Written by Rob Caso Scale As seen in the SPRING 2019 issue of Park Pilot
For building, painting, and detailing smaller models, nothing beats a turntable. I am currently (still) working on a 55-inch wingspan Hansa-Brandenburg W.12 floatplane, which is in the detailing and minor “finishing up” construction stages. It will soon be getting some paint. During these processes, the model has to be moved around to expose the side I am working on, and it never seems convenient with a stationary stand. On the other hand, I don’t want to move the model around very much, and some of the operations require a steady model and a steadier hand. I need to move the aircraft and have it stay put after it’s been moved. A locking turntable is the answer, and it is quite easy to make. I recently found a wooden turntable in the homewares section of a large discount department store and modified it to fit my modeling needs. Plastic turntables are also available, but the wooden one seemed steadier and had a larger diameter. Plus, wood is easier to work with for the modifications that need to be made. 
A closeup of the locking mechanism shows the trapped spring.
The first step is to mount the turntable on a platform to elevate it and to give you something on which to mount the locking feature. I used some leftover fiberglass deck posts, but almost anything could be used. Next, the locking feature is constructed. It starts as nothing more than a sturdy plywood box that is solidly mounted to the platform (not the turntable) and has a hole drilled through it for the sliding lock. The photos are self-explanatory; however, from here you will need a reasonably sturdy spring, a piece of brass tube, and some music wire for the pins. A large washer for the spring to bear against is also a nice feature. 
The internal bearing pin and the outside pin that holds the lock open can be seen in this photo.
A hole is drilled through the tube for the pin approximately a third of the way down. Leave the tube long on either side for now. The tube, spring, and washer are inserted in the box and the pin is then let in through the tube, trapping the spring. Although I made a rather elaborate aluminum knob for the “pull” end, a wooden cabinet knob would work as well. At the table end of the tube, I glued on a wood cap and a piece of soft rubber to keep the table from slipping when the lock is engaged. To allow the table to turn freely by using a single hand, I added a second pin to the sliding tube, but this one is outside and near the edge of the box. A couple of plywood strips allow the locking tube to be held open, away from the table, simply by turning the pull knob approximately 90°. The photos clearly show how I did this. 
Here is the platform for the table from underneath. The mounting blind nut can also be seen.
A closeup of the blind nut installation also shows the platform’s rubber blocks.
The table is only half of the battle. The other half is how to mount a model to it. For this, I installed a pair of 8-32 blind nuts to the underside that were oriented 180° from each other and at a prescribed and easy-to-remember distance apart. This way I can make a number of model mounts that have a standard plywood base that will fit the table. From this point, foam or model-specific mounts can be constructed on the base—the latter I show in the photos. Even a model-specific mount could be modified for other models because the fixture is screwed to the base and is not permanently attached. A couple of design afterthoughts would be to make and position the entire locking mechanism so that it would wind up below the working surface of the table. This way, larger mounts that overhang the edge of the rotating table could be used. The heavier the table platform, the better because it adds more stability to the setup. It’s certainly a little bit of work, but the convenience overshadows a little “off model” time that is spent, and helps me avoid beating up an airplane before I even get it into the air. 
Rob’s Hansa-Brandenburg W.12’s removable carbon-fiber tube. Lower wing mounts fit the table’s model-specific mount.
