3D PrintingCarbon FiberESCNAVIOQuadcoptersRaspberry Pi

New ESCs, 3D Printed Raspberry Pi Mounts

The last incendiary event made me soon figure out that new ESCs would be required if I’d want to get the craft off the ground anytime soon. I went and grabbed a bunch of T-Motor Air 20A ESCs, whic turned out to be quite the reliable little beasts, and quiet too. Granted, the whole cable management business was a bit more messy, since the ESCs now had to be strapped on the motor arms, one on each. So no question about passing the motor cables through the tubes anymore. Nonetheless, I was quite happy with the setup.

Another issue was that the new ESCs did not have a built-in BEC, so I had to grabb a tiny PDB/BEC combo to go together (DALRC Micro PDB):

DALRC PDB with 5V BEC

Below the arrangement of ESCs with the quadcopter PDB and LiPo connectors:

ESC, PDB, BEC and LiPo connector

As you can see I’m still using the quad’s PDB, since it allows for shorter leads, plus I have the impression that it can handle a bit more current than the 50amps of the DALRC PDB1.

The connection between the battery pads and the BEC turned out to be quite fragile and unstable, which led to the Flight Controller losing power on some occasions. I found out the hard way, when during an indoors flight the aircraft yawed uncontrollably to the right and crashed. Luckily nothing at all was damaged, apart from a broken zip-tie at the motor mount:

Broken Motor mount zipties

Seen from an optimist perspective, the damage kinda shows that the frame did break where it should, and contained the damage from breaking any critical components. Who knows what will happen if it falls from a height of 20m (60 ft) though..



I eventually wanted to attach a Raspberry PI 2 (RPi), in order to be able to capture video and perhaps do all kinds of cool stufffs when my NAVIO2 flight controller would arrive, including computer vision and autonomous flight. I thus started planning where the RPi board would go. The most sensible place seemed to be above the top plate at a distance so that the battery can go underneath it. To make mounting easy I wanted to design customized spacers that could attach to the mounting holes on the RPi but also to the existing arm fixing holes on the top plate of the quadcopter. The following diagram captures the gist of it:

Mounting scheme for the Raspberry board and custom spacers

I first tried to print the spacers by positioning them standing (long dimension facing up), as shown in the figure above, but wiggling of the upper layers caused a mangled up print:

Mangled up 3D printed spacers..

Eventually I realized that I had to print them by laying them down on the print bed. The result came out good, and I didn’t have to use any support at all, because of the small dimension of the holes and overhangs. In use, the standoff looks like this:

And this is what the finalized “beast” looks like:

Finished CF450 Quadcopter

Finished CF450 Quadcopter

Aircraft just before maiden flight

Aircraft just before maiden flight

And, guess what: it flies! And pretty darn well too! Here’s is an animation taken from the video of the maiden flight (video coming as soon as I find the time to process and upload it):

 

 

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  1. Not that I’m getting anywhere close to that current range anyway but just in case

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  1. Pingback: On the Road to a Full-CF Aircraft – UAV Build

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