Rotary Switch Failures?

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The WiFi Switch turns off power to the device, the same as a physical switch. What NAR doesn't want you to do is to simply disarm your altimeter to turn deployments "off"; they want the power to the deployment initiator disconnected. Using a WiFi Switch (or any other electronic switch, such as a Featherweight Magnetic Switch) between your deployment battery and the deployment device satisfies this requirement.
 
cerving said:
The WiFi Switch turns off power to the device, the same as a physical switch. What NAR doesn't want you to do is to simply disarm your altimeter to turn deployments "off"; they want the power to the deployment initiator disconnected. Using a WiFi Switch (or any other electronic switch, such as a Featherweight Magnetic Switch) between your deployment battery and the deployment device satisfies this requirement.
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In what way do the WiFi switch and Featherweight Magnetic Switch physically break the circuit?
 
Steve Shannon said:
With a mechanical device, such as a relay, or with a solid state device, such as a FET? That's the crux of my question. If you'd like to take it offline I would be happy to.
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No, I think this is a good public discussion, it relates to other devices besides the WiFi Switch.

Like the other electronic switches that I know of, the WiFi Switch uses a FET to disconnect the battery from the load circuit. The net effect is the same as a mechanical switch; no power to the load, so no chance that a glitch in the controlling device can fire a charge.

I would submit that using a WiFi Switch for a L3 altimeter (or on the deployment power if it's separable) is safer than using a mechanical switch. With a mechanical switch, you've got your face right up against the rocket. If you have a shorted FET in your deployment controller (and they do happen...), once you turn on the power there's the potential for that charge to go off. With a WiFi Switch, you're a safe distance away when you apply power to the device, so if it blows it's an "oh damn" moment instead of a 911 call.
 
cerving said:
No, I think this is a good public discussion, it relates to other devices besides the WiFi Switch.

Like the other electronic switches that I know of, the WiFi Switch uses a FET to disconnect the battery from the load circuit. The net effect is the same as a mechanical switch; no power to the load, so no chance that a glitch in the controlling device can fire a charge.

I would submit that using a WiFi Switch for a L3 altimeter (or on the deployment power if it's separable) is safer than using a mechanical switch. With a mechanical switch, you've got your face right up against the rocket. If you have a shorted FET in your deployment controller (and they do happen...), once you turn on the power there's the potential for that charge to go off. With a WiFi Switch, you're a safe distance away when you apply power to the device, so if it blows it's an "oh damn" moment instead of a 911 call.
Click to expand...

Please don't get me wrong; I love the idea of a switch that I can arm without being on a ladder a few feet or more in the air and face to face with the charges. 2.4 is pretty clear to me though and I know that when we voted on it we really meant a mechanical break, not a solid state break.
I would probably wire it in series with a mechanical switch and use the WiFi switch to open the circuit, then close the mechanical switch, back away to a safe distance, then close the WiFi switch. I realize that reduces reliability slightly.
 
Steve Shannon said:
Please don't get me wrong; I love the idea of a switch that I can arm without being on a ladder a few feet or more in the air and face to face with the charges. 2.4 is pretty clear to me though and I know that when we voted on it we really meant a mechanical break, not a solid state break.
I would probably wire it in series with a mechanical switch and use the WiFi switch to open the circuit, then close the mechanical switch, back away to a safe distance, then close the WiFi switch. I realize that reduces reliability slightly.
Click to expand...

To each his own but you're adding additional points of failure to the chain. Does this mean that NAR disapproves of magnetic switches too? The hierarchies need to move away from the "rotary phone" and to the "touch tone phone" world instead
of being incessantly obsessed with mechanical switches that have no proof that they add to the safety of anything. I can think of many scenarios where a mechanical switch or shunt isn't going to prevent an accident from happening.

If the only failure mode available to a wireless switch is for it to blow when the switch is remotely activated and not when the battery is connected to the switch then you people need to "smarten up" and approve them.
NAR especially was stuck on a "switch obsession" on every circuit with no thought as to whether or not it improved safety in reality or not in the past.

If the failure mode of the wireless switch is as Cris describes, both NAR and TRA should jump to approve them. If Cris or anyone else comes up with an electronic device that can arm the ignition circuit for a multi staged rocket at a distance
before launch, it should be embraced without the encumbrances of stupid external switches. If not, I feel sorry for the clown who breaks their neck falling off a ladder trying to actuate an unneeded switch. Kurt
 
Exactimator said:
I see no reason why the EggFinder WiFI switch would be an issue, but that's something you should confirm with your L3CC.

I would wonder more about the key switches. One of the requirements is that the ejection charges can be disabled. If someone needed to disable the charges and didn't have a key, that would be an issue. Again, something that would need to be checked with your L3CC.

