use metric gears with inch gears ?
use metric gears with inch gears ?
(OP)
Anyone have experience driving metric #1 module spur gear with a 24DP gear. I can adjust the center distance between the gears.
FYI:
Circular pitch of #1 mod gear is pi mm....(.12368")
Circular pitch of 24dp spur gear is... (.1309)
Thanks for any info.
FYI:
Circular pitch of #1 mod gear is pi mm....(.12368")
Circular pitch of 24dp spur gear is... (.1309)
Thanks for any info.





RE: use metric gears with inch gears ?
In theory, an involute is an involute, and differences in center distance result in a difference in pressure angle. However, if the pitches aren't the same, you don't get continuous contact between sequential sets of teeth. One set of contacting teeth will grab a little too soon or a little too late. This will result in chattering and unusual wear.
That said, I would say don't do it.
RE: use metric gears with inch gears ?
The tooth pitches are close. If you back them off, both gears are no where near their line of action. It should not be any worse than a wheel of toothed pegs. If you don't mind slop, and low efficiency...
--
JHG
RE: use metric gears with inch gears ?
RE: use metric gears with inch gears ?
Occasional / intermittent / light load low speed / gears substantially overdesigned, perhaps you can get away with it.
I know there is a retrofit kit for a motorcycle that I own, to get a lower 1st gear ratio, and they are only changing the driven gear on the output shaft (for one having one tooth more), so there must be some sort of mismatch - and I've heard that the gearbox howls a fair bit in 1st gear when this is done, which is indicative of mismatched tooth profiles. But 1st gear is only used for a brief moment when starting off, and after that, it's just spinning with no appreciable load on it. I have no doubt that if you tried this stunt for top gear, it would not live long.
RE: use metric gears with inch gears ?
If you're talking about "adding a tooth" or "dropping a tooth" on a motorcycle, that refers to the output sprocket that connects to the drive chain. I did it on my motorcycle years ago, and the difference in chain length is near negligible.