3D Printed Christmas Billboard.
Introduction: 3D Printed Christmas Billboard.
I try to design table centerpieces for our holiday parties and "3D Printed Christmas Billboard" is yet another. Pressing the momentary switch on the front of the model presents three Christmas themed images in the style of the old electro mechanical outdoor billboards.
The mechanism uses a worm gear driven six slot Geneva wheel to provide dwell, rotation and positioning of the towers. The mechanism also uses magnetics to assist in snapping the panels in place in order to overcome the cumulative backlash from the 3D printed gear train.
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 4.8.0, and 3D printed in Ultimaker PLA and Tough PLA on an Ultimaker 3 Extended and Ultimaker S5s.
Supplies
* Double sided tape.
* Solder and soldering iron.
* AWG28 stranded wire.
Step 1: Parts.
I acquired the following parts:
* One N20 150RPM 6VDC gear motor.
* One 2AAA battery pack.
* Two AAA batteries.
* Two micro lever switches (search for "CYT1073").
* One momentary push button switch (Jameco 315651 or equivalent).
* Fifteen 3mm (diameter) by 1.6mm (thick) neodymium magnets.
* Four M2 by 10mm cap screws.
* Four M2 nuts.
I 3D printed the following parts at the following settings:
* Two "Axle, Gear, Idler.stl", .15mm layer height, 20% infill.
* One "Axle, Geneva Drive and Gear.stl", .15mm layer height, 20% infill.
* One "Axle, Geneva, Driven.stl", .15mm layer height, 20% infill.
* One "Base.stl", .15mm layer height, 20% infill, with supports (touching build plate only).
* Three "Bolt, Gear, Tower.stl", .15mm layer height, 20% infill.
* Four "Bolt, Top To Base.stl", .15mm layer height, 20% infill.
* Two "Gear, Idler (1.5m 12t).stl", .1mm layer height, 20% infill.
* One "Gear, Tower, Center (1.5m 12t).stl", .1mm layer height, 20% infill.
* Two "Gear, Tower, Ends (1.5m 12t).stl", .1mm layer height, 20% infill.
* One "Gear, Worm.stl", .1mm layer height, 20% infill.
* One "Geneva Drive and Gear.stl", .1mm layer height, 20% infill.
* One "Geneva, Driven.stl", .1mm layer height, 20% infill.
* One "Skirt.stl", .15mm layer height, 20% infill.
* One "Top.stl", .15mm layer height, 20% infill.
* One "Tower, Center.stl", .15mm layer height, 20% infill.
* Two "Tower, End", .15mm layer height, 20% infill.
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 printed the gears and wheels using the Ultimaker Cura 4.8.0 "Engineering Profile" on my Ultimaker S5s, which provides a highly accurate tolerance requiring minimal if any trimming, filing, drilling or sanding. 654
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 set (6mm by 1, 8mm by 1.25) if required for thread cleaning.
Step 2: Tower Preparation. 632