Marblevator, Rube Goldberg Style.

How many mechanical components are necessary to lift a marble from the end of a marble run track to the beginning? Well in "Marblevator, Rube Goldberg Style" I added as many as I could to create this Rube Goldberg / Erector Set themed Marblevator.

The marble lift incorporates quite a few mechanical components including a cam arm, scotch yoke, rack gear, pinion gear, clevis arm and clevis, a clevis track for the clevis to follow, a pivoting clevis to coordinate arm movement, an arm to which a marble pick up mechanism is attached and finally a marble pick up mechanism itself, all to simply move a marble from the end to the beginning of a marble track.

In memory Rube Goldberg and his wonderfully complicated machines.

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 ask 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.

1. Wire Tie.
2. Soldering Iron and Solder.
3. Thick cyanoacrylate glue.
4. Thick double sided tape.

I acquired the following parts:

1. Four 3mm diameter by 1mm thick neodymium magnets.
2. One N20 6VDC 30RMP gear motor.
3. One four AAA cell battery pack with wires and switch.
4. Four AAA batteries.
5. Two 11mm diameter ball bearings.

I 3D printed the following parts at 20% infill, .15mm layer height and no supports:

1. One "Arm Clevis.stl".
2. One "Base.stl".
3. Ten "Bolt (M8 by 8mm).stl".
4. Ten "Bolt (M8 by 12mm).stl".
5. One "Brace.stl".
6. One "Cam Pin.stl".
7. One "Cam.stl".
8. One "Clevis Arm.stl".
9. One "Clevis Pivot.stl".
10. One "Clevis Track.stl".
11. One "Cup Arm.stl".
12. One "Cup Guide End.stl".
13. One "Cup Guide Start.stl".
14. One "Cup Plunger.stl".
15. One "Cup Retainer.stl".
16. One "Cup.stl".
17. One "Gear Rack (1.5m 18t).stl".
18. One "Motor Mount.stl".
19. Eight "Nut.stl".
20. One "Rack.stl".
21. One "Stand Base.stl".
22. Four "Stand Leg.stl".
23. One "Track Left.stl".
24. One "Track Right.stl".

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. Soldered the battery pack wires to the gear motor.
2. Pressed the gear motor into "Motor Mount.stl" then tied the motor wires to the motor housing using a wire tie for strain relief.
3. Attached the motor mount to "Base.stl" using two "Bolt(M8 by 8mm).stl".
4. Threaded "Cam Pin.stl" into "Cam.stl".
5. Pressed the cam assembly onto the motor shaft, then carefully rotated the motor shaft and cam until the cam was positioned 180 degrees away from the sliding dovetail cavity on the base, as shown.
6. Partially inserted "Rack.stl" into the sliding dovetail cavity on the base, carefully flexed the cam pin into the scotch yoke slot, then carefully rotated the cam 180 degrees until the rack was fully inserted into the sliding dovetail cavity.

To assemble the clevis track, I performed the following steps:

1. Slid "Arm Clevis.stl" into the center hole in "Clevis Track.stl".
2. Slid the threaded pin on "Clevis Arm.stl" through both the clevis arm and track slots then secured the clevis in place using one "Nut.stl", making certain the clevis rotated with ease.
3. Slid the threaded pin on "Clevis Pivot.stl" through the pivot hole in the clevis track then secured the clevis in place using one "Nut.stl", making certain the clevis rotated with ease.
4. With clevis arm positioned as close to clevis pivot as possible (as shown), pressed "Gear Rack (1.5m 18t).stl" onto the clevis arm shaft with the index hole positioned upward as shown, then secured the gear to the clevis arm shaft using one "Bolt (M8 by 8mm).stl".
5. Pressed two magnets, one into each side of "Cup Plunger.stl", with opposing polarity (e.g. both North poles facing outward).
6. Pressed four magnets, two into each side of "Cup.stl", matching the polarity of the plunger magnets.
7. Slide the plunger into the cup making certain the plunger slid with ease inside the cup.
8. Pressed "Cup Retainer.stl" through the cup retainer slot, plunger retainer slot, through the opposite side cup retainer slot making certain the retainer edges aligned with the outside edges of the cup.
9. Pressed the cup assembly fully onto the end of "Cup Arm.stl".
10. Slid the cup assembly arm through the pivot clevis, making certain the cup guide arm faced rearward, then through the arm clevis such that approximately 4mm of the arm extended beyond the arm clevis, and finally secured the arm clevis in place with one "Bolt (M8 by 8mm).stl". Final adjustment of the arm position will be made later.
11. With the rack gear and rack aligned such that the dot between the teeth aligned with the first tooth on the rack gear (as shown), attach the clevis track assembly to the base assembly using four "Bolt (M8 by 8mm).stl".

To assemble the stand, I performed the following steps:

1. Pressed "Brace.stl" and one "Stand Leg.stl" into "Stand Base.stl" as shown.
2. Attached "Cup Guide Start.stl" to the stand assembly brace and leg using four "Bolt (M8 by 12mm).stl" and four "Nut.stl".
3. Attached "Cup Guide End.stl" to the stand assembly leg using two "Bolt (M8 by 12mm).stl" and two "Nut.stl".
4. Attached "Track Right.stl" to the stand assembly using two "Bolt (M8 by 8mm).stl".
5. Attached "Track Left.stl" to the stand assembly using two "Bolt (M8 by 8mm).stl".
6. Pressed the remaining three stand legs into the stand assembly as shown.

For final assembly, I performed the following steps:

1. Positioned the clevis track assembly between the four stand legs, then secured the clevis track to the stand legs using four "Bolt (M8 by 12mm).stl".

With final assembly complete, I placed a ball bearing in the cup guide end pocket then turned on the battery back to make sure the cup would pick up the ball bearing. If not, I raised or lowered the cup guide end until the ball bearing was reliably picked up by the cup. Next, I slid the cup guide start assembly left and right until the cup would reliably drop the ball bearing onto the right track. Small adjustments may be also made to the cup arm in the arm clevis.

With all adjustments complete, I applied small dots of glue between the stand base and the four stand legs and brace to secure them to the stand base. Finally, I applied doubled sided tape to the battery box to secure it to the stand legs.

And that is how I 3D printed and assembled "Marblevator, Rube Goldberg Style".

I hope you enjoyed it!