Electronic ejection with remote on my hand

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20333

20333

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Is it possible to buy