Thank you Guys! Based on what I’m hearing, I think it would be prudent for me
to replace the current 110/220 rotary switch with something else for my L3
back-up system*. Like I said, I’ve tested the current switches with no issues.
So, I’m going to order some different switches from Aerocon and check them out.
Also, try to retrofit one of the 110/220 switches.
*The topic of redundancy is interesting and maybe deserves a separate thread.
I’ve seen it has different meanings. For example, someone says their
deployment system is redundant but the two systems share the same battery or
activation switch, which can be done with the 110/220 because it has two
circuits. So, what if you are using the same type of switch, or say deployment
system (i.e. two e-matches from the two triggering systems in the same BP
canister), is your system truly redundant? I’ve even considered using
different makes of batteries, or not using ones from the same package.
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
From: Gregory Lyzenga<mailto:lyzenga@xxxxxxxxx>
Sent: Thursday, January 12, 2017 9:36 AM
To: roc-chat@xxxxxxxxxxxxx<mailto:roc-chat@xxxxxxxxxxxxx>
Subject: [roc-chat] Re: Switch Warning with StratoLogger CF
Like Kurt, I’ve used the switches for many years without an in-flight failure,
including my L3. But… a couple of things started to make me wary of them, and
I have migrated away from using them in any future projects. I started to hear
the same reports of failures and limited life cycles, which made me uneasy.
And then, although I never had one fail in flight, I had one in a ground test
that didn’t close until I cycled it a few times. I chalked it up to dust in
the contacts, but ever since then have looked at them with less trust than I
used to. So my attitude now is that I got lucky and did not have my number
come up with a fatal failure, but I won’t press my luck with them any more.
(On my latest projects, I’m thinking of using the Featherweight magnetic switch
which is pricey but seems pretty slick with no moving parts or holes in the
airframe.)
- Greg
On Jan 12, 2017, at 9:12 AM, Kurt Gugisberg
<kurtgug@xxxxxxxxx<mailto:kurtgug@xxxxxxxxx>> wrote:
I have used those rotary switches for years. I haven't had one split apart on
me and I'm not sure if I have had any failures either, although I had one in
the ill fated Nibbles flight last year with it's total electronic failure. So
it could have failed. I also use screw switches alot, the Featherweight switch
as well as the Aerocon screw switch. They are, more or less, foolproof.
Also, three hundred operating cycles would be a lot in rocketry.
Kurt
On Thu, Jan 12, 2017 at 8:13 AM, R Dierking
<applerocketry@xxxxxxxxxxx<mailto:applerocketry@xxxxxxxxxxx>> wrote:
Hum, that doesn’t sound good. I’ll have to take a look at what Mike has
designed. It would be nice if a retrofit would fit inside the existing hole
used for the 110/220 switch. Or, perhaps remove the guts from the 110/220 and
replace it with something more durable/reliable.
From: James Dougherty<mailto:jafrado@xxxxxxxxx>
Sent: Thursday, January 12, 2017 8:09 AM
To: roc-chat@xxxxxxxxxxxxx<mailto:roc-chat@xxxxxxxxxxxxx>
Cc: Mike Kramer<mailto:kramer@xxxxxxxxxxxx>
Subject: [roc-chat] Re: Switch Warning with StratoLogger CF
They split in half!!
Ive also seen people turn them and they split in half.
Its designed for a wall socket!
Yes, do what Mike said - great plan; Never seen that fail ...
Sent from my iPhone
On Jan 12, 2017, at 7:22 AM, R Dierking
<applerocketry@xxxxxxxxxxx<mailto:applerocketry@xxxxxxxxxxx>> wrote:
Yes, I would like to try this out Mike, please send the file. I’ll look into
the materials available for the printer. I think I only have PLA at the
moment. How about ABS?
From: Mike Kramer<mailto:kramer@xxxxxxxxxxxx>
Sent: Thursday, January 12, 2017 7:09 AM
To: ROC Chat<mailto:roc-chat@xxxxxxxxxxxxx>
Cc: ROC Chat<mailto:roc-chat@xxxxxxxxxxxxx>; James
Dougherty<mailto:jafrado@xxxxxxxxx>
Subject: [roc-chat] Re: Switch Warning with StratoLogger CF
richard,
I use micro switches with a screw to arm them. Uses a small hole in the side of
the rocket and makes it highly unlikely that the electronics can be in
advertently armed.
Easy to 3d print the mount for it. I will send you a file tonight.
Side note, don't use PLA ( unless it is the pro spec kind) for parts, it can't
survive the temperatures on the lake bed. I'm using PETG or Nylon.
Mike K
On Jan 12, 2017, at 6:47 AM, R Dierking
<applerocketry@xxxxxxxxxxx<mailto:applerocketry@xxxxxxxxxxx>> wrote:
I just purchased a PerfectFlite StratoLoggerCF altimeter and the documentation
came with a Switch Warning about failures of the 110/220 rotary switch that
some people have been using for powering electronics. High resistance and
intermittent connection are noted in the document.
The document says “numerous reports” of failures, but I’m curious if this is a
problem with a group/lot of these switches or a pervasive problem to this
particular switch or rotary-type switches in general when used for rocketry.
I’ve used these switches in the past and tested the 4 I’m currently using on
two projects. I’m not detecting any problems with these switches.
Please keep in mind that there are several variations for this make of
switches. Here’s some info on what I have:
Schurter, Voltage Selector Switch, 2 Stages, Series-Parallel, SWA1 or SWA2
Also, it’s interesting that the spec sheet says that the lifetime is 300
operating cycles (without load).
So, does anyone have a personal experience that was bad with these switches?
Also, I think many people would be interested in recommendations on arming
switches both commercial and custom.
Thank you,
Richard Dierking
----------------------------------------------------------
Gregory A. Lyzenga <lyzenga@xxxxxxx<mailto:lyzenga@xxxxxxx>>
Dept. of Physics, Harvey Mudd College (909)
621-8378<tel:%28909%29%20621-8378>
Claremont, CA 91711-5990 mobile (626)
808-5314<tel:%28626%29%20808-5314>
