Step 6: Constructing the Drawer
The motorized ice/mixer drawer goes in the bottom section of the robot keeping the center of gravity lower to the ground.
Purchase a set of 14 inch drawer slides and mount them to wood strips as pictured. We then use some 3/4 inch plywood to make a base that slides in and out. The drawer will be attached to that.
Use one of the rings we had set aside and cut two identical pieces from it to create the curved front of the drawer (20.5 inches of diameter) Use some of the vertical stringer scrap to make the vertical pieces. (face is 8.5 inches tall) Once the drawer face is done, use paper to create a template for the drawer bottom and cut that from 1/4 inch plywood. The sides and spacers can then be added. For the ice bin, I found a blue translucent one with a handle at the dollar store. It needs to be translucent for the light to illuminate the ice. The drawer body without the face is 14.5 inches wide.
Note - Continuously test fit the drawer. Spacer blocks were used to shim the drawer front to proper alignment level. The front will be sheeted with blue Sintra plastic in a later step.
To motorize the drawer, I purchased a 12 volt DC gear motor from a surplus store. 15 rpms gives the drawer a perfect speed when attached to a three-inch traction wheel. This wheel rides on the inside floor of the robot. I used screws and small springs to mount the motor. This allows you to adjust the tension and traction.
To control the elevator via the remote, I visited Team Delta and purchased a RCE220 rc switch. This allows the motor to operate in both directions, stop at limit switches, and be controlled from one button on the remote. Follow the instructions that came with the RCE220 to wire it.
I insulated the area below the ice bin with foil back bubble material. Simply make a paper template and then use that to cut the insulation. Use spray adhesive to attach it to the drawer.
To illuminate the ice, I installed two LED light pucks. I found a three-pack of these at the local drugstore.
The drawer gets trimmed a little later.