Viceroy 280 synchro getting hot.

[patrick oates]

i agree with what you say as i have got my old gear cutting books out and using the formulae provided the drawing sizes appear to be correct.i can only suspect that the plastic [delrin] has distorted over time to create a more elongated gear tooth or some previos owner made there own gear causing the 100 thou od difference.the 10 thou shaving of the gear has definetley freed it up somewhat

[patrick oates]

this bvs 100/105 for the lay gear where is it.i have trawled through the sites but cant find it

[Pete.]

It's right here!

[rpwilson]

It's right here!

Yes, thats the final version, incorporating the reductions in OD, PCD and width, following problems with binding.

[patrick oates]

many thanks for the diagrams.i think i am going to make one

[patrick oates]

the problem is definetley caused by by the technyl distorting over the years.only this can account for the expanded o. d. i have found on both gears.i have reduced both and this has helped will probably need to make new ones though

[rpwilson]

the problem is definetley caused by by the technyl distorting over the years.only this can account for the expanded o. d. i have found on both gears.i have reduced both and this has helped will probably need to make new ones though

Its still a bit odd. I wouldn't have expected the gear to grow by 100 thou, were they both like that? That much oversize, how could they possibly mesh with the steel gears?

[Pete.]

When they are cold they mesh fine. When hot you can barely move the handle on the front.

[patrick oates]

just to give an end to this,it was indeed the expansion of the technyl material.i took the layshaft gear out and using a friends milling machine and dividing head I shaved the gear down using a flycutter,a bit slow but it appears to have done the trick,so far it been working fine.i did have to shave agood bit off using drawings previously supplied

[Pete.]

Patrick,

That's for the follow-up. It will probably help someone in the future.

Pete.