Revision to Tripoli Rule Regarding Wireless Remote Switches

Advertise with us
SilicdyneTRF
eggtimer rocketry
The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Status
Not open for further replies.
Perhaps the board needs to consider a process by which new electronics are "certified". The manufacturer has to document to the board the failure modes and provide a few basic wiring configurations as part of their documentation that show how their device could be wired so to meet the necessary provisions for security.

Having thought about it a bit, while I like and respect the members of the TRA board, this was a serious pooch-screwing from an implementation point of view. Rates right up there with the ad-hoc requirement for electronics with VMAX propellant. That was another case where a national board said something was unsafe and seemed unwilling to share any data to support their assertion - again the result was stranding flyers with things they could not use for no other reason than "we said so".

Disclosure - I agree with the idea. I just think the communication and implementation was sub-par.
 
Last edited:
H_Rocket said:
Perhaps the board needs to consider a process by which new electronics are "certified". The manufacturer has to document to the board the failure modes and provide a few basic wiring configurations as part of their documentation that show how their device could be wired so to meet the necessary provisions for security.

Having thought about it a bit, while I like and respect the members of the TRA board, this was a serious pooch-screwing from an implementation point of view. Rates right up there with the ad-hoc requirement for electronics with VMAX propellant. That was another case where a national board said something was und=safe and seemed unwilling to share any data to support their assertion - again the result was stranding flyers with things they could not use for no other reason that "we said so".

Disclosure - I agree with the idea. I just think the communication and implementation was sub-par.
Click to expand...
He who certifies carries some portion of the liability should something go awry when the criteria of the certification was met. That is no doubt what Tripoli wants to avoid, and I don't blame them. It's a fine line they're walking - asking for what I'll term "best practices" while not getting to deeply in mandating what those best practices are.
 
H_Rocket said:
Perhaps the board needs to consider a process by which new electronics are "certified".
Click to expand...

Hard No. The rocket builder is the system integrator. Safety certification responsibility lies wholly with the rocket builder. The manufacturer should provide all the necessary information necessary to the builder to make the safest system possible. But at the end of the day, the rocket owner is responsible for their and other's safety.
 
jderimig said:
Hard No. The rocket builder is the system integrator. Safety certification responsibility lies wholly with the rocket builder. The manufacturer should provide all the necessary information necessary to the builder to make the safest system possible. But at the end of the day, the rocket owner is responsible for their and other's safety.
Click to expand...
Well played. Flyers need to remember that their HPR certifications aren’t just an inconvenience that they have to go through to buy bigger motors, but a way to make sure they know how to build and fly safely, and know how to do it within the rules.
 
jbr said:
almost any rocket without deployment can cause major damage
ask Ross Dunton about the estes alpha that went thru his front window, thru the radio and stuck into the floorboard
had this hit a person instead.......................................
Click to expand...
Or, the Gyroc that pierced a house roof under construction only 30 feet from a roofer...
(Not a Ross Dunton episode, but GAMMA back in the earlier days.)
 
cerving said:
Well played. Flyers need to remember that their HPR certifications aren’t just an inconvenience that they have to go through to buy bigger motors, but a way to make sure they know how to build and fly safely, and know how to do it within the rules.
Click to expand...
Absolutely. It seems that TRA is taking a wrong turn towards getting into approval and certification of electronic and deployment systems. It would be much better to make reccomendations in the form of technical publications. The L3 cert process is in place to review designs for M motors, but there is no other cert process for dual deploy or electronic staging at lower impulses. Perhaps additional certs with tests, design reviews, and flights would be an easier way to accomplish our goals and ensure that fliers have safe designs.
 
Since electronic deployment is a prerequisite for L3 certs, maybe it’s time for a separate cert for it. L1 would be a prerequisite... although personally I had done dozens of them before I got mine.
 
Yes, additional certs for DD (required prior to L3) and staging (DD as prerequisite). It would be cool to get extra pins for them too.
 
cerving said:
Since electronic deployment is a prerequisite for L3 certs, maybe it’s time for a separate cert for it. L1 would be a prerequisite... although personally I had done dozens of them before I got mine.
Click to expand...

I think there’s something there, Cris.

I would also take it a step further and advocate for some best practice training around wiring and soldering techniques. I may be in the minority with this idea, but as a part of the certification process we spend a lot of focus on the mechanical aspects of rocket construction - which of course is very important - with a lot less conversation around building a reliable electronics bay. “This is left as an exercise for the student”, as college textbooks like to say.
 
rrobe99999 said:
Yes, additional certs for DD (required prior to L3) and staging (DD as prerequisite). It would be cool to get extra pins for them too.
Click to expand...
I agree I wouldn't be against be that either it's a big jump to dd if you have never done it before the additional certification might be a good idea but it needs to be implemented well and any testing needs to be written by people who have a good understanding of electricity and electrical components
 
g.pitts said:
I think there’s something there, Cris.

