Finally the temperature has risen enough to make working in the garage bearable (almost!) so I ventured out to do some more traverser experiments. For those of an engineering bent who appreciate precision and neatness this is the time to abandon this thread. If you appreciate the the work of Heath Robinson, you'll feel right at home!
I'm trying to build a wagon traverser for the area of board in front of No.1 fiddleyard. It will have one approach track and 3 or 4 exit roads into another works building. Current ideas are based on using a screw thread and captive nut as the drive mechanism. After rummaging around I came up with an old Triang 0-4-0 chassis, a fence wire tensioner, a couple of brackets and some MDF. From this, with judicious use of the hot glue gun, I was able to mock up something to test the idea.
Here's the first experiment.
It 'aint pretty but the motor turns the threaded shaft OK and with a bit of running (this motor hasn't turned for 35 years!) and some lubrication it will run quite slowly. The motor is coupled to the shaft by engaging the coupling rod securing screw in the loco wheel with a slot in a nut on the end of the shaft. The nut is the wrong thread so I simply tightened it onto the thread till it jammed! High tech or what?
Given that this seems to work I disassembled it all and got out the epoxy to make the assembly rather more permanent. I also broke out the plasticard to build an actuator slider to hold the nut captive. Onto this was epoxied a length of old rail to act as the actuator rod to drive the traverser bridge itself.
This mess was then built into a sub-assembly with the floor of the traverser pit and side walls which is then bolted to the baseboard. It needs to be removable as it is bound to break down! Here's a view of the thing fitted to the underside of the baseboard.
Finally a view from the top (unfortunately out of focus) that shows how the actuator rod (over long at present) emerges into the pit. The traverser bridge itself will sit parallel with the actuator and hide it.
Rather a lot still to do before I can see whether the thing will actually work well enough to be usable but I'm having fun.