Marblevator, Marbles Go Round or Back and Forth?

"Marblevator, Marbles Go Round or Back and Forth?" is yet another "follower challenge" as a follower sent me a video of a mechanism and asked me how I thought it worked. Well I do not know how the mechanism in the video works, but this one replicates the motion of the mechanism in the video and, of course, the grandkids and follower love it!

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.

Soldering iron and solder.

1. Cellophane tape.
2. Thick cyanoacrylate glue.

I acquired the following parts:

1. One N20 30RPM 6VDC gear motor.
2. One 4 AAA battery box with switch.
3. Twelve 6mm diameter by 3mm thick neodymium magnets.
4. Twelve 6.35mm (1/4") ball bearings.

I 3D printed the following parts at .15mm layer height and 20% infill unless noted otherwise:

1. One "Arm.stl".
2. One "Axle, Gear (8t 2m).stl".
3. One "Axle, Magnet Mount.stl".
4. One "Base.stl".
5. One "Gear (8t 2m).stl".
6. One "Gear (16t 2m).stl".
7. One "Gear, Motor (8t 2m).stl".
8. One "Magnet Mount Gear.stl".
9. One "Magnet Mount.stl".
10. One "Track.stl", .1mm layer height.

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. Prior to assembly, I 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.

This mechanism also uses threaded assembly, so I used a tap and die set (M8 by 1.25) as required for thread cleaning.

To assemble the base, I performed the following steps:

1. Pressed the gear motor into the motor compartment on "Base.stl" then soldered the battery box wires to the motor terminals such that the motor rotated clockwise when viewed from the shaft end of the motor.
2. Secured the wires into the wire slot in the bottom of the base assembly using cellophane tape.
3. Pressed "Gear, Motor (8t 2m).stl" onto the motor shaft.

To assemble the arm, I performed the following steps:

1. Placed "Arm.stl" onto the center tower of the base assembly with the flat surface of the arm oriented upward.
2. Threaded "Gear (16t 2m).stl" onto the threaded shaft on the base assembly making certain that one tooth of the gear faced toward one of the four track mount towers on the base assembly.
3. Attached "Gear (8t 2m).stl" to the arm assembly using "Axle, Gear (8t 2m).stl" making certain the gear rotated with ease.
4. Pressed twelve neodymium magnets into the magnet cups on "Magnet Mount.stl" making certain the magnets were flush with the top of the cups.
5. Glued "Magnet Mount Gear.stl" to the magnet mount assembly such that a gear surface (upper or lower) was flush with the magnet side of the magnet mount assembly.
6. Secured the magnet mount assembly to the arm assembly using "Axle, Magnet Mount.stl" making certain that one of the magnets was centered on the track mount tower that the 16t 2m gear tooth pointed to.

For final assembly, I performed the following steps:

1. Pressed the four tabs on "Track.stl" into the for track mount tower slots.
2. Place the twelve ball bearings over the twelve magnets in the magnet mount.

With final assembly complete, I turned on the battery box switch and the marbles traversed the track!

And that is how I 3D printed and assembled "Marblevator, Marbles Go Round or Back and Forth?".

I hope you enjoyed it!