Marblevator, Perpetual?, Cradle.
Introduction: Marblevator, Perpetual?, Cradle.
"Marblevator, Pertual?, Cradle" like "Marblevator, Perpetual?, Version 2" and "Marblevator, Perpetual?" is not perpetual at all as it is simply another illusion. And like its predecessors it is a very quiet illusion with the only noise being that of the marble as it rolls back and forth in the cradle.
I've incorporated an Arduino Nano 33 IoT in this model. The Nano software controls the illusion using two interrupt service routines activated by two infrared transceivers. When the ball bearing passes over an infrared transceiver, an interrupt is generated via the Nano input pin associated with the infrared transceiver, causing the interrupt service routine associated with the pin to be called. Each interrupt service routine utilizes the interrupt history of both interrupt service routines in order to detect downhill ball bearing motion. When downhill motion is detected, the software pulses an electromagnetic coil in order to accelerate the ball bearing up the other side of the track (as the model uses infrared transceivers to sense the ball bearing, it cannot be operated where an external source of infrared is present as that will flood the infrared transceivers thus render the model inoperative).
I've also included software that monitors the battery voltage via a resistor divider and analog input pin to put the Nano to sleep when the LiPo battery voltage drops below a specified cutoff level (9.6vdc).
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.
One final note, I receive no compensation in any form for the design, parts and/or materials used in this model.
Supplies
* Soldering iron and solder.
* One roll each of red, black, green and blue 28AWG stranded wire.
* Micromesh polishing sheets (1200, 1500, 2400, 3200).
* Sandpaper (120, 220, 400 and 600 grit).
* Thick cyanoacrylate glue.
* Double sided tape.
* Velcro.
* Heat shrink tubing.
Step 1: Parts.
I acquired the following parts:
* One Arduino Nano 33 IoT [ABX00027]
* One 11.1vdc 300mAh 3S 30C battery LiPo battery.
* One JST mating connector for the battery.
* One Gikfun EK1909 "magnetic levitation coil".
* Two TCRT5000 infrared transceivers.
* One FQP30N06L MOSFET.
* One 1N4007 diode.
* One 10kΩ resistor.
* One 2.7kΩ resistor.
* Two 1KΩ resistors.
* One M3 by 8mm cap screw.
* One 11MM diameter ball bearing.
* One M3 by 8mm cap screw.
I 3D printed the following parts at .1mm layer height, 20% infill:
* One "Base.stl" with PLA support.
* Two "Bolt, Mount, Coil.stl".
* One "Bottom.stl".
* One "Mount, Coil.stl".
* One "Track.stl" with breakaway or PVA support (requires a dual extrusion 3D printer, see Cura image above).
This is a precision print and assembly model using at times very small parts and in very tight spaces. 654
Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on you printer, your printer settings and the colors you chose, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step. After 3D printing "Base.stl" and "Track.stl" I carefully removed the support material using a flat jewelers screwdriver and needle nose pliers.
The model also uses threaded assembly thus an M8 by 1.25 tap and die will assist with thread cleaning if necessary.
Step 2: Board and Coil Mount Assembly. 632