Monday, 26 November 2018

A 3D-printed case for the RX6R

FrSky's latest RX6R receiver is tiny, yet it offers excellent range. On paper, it's perfect for F3F. There's just one thing: it comes with a cardboard wrapper, which offers little protection and is awkward to handle. Maybe okay for a foamie, but definitely for my Stribog...

RX6R with flimsy wrapper. Note exposed conductors!

... So I decided to make a proper case for it, as my first 3D printing project! To keep the dimensions small, the case would completely replace the wrapper. There would be an access hole for the bind button, however for simplicity there would be no access to the multi-function socket (which I didn't intend to use anyway).

RX6R case version 1

The first task was to model the case in the computer. For this I chose TinkerCad, an entry level CAD program which generates industry standard STL files. TinkerCad is free and runs in a browser. Thanks to some good tutorials I soon had something resembling a case:

TinkerCad work in progress

As I didn't yet have my own printer, I took the STL file to friend and local printer guru Pete Houghton. He turned the design into G-code (via Simplify3D slicer software) which was then fed to his 3D printer. In less than 15 minutes, my little case had taken shape from under the nozzle.

First steps!

Magic! A milestone had been reached - and my appetite for 3D printing well and truly whetted.

RX6R case version 2 [updated 22 December 2018]

The first version was functional but the fit wasn't perfect, and it also looked a bit brick-like. So I decided to redesign it from scratch, this time using Fusion 360. This software has some cool features lacking in Tinkercad, for example you can add fillets and chamfers. Fusion 360 is free for non-commercial use. The learning curve is quite steep though.

Version 2 in Fusion 360. Note rounded vertical edges.

By now I had also acquired my own entry level printer. This allowed me to experiment at leisure, and after a couple of iterations I arrived at the final design:

Version 2 of the case

The last task was the easiest - installing the RX6R in the Stribog. The new receiver is much smaller than the X8R it replaces. This means it can lie flat across the top of fuselage, leaving lots of room underneath for the servo cables and some foam packing. A slight downside is that a Y-lead was required to share one of the servo outputs with the battery, however it was worth the extra few minutes with the soldering iron.

RX6R + case + Y-lead installed in Stribog. Red gismo next to servo is magnetic switch.

Download STL file

The STL file for the RX6R case is available on Thingiverse.

In conclusion

This little project has been a great intro to 3D printing - there is something rather satisfying about designing and printing a simple item which is genuinely useful. Even something as simple as this can throw up some interesting design and printing issues.

For anyone wanting to get started with 3D design, I can recommend TinkerCad, moving on to Fusion 360 as experience is gained. The videos by Angus Deveson ('Maker's Muse' on YouTube) are also well worth a look.

Meanwhile, my next project is rather more complex, it's this digital CG scale published by Olav Kalhovd.

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