Marblevator, Circus.

https://youtu.be/fvN_tQgDMqs

"Marblevator, Circus" (as named by our grandkids) is a somewhat circus themed Marblevator with elephants, a giraffe and a giraffe wagon participating in the animation. As the elephants "push" the giraffe in its wagon back and forth, the giraffe picks up a marble (ball bearing) from the end of the track, places it at the start of the track, then returns to repeat the process.

This model is a high precision 3D print and assembly with fifty unique parts requiring both time and patience to 3D print and assemble. But when I finally completed mine, our kids and grandkids really enjoyed watching it so it was certainly worth the effort!

As usual I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to comment as I do make plenty of mistakes.

Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.12.1, and 3D printed in PLA on Ultimaker S5s and an Ultimaker 3 Extended.

Parts.

I acquired the following parts:

• One 6VDC 30RPM N20 gear motor.
• One 4.5VDC power supply.
• One coaxial connector matching the power supply connector.
• Thirty two 3 by 1.5mm neodymium magnets.
• Two 6 by 1.5mm neodymium magnets.
• Two 8mm ball bearings.
• 8mm length of 2mm diameter music wire.
• Thin rubber band (approximately 100mm).

I 3D printed the parts as listed in the attached file "Parts.pdf".

This mechanism is a high precision print and assembly using at times very small precision 3D printed parts in confined spaces with highly precise alignment. I sliced my parts using Ultimaker Cura 4.12.1 "Engineering Profile" which provides a highly accurate tolerance requiring minimal if any trimming, filing, drilling or sanding. However, prior to assembly, I still test fitted and trimmed, filed, drilled, sanded, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on your slicer, printer, printer settings and the colors you chose, more or less trimming, filing, drilling and/or sanding may be required to successfully recreate this model. I carefully filed all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth using small jewelers files and plenty of patience to perform this step.

This mechanism also uses threaded assembly, so I used a tap and die (8mm by 1.25) if required for thread cleaning.

Giraffe Assembly.

To assemble the giraffe, I performed the following steps:

• Pressed "Giraffe, Eye, Right.stl" and "Giraffe, Pupil, Right.stl" into "Giraffe, Body, Right.stl".
• Pressed "Giraffe, Eye, Left.stl" and "Giraffe, Pupil, Left.stl" into "Giraffe, Body, Left.stl".
• Painted the raised sections of the giraffe body halves.
• Painted "Giraffe, Ear, Brown, Left.stl" and "Giraffe, Ear, Brown, Right.stl", pressed the left and right brown ear components into "Giraffe, Ear, Yellow, Left.stl" and Giraffe, Ear, Yellow, Right.stl" respectively, then glued the left and right ear assemblies to the left and right body halves.
• Glued the left and right body halves together.
• Painted the tips of "Giraffe, Horn.stl", then glued them to the giraffe assembly.
• Painted "Giraffe, Mouth.stl".
• Glued the mouth to the giraffe assembly.

Elephant Assembly.

To assemble the elephants, I performed the following steps:

• Glued "Elephant, Left, Body, Left.stl" to "Elephant, Left, Body, Right.stl".
• Pressed "Elephant, Eye.stl" and "Elephant, Pupil.stl" into the left elephant assembly.
• Pressed one of the 3 by 1.5mm magnets into each of the body halves, opposing polarity.
• Pressed one of the 3 by 1.5mm magnets into each of "Elephant, Wheel.stl".
• Positioned "Elephant, Gear (1.5m 8t).stl" between the body halves.
• Pressed one of the wheel assemblies through the elephant body halve and into the gear.
• Pressed the second wheel assembly through the opposite body halve and into the gear 180 degrees out of phase with the first wheel.
• Pressed two 3 by 1.5mm magnets into "Elephant, Leg, Upper.stl" such that the magnets matched the polarity of the body halve magnets.
• Magnetically attached the upper leg to the elephant body assembly.
• Pressed two 3 by 1.5mm magnets into "Elepant, Leg, Lower.stl", one oriented to match the upper leg, and the second (in the foot) matching the polarity of the wheel magnet.
• Attached the lower leg to the elephant body assembly.
• Repeated the previous four steps for the remaining leg.
• Repeated all of the steps for the right elephant.

With assembly complete, I verified the wheels and gears rotated with ease.

Wagon Assembly.

