One credit unlocks one winding schedule — gauge, turns and capacitor for a stator. Everything else on the site costs nothing, and that is deliberate: if reporting a bench result cost money, nobody would report one, and those reports are the only thing making the engine better.
One job, one payment.
A month of a small shop.
A production line's year.
Unlimited developments for a year.
You see the predicted performance before you pay. If the watts and the speed are not what you want, change the stack and look again — that costs nothing. The annual plan removes the credit entirely; renewing early adds a year to the end rather than restarting it.