Richard, keep in mind I'm running sometimes bursts of 3A of power in my
sleds, so you don't need
to do any of that beefing up an Aerocon switch. Just get an aerocon screw
switch and you're good :-)
On Thu, Jan 12, 2017 at 9:03 PM, James Dougherty <jafrado@xxxxxxxxx> wrote:
Yes! The Aerocon screw switches are excellent. I've never had one fail.
I've been making my own with sturdier contact by soldering a brass washer
onto a slightly larger screw. (e.g. solder washer onto socket head, tap
out
screw switch body, silver solder lead contacts); parts list for 10 below:
McMaster Parts
1 93465A144 Brass Socket Head Cap Screw, 6-32 Thread, 1/4" Length, Packs
of 10 1
1 98044A212 Electrically Conductive Copper Flat Washer, M3 Screw Size, 7MM
OD, .45MM-.55MM
McMaster (nice to have part)
1 5497A38 Comfort Grip Ball Driver, Long Length, 7/64" Hex, 5-7/8" Blade
Length 1
10 Aerocon Screw Switches - http://aeroconsystems.com/
cart/switches/pcb-screw-switch/
Erik, Jim Green and others have been using these:
http://www.robotmarketplace.com/products/0-ft-mini-switch.html
http://www.fingertechrobotics.com/proddetail.php?prod=ft-mini-switch
I just got some for Christmas this year! Yayyyyy! :-)
On Thu, Jan 12, 2017 at 10:30 AM, Kurt Gugisberg <kurtgug@xxxxxxxxx>
wrote:
Richard,
I have used the PCB screw switch more than any and have no problem though
they are more difficult to mount. The featherweight switches have one
issue that got me one time. On a long trip to Black Rock, I had the little
screw vibrate out of its nut and was lost. I suppose it could vibrate
closed also and if you have everything already prepped, it could turn on
your electronics. What I do now is place something in the hole, like a
Q-tip, and tape it down so that the screw won't move. The PCB switches
don't have this problem.
On Thu, Jan 12, 2017 at 10:18 AM, R Dierking <applerocketry@xxxxxxxxxxx>
wrote:
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 <lyzenga@xxxxxxxxx>
*Sent: *Thursday, January 12, 2017 9:36 AM
*To: *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> 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>
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 <jafrado@xxxxxxxxx>
*Sent: *Thursday, January 12, 2017 8:09 AM
*To: *roc-chat@xxxxxxxxxxxxx
*Cc: *Mike Kramer <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>
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 <kramer@xxxxxxxxxxxx>
*Sent: *Thursday, January 12, 2017 7:09 AM
*To: *ROC Chat <roc-chat@xxxxxxxxxxxxx>
*Cc: *ROC Chat <roc-chat@xxxxxxxxxxxxx>; James Dougherty
<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>
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>
Dept. of Physics, Harvey Mudd College (909) 621-8378
Claremont, CA 91711-5990 mobile (626) 808-5314
