The mechanism that attaches the doors to the opener is very simple and easy to build. I just used hinges from the hardware store and cut down some 2 x 4's for the arms. I made my brackets from scrap 3/4" plywood. Lots of folks have wanted to 'improve' it by using steel and that's fine, but it's overkill. There is no weight on the opener, once released from the door opener a 3 year old and open and close the doors. Wood is more than adequate strength wise.

This view show everything in working order.

With the doors open you can see how I built it, I think is pretty self explanatory.

The door end.

The length of the arms and where you attach them to the doors are very important. Changing either of these can have a dramatic effect on how much travel is required and therefore the speed at which the doors open and close.

I made a scale drawing and drew the doors and the track length. I then tried several different length arms and mounting locations on the doors. What I settled on opens and closes about as fast as a standard roll up door. It takes exactly 10 seconds which sounds faster than it is. Like so many people i am impatient and I would like the doors to open faster. I decided this was safer and the slower opening and closing speeds put no strain on the doors. There is also more time for a person or animal to get out of the way. I just need to remember to hit the button before I turn into the driveway.

I feel it necessary to repeat my warning. There is a risk of serious injury if someone gets caught between the doors. Make sure you have ALL safety items working properly! Test and retest them before you start using them. Never allow children to play around the doors when they are opening or closing!