Built one Of Ian Rice’s(thanks Ian) small shelf layouts. I’m having a hard time figuring out how to move the track (he shows using a rod). The problem is the alignment. Question - is it possible to use a turntable mechanism to make it automatic. Thanks for any guidance. Robert
Obbie
Is your movable track a sector (rotational motion) or a traverser (rectangle with forward and back motion)?
In either case, the simplest mechanical indexing system is a spring-loaded pin with locking holes at the correct locations. The tricky part is retracting the pin when you want to move the sector or trraverser. A solenoid with a steel pin or a mechanical lock in the up position seem to be the simplest.
You can use a motor to drive either, in which case the solenoid pin retraction makes the most sense, and can be automated to work in conjunction with the motor through a relay.
The traversers often use sliding drawer hardware to provide smooth movement. This lends itself to adaptation of the cartridge belt drive mechanism from a broken ink jet computer printer.
For a sector plate or table, I would suggest a hand crank or motor geared to rotate the track slowly at its point of rotation. Unless there are a lot of possible stops, a conventional turntable mechanism probably won’t help your very much. The Atlas turntable mechanism has fixed rotation intervals built into its mechanism which are unlikely to match your situation. Most of the other turntable mechanisms are quite expensive.
My thoughts, your opinions and choices may vary.
Fred W
Thanks for the info Fred, forgot to mention it is a sector plate. As re. the solenoid pin, rather than get complicated with more electric can a spring loaded ball catch (like for cabinets) perform the same function in conjuction with a slo-mo motor. And would the motor need to be geared to a difinate ratio?
Thanks for the info Fred, forgot to mention it is a sector plate. As re. the solenoid pin, rather than get complicated with more electric can a spring loaded ball catch (like for cabinets) perform the same function in conjuction with a slo-mo motor. And would the motor need to be geared to a difinate ratio?
The only hitch with a spring-loaded ball catch is the amount of torque the motor would need to overcome the drag of moving the plate, especially at first when the torque needs to force the ball to retract some against the spring. It might take some fiddling to get just the right adjustment of spring pressure.
Recommended speed for a turntable is about 1 rev/minute. I would think this would be about right for a sector plate as well.
Hope this helps.
Fred W