Design considerations for a worm gear sets using helical gears

[eliehaidar3]

Hello,
I am trying to design a simple worm gear set using a worm and a helical gear, but I couldn't figure out what conditions must be met for the worm and the gear to mesh properly.

The intent of the design is for a tuner device (like those found on guitars for example),it seems very common for guitar tuners to use this particular combination to reduce cost and because the extra inefficiency is not really noticed.

From what I understand they must have the same pitch and the same pressure angle, and the axis of rotation must be at a particular distance and orthogonal to each other.

Is it possible to use a standard ISO metric thread profile for the worm instead of the conventionally used ASME like threads ?

Please excuse my ignorance, I never designed any worm gear train before.

Thank you in advance

[Kelly_Bramble]

See:

https://www.engineersedge.com/calcul...tors_15310.htm

Which is per. industry standard ANSI/AGMA 6034-B92