2 Altimeters one switch
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One switch is not true redundancy. Your altimeters need to be independent. I assume you were also considering one battery, too?
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Two altimeters, two batteries, two switches, two sets of ematches. You CAN put both ematches in the same charge well if it's oversized, but two charges/wells is safer.
Just like everyone said, if the one switch fails, both alts loose power.
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I’ve seen encapsulation failure on deployment charges. So I get a bit nervous when I see a ”redundant” system where both initiators go into a single charge holder.
On another note, I think activating two altimeters at the exact same time is going to make it tough to decode audible status reports. Better to let one start up and make sure all the reports are good then start the other.
The rrc3 has the dedicated terminals for the battery and a switch. The switch terminals just need to be connected together.
I did a bunch of bench testing during the wifi switch debat. I did plan to figure out if full battery current is passed through the switch terminals on the rrc3 but this would only be for curiosity sake.
If the switch is left unarmed or fails in some way during the flight it's possible both altimeters will shutoff and not perform the intended flight duties.
As said above for redundancy: 2 or more of everything. As for the original question can you run both rrc3 altimeters with 1 switch, yes you can. I am not sure anyone would recommend this for many reasons. The rrc3 has the option for a high and low audio tone, so the 2 could be distinguished.
I did a bunch of bench testing during the wifi switch debat. I did plan to figure out if full battery current is passed through the switch terminals on the rrc3 but this would only be for curiosity sake.
If the switch is left unarmed or fails in some way during the flight it's possible both altimeters will shutoff and not perform the intended flight duties.
As said above for redundancy: 2 or more of everything. As for the original question can you run both rrc3 altimeters with 1 switch, yes you can. I am not sure anyone would recommend this for many reasons. The rrc3 has the option for a high and low audio tone, so the 2 could be distinguished.
Just stagger the power up of each altimeter by 5-10 seconds and you can hear both reports fairly easily.
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Why not....just put the switch in the ground leg.
Tie the grounds together and switch that going to the altimeters.
Rules are SO vague this is legal and electrically valid.
True that if that switch fails you'll lose both altimeters.....but shouldn't be a problem in the real world.
Tie the grounds together and switch that going to the altimeters.
Rules are SO vague this is legal and electrically valid.
True that if that switch fails you'll lose both altimeters.....but shouldn't be a problem in the real world.
I wouldn't recommend this. It's still not redundant. For the sake of one extra switch why would you risk it?
Can't do it for L3
SnapRoll
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I use pull pin switches on my rockets which depending on configuration turn on the whole family at the same time.. to combat what you remarked, I change the piezo tone of the altimeters to opposite spectrums so it’s a bit more identifyable..
With the MW Alts, that can be done on the USB or with the LCD config..
Hope that helps.
i just hope to own just 1 RRC3 one day.
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Yes, not for an L3 but that's a singular event.
And now we hear that we should add switches....wow such inconsistency.
In another thread people went crazy "ANGRY" when I suggested using a switch even with redundant contacts.
Do what you want - the rules don't stop you from using one.
And now we hear that we should add switches....wow such inconsistency.
In another thread people went crazy "ANGRY" when I suggested using a switch even with redundant contacts.
Do what you want - the rules don't stop you from using one.
Titan II
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Addition to my post #3. It has been mentioned to use one charge well for two alts. Absolutely not. Why would anyone do that and reduce the redundant factor? One cannot say the problem is room. Charge "wells" are generally not needed. A couple charges in finger tips with surrounding tape is good to go.
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I use the pull pin switches and use the vent hole for the pin.
Single and double switches.
Check out labrat rocketry.
Single and double switches.
Check out labrat rocketry.
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I just received three position pull switches from lab rat. I’m working on the layout. They look easy to install an use.
Tip:
I drilled one vent hole larger in diameter so I knew easily which hole and set up that one vent hole to be in the front of rocket.
This is if you ever had to disarm while on the pad for any reason it is simpler this way.
I also secured switch (not permanently) to sled until it was in right position. So yes it was easy to install and mount.
FWIW
I was unable to disarm my rocket one time (Oct 21') as the altimeter was not responding. Removed from the rail and walked it back to my set up. Set it down, picked it up and it blew apart in my hands 8" from my face. Scared the daylights out of me and is why I do the pin switches now.
My mentor told me about these switches after the fact and now he has done the same set up on all his dual deploy.
I have seen switches fail in-flight. It wasn’t my rocket, but it was a rocket belonging to a TAP. The switch was a push-push switch, the kind with a red button that alternates between on and off with each push. Because he had two separate switches the rocket survived.
A single switch to power up two devices would not meet the definition of redundancy. Redundancy is only required by our Safety Code for L3 certification flights and only for the primary event, but in my opinion it’s poor judgement to risk safety when redundancy is easy to do.
A single switch to power up two devices would not meet the definition of redundancy. Redundancy is only required by our Safety Code for L3 certification flights and only for the primary event, but in my opinion it’s poor judgement to risk safety when redundancy is easy to do.
I’m sure you already know now (and why!
), but for others’ education taking a rocket off the rail without disarming it is a violation of the Safety Code. I know of times where people have ended up having to drill larger holes in their rockets so they could reach wires that had been twisted and pushed back into the airframe. They weren’t happy. They would have been less happy if one of them had been injured.Black powder doesn’t fail, altimeters, batteries, wiring, switches, and e-matches can fail. If properly sized (a little oversized actually), properly contained, and properly ground tested the black powder does not fail.
Yes I do.I’m sure you already know now (and why!
In my case we could not tell if it was disarmed or not so I was forced to take it down and rco and myself were not to keen doing it either.
This is one of the reason to ALWAYS have an external switch, I use Lab Rats's pull pin switch.
And for 2 alts i ust their double switch. if I have a tracker also. I use the triple switch. One pin, 3 switches.
And for 2 alts i ust their double switch. if I have a tracker also. I use the triple switch. One pin, 3 switches.
One switch. What could possibly go wrong. One switch can fail. This was one of mine 10 years ago. The slide contacts should be in the black bit below This one switch was only for one controller. But had enough contacts it could have done 2.
I have seen the back of a rotary switch be pushed out by a bump on the shaft during moving the rocket around. Luckily I spotted it before needing to fly it. Switch was replaced and a plastic collar added to stop the shafts pushing through. Three poles on that switched did power and ematch connections for one altimeter (off-on-armed).
Personally, if you are pushed for space I would consider using one switch, and make sure it is a reliable one. If you have enough space I would use a second. YMMV.
Personally, if you are pushed for space I would consider using one switch, and make sure it is a reliable one. If you have enough space I would use a second. YMMV.
AHansom
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What motivated you to the idea that you would try one switch? Money? Space/room? Complexity? Wanting to be the cover photo of "Lawn Dart Monthly"