I would also take it a step further and advocate for some best practice training around wiring and soldering techniques. I may be in the minority with this idea, but as a part of the certification process we spend a lot of focus on the mechanical aspects of rocket construction - which of course is very important - with a lot less conversation around building a reliable electronics bay. “This is left as an exercise for the student”, as college textbooks like to say.
Click to expand...

I like the idea of best practices and training very much.
 
For what it's worth, our club had our weekly 'rocket lunch' today, and no one, including at least 5 L3 flyers, thought the new rule was based on practical reality. We all felt solid state switches were in practice safer than the myriad mechanical solutions we have used and seen over the years. It is this disconnect between practice and the rule that I think is the basis of so much discord over this issue.

Tony
 
Last edited:
cerving said:
Since electronic deployment is a prerequisite for L3 certs, maybe it’s time for a separate cert for it. L1 would be a prerequisite... although personally I had done dozens of them before I got mine.
Click to expand...

Yes, we support Chris on this purposal. There should be a separate "electronics" certification and it must be achieved prior to using an electronic flight/recovery system. Again, prior to, this means that if you fly a rocket, even prior to your Level 1 attempt, and it uses an electronic flight/recovery system then you will need to get your Electronics Level certification.
 
In January, prior to knowing about Tripoli's ruling revision, I had decided to use Eggtimer Quantums on my current build (primary and back up). I opted for the double battery set up in which one battery will energize the computer side, and the other battery would the energetics (deployment) side. I'm using a pull pin switch kit from Rat Lab Rocketry that has two Omron SS-5GL switches (one for each Quantum) in which I'm hooking to the positive lead of the deployment battery. This I did for my personal peace of mind thinking of being overly safe. It happens to be what Cris Erving is stating in post #309 to satisfy Tripoli's ruling revision. Attached are images showing the primary Quantum in place on the avionics sled (the back up Quantum I still need to build this weekend).

IMG_7415.JPG IMG_7416.JPG
 
rockladen said:
In January, prior to knowing about Tripoli's ruling revision, I had decided to use Eggtimer Quantums on my current build (primary and back up). I opted for the double battery set up in which one battery will energize the computer side, and the other battery would the energetics (deployment) side. I'm using a pull pin switch kit from Rat Lab Rocketry that has two Omron SS-5GL switches (one for each Quantum) in which I'm hooking to the positive lead of the deployment battery. This I did for my personal peace of mind thinking of being overly safe. It happens to be what Cris Erving is stating in post #309 to satisfy Tripoli's ruling revision. Attached are images showing the primary Quantum in place on the avionics sled (the back up Quantum I still need to build this weekend).

View attachment 406496 View attachment 406497
Click to expand...
Thanks for sharing. A question if I could. I see your switches are a lined with the center line of the rocket, are you concerned about G forces in the rocket flight could adversely effect the micro switch contacts which are also in line with the same rocket centerline? Would have rotated them 90 degree possibly be better?
 
LRF said:
Thanks for sharing. A question if I could. I see your switches are a lined with the center line of the rocket, are you concerned about G forces in the rocket flight could adversely effect the micro switch contacts which are also in line with the same rocket centerline? Would have rotated them 90 degree possibly be better?
Click to expand...
My understanding on the Omron switches is that they're pretty impervious to G forces, but that is a good question. I'll research and see if I can find a schematic of an Omron switch.
 
microswitches can bounce, any switch that is spring loaded will do this with enough force
 
If you have a switch that isn't rated for high-G, high-vibration then it is best to put it on the deployment side, either on the deployment power or between the igniters and the altimeter. Things are likely to be much less stressful near apogee and on drogue, so they probably will be fine when they're needed. If it's for an airstart... spend the money and get a good switch that can handle the stresses.
 
SDramstad is correct. Also checked out the Omron Datasheet for the SS-5GL, and its a pretty rugged switch. Switch malfunction at 30G's and destruction at 100G's. Mechanical service life is a ridiculous 30 million min. at 60 operations per minute.
 

Attachments

  • Omron-SS-5GL-datasheet.pdf
    578.2 KB · Views: 21
cerving said:
If you have a switch that isn't rated for high-G, high-vibration then it is best to put it on the deployment side, either on the deployment power or between the igniters and the altimeter. Things are likely to be much less stressful near apogee and on drogue, so they probably will be fine when they're needed. If it's for an airstart... spend the money and get a good switch that can handle the stresses.
Click to expand...
Thanks for the comment above.
Chris, if you have a part number suggestion, or anyone else please share as you would be doing the community a favor.
 
rockladen said:
SDramstad is correct. Also checked out the Omron Datasheet for the SS-5GL, and its a pretty rugged switch. Switch malfunction at 30G's and destruction at 100G's. Mechanical service life is a ridiculous 30 million min. at 60 operations per minute.
Click to expand...
You are in good shape. Design and (even soldering :)) look nice. Love the offerings from Additive and Lab Rat. People like to pick things apart here. Applaud your efforts to be "extra safe" before it was mandated.
 
as an rso, I guess you have to trust the flyer when they say...just because it is beeping does not mean there is not a switch in the deployment circuit

so that would be a good thing to say even if you didn't have a switch, or how would or could an rso even know?
 
