Combine Door

First Generation

I did this little effect for the Mountain Vista Railroad on the spur of the moment; it's paired with the hobby shop layout. It's a perfect example of a crank drive with a two-position windshield wiper control.

First, I removed the baggage door from the combine with a sharp knife. Then I created a pair of tracks using Evergreen styrene angles (above).

From a spare baggage car, I extracted a new door, and shaped it until it slid in the track perfectly. Then I attached a small bit of brass tubing (above).

I created the mechanism from a low-RPM geared motor by attaching an eccentric crank made from bent brass tuning. I also added a limit switch to stop the motor in the open and closed positions (above).

After installing the mechanism under the combine, I connected the drive to the door with a bit of brass wire shaped like a staple (above).

Second Generation

When it came time to decommission the Mountain Vista, I needed to change the way the door opened, because I wanted to move the model layout from behind the window to behind the door for better visibility, and there was no longer room for the existing linkage. So, I turned everything upside down, stuffing all of the guts under the roof. It was a really tight fit, but it still worked. The roof remains removable for maintenance.

(1) crank; (2) limit switches; (3) connecting link; (4) retainer plate, keeps the connecting link from popping out of the door.

It now resides on the Saturday at the Park diorama.

Return to David's Animation Workshop

Copyright © 2021-2022 by David K. Smith. All Rights Reserved