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Designing a Simple 3D Printed Rubber Band Car Using Autodesk Fusion 360

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"Designing a Simple 3D Printed Rubber Band Car using Autodesk Fusion 360" is an Instructable illustrating how I designed, printed and assembled a simple rubber band powered car for the kids and grandkids.

This little "pocket size" car will not win any distance or speed records, but the kids and grandkids love it for table top racing, it's quite durable, and it runs in two modes; "power" and "coast". Power mode is when the car is unwinding the rubber band from the axle. When the rubber band is completely unwound, it disconnects from the axle allowing the car to enter coast mode for additional distance.

The symmetrical design of the car requires eight 3D printed parts (two chassis sides, two axles, and four wheels) yet only three unique parts (chassis, axle and wheel), with all parts small enough to fit on most if not all 3D printers.

I've included a step by step video of the design and assembly process, the Autodesk Fusion 360 cad file "Rubber Band Car v1.f3d" containing the design (familiarity with the Autodesk Fusion 360 environment is highly recommended), and all .STL files required to print the car.

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 Cura 3.5.0, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

Step 1: Purchase, Print and Prepare the Parts.

I purchased eight "R20" sized O-Rings (25mm ID, 3.5mm Section) for use as the tires and a bag of assorted rubber bands to use as the "motor".

I printed all parts at .15mm layer height with 50% infill. I printed two "Axle.stl", two "Chassis.stl" and four "Wheel.stl".

Prior to assembly, I test fit and trimmed, filed, sanded, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. If you decide to make your own Simple 3D Printed Rubber Band Car, depending on the colors you chose, your printer model and your printer settings, more or less trimming, filing and/or sanding may be required. I carefully filed all edges that contacted the build plate to make absolutely certain that all build plate "ooze" was removed and that all edges were smooth. I used small jewelers files and plenty of patience to perform this step.

micromender6 months ago
Now maybe you could possibly make it with your Floating Pinion rig as the drive for it instead of the rubber band...
gzumwalt (author)  micromender5 months ago
gzumwalt (author)  micromender5 months ago
Here's a start:

If the interest is there, I'll be happy to complete the design process.

gzumwalt (author)  micromender6 months ago
Hi micomender,

That's an idea...

RobinH61 made it!6 months ago
Using a Prusa i3 MK3S, with Prusament PLA, I printed all of the parts and found nothing needed to be filed or cleaned up. All parts sliced and printed easily. I did mine in 3 passes, 1 for each of the part types, (Wheels, Axles, and Chasis). I also used some slightly larger O rings, (Danco #15, 1" by 1/8")
3D Rubberband Car.jpg
gzumwalt (author)  RobinH615 months ago
Hi RobinH61,

That looks wonderful, congratulations!

popi18546 months ago
Nice toy, my grandchildren will love it.
What I have found is that if I design parts with champhered and or radiused edges, it eliminates 90% of the filing and sanding. Another tip is to set the retraction on your printers hot end around 4 to 6 mm.
gzumwalt (author)  popi18546 months ago
Hi popi1854,

Thanks for the tips! I've learned something new!

cuPLTW6 months ago
Great project! Can you provide the vendor where you purchased the R20 sized O-Rings?
Thank you
gzumwalt (author)  cuPLTW6 months ago
Hi cuPLTW,

Thank you very much, I'm glad you enjoyed it!

I've purchased these and other sized rings at my local "Ace Hardware" store, and I've also purchased them in an assortment box (see photograph) online. It is much cheaper to buy the assortment box than individual o-rings, and I use them often in my designs, so I usually buy the assortment box.

Hope that helps!

randofo6 months ago
Nice design! I tried to make something similar a year or two ago with laser cut parts. In my version the rubber band did not disengage from the rear axle. Instead it had a cam-like thing which would catch the rubber band when rotated in one direction and allow the axle to free spin in the opposite direction. However, since the rubber band never fully disengaged, there was friction from the rubber band on the free spinning axle and it never worked very well. I was always planning on revisiting it, but recently scrapped it to reuse some of the parts. ¯\_(ツ)_/¯
gzumwalt (author)  randofo6 months ago
Hi randofo,

Thank you very much, I am truly honored that you enjoyed this model!

I learn by making quite a few mistakes, and I began this design with a concept similar to what you described, and as you experienced, it did not work very well. So I altered the design to allow the rubber band to release from the axle and, well, here it is.

I indeed learn from my many mistakes and have discovered that mistakes are not bad at all, as long as I learn something new from them :).

Thanks very much again!