Good advice I've heard on cert flights is go with what you know. Use whatever acceptable switch you're most familiar with.
Click to expand...

Yes, I have email out to my L3CC. He is traveling at the moment and I don't need to make a choice in the near future.
 
CzTeacherMan said:
+1...
Basic, mechanical, small. Can't go wrong.
Click to expand...

+1 more, I used two Missleworks screw switches on my L3, they were used between the batteries and the altimeters, the RRC3 had a jumper in the switch terminal so that closing the switch powered up the unit, the Quark has no switch terminal so the same thing occurred when the switch was closed. One switch per altimeter, as long as they were open no power to either of the altimeters was possible, my L3CC approved.

I no longer use the Schurters in new rockets as I now prefer the Missleworks screw switches.
 
gdjsky01 said:
But I am not into twist and stuff.
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Never stuff! Tape it to the outside with quality electrical tape.

I have flown well past mach 2 without a single problem to date. From time to time the tape will partially disintegrate, but never fully, and the wires have never come apart.
 
I have used many of these Schurter rotary switches over the years and not had any issues. I am wondering if maybe the problems some people have had with them is related to soldering. I just did a quick test and discovered that the surface finish on the internal switch contacts does change visibly if a terminal is heated to soldering temperature for more than a few seconds. With the soldering iron I used, a couple seconds is okay but at about 4-5 seconds there was enough heat conducted into the switch to change the contact surface finish. I have no proof this change in surface finish is detrimental to the operation of the switch but frankly, under the microscope, it does look somewhat “degraded”. The finish is not as nice and smooth. It would not surprise me if the number of reliable switching cycles is significantly reduced by this but I have not tested it. (By the way, the switch is very easy to take apart for inspection. Just squeeze together the two plastic posts sticking out the bottom. It is also very easy to re-assemble. Just push it back together.)

It would be easy for someone to do some testing to see if this is a problem. (hint, hint!)
 
I use eggtimer wifi switches, and/or Quantum altimeters (wifi built in). I arm everything from my cell phone while standing a few feet away from the pad. I receive battery status, main and drogue continuity. I can change flight events on the pad with my phone if I need to.

I've only been flying rockets for a year. I started last December with Estes rockets for the grandkids. So everything that's new fangled technology to you old timers is just the equipment that was available when I started out.

Old timers being those of you who have been shoot'n rockets longer than me... more than a year. Everyone else is an upstart! :smile:

I've never known a world without a JL chute release or wifi switches.
 
watermelonman said:
Never stuff! Tape it to the outside with quality electrical tape.

I have flown well past mach 2 without a single problem to date. From time to time the tape will partially disintegrate, but never fully, and the wires have never come apart.
Click to expand...

Ditto. This is what I do with most of my rockets and it's easy, cheap, secure and reliable. The only issue I run into occasionally is electrical tape doesn't stick so well in the cold, so sometimes I'll use an additional cover of masking tape or duct tape.

-brant
 
Thanks for all the replies. I've use the shurtler switches for years. Maybe its the StratologgerCF I need to get rid of.
Not sure... and no one is giving me data to suggest one versus the other. :(
 
gdjsky01 said:
Thanks for all the replies. I've use the shurtler switches for years. Maybe its the StratologgerCF I need to get rid of.
Not sure... and no one is giving me data to suggest one versus the other. :(
Click to expand...

There is nothing about the SCF that makes it more susceptible to rotary switch failure than any other computer. However I would be glad to take one off your hands if it is working order.
 
Zauskycop said:
What is the verdict on the 2P SPST On-Off 1.5A Push button Switch available from MAC Performance? I like the ease of the push switch...anyone have reviews or know if these will hold up?

IMG_20160918_155253_012-1_1024x1024.jpg
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The switches we offer are not from Radio Shack. We've been using these switches for many years with perfect results and that is why we have added them to our components. These switches are very robust in construction and have a very positive click action as they are cycled. This eliminates any doubt as to weather they activate/deactivate. I think that simplicity sometimes adds to function. We've flown them close to Mach 2, They have survived a drogueless landing without a main deployment, And I even used one once to take a core sample:facepalm:. Those same switches I still use...........They just work.

Mike Crupe
MAC Performance Rocketry

What's In Your Rocket?
FLY CANVAS!
 
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One thing I dislike about the Schurter rotary switches is that over time it is easy to damage the slot that you use to activate it.
 
blackwing94 said:
I use eggtimer wifi switches, and/or Quantum altimeters (wifi built in). I arm everything from my cell phone while standing a few feet away from the pad. I receive battery status, main and drogue continuity. I can change flight events on the pad with my phone if I need to.

