I have a Dremel 300, i think, lol.. standard Dremel... To losten the collet nut, you have to press down a button that locks the spindle so you can loosen it.. the spring and *** have stipped and it won't stay locked to be able to loosen the collet... Can I buy those 2 pieces?

Perhaps the best thing to do is get a second dermal tool with the appropriate size nut. I saw where Harbor Freight had kits for as low as ten dollars.

These can get a little tight. Try a little WD40 on it. Hold little button to lock in place and use the wrench provided to unscrew it.

it is possible that you stripped lock mechanism on the collet, for the beginning, never, ever, use wrench to tighten the collet! just hand tied, if it slips, tight it bit more, but with hands only.

i never used wrench on the collet and never have any trouble with any of my dremels.

to close, just hold firmly in one hand pressing locket button, tighten up with other hand, to undo, reverse procedure.

if you find bit is too lose, then you have collet inserts, find that one which hold bit firmly and use it on this particular bit. standard collet is 1/8" (3.175mm), but in the set there are collets from 0.0394'' (1mm) to 0.177" (4.5mm). do not use wrench...

just inspect now if thread is not stripped, on spindle and on collar, if locket still hold, if these are damaged, you need to change damaged part. and follow the advice :-)

if you find this advice useful, pleasae do not hesitate leave your remark and vote4 for me, thanx!

The "nub" on the shaft lock assembly (internal) has worn down and the assembly needs to be replaced.

If you feel competent to open your Dremel yourself (and it's not on warranty) then order the shaft lock assembly from Dremel (early 2011 price: $1.25, not sure how much postage & handling might be). After opening the tool you will find a metal ring and a small piece (the lock) which it holds in place around the shaft where the lock button is located. Remove the old pieces and replace with the new ones and reassemble the tool.

Otherwise you can send the tool to Dremel to be fixed.

the collet is either the wrong size for the shaft on the attachment or is missing alltogether

remove all the star head screws, unscrew the top plastic collet holding the plastic outer casing on. take a pair of vise grip locking pliers open the plastic casing just enough to expose the inner shaft inside the casing lock the vice grips onto the metal shaft between the bearing casing and the collet that is stuck enough to hold but not to dent it up. now that the vice grips are locked onto the main shaft get an adjustable wrench and size it to the collet screw size and turn it should come off rather easily or at least mine did just did it as i wrote this then screw the casing back together and happy dremeling hope this helps

You didn't state the model number. The older Craftsmen routers had a red lever lock on the top of the router, one position allows the spindle to turn, the other position locks the spindle. Here's the instruction for the older style routers:

1. Unplug the tool.
2. To lock the spindle press the red button in and slide it to the locked position.
3. Unlock the height adjustment knob.
4. Raise the router motor using the height adjustment collar until you can get a wrench onto the collet nut.
5. Loosen the nut until it turns freely.
6. The bit may still be locked in the spindle, tap it gently (not on the blade!).
7. The bit will come loose in the spindle and can be removed.
8. Replace the bit, tighten the nut snug but don't use excessive force.
9. Unlock the spindle, returning the red lever/button to the free position.
10. Adjust the height of the bit as you wish, then lock down the motor using the locking knob.

Trying to fix a similar issue. The pin that gets pushed in by the button (and returned by the spring) seems to be fine. The hole in the rotating shaft that the pin fits into, however, is in the wrong place, so the pin never goes into the hole! All I need to do is somehow pull the whole front part of the shaft out about 1/16th of an inch, and it'd be fine. I just can't seem to budge it though. Any tricks, anyone?

Looking down on the collet end of the dremel, push red button and take pliers and turn locking nut in a counter-clockwise direction.

Unplug it, then while pushing in the little silver button near the head use a wrench on the hex nut and turn counter clockwise about a 1/2 turn. Push the bit in, then pull it out (that releases the little fingers that hold it).

The silver button locks the head so it won't spin while you are changing bits. Always be sure it is released before plugging in or turning on the power.