[AR] Re: "How Hard Can It Be" rocket episode
- From: George Herbert <george.herbert@xxxxxxxxx>
- To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
- Date: Tue, 19 Nov 2013 14:26:06 -0800
Personally, I believe in engineered crush structures. A lot.
If you can establish the G-load limit (and possibly, if applicable, jerk
and jounce limits) for the electronics, you can mount it so it can slide
vertically, with a known resistance foam or honeycomb above it for some
distance.
Combining that with how hard you think the lawn dart impact will be (tank
length, expected terminal velocity, etc), you can use calibrated
foam/honeycomb to keep loads safely below the established limit. You need
enough space for that to happen over the impact event, with some margin
(and some higher resistance foam / honeycomb as a final bumper in case of
mistake / exceptional situation).
These are rockets; 10, 20, 50 cm of cylinder for it to decelerate in is
probably Just Fine...
Some of my lawn-dart style manned capsule landers kept G-loads to 10 Gs or
less for the crew. That should be within tolerance bands for electronics,
though one needs to look at the specific equipment.
On Tue, Nov 19, 2013 at 1:55 PM, Henry Spencer <henry@xxxxxxxxxxxxxxx>wrote:
> On Tue, 19 Nov 2013, George Herbert wrote:
> > For liquids, one might consider recovering using a front-mounted
> propellant
> > tank (possibly open-cell foam filled) with integral nosecone, with
> > mid-mounted electronics with a really good shock mounting and really
> SOLID
> > nose bulkhead between it and the front tank, and just use lawn darting
> > recovery and assume replacement of the nose tank after flight.
>
> One possible downside of this is something Armadillo ran into once:
> electronics that seemed all right after a mild crash, but in fact were
> flakey and unreliable later. Cracked traces or solder joints?
>
> Recovering the electronics package sufficiently intact to get the data out
> is one thing; treating it gently enough that you can still depend on it
> for future flights is a rather more demanding requirement, and a somewhat
> ill-defined one too.
>
> Henry Spencer
>
> henry@xxxxxxxxxxxxxxx
> (
> hspencer@xxxxxxxxxxxxx)
> (
> regexpguy@xxxxxxxxx)
>
>
>
--
-george william herbert
george.herbert@xxxxxxxxx
Other related posts:
