to detect until I tried a different bit. Then it was obvious something was wrong. Close examination showed a slight bend it the shaft. I guess I was too heavy handed.

this happened with 4 different bits 2 of them were brand new.

yes, actually there is a stop inside the collet that stops you from inserting it when it is at the correct depth.

Another idea, are you putting the bit too far in, as in bottoming it? Make sure the bit isn’t touching the base, have it a little off the bottom a little.
See second answer above.

I think I found it. There is a little groove deep inside the nut that can collect saw dust and it was caked into this groove. Apparently you just can't bang the nut on the table and blow it out between tool changes. I had to use a little tiny allen wrench in order to clean it out.... live and learn....

I was able to make several cuts without any problems.

Oh well it looks like a have a spare collect and Nut on the way.
 
Normally, the nut snaps onto the groove in the collet and stays with the collet. Some even have a snap ring to keep the nut attached to the collet. When you loosen the collet nut, you should then need to turn the nut another half to full turn and then use the wrench the second time. This second time pulls the collet and it's installed bit out of the tapered hole in the shaft and the bit becomes easy to change at that point. Since you showed only the collet, I'm wondering if you are using the nut without it being seated in the groove on the collet. They will only snap together when out of the router and on the bench. They should then stay together from then on. They do not snap together in the router, but do cause problems with getting the bit and collet out of the router if the collet decides to stick in the router shaft. You will have a pretty rough time getting the bit and collet out of the router if this happens.

Charley
 
I had the same experience, was mostly trying to figure out how to get the collet out of the spindle after the threaded ring came off. Saw this and had that duh moment...

 
Agree with Charlie on the ER collet and nut.

Make sure you install the collet into the nut like the vid from Darren.

Never clamp on the flutes, but get collet as close to the flutes as possible.

Not like a Bridgeport collet.

Keep the nut and collet and spindle clean.

In the machine shop I last worked in the best machinist would Safety clean degreaser then run all his tools through the industrial wash tanks when he finished a job. He put away all his tools (cutters, collets, nuts, tool blocks) very clean and dry.
 
Another thing that I do now, thanks to Marc Sommerfeld, is to place a rubber grommet or "O" Ring in the router shaft below the collet. This provides a soft cushion to keep you from inserting the bit too far. You can bottom out the bit shaft against this cushion, tighten the collet, and not have to worry about the bit being too far in or out of the collet. If bottomed out against the hard stop, sometimes the collet won't tighten enough, allowing the bit to move out during use. It's a cheap fix to add the grommet or "O" Ring too. Just find one that slides into the router shaft with enough friction to stay there, and then re-install the collet.

If you use guide bushings and have trouble with the bushing nut loosening due to vibration, Peachtree sells wave washers (they call them "guide bushing wave lock washers") that you can put under the guide bushing nut. This keeps the nut from loosening during use. https://www.ptreeusa.com/rtr_bushing.htm Item 2903 (down the page) $5.99 for 2 pack plus shipping. Since I began using one of these, I have never had a bushing loosen while in use.

Charley
 
Top