TV cabinet automation -Build and test

[Mark]

Now it’s time for the rubber to meet the road. The model has been designed in CAD, Small parts have been built and tested, what could go wrong. Using a Biesse 5 axis router I was able to easily bring the CAD parts to life out of ¾” laminated plywood with minimal scrap.

The complete cabinet was comprised of three sections: the electronics area, the TV area, and a small storage area. The center section holding the TV was the first to go together. To power the upward movement of the TV a 200-pound actuator was used. Attaching it to the back of the tv sled just below the top roller bearings allowed the top bearings to reach the end of their track and then kick the bottom edge of the tv out into position. Below is the TV sled mounted in the cabinet and a close up of the finished track sections.

The bearing slides can be seen at the top of their paths for the TV section and the TV mounting plate all the way in viewing position. The vertical path mid-way up and the hockey stick path next to it are for the mid panel door. The pocketed-out section along the TVs lower guide path is for switches to detect the bearing slides and a chase to hide the wires in.

For the mid door panel movement, I got the assembly to this point with no real plan for how it was going to move. My initial idea was to have the top ride on bearing slides and use a gear motor and create a rack and pinion setup to allow it to climb up. I created a gear design and a rack that bent over the hockey stick. In theory it worked and managed to drive the door up and down a few times but, in the end, if either side got bound up slightly and out of time with the motor on the other side, the gear would strip itself on the shaft. This didn’t give me confidence to move forward with this design.

 

 

I was forced to rethink how to use the space I had. The door needed to move up 15” from the parked position to closed. An actuator would be the easiest solution but finding one with that much stroke and still compress down under 13” to fit below the TV wasn’t going to happen. Then I thought of a forklift, and the new actuator driven pulley lift was created. With only 8” of stroke I could get more than enough door movement.

The new door system uses 3D printer belts that roll over pulleys on the end of the actuator. This set of pulleys also is constrained to the door via a 3D printed track. Now I can have a smaller short stroke actuator positioned closely to the door leaving ample room for the TV to fit behind it. The force from the actuator caused the front panel to bow out so this rib was installed to keep it straight.

Time to test the motion. Video attached