Need help calculating spur gears

[gharryh]

I need to go between 7.7 degree station using a 0.9 degrees stepper motor.
This meens a 300:1 gearbox.

Now i need to calculate this using small spur gears from 12-80 theeth.

Is the a website that has a calculator online to calculate the correct gears to use or a simple calculater somewhere else?

[RICHARD ZASTROW]

Try to "google" Gearotic Motion . Might be helpful.

Dick Z

[gharryh]

After downloading the package i got a vires message from my scanner.
But i found a better one here:


But now i have a mental block.
Using the above calculator i came up with a three stages gearbox.
The first gearset being 32:80, the second 48:80 and the third and last 40:80.
But now i need to know how many steps the stepper must make to turn the last gear once.

Any input would be helpful

p.s. the 7.7 in my first post should be 7.5