hi, my name's drew, i'm 19 and this is my first post on this forum. I plan to start college for mechanical engineering in fall but i have a project i'm working on that i want to be able to finish, well, in less than 4 years time see, i also study martial arts, and for awhile now i've had this idea for a training tool that actually hit back, but just recently found myself sitting down & actually figuring out the mechanics of such a machine, partly due to a newly acquired & extremely boring job now i have all the gears & all that figured out, but for this project i decided to use an electric motor rather than gas powered like all my other projects, mainly because gas prices are ridiculous now & i wanna be able to just turn it on & go for as long as i please, not as long as i can afford So far i've run into a couple problems. First of all, electric motors are more expensive so my usual "get as much hp as i can for under $150" is out the window, i can't just pull a motor off an old motorcycle & have more hp than i'll ever need for this project, so i have to be pretty precise. I'll have one main horizontal gear running 2 side vertical gears, and the side gears need to be able to turn about 160 rpm max. For cost & conveniance all the gears will be mostly made of wood, but the side gears are going to be about 2 feet in diameter, and for overall size reasons, i don't want the horizontal gear to be much bigger than that, if at all bigger than that. So, while i'll be using bearings to cut down on resistance, i still have no idea how much HP i'll need to run it at that rpm. I know to calculate that i'll have to find out how much torque it takes to turn the gears, but i don't know how to calculate that either. The other problem is controlling speed. I'd like to use something like a potentiometer to control the rpm instead of just a switch between lets say 80-120-160 rpm, that way i can gradually increase the rpm, but i don't have expirience in controlling electric motor rpm, so i'd like some advice on that too thanks in advance, and sorry for the long post. Also, If any of you are feeling generous and would like to volunteer to be my indefinate consultant on this project via e-mail or something like that i would greatly appreciate it.