Free STL files now available for download for basic quad-copter - all 3D printed

jstroup1986 · March 13, 2025, 5:18pm

Over the winter I developed a quad-copter designed to be inexpensive to construct.

The entire frame is 3D printed, and can be used with very inexpensive components.

I’ve made them available on my website, along with some general comments and advice about a build. I plan to used this as an excuse to finally learn the Methodic Configurator developed by @amilcarlucas and include information about using it to tune a quad on this frame.

My goal is to provide another way to help people have an inexpensive way to get started with autonomous quad-copters.

It’s available at Copter Parts – Download STL Files | Copter Cam Tech

amilcarlucas · March 13, 2025, 5:31pm

Nice, I like the transparent dome! You can see his brain

Michail_Belov · March 13, 2025, 5:34pm

Interesting… The arms are also printed?

jstroup1986 · March 13, 2025, 5:41pm

Yes @Michail_Belov - using Polymaker PLA-Pro.

In this size frame, the important attributes are stiffness and layer adhesion. PLA-Pro does a good job at both. (as do many others)

I’ve experimented with tougher materials such as ASA, ABS, PETG, etc. But plain old PLA-Pro does the job.

Here’s a BIN file from a grid mission that gives a good indication of vibes, tune, etc.

Michail_Belov · March 13, 2025, 5:46pm

I do not understand why you do not want to use old fashioned carbon fiber tubing? In terms of weight, my guess is that arms would be about 3 times heavier than carbon fiber tubes for the same strength, even if you do a nice internal lattice.

jstroup1986 · March 13, 2025, 5:52pm

Good question.

My idea is to allow someone with no more resources than a FDM printer to make everything they need. Some places have less affordable access to things like carbon fiber sheet and tubes.

Also, with carbon fiber tubes you have to be able to cut them properly.

And then there’s the issue of mounting the arms and motor mounts so that the motors are perfectly aligned.

I started this project with carbon fiber tubes for the arms. But I got the idea of trying to print teardrop shaped arms from my experience with the copter kits from Hexsoon. They turned out better than expected.

Lastly - the motor mounts with these arms are super simple.

I do welcome suggestions for improvements - and constructive criticism. But these are the reasons I’m using printed arms for now.

One more thing - It turns out the printed arms are not appreciably heavier than carbon tubes - especially if you consider the fuselage and motor mounts. And on a copter this size, the frame wait is no where as significant as the weight of the components.