A while ago now, I was attempting to rout out some of the wood from a guitar body and then went a little to hard, too long, and got my rotary tool bit stuck in the tool itself.
I let it be for a few months trying not to remember how I had broken a tool... Then one day I looked it up on this brilliant site and found that someone had made a 'structable for the same tool by a different company. I followed it, and adapted my tinkering to my tool, and then I got it all done!
So thank you to my friend wilwrk4tls, and his instructable on how to free a stuck rotary tool bit!
Here is a link to his instructable here: https://www.instructables.com/id/Freeing-a-Black-and-Decker-RTX-or-Dremel-Bit/
Step 1: Getting Inside
At first you have to get inside the tool in order to get at the stuck rotary bit.
To do so on this specific brand tool, you will have to unscrew 6 screws and slowly pry apart the 2 sides of the body.
Be careful not to pull too hard so you don't yank out the switches and cables inside that are attached to the body.
Step 2: Separating the Axle
Once inside, you need to get at the axle, and free it up so you can get a locking wrench around the mounting part.
To do so, you will need to remove the motor from the body and make sure you don't dislodge too many parts as they fit snugly in the body and hold themselves where they are supposed to be.
If you do dislodge them, do not panic and slowly take a step back put everything back in place the way you remembered it.
And, if things don't seem to be fitting where you want them to be... You're most likely wrong.
Step 3: Freeing the Stuck Bit
Now that you have separated the axle from the body and the motor cavity, you can grab your locking wrench, and lock it around the axle.
You can also do this with a pair of pliers, you will just need to maintain a firm hold on your pliers so the axle doesn't spin on itself and make the pliers leave wear marks on the axle.
With your other hand, grab a pair of pliers grab onto the rotary bit holder, and twist either way until the part loosens up. Once loosened, unscrew the part and you should be able to free your bit from the axle.
If not, you will need to loosen the holding part as much as possible, grab onto the rotary bit, and loosen it by rocking it from side to side until it comes loose.
There you go! Your part is now loose!
Step 4: Putting It Back Together
All you have to do now is make sure you didn't loose any parts, and that you remember where everything goes, and that you can in fact apart a rotary tool and completely put it back together.
Basically, you can follow the steps backwards, save for the removal of the bit, and you should be able to put it back together.
Thanks for reading, and happy tinkering!