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I am working on a project intended as a flight stability module for amateur high power rocketry. Basically in the event of asymmetrical thrust due to a motor failing to ignite, or just too much wobble in flight due to various reasons, slats would be extended/retracted by a motor to counteract the tilt in a given direction.

I was wondering if there is any data on how many G's of acceleration a Pi3 and its components can withstand.

I have launched projects from as low as 8 G's, to 20+ G's (sustained @ 3seconds+) So payload survival is somewhat of a concern.

NZKshatriya
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  • I have no idea what the answer to this might be, but if you can afford to destroy a 'spare' Pi in the name of science you might consider potting one, or applying something similarly tough to as much of the board as you can without gunking the connectors. That should certainly help to alleviate the force on the components, although it does come with its own challenges. – goobering Feb 06 '17 at 01:24
  • You might also get some mileage out of this writeup of Pis and rocketry. – goobering Feb 06 '17 at 01:29
  • Looks like a good read, I know of people using Pi's for guidance systems (which is seriously a bad idea for the hobby in my opinion) – NZKshatriya Feb 06 '17 at 02:35

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The weakest point on the Raspberry Pi seems to be the SD card slot. G-forces aren't in the specifications, but this site says "low vibrations." This was built as a classroom learning computer, but we're all using it as a real-world mobile sensor and servo platform with a built-in webserver, aren't we? :D

EDIT This guy built a rocket using a stripped version of a Pi (i.e. with HDMI, LAN/USB, audio jack and the like removed) and flew his rocket at Mach 1.2 all the way up to 48k feet. He says he dampened the G-forces using Cotronics's Colaco 4525 Epoxy. Still dunno what the max G-force was, but the Pi can handle it in his rig. :D

KDM
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tlhIngan
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  • Hmmm Low Vibrations....that's not vague or anything. Something tells me I am going to have to find something a bit more shock absorbent than the standard plastic housings that are used for flight timers and altimeters for staging and recovery deployment. Maybe some sort of enclosure with a non-conductive gel for shock absorption, after reinforcing on-board receptacles with hot glue lol. – NZKshatriya Feb 06 '17 at 04:52
  • @NZKshatriya Updated my answer with new info – tlhIngan Feb 06 '17 at 05:14
  • @goobering already beat ya to that one in an above comment lol – NZKshatriya Feb 06 '17 at 05:30
  • @NZKshatriya The comment didn't have any actual info, just a link to the info. Those are frowned upon. :D – tlhIngan Feb 06 '17 at 06:25
  • Hmmm, true. And you mean it "handled" it in his rig, up until the nosecone met a less than happy end due to not being able to withstand the forces encountered going over Mach 1. You should see the second video on the page. Nose cone collapses and the entire rocket flight goes fubar (not even what I am designing could counteract that sort of departure from normal flight) – NZKshatriya Feb 06 '17 at 06:41
  • Is vibration the same thing as high G-forces ? I would assume them to have quite different effects , especially considering the SD card slot. – flakeshake Feb 10 '17 at 09:43
  • @flakeshake Vibrations and G-forces are different things, yes, but they are related. Vibrations cause G-forces (at the extreme end of the vibration) when the component is changing direction. – tlhIngan Feb 10 '17 at 18:56
  • It seems to me, that I am going to need to bite the bullet (or in this case rocket) and just do a test launch with a Pi3 in a payload bay, testing both vertical and horizontal mounting, as well as shock absorption methods to determine the maximum it can handle. Thankfully these things are not too expensive (when just the Pi3 itself). If I were trying the project with say, a Parallella board..........I would be much more hesitant. – NZKshatriya Feb 16 '17 at 17:31