OzVMX Forum

Clubroom => General Discussion => Topic started by: rough rider on August 24, 2011, 09:55:33 pm

Title: key removal
Post by: rough rider on August 24, 2011, 09:55:33 pm

hi guys , has anyone got any good ideas no how to get a flywheel key out that has sheered off and welded it self in to a crakshaft  ??
any help will be muchly appreciated  :) 

Title: Re: key removal
Post by: LWC82PE on August 24, 2011, 10:19:03 pm

Try and move it with a sharp center punch & a hammer.

Title: Re: key removal
Post by: rough rider on August 24, 2011, 10:53:40 pm

hmm yes tried that wont move , in fact i think that may have spred it a little and wedged it in harder  ::) . think i may have to try and grind it out with a dremal . would heating it help ? seals can easily be removed

Title: Re: key removal
Post by: Frank M on August 24, 2011, 11:23:32 pm

woodruff keys are not hardened. Try to drill in a small hole and cut a thread, so you can grip the mounted screwhead with a self locking plier und punch it out.

Title: Re: key removal
Post by: Gippslander on August 25, 2011, 02:27:34 am

And, you will at some stage before reassembly need to lap in the flywheel so best do that now to remove any buildup along the edge of the key, until you see the clear outline of the key, then you can punch or drill more acurately and drilling with an old hand drill is safer, with a 1/16th drill bit and a hand drill you should be able to "swiss cheese" the key so it collapses especially if you have a fine punch to help it along.

Title: Re: key removal
Post by: pancho on August 25, 2011, 08:35:34 am

 Also, Iwould clean up the inside of the taper on the flywheel, by making a mandrel the same taper as the c/shaft.
 Then lap the flywheel to the mandrel cleaning up any high spots and ridges before lapping the flywheel to the c/shaft.
 cheers pancho.

Title: Re: key removal
Post by: TooFastTim on August 25, 2011, 09:59:56 am

Quote from: rough rider on August 24, 2011, 10:53:40 pm

would heating it help ?

I'd be careful there, you could end up tempering the crankshaft.

Title: Re: key removal
Post by: Slakewell on August 25, 2011, 10:23:02 am

In my younger days when my eye sight was better I have carefully Tig welded the key enough so you can get vice grips onto it.

Title: Re: key removal
Post by: rough rider on August 26, 2011, 08:01:41 am

well still no luck , looks like i will be splitting the motor and fitting a spare crank i have  ::) good job to be doing 2 weeks before the nats !

Title: Re: key removal
Post by: Mike52 on August 26, 2011, 08:23:33 am

You can remove a small area of the crank around the key if it's sorta welded to the crank on that outside lip.
Could also try the dremmel with a cutoff wheel in it and cut the centre of the key longways.

Title: Re: key removal
Post by: rough rider on August 26, 2011, 10:55:55 am

thanks mate , have tried the dremel but cant get it in there straight enough to cut it

Title: Re: key removal
Post by: Slakewell on August 26, 2011, 11:43:13 am

If your desperate one way is to use a mig welder.  carefully coat the crank in mig paste ( anti splatter paste ) making sure to get none on the key.
As the crank is thick steel and the key thin steel carefully give one zap then use vice grips to remove.