This is not a usual thing to do, but I will try to describe what I am building. First off, this is not longer going to be used in a hand held fashion, secondly, it is no longer going to be used for any other purpose for what I am about to describe, so not worries about permant.

So with that out of the way, I am building a remote controlled tank, weighs in at about 300 pounds and is propelled by - you guessed it - 2, 110v 10 amp 5" makita grinders connected directly via chain to the drive wheels. To keep this thing from taking off like a bat out of hell upon plugging in the grinders, and allowing me to steer it, I was thinking of placing a router speed controller to adjust the speed. But how to get it to go reverse. Is this possible to do, rather inexpensively, say for $100.00, or would it be better to buy different motors? These are my old power tools, so I won't miss them, I just love the power they provide, and they are bought and paid for many times over.

Also the size and weight of the grinders are conveinient, allowing for electrical stowage for the necessary remote control boards and cooling fans.

Any ideas out there I have not thought of?