3d print the mechanical Robby the Robot Gyro/dome light .

[robothut]

 

[robothut]

The hardest part of this build is the gyro units. I have 3 main ways of doing it. The screen used Robby has a main gyro part that is machined from clear plexiglass and wire hoops are passed threw holes in that part. But you can 3d print this main gyro part. If you have a FDM printer the parts will not come out clear but if you have a resin printer the parts should turn out more clear. Not as clear as machine clear plexiglass that has been flame polished but useable. Another option is to 3d print the main gyro part and use it as master4 for a silicon rubber mold, the you can cast clear resin parts from that mold. I have done that on the first "prototype" gyro unit in this build. Another way would be to 3d print the main part with a second design file I provide on thing-i-verse  white PLA. Now with this part you can either pass the wire hoops threw the holes or you can print the version with PLA hoops that you glue in place.

[robothut]

The metal rings can be made from copper AC wiring or I used aluminum wire that I found on line as it is easy to bend, cut and does not add much weight.

When adding the wire rings start in the center and work outward. The very center ring will be the hardest. I formed the wire around a pencil. you then have to twist it in the middle so its S shaped to get it started in the center hole then un twist it and feed threw the other center hole. close the ends together near the clear gyro part and glue in place. As you work out ward it becomes easier, by the third ring or so you will not need to twist the wire ring to get it started, just open up the ring a bit and feed it from the outside inward to the hole, feed the ring threw about 1/2 way and rotate the rest of the ring over the gyro to the other hole.

[robothut]

So to build the bell of the gyro just print out the parts as shown. I did use a little support on the bell just on the inside rim. The gyro gears, axles and support hubs print as shown , no supports. The axles have small wedge parts that you glue on to complete the round part of the axle. I glued the axles to the support hubs first. the pushed that in to the bell. Make sure every thing turn free at this point, if not then do some sanding. The gear glue on the axle shafts with the tapered side toward the bell. Every thing should turn freely at this point. One thing that you can do is before installing this to the bell you might want to install the gyro parts to the support hub, it might be easier than the way I did it.

[robothut]

Ok lest build the motor gear box. It is very simple. Use any TT gearmotor you want . I only had the 48:1 speed versions with dual shafts but the single shaft ones are fine and the 120:1 speed ones are fine. If you use a dual shaft gearmotor you will have to snip off the shaft that is not used. the motor screws on to the gearbox frame. A small gear slips on to the motor shaft. Now glue the long support tube / axle to the gearbox frame as shown. This part is hollow so that the dome light wires can run down threw it. Now slip on the large  gear. Test the unit at this point to make the motor and gears are running smooth. Then glue the gear box assembly to the display frame. you will see it can only fit one way. I printed the display frame top side down on the build plate, no supports. Next you can glue in place on the top side of the display frame the crown gear support part. The crown gear will glue on to this support part.

[robothut]

I run my units off 3 AA batteries. I had a battery holder that had a switch on it but did not want to have to reach under the unit to turn it ON and OFF. So I glued that battery holder in with the switch in the ON position and facing inside, then used a sperate slide switch on the side of the display base . The prototype unit had a different battery holder as this was all a after thought.

[robothut]

Lets build the Dome light assembly. Print out the Dome light support parts first. They all print flat and no supports. Lay them out in the order you see in the picture and glue them together. The bottom should have the smallest hole opening and the top should have the largest hole opening. One glued together then paint with chrome paint.

[Atomic Robot Bob]

Awesome as always, John!

 

Tim L.

[robothut]

The dome light is 3d printed in clear filament, and on a FDM printer this will come out frosted looking your good to go as the screen used auto brake light bulb was frosted. I used a 10mm jumbo White LED and a 39 ohm current limit resistor. 39 ohms to 220 ohms will be fine for this application. The Dome light has top cover that should be clear plastic but unless you plan to make yours from clear plexiglass or have a resin 3d printer that can print clear parts you will have to live with a frosted looking dome light cage.

[robothut]

Here is a shot of the screen used Robby top gyro section .

[robothut]

So once you have the gyros glued in place you can slip the gyro bell down on the unit and test run it to make sure everything is working. The you can put the dome light assembly in place. A small amount of glue placed inside the bottom hole of the dome light unit will hold it in place. Do not use so much glue that it runs down and glues the gyro bell to the shaft ! The dome light wires should be sticking out the opening in the gearbox and you can solder then to the switched power. LED's have a + and a - if you get it wrong just flip the wires around and things should light up. Same with the motor, if the gyros are not running counter clock wise then just reverse the wires.