HELP - Dismantling older Dremel flex shaft tool

Hello,
I have an older style Dremel flex shaft tool (model 255-T2) as per the stock pictures.
Attachment 44834
The issue is that the flex shaft "core" appears to be intact and with its square ends all OK. but under speed or load the collet chuck end will not turn. This leads me to think the engagement inside the "pen" bit is damaged.

The spring slides off with a little force, but the flex shaft outer is crimped to the back of the 1/2" OD barrel.
Attachment 44835
Does anyone know how to open one of these type tools up for repair?
Any other checks you can recommend before potentially permanent damage?

these style are great for narrow areas, and the 1/2" diameter means I can mount it easily in a tool post. I really want to keep this operable if possible.

Thanks,
Des

I can understand wanting to fix it but if you can’t then buy a new one.

Look on the other end and see if there is a small internal snap ring you can remove. If there is you may be able to pull the shaft out from that end.
My flex shaft is also an older one, but it has a 1/4" drill chuck.
You might look real close at the pen and see if you can spot a joint right next to 1 of the knurling's it could be threaded together. If there are no snap rings or machined connections trying to de-swedge the housing from the pen is probably going to destroy it, But if you have a way to slice the swedge open neatly, you may be able to insert a flat screwdriver and spread it enough to slide the pen out then tig weld the cut repair what ever is broken on the inside and put it back together and re swedge it.

Quote:

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Originally Posted by Frank S

Look on the other end and see if there is a small internal snap ring you can remove. If there is you may be able to pull the shaft out from that end.
My flex shaft is also an older one, but it has a 1/4" drill chuck.
You might look real close at the pen and see if you can spot a joint right next to 1 of the knurling's it could be threaded together. If there are no snap rings or machined connections trying to de-swedge the housing from the pen is probably going to destroy it, But if you have a way to slice the swedge open neatly, you may be able to insert a flat screwdriver and spread it enough to slide the pen out then tig weld the cut repair what ever is broken on the inside and put it back together and re swedge it.

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Thanks Frank!! - I'll have a look when I get back in the shed - Mine has a tiny chuck screwed on where the collet closer would normally sit, so I'll take that off and have a good look for a snap ring.
Cutting the swage/crimp is my last resort - I reached out to the forum in the hope it won't come to that. if it does, I'm not liking my odds of returning it back to service "nicely".

thanks,
Des