I've only been flying rockets for a year. I started last December with Estes rockets for the grandkids. So everything that's new fangled technology to you old timers is just the equipment that was available when I started out.

Old timers being those of you who have been shoot'n rockets longer than me... more than a year. Everyone else is an upstart! :smile:

I've never known a world without a JL chute release or wifi switches.
Click to expand...

Try and get your Wifi switches by a TAP or L3CC without an external switch to turn them on! Sure, you may fly your current projects by attaching the battery to the Wifi switch(es) with your deployment devices already
with charges attached, button up the ebay and go fly. That likely won't pass muster on an L3 certification flight as the NAR guys will definitely insist on an external switch somewhere as the TAP will insist you stick
an on/off switch of "the approved kind" on the battery going to your WiFi switch. So be ready to do that for an L3 cert flight.

Me bets folks are prepping their altimeters with charges, attaching their WiFi switches sans any external power switch, buttoning up their ebay, taking the rocket to the pad, setting it upright, turning on the device(s)
with their Phones or Android devices and flying. I bet they are doing that all the time at major launches without any issues because the RSO's don't give it a second thought (or don't recognize the situation anyways). No need to because it's a safe practice........
Just don't do it with an L3 certification!! Kurt
 
gdjsky01 said:
I have a question.... Deans plugs... used to ARM high amp RC setups. But not by pulling... but by inserting... How might that be done with pulling?
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Interesting idea. I've been pondering the same for the situation where I use only internal switches like the Eggtimer Wifi switch or the Quantum - how to make the rocket safe to anyone who picks it up? Came up with this:
Put the "open" side of the Deans plug in the wire harness. Create the other half of the Dean's plug as a "pull-cord" permanently part of the vent band. Drill a small hole in the coupler. Over that hole, cut a larger piece of the vent band out and add to it two small holes like a shirt button. Fasten the Deans plug "open" side to the sled. Insert the other side as a jumper with a Kevlar cord around it. Pass the Kevlar cord out of the un-used vent hole, and tie it to the "button". Push the cord back in the hole once the av bay is assembled, and replace the "button" into the vent band. Cover it with a piece of aluminum tape. Add a label to peel the tape and pull the cord to de-power the charge (s). No tools required for the public who gets to your rocket first, and if they can read, they can make the rocket safe to pick up.

"DISARM Rocket before handling! - Peel tape. Pull cord firmly." ---->
 
I will buy any and all Schurter switches people want to dispose of. Name your (reasonable) price and I will pay shipping.
 
dixontj93060

:wink:
Not Selling! At least not yet. :wink:

I have 20 or so bought 'back in the day'... it's just that the PerfectFlite folks saw the need to included a new insert in the StratoLoggerCF instructions advising against them. Again... this took me by surprise as ALL my HPR Rocketry Warehouse rockets (Pre MadCow), Sublime, Formula 75, Formula 98, Broken Arrow, and Nike-Smoke are using them. Maybe they are no good anymore... But mine ware from 5 or 6 years ago. (I stocked up on Q2G2's back then as well!)
 
I have altimeter bays that use a single vent hole of 3/4 inch, regardless of any rocket works every time.
Inside the vent port I place 2 of the mini slide switches PML used to or maybe still sells. I mount them side by side, direction of switch travel perpendicular to the length of the rocker so g forces at launch or ejection wont turn a switch off.
It's easier to switch them on and listen to the altimeters right there. Never had a switch failure and I have tried many others.
I do use a rotary switch to arm my wireless controller in every nose cone 6" and larger.
 
gdjsky01 said:
dixontj93060

:wink:
Not Selling! At least not yet. :wink:

I have 20 or so bought 'back in the day'... it's just that the PerfectFlite folks saw the need to included a new insert in the StratoLoggerCF instructions advising against them. Again... this took me by surprise as ALL my HPR Rocketry Warehouse rockets (Pre MadCow), Sublime, Formula 75, Formula 98, Broken Arrow, and Nike-Smoke are using them. Maybe they are no good anymore... But mine ware from 5 or 6 years ago. (I stocked up on Q2G2's back then as well!)
Click to expand...

Awe com'on?!
 
No smiley face.... what did I say ?????


What should I do Big Bucks? Twist and tuck? Are altimeters prepared to deal with that 'switch bounce'?
 
gdjsky01 said:
No smiley face.... what did I say ?????


What should I do Big Bucks? Twist and tuck? Are altimeters prepared to deal with that 'switch bounce'?
Click to expand...

I am calling out to all the scared and worrisome rocketeers. Don't chance that L2 or L3 on those crappy Schurter switches, I'll take those high-quality German designed items off your hands at a "fair price."
 

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