hidden mirror ball

This is what I do for a local amateur theater.
Until the second to the last scene, the ball is hidden on the roof and retracted when it drops to a dance number.
Because there is not enough space to lift the ball completely, a set of doors is needed for the rest of the game to prevent the ball from interfering with other stage lights.
I bought nothing for this project.
All the materials and parts are what I have found in the theater.
Mechanical drill bit.
2 The length of the steel U section is slightly longer than the distance I need to lift the ball. .
3 wheels suitable for U part. (
I had to trim my to make them fit).
3 long M6 bolts for wheels. 35 M6 washers.
2 long M8 bolts for U section.
2 M6 bolts and wing nuts for connecting the mirror ball and motor to the plastic pipe track.
1 mop bucket with spare wheels and pulleys for counterweight. . 4 hinges. nails.
Screws of various lengths.
Length of plastic rope.
The length of black plastic is 20mm.
Small ring of fishing line.
2 thin hard board strips to align with the U segment.
All kinds of wooden blocks.
Cardboard scrap.
Thin plywood large enough to encircle the ball.
Mirror Ball and motor.
Black paint for electrical appliances.
24 v power supply (
Rescued from the old amp).
4 Single knife change on relay.
Suppress 4 diodes on the back E. M. F.
Coil from relay.
1 replace the non-locking button switch. .
3 Non-locking button switches that are normally closed. .
1 24 v motor with 500 to 1 gearbox and strong drive shaft for lifting the winch. .
1 24 v motor with a 200 to 1 gearbox for the door winch.
1 the supply voltage coil for stage light dimmer control changes on the relay.
2 pieces of scrap. lots of wire.
I use red, black, orange GreenTools usettable sawchop sawelecc finnishnail gunelecc drillset hole sawsset drills 20mm shovel drill bithammerAllen art place a wood anddrilledan 8mm hole Wood at both ends of the U section of steel
Isandwicheda is a piece of wood between the two U segments and connects them together with m8 bolts.
Extra length used to prevent the saddle from falling off the end of the track.
The wood sticking out at each end is used to hold the track to the roof structure.
And then I found the saddle stuck half way.
The way, because the inner surface of my track is too rough, I cut a hard plate and align it on the inside of the two U segments.
I placed the wheel on the track and measured the distance between the axes.
The saddle is made of a piece of cardboard floor.
I cut two rectangular pieces for the side and screw them together for the time being so that when I mark and drill holes for the wheel axle they don\'t move.
Now that the two front wheels are installed, use the washer to separate the wheels from the side blocks.
The wheels run freely because the tubes along the center are slightly wider than the wheels.
The 3rd rear wheels are installed in the same way after the saddle is installed around the track.
Then screw into the mounting position of the mirror ball motor under the front suspension.
This is what I already have, all I need is a big pulp that drives the shaft.
This is made of a few pieces of disk cutoutofchipboard with a set of hole saws and nailed together.
The center hole is enlarged in order to install the output shaft with a 20mm shovel bit.
The metal collar pressed at the bottom of the drive shaft is nailed to the end of the stack and secured in place with the 3 flat head screws in the collar.
To improve the friction on the rope, the cutting surface of the cardboard remains rough.
The pulley is long enough that the rope can be simply tracked along the pull when turning, so that the rope is not worn out too much by the rough surface.
2 eyes screwed into the top of the saddle behind the track to tie the rope.
The rope then turns around the pull of the motor, and then continues to move freely, passing through another free pull.
Back again and tied to the weight. See picture ?
Wiring diagram for winch relay and motor.
2 screws were used to activate the top and bottom limit switches.
Note that the top limit switch needs to change the type in order to close the door after the Mirror Ball is lifted.
I have a 400mm ball so the enclosure is about 450mm.
Since the ball is only 15mm visible at the bottom of the front edge, the front sheet is only 25mm high in order to save plywood.
The rear panel is also made up of two pieces to make the most of the thickness I have.
The corners are connected with triangular pieces of wood and afinish nail guns.
The hinges are tested by screwing through the plywood and having the screws reach out to the other side.
To securely install the hinges, a piece of wood is extended along the bottom on both sides of the box for the screws to enter.
On the door, just placed a block on each hinge so that the ball can leave without hitting anything.
The weight of these blocks inside also helps to change the center of gravity of the door so that when opened they drop slightly vertically.
The rear corner of each door is secured with a circle of fishing lines, passing through a U-bolt until a large wheel connected to the motor shaft.
This wheel is large enough to wrap enough fish lines and close the closed door without fully rotating, because when the door is opened, the nail on the wheel opens the limit switch.
When the door is closed, another limit switch at the bottom edge of the back plate is turned on, and since the wheel has never turned completely, the nail cannot hit the back of the other limit switch.
When the door closes the 12 v regulator to the door to close the circuit to slow down the motor, reduce the noise of the motor.
The first part to be installed is the track and saddle.
Once fixed, the mirror ball is pulled up with a rope and temporarily fixed in the \"hidden\" position so that the length of the pipe can be measured.
I cut a slot at each end of the catheter and drilled a 90 degree 6mm hole in that slot.
Then install the mirror ball and the ring on the electric machine into the slot and fix it in place by a M6 bolt through the hole and ring.
Once the mirror ball and motor are connected together, the rope can be tied to the saddle, through the pulley and connected to the weight bucket.
Then add more weight until the system is balanced.
After the experiment, I found that it would be better if the weight was slightly larger than the saddle.
The mirror ball is in its shidden position, then the box is dragged up and fixed to the back of the stage arch.
Once completed, connect the two control circuits together and test the entire mecanisim.
The main coil relay used to control the drive from the lighting station was originally used to stop the heat transfer pump when the boiler was turned off by the time switch.
Because this relay is plugged into the dimmer circuit, additional lights are required to increase the load, otherwise the channel will not be completely closed and the relay will make a lot of buzz.
Additional lights can be seen in picture 1.
I decided to install a red filter and point it to the roof vent to confuse anyone who happens to walk through the outside.
The last two pictures are the animation of the ball in motion and the circuit diagram of the whole system.