dremmel collet creep

[project5k]

i have noticed that when i use my dremmel for certain operations, the bits tend to creep in or out of the collet. I'm getting it just as tight as i can but i still have this issue.. I'm just wondering if anyone out there has ever had this problem, and how you fixed it... now that im considering making a mini router, i was thinking that the dremel would work just fine for making small items, engraving, and making my pcb's but im worried that this bit creep issue would cause my effective z height to be changing un controllably... ideas? suggestions?

[ger21]

If yoou get it as tight as you can, and still have the problem, try buying new collets. And use new tools if the shanks have any signs of damage.

[project5k]

i can try that, maby the ones that i was using were more worn that i thought.. ofcourse when i have this problem, im using the dremmel by hand, and im probably loading it far beond its proper abilities..(i tend to be hard on stuff)

[Mr.Chips]

Im woodworking they recommend cleaning the router collet and tool shaft. I think it was with acetone Seems they get buildups of oils and such from handling them causes the same problem.

[widgitmaster]

I would think the problem is in the cap nut that you are tightening over the collet! If it is too long, it will bottom out on the flat surface on top of the spindle thread. Try gringing 1/32 off the end of the cap to see if it is now screwing on further and tightening more!

This could also be contributed by a smaller than 1/8" shank on the tool bit, whereas, the collet cap has to move further to close on a smaller diameter!

Hope this helps!
Eric

[project5k]

well, i was just sitting here and had a thought.. what if i chucked the tool shafts up in the lathe and make tiny little rings around it, say maby .001 deep and about the same wide, and about .002 apart.. this might give the collet something to grab hold of...

i checked the collet nut, and its not bottoming out, but that was a good thought...

[widgitmaster]

Instead of turning grooves on a lathe, use the Dremel or hand drill with a large corse stone, and let the lathe turn the stone on the shank of the tool, this will rough it up a bit so it doesn't slip in the collet!!
Eric

[project5k]

i'll have to give that a try

[jphagen]

Used to know a guy that applied fine diamond compound to the bit shank
and collet. The diamond would embed itself in both and really lock tight.
However if it spun in the collet, get a new one!

[project5k]

yea i could imagine that would really eat up the shank...

[gotis]

The guys at the cnc department here are using blackboard chalk on the collets, no idea if it would work on a dremel.

[project5k]

hmm, and i woulda thought that woulda acted like graphite powder and let it slip...