The new anti-backlash timing gears now have 200 quiet miles on them and show no distress. Wish it was warm here so I could do some major miles. James

Could these be developed to mate with a starter motor in the old magneto position, likely to be easier than adapting the primary side.

[quote="comnoz"]The new anti-backlash timing gears now have 200 quiet miles on them and show no distress. Wish it was warm here so I could do some major miles. James

Very nice indeed

Comnoz why is the extra intermediate a three piece gear

Yes, I am working on a gearset to put the starter back on the timing chest. That is what got me involved in this.

The idler gear is three pieces with ramps cut in the sides. Ball bearings fit in the ramps and the three gears are pressed together with a wave spring which causes the teeth to be offset and take up the backlash. This is what keeps the gears from rattling at certain speeds and is why this has turned into more of a project than I expected. James

Yes mate go on I'm waiting for it!
Andy

comnoz wrote:The idler gear is three pieces with ramps cut in the sides. Ball bearings fit in the ramps and the three gears are pressed together with a wave spring which causes the teeth to be offset and take up the backlash. This is what keeps the gears from rattling at certain speeds and is why this has turned into more of a project than I expected. James

Clarifying, thanks. Keep up the good work

Gday Jim, them gears are looking beautiful! Im holding off building my motor to a degree, contemplating those gears? Im not up to speed with the knowledge of gear ramps, is there a good link on the net explaining in more detail the theory? Keep up the excellent work mate, Ive already got your crank vent! Rgds Foxy

The ramps I am speaking of are the 4 pockets cut in the side of each gear. They are slots that are deeper on one end than they are at the other. Then when you put a ball in the pockets and lay another gear with pockets on top of it they roll to the deepest part of the pocket. They are positioned so when the balls are at the deepest part of the pocket the gear teeth are out of line with the gear next to it. Spring tension is applied to hold the gears together and the teeth out of line. This keep pressure on the teeth and prevents them from rattling against one another. James

Thanks for the good explanation James, so the gears line up under load to spread the tooth wear, Mmmm... very clever!
Rgds Foxy

comnoz wrote:The ramps I am speaking of are the 4 pockets cut in the side of each gear. They are slots that are deeper on one end than they are at the other. Then when you put a ball in the pockets and lay another gear with pockets on top of it they roll to the deepest part of the pocket. They are positioned so when the balls are at the deepest part of the pocket the gear teeth are out of line with the gear next to it. Spring tension is applied to hold the gears together and the teeth out of line. This keep pressure on the teeth and prevents them from rattling against one another. James

Would helical gears be quiet? I assume too expensive to produce?

Helical gears will cut down on gear whine but the noise problem I have is caused when the pulsing load of the camshaft makes the gear teeth rattle against one another . Only less clearance will solve that. James

comnoz wrote:Helical gears will cut down on gear whine but the noise problem I have is caused when the pulsing load of the camshaft makes the gear teeth rattle against one another . Only less clearance will solve that. James

So the gear solution you use is similar to how they handle modern bikes with gear drives or do they use something else?

Yes it is pretty common to use a spring loaded segment on timing gears to eliminate rattle. Some bikes use them on the primary drive gears also.

Whew! that took a turn. You've got perseverance that's for sure, nice work!