Disaster Broken mandrel?

I was cutting a hole in the back panel of a case today, and was just finishing one side of the cut, when the reinforced wheel got stuck, and the mandrel screw sheared off. I mean, the damn screw head just fell off, and lay there on what I was working on... the disk was stuck in an upright position, and my dremel was in my hand. Weirdest thing I've ever seen. Plenty of broken disks before, but the mandrel?

 

It can happen rather easily, the inside hole of the disk gets wollowed (sp?) out and starts to "cut" the screw. i have had two mandrels break on me :/

 

WTF is a mandrel?

 

It's the metal piece that you screw a disk onto, that goes into the chuck .

 

This is a mandrel

The internet is a hive of information

 

Well, on the subject of mandrels, last time i came to use my dremel (to mod my case to fit the nice 38mm thick panaflo fan into the back) I noticed the cut wasnt quite right, something a bit off. Took the disc off the work and looked at it for a second, it wasnt just rotating around its axis. Bloody mandrel was bent! Im amazed that the disc didnt shatter as soon as I put it to the work. I love these fans btw, Panaflo M1A's from Dorothy Bradbury. Awesome.

 

WOW that looks a super intresting thing to start a thread on !!1

 

never heard of one of those breaking!

btw do dremels have any sort of warranty.. mines just stopped working.. no reason and checked fuses.

 

chech the brushes

 

how would i go about doing that :S

 

i had that a cople of times. 2 times the disk stood stil and the rest keep on turning and the litle scruw flown off. and onse i had the disk flown away in cluding the scruw. it was nice in bedid in the table not far wer i was standing lol. perents wernd to hapy a bout it but it was kinda funy. thinking back to it

 

it should be those 2 big screw type things on the side.

 

Mandrels break or bend because people apply too much pressure; unless of course there is a design fault.

Always use sharp tools, so that the tool can do the cutting with little feed pressure, then you will suffer less mandrel faults. Finally, always ensure the rotating tool is in contact with the material being cut, ground or polished before you engage high revs, because by not doing so you may cause the mandrel to bend. These are the two main causes of this problem associated with the untrained.

Better luck next time,
Touchwood

 

I have found that often the reason for mandrels failing is either not tightening them down all the way and the disk spinning and cutting the mandrel. Or they just break from applying too much force. I have borken many dremels this way. And not just the bits a couple of units as well. So make sure your disks are tightened down

 

I've had a mandrill that the threads went on. Just used superglue to glue the screw and disk on. Worked fine and it was easy enough to change disks and do it again.

see here: http://en.wikipedia.org/wiki/Mandrill

 

Hope this doesn't happen to me, i've just ordered a multipro and i'm kind of skint at the moment! (£280 for my college course and girlfriends birthday present!)

 

You want to mod a monkey?!!

 

I think he means MANDREL. http://en.wikipedia.org/wiki/Mandrel
Lol at that, though. I've broken many cutting disks, and one electric saw, but no mandrels. Almost broke the Dremel in half when making cabinet handles, though.

 

this isn't that big of an issue. that part of the multi tool is cheap and doesn't really fail unless it is just majorly mistreated or used enough to acually wear it out.

 

I've never broken one *touch wood*, but they cost all of a dollar or so to replace. I've probably got at least five sitting around from getting extra wheels and a cutting kit.