Broken Teeth on Firefly Flywheel

Jimbo70

New Forum User
Non-VOC Member
Hi , I have inherited an old firefly. The flywheel has a lot of broken teeth. A friend has offered to make a new flywheel for me. How would you get the magnets out. Perhaps heating the flywheel and what looks like an inner ring may fall out. Any advice would be appreciated.
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vibrac

Well Known and Active Forum User
VOC Member
I think you need more information perhaps the key is in those 3 rivets in each segment a certain level of heat will destroy magnetism as I understand it
 

vibrac

Well Known and Active Forum User
VOC Member
The request was about removing the magnets you cant leave them in if its going to get hot my other thought was perhaps there is a chance of getting new (improved) magnets or making new segments and getting them magnetised I was well impressed when I had a villiers flywheel remagnetised by Villiers services it was a bit like Frankenstein's workshop all buzzing and flashing light bulbs.
 

vibrac

Well Known and Active Forum User
VOC Member
I cant see that removing the magnets is too difficult (unless the photo is not showing some hidden rim or lock) if it is as shown then I would be selecting a suitable drill and giving those countersunk rivets the goodby kiss
 

Jimbo70

New Forum User
Non-VOC Member
The magnets had 2 countersunk screws in each one, going through from front face. Which i have removed. The rivets seem to just hold the magnet plates together. The magnets are constructed as layers of plates. The magnets are v tight in the flywheel. Cant squeeze a fag paper between them.
 

vibrac

Well Known and Active Forum User
VOC Member
If you are sure that that is all the rivets do then it looks like you friend will have to carefully destroy the blocks between the magnets perhaps by incremental milling the magnet plates may interlock with the block but I doubt it. remaking a new flywheel and teeth will be a big job I would make those blocks removable as well on the new drum.
Alternatively looking at the teeth themselves I wonder if a sprocket maker could make you a new sprocket and you turn off the old teeth mount the new sprocket on the drum and selectively weld the tooth ring in place avoiding the magnet area as heat may reduce the magnetic strength.
Whatever it looks like a complex and not a cheap job
 
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