LRF said:
Thanks for the comment above.
Chris, if you have a part number suggestion, or anyone else please share as you would be doing the community a favor.
Click to expand...
I do not at this time, but obviously I'm going to be looking at it. I can tell you that I have used both the Featherweight and MissileWorks screw switches and they work fine; I used the Schurter switches once upon a time and stopped using them because of durability issues. I think any decent industrial-rated switch will be fine on the deployment side, I'd still avoid the cheap generic switches though.
 
When I first got into High Power, we used to make our own igniter using wire and pieces of fuse cord. It was normal practice to completely assemble and prep the rocket before we went to the RSO table. It was at Danville one evening when the “impossible” occurred. Fortunately no one was seriously injured. It makes sense to most people never to put an igniter in until you have the pointy end up at the pad. Now we are being asked to make another change, this one is to show up to the RSO table with the ejection charges and ignition methods completely disabled. I think this just means, “ don’t hook up the batteries until after you have passed the RSO.” Kind of makes sense, it doesn’t require you to have a mechanical switch necessarily, you just will NOT have power applied to any energetic loads while the RSO is checking your rocket.
 
jbr said:
as an rso, I guess you have to trust the flyer when they say...just because it is beeping does not mean there is not a switch in the deployment circuit

so that would be a good thing to say even if you didn't have a switch, or how would or could an rso even know?
Click to expand...
You have to show the RSO where your switch is. I used twist-and-tape at ROC last weekend, so it was pretty obvious... but they asked me anyway. They probably thought, "It's Eggtimer Cris so he's going to be trying to skirt the rules..."

And yes, beeping does not equate to "DANGER!". Case in point, I was flying with a TRS that was being used just as a GPS tracker, there aren't even any wires on the deployment side... but it still makes the same "I'm ready" chirp that TRS users know and love.
 
kc9qzf said:
When I first got into High Power, we used to make our own igniter using wire and pieces of fuse cord. It was normal practice to completely assemble and prep the rocket before we went to the RSO table. It was at Danville one evening when the “impossible” occurred. Fortunately no one was seriously injured. It makes sense to most people never to put an igniter in until you have the pointy end up at the pad. Now we are being asked to make another change, this one is to show up to the RSO table with the ejection charges and ignition methods completely disabled. I think this just means, “ don’t hook up the batteries until after you have passed the RSO.” Kind of makes sense, it doesn’t require you to have a mechanical switch necessarily, you just will NOT have power applied to any energetic loads while the RSO is checking your rocket.
Click to expand...

That’s exactly right. It just means no power until you’re safely away from the RSO table and spectators.
 
  • Like
Reactions: LRF
the job of an rso is not to trust the flyer, but to verify that the rocket is safe to fly

me as an rso would reject a rocket with a powered on altimeter unless the flyer was willing to take apart the ebay and prove to me that the switch was really on the deployment side
 
jbr said:
the job of an rso is not to trust the flyer, but to verify that the rocket is safe to fly

me as an rso would reject a rocket with a powered on altimeter unless the flyer was willing to take apart the ebay and prove to me that the switch was really on the deployment side
Click to expand...

Wait, what? You're going to ask that a flyer disassemble the Ebay on the RSO table? I definitely see asking the question, but I thought we as a hobby were in the business of trusting the flyer. Would you at least trust the phone screen on a Quantum/Proton that says there's no continuity on the deployment channels? Do you also review the OpenRocket/RockSim file at the RSO table?
 
Status
Not open for further replies.

Similar threads

Dave A
Sold Missile Works--WRC2--2CH Wireless Remote Control
Replies
0
Views
476
Dave A
Dave A
F
I2C Rocket Starter Controller
Replies
8
Views
1K
HyperSpeed
HyperSpeed
B
Opinions solicited regarding proposal for Horizontal Spin Recovery Duration as a NAR competition event
Replies
29
Views
1K
astronguy
A
Kane
Design and Build Thread: ARO-B Two-Stage
Replies
22
Views
2K
Kane
Kane
Mark Weidhaas
Simple Wireless Launch Controller
Replies
5
Views
2K
Mark Weidhaas
Mark Weidhaas

Latest posts

Back
Top