unusual situation, dump truck tarp

I am a dumptruck driver. Most trucks have an electric motor that rolls/unrolls the tarp,like a convertable top on a car. I found a 12V gearmotor to retrofit my truck from a hand crank. What i need to know is 2 things, what is an easy / inexpensive way  to make the motor forward and reverse, and how do i tell the motor to stop at the end of it's stroke and turn off? I'll be happy to provide more details if needed

Thanks,

Shaun

You might want to contact hotwaterwizard.

https://www.the12volt.com/installbay/members.asp?SF=Hotwaterwizard&Submit=Search

For a Tarp on a Big Dump Truck, you need a Big motor.

Usually something like a Wench Motor.

I deal with Electric Hose Reels that have a Wench Type Motor with a Chain drive.

These are expensive Motors.

With a hose reel they pull the hose out manually and just push a button and hold it in until the hose is all rolled up then you release the button.

This involves a push switch and a relay. You could simplify this with a push switch for starting a car. These are Heavy duty enough to operate the motor without a relay.

I will see if I can find pictures for you when I have more time.

You could buy it already made.

http://www.harpstarps.com/electricwindupsystems.php