That would bring it to 2.5CM per revolution, so right in the sweet spot for plasma when using steppers as you can still achieve decent velocities for rapids. Even 1:3 will do just fine, there are some very cheap ones using T2 belt and 20:60 pulleys on ebay, seller is "ideaformer", i got 6 of them from him and some other stuff, he is the only one i never had issues with delays, and almost always provides a valid tracking number. BTW, they are under 5$ per set, if i remember correctly, just be sure to select the inner holes for your needs.
