The revolve is based on a common design that uses floor mounted casters for support. All of the steel was rolled by hand using a cheap harbor freight roller and custom machined square tube roller dies from a shop in Canada. Ironically a year later the university purchased a motorized roller. Each wedge was tacked together in a jig and then welded and skinned with plywood. The top layer of plywood is removable so that the wedges can be bolted together. A Creative Conners Revolver unit is used to power the revolve.
The brain of the unit is a click programmable logic controller manufactured by Koyo. This is a relatively inexpensive PLC platform that allows us to easily control multiple pneumatic cylinders and simultaneously monitor the cylinders position with limit switches. Pneumatic solenoid valves enable the PLC to electronically control the cylinders. There are a total of four solenoid valves in the control box; 2 two position valves and 2 three position valves. As-is the box can control four independent cylinders. The click has additional outputs so if desired more solenoids could be added to fit the needs of the show. This control box can be remotely operated using the control pendant or triggered from the Creative Connors Spikemark software when connected through the stagehand FX.
Air enters through a quick connect and goes through a ball valve that is used to turn the air on or off. The air then flows through an air cleaner/ dryer and into the pressure regulator. From the pressure regulator the air is piped into the valve manifold and then distributed to the pneumatic solenoid valves. Cylinders are then connected to the valves depending on the requirements for the show. AC enters through the power cord and is then wired to a courtesy outlet and a fuse block. The DC power supply is connected to the AC power through the fuse block. 24 VDC is distributed using a DIN terminal block to the Click PLC. The Click PLC has a 16 channel input module and an 8 relay output module. The control pendant plugs into two cat 5 jacks on the outside of the box and is then wired to different input channels. There are also two cat 5 jacks that are dedicated for the e-stop switches that can be placed anywhere using cat 5 cable. These are also wired to inputs on the PLC. The solenoids are connected to 24 VDC and the relay output of the click. When the Click turns on a relay the circuit is completed and the solenoid is actuated. Also on the terminal block are connections for limit switches to be wired. There are six sets of two block groups. Each group is wired to 24 VDC and an input on the click. When a limit switch is pressed the input on the PLC goes high signaling that the limit has been reached.
The control pendant is constructed using a plastic project box, 5 SPDT momentary toggle switches, two cat 5 jacks, and a momentary push button switch. In a cat 5 cable there are four pairs of wires for a total of eight. One wire on each set of cat 5 cables carries 24 VDC into the control pendant and is connected to one side of all the switches. A SPDT or single pole- double throw switch is like two switches in one. Depending on which direction you push the switch a different output is turned on. For the SPDT toggle switches 24 VDC is connected to the center terminal of the switches and one cat 5 wire to either output terminal of the switch. For the five toggle switches ten cat 5 conductors are used. The momentary switch is a used as a dead man switch so that if for any reason the operator was to release it the movement would stop. For the dead man switch a conductor from each of the cat 5 cables is connected so in the event that one of the cat 5 cables got disconnected or cut the dead man switch would still be operational. The control pendant is simply a box with switches; there are no other electronic components in side. No batteries are required because it receives power from the main control box.
The Stagehand FX is an extremely overpriced 4 channel computer controlled relay. The unit costs nearly $1000 and is only capable of switching 4 devices. Using the Click PLC I was able to devise a way to expand the abilities of the Stagehand FX unit to control up to 16 different devices. The four output channels from the Stagehand FX were connected to the inputs of the PLC. The PLC was programmed to monitor the 4 channels and respond to different combinations of on and off. For example ch1 on ch2 off ch3 on and ch4 off meant to turn on output 11 of the PLC. (Please see the output channel chart in the above gallery for more info.) This turned out to be extremely useful to control multiple pneumatic effects and other Creative Conner motors from one integrated program.