To assemble the wagon, I performed the following steps:

• Glued "Wagon, Mount, Giraffe.stl" to "Wagon, Base.stl" making certain the mount was flush with the underside ridge and perpendicular to the base front to back and side to side. This alignment is critical.
• Positioned the giraffe assembly into the base assembly and secured them together with "Wagon, Axle, Giraffe.stl". Once in position, I verified that giraffe rotated with ease in the mount.
• Glued "Wagon, Bars.stl" to "Wagon, Sides and Back.stl", carefully aligning the top and bottom edges.
• Slid the head of the giraffe up into the bars, carefully slid the head through the bars, pressed the bars and sides into the slot in the wagon base, then glued the bars and sides to the base.
• Pressed one 3 by 1.5mm magnets into each of "Wagon, Wheel and Axle.stl" in the same magnetic orientation.
• Slid the wheel and axle assemblies into the wagon base assembly from the front.
• Pressed one "Wagon, Wheel.stl" onto each of the axle assemblies such that the hub faced outward.
• Routed the rubber band around the rubber band mounts and over the giraffe tail.

With wagon assembly complete, I verified the wagon rolled with ease.

Base Assembly.

To assemble the base, I performed the following steps:

• Secured "Yoke, Gear (1.5m 38t).stl" to "Base.stl" using "Yoke, Gear, Axle.stl", making certain the gear spun with ease.
• Glued "Lift, Magnet, Guide.stl" to "Yoke.stl" making certain the guide was flush with the bottom of the yoke, and perpendicular to the yoke rail. This alignment is critical.
• Pressed "Gear, Compound, Mount.stl" into the yoke assembly.
• Secured "Gear, Compound (1.5m 12t, 1.5m 24t).stl" to the mount using "Gear, Compound, Axle.stl", making certain the gear spun with ease.
• Attached "Slide, Guide.stl" to the base assembly using two "Bolt (M8 by 1.25, 6mm).stl".
• Inserted "Slide.stl" into the guide with the center index dot facing upward (this dot will assist in alignment).
• Attached two "Slide, Spacer.stl" to the slide.
• With the slide centered in the guide, slid the yoke assembly into the guide making certain the index dot on the slide aligned with the index dot on the compound gear.
• Soldered 120mm lengths of wire from the motor terminals to the coaxial connector.
• Inserted the motor, shaft end first, into the top of "Rack.stl".
• Pressed "Gear, Motor (1.5m 16t).stl" onto the motor shaft.
• With the yoke and slide indexed, slid the rack assembly onto the base assembly such that all index dots aligned.
• Secured the rack assembly to the base assembly using two "Bolt (M8 by 1.25, 6mm).stl".
• Positioned "Giraffe, Guide.stl" onto the back of the slide guide and secured in place with two "Bolt (M8 by 1.25, 8mm).stl

With the base assembly complete, I applied power and made certain the slide traversed the guide equidistant.

Top Assembly.

To assemble the top, I performed the following steps:

• Pressed the 2mm diameter by 8mm long music wire into "Lift, Magnet.stl".
• Pressed two 6 by 1.5mm magnets into the top of the magnet lift.
• Inserted the magnet lift assembly into "Top.stl" such that it sloped toward the front of the model.
• Positioned the top assembly over the base assembly, routed the motor wires through the slot on the underside of the top assembly, then attached the top assembly to the base assembly using two "Bolt (M8 by 1.25, 6mm).
• Secured the coaxial connector to the assembly using the included washer and nut.

With the top assembly complete, I applied power and made certain the model moved with ease and that the magnet lift and guide aligned.

Final Assembly.

For final assembly, I performed the following steps:

• Placed the wagon assembly on the track such that the rear wheel hubs extended through the slot in the giraffe guide and the giraffe tail rested on top of the sloped guide on the giraffe guide.
• Pressed the one "Gear (1m 36t).stl" onto each of the wagon axles.
• Pressed two 3 by 1.5mm magnets into each hole of "Slide, Arms.stl" matching the polarity of the wagon wheel and axle magnets.
• With the wagon aligned over the center of the slide, attached the slide arms magnets to the wagon wheel and axle magnets, then attached the slide arms to the slide standoffs using two "Bolt (M8 by 1.25, 6mm).stl".
• Pressed "Track, Marble.stl" onto the assembly.

At this point, I applied power and made certain the model would pick up a marble at the end of the track, and drop the marble at the start of the track.

Finally, I pressed the left and right elephant assemblies into the holes on the wagon sides aligning them carefully with the track below and perpendicular to the wagon sides. Once I was satisfied with the alignment and operation, I applied small dots of glue between the elephant and wagon sides to secure the elephants orientation.

And that is how I 3D printed and assembled "Marblevator, Circus".

I hope you enjoyed it!