Helical gear guide / generator

Hello all.

I need to create a heilcal gear for my project.

I’ve tried a few on Youtube but cant get them to work.

Does anyone know of a good guide to follow...or even on online generator where i can input my data and download a stp file?

I found one online generator but it wont accept my data - out of range.

I’m on Creo 11.

Thanks