Fly Wheel lightening ?

[Varastorm]

Been busy today & cut another flywheel, it was the VTR one I had with the crank that I cut for the mandrel.

I used a new bolt for the centre & used the dimensions given on the first page of the thread as a guide





The gauntlet has been thrown

[lloydie]

When you fit that it will spin up super fast !!!

[Varastorm]

When you fit that it will spin up super fast !!!

I was hoping to beat Carl's light one but it was a bit of a fluke to be honest, as once it (the flywheel) has been removed it would of required an new bolt to centre & I ain't got one.

Has anyone ripped one apart just to see how thick the magnet basket is or do we keep going until someone loses a foot?

Just hope its not gona be me

Big thanks to my mate for letting me use his machine, top bloke

[lloydie]

The pic I posted of Benny's fly wheel was the limit as Benny scrapped a few to find out

[Varastorm]

I had turned it to 136mm⌀ as Benny's/your diagram advises, but then emery clothed & scotch padded the finish.

That process took 0.2mm off again, which is only 0.1mm off the radius... oops.

The bowl now measures 135.8mm⌀ & the flywheel weight is down to 114.8mm⌀.

I would just like to know what the original basket thickness is before I fit it

[lloydie]

Drill one to find out

[Varastorm]

Drill one to find out

I am out of VTR ones now....

Any one got a knackered one spare & would like to share the info??

[VTRDark]

Only another 4.4 gms to go

(:-})

[fabiostar]

rite just so i got this in my head one last time..... do you strip the weight of the back or the basket and cut them down as separates and bolt them back together again?

[Varastorm]

rite just so i got this in my head one last time..... do you strip the weight of the back or the basket and cut them down as separates and bolt them back together again?

No, leave the rivets well alone

I cut it as one piece, taking care not to cut into the back of the magnet bowl.

I cut the tail off the crank with a 9" grinder, trying to keep as much of the main as possible. Then tighten the chuck on the main bearing.

I then place the DTI gauge on the crank tail section just after the fat end of the keyway (not the sprag section). spin & tap till the DTI gauge shows "0" runout. This requires patience, but is possible.

Once the crank is running true place the flywheel on the taper & nip up the bolt. Place the DTI gauge on the weight section & spin by hand again making sure the gauge still has "0" run out.

If the gauge still shows "0" run out, I then centre drill the bolt, & wind in the live centre in to support the crank tail & stop harmonics.

I then cut away 0.3mm at a time till I reach the desired diameter. Once I am close to the required size, I tidy it up with small cuts & emery paper/scotch pad smooth.

When the Varadero flywheel was clocked with the DTI gauge the weight was true but the basket was out slightly (0.2mm), so I never touched the basket.

With the Vtr flywheel the weight & the basket were running true so I cut the basket also

[fabiostar]

happy days that has explained it.. cheers sir..

without using the end of an old crank have you or anybody turned down a flywheel holding it any other way? can it be held say using the chuck jews on the inside as in the magnets?

[Varastorm]

without using the end of an old crank have you or anybody turned down a flywheel holding it any other way? can it be held say using the chuck jews on the inside as in the magnets?

I asked similar questions & was warned not to

If you were to hold it with the basket, you would have to use a 4 jaw chuck & DTI the weight section to "0" run out then cut it

It might be okay? It would have to be your call though.

[fabiostar]

ay i was a bit worried about that. i had mine to an enineering shop and thats how he wanted to do it so decided not to use there services...

[E.Marquez]

Yes the basket was out but i skimmed that up as part of the job anyway to make sure it wasn't a problem when removing any balancing holes..

Same thing here, basket is always out of true.. I skim all of them now, or take down a bit depending on what is wanted for a final weight.

Of note.. I found that using a crankshaft snout as a mandril and a bolt to tighten and as a place for the live center was problematic,, The bolt is not designed to be center to the axis of the crank,, it's close, but not great,, so reusing a bolt and the countersink hole for the live center produced an off center setup.

The fix was a completely new flywheel mounting system

[8541Hawk]

without using the end of an old crank have you or anybody turned down a flywheel holding it any other way? can it be held say using the chuck jews on the inside as in the magnets?

I asked similar questions & was warned not to

If you were to hold it with the basket, you would have to use a 4 jaw chuck & DTI the weight section to "0" run out then cut it

It might be okay? It would have to be your call though.

That is how I cut mine...... using a "Buch Chuck" then adj for "0" run out and you are good to go.
At least that is how I did them.