ATD

[rgsjohn]

Just removed the magneto from my A10 to have it refurbished. I noticed one of the fibre gear teeth was chipped so I'm seeking advice. Go with a new fibre gear or opt for an ally one. I'm leaning towards ally because fibre gear failure appears to be a relatively common occurance. Personal experiences anyone?

[Rex]

Never had any problems with the fibre gears personally, but go for the alloy one as it will give you an extra 10mph on the top speed.

[iansoady]

The fibre ones do occasionally shed teeth. I did read that their advantage over alloy ones was that they would act sacrificially in the case of the mag seizing. No, I've never heard of that either......

[rgsjohn]

Rex, Lol! well that's convinced me ally it is. That is an irresistable argument

[rgsjohn]

Ian, no I have never heard of a mag seizing either, but I am worried by the fact that repro fibre gears have an iffy reputation in some quarters.

[chaterlea25]

Hi All
I have seen the old shellac insulated magnetos "seize"  when the insulation runs out of the winding's when hot then solidifies into a "glue" as it cools


John

[iansoady]

Ah, that's maybe where the story comes from.

[R]

The name of that disease is 'shellacticus'.

Them being insulated with shellac.
When it degrades and turns to mush, you have a problem.

[john.k]

The fibre gears are also used  to transmit heavy loads without noise......quite common on some electric motor drives in largish horsepowers.........also use in lathes and drill presses to reduce noise from meshing gears..........which would be why they are used in mag drives ,to cut noise.......Only time I see them stripped is when large spanners are applied to mag drive nuts.......They are however notably abrasive ,and will wear contacting steel gears,unless the steel is very hard.......Ally used for cheapness,the fibre is very costly.........The large ally idler gear in the Vin. cam drive was notorious for shedding teeth.