Sofa-bed continued:
I've fixed the first design problem by replacing my home-made slides with drawer hardware. Now to tackle the other issue with the drive mechanism.
The drive mechanism can move off of center as the picture shows. This can cause the Seat Platform to jam at an angle.
Bolt two different angled pieces together so they look something like a backwards "Z".
Attach the backwards "Z" to the Center Support so it acts as a guide for the bottom edge of the "L" bracket. The "Z" will keep the "L" bracket, and the drive mechanism, from swinging off center.
The "Z angle is installed along the length of the "L" bracket travel.
There is not enough of the "L" bracket under the "Z" angle for me to be totally happy with this design. I'll revisit it in the future.
Funny thing. Just in typing up this posting I've come up with a similar but better plan. That will have to be in a different posting since I haven't tried it yet.
continued -