Working Tank Tracks!
But wait, it gets better.
This entire project can be printed without any supports. With a well dialed in printer, you can expect to easily get fantastically finished tracks just like ours in the photo.
It was important these bushings were low friction, so Nylon’s low friction coefficient worked brilliantly.
In the end, the tracks ran almost continuously for 3 days for the TCT show where we exhibited them. So it’s safe to say the design and material choices worked out great for the purpose intended.
You'll see here what exactly I mean by "extremely rudimentary".
To create a complex design with multiple moving components that need to be assembled after printing to not just print reliably, but also be assembled easily and work well enough for purpose takes a considerable level of design skill.
This whole concept is made from just 12 individual designs. You can see that it’s of a modular layout (any other way of saying this more simply?). You can easily increase the size and length of the tracks by simply printing more track and suspension components.
My printing recommendations for the tracks
- PETG was chosen for most components due to its durability (strong but with a very slight flex) and very good layer adhesion. Especially appropriate for the bolts, where tightening them will force the layers to split with a weaker material.
- Axle [Trans Black PETG] x 1
- Axle Carrier [Trans Green PETG] x 2
- Bolt [Opaque Black PETG] x 4
- Bushing [Black Nylon] x 8
- Rocker Wheel Inner [Silver ABS, acetone smoothed] x 2
- Rocker Wheel Outer [Silver ABS, acetone smoothed] x 2
- Roller Wheel [Silver ABS, acetone smoothed] x 1
- Segment [Trans Green PETG] x 47
- Sprocket [Silver ABS, acetone smoothed] x 1
- Suspension Arm [Trans Black PETG] x 2
- Suspension Mount [Trans Green PETG] x 2
- Track Pad [Black TPU] x 47
If you opt to print these in something flexible, you may wish to print in 100% infill for enough stiffness to support the tank/robot they’ll be under.
If you plan to print your tracks in the same materials as we used, it makes sense to spend a few minutes making the most of your print bed area printing duplicate items, or mixed objects of the same material.
The model has a reassuringly low amount of slackness to it.
We needed to fine tune how tight the tracks were, so carefully used a heat gun to lightly add more bend to the Suspension Arms, which also allowed better suspension. Be careful if you opt to do something similar.
Make sure you choose an RPM that suits. Our first motor was a 100rpm output, which gave the tracks around a scale speed of 30 KPH.
There you have it. To download the files and have a go printing it yourself, click the links below.
Roller Wheel STL
Suspension Mount STL
Suspension Arms STL
Rocker Wheel Inner STL
Rocker Wheel Outer STL
Axle Carrier STL
Track Pad STL