At 22.04 2012.06.20, you wrote:
>> In answer to other messages, the accelerometer I'm using is +/- 6g on al=
l
>> 3 axis, I don't think it's clipping anymore (it was when it was +/- 2g )=
,
>
>That's still pretty slim margin. Acceleration is deceptive.
>Can you mount a temporary unit with more like a 20G range, to confirm
>that you aren't seeing larger events?

I have some 10g accelerometers and I will mount them when I make new boards=
,
i.e. when the PCB manufacturer sends them (2 weeks? as I haven't sent the o=
rder
yet because I have to spend some days updating some other parts), the one I=
'm
currently using is already potted in epoxy and I cannot rework it. I had ma=
de
this PCB by hand but with PTH components which need both sides soldered and
offer physical access only to the bottom side, it's a nightmare (to solder =
the
connector for example I had to bend all the pins to gain access to the top =
side,
then re-bend each, and so on. With the cap the height was 1mm too high and =
I had
to invent other things to overcome the lack of PTH, the board was generally=
 not
easily solderable, etc.. a nightmare when you try to make a professional (0=
403
components, QFN, etc..) PTH prototype board by hand).


>I had a project where we were doing somewhat worse things to the PCBs,
>but we were able to get the events DOWN to 2000G, with carefully
>designed Norsorex dampers. We also had to pay careful attention to
>mass distribution on the PCB so that we didn't flex much during those
>events.

The original ECU alredy used silent blocks (just thick rubber washers), and
that's what I'm using too. I wonder if there's some better way to damp the
vibrations, but I cannot use any extra mm of space than the original uses,
and it's mounted on a small plate which flexes. A question: what is more
rigid, a 1mm thick plane of aluminium or steel? Is there any rigid material
which will damp vibrations? Or is it even a contraddiction in terms?


>--=20
>http://www.piclist.com PIC/SX FAQ & list archive
>View/change your membership options at
>http://mailman.mit.edu/mailman/listinfo/piclist

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.