stragenmitsuko
Well-Known Member
- Joined
- Jan 19, 2016
- Messages
- 327
- Reaction score
- 143
I took apart a bicyle hub with internal gearing hoping to find a ring gear
to possably build an elmer's no5 geared engine .
It did have a ring gear of aproximately the right size and with an even number of teeth .
So that would be ok .
The orbiting gear needs to be half of the ring gear .
Meaning I would need to make a gear with 30 teeth .
No problem there either .
To determine the gear cutter needed , I've measured the planet gears and the sun gear .
They all are OD 17.03 mm(0.670") give or take 0.01mm .
With z=20 that would make a module of 0.774 or a DP of 32.813 .
Does that make any sense at all ?Is my math correct ?
I mean for a module gear it's an impossible number , andI've never even heared of 32.8 or even 33DP .
Could it be the bicyle company 's have their own dedicated gear sizes ?
Pat
to possably build an elmer's no5 geared engine .
It did have a ring gear of aproximately the right size and with an even number of teeth .
So that would be ok .
The orbiting gear needs to be half of the ring gear .
Meaning I would need to make a gear with 30 teeth .
No problem there either .
To determine the gear cutter needed , I've measured the planet gears and the sun gear .
They all are OD 17.03 mm(0.670") give or take 0.01mm .
With z=20 that would make a module of 0.774 or a DP of 32.813 .
Does that make any sense at all ?Is my math correct ?
I mean for a module gear it's an impossible number , andI've never even heared of 32.8 or even 33DP .
Could it be the bicyle company 's have their own dedicated gear sizes ?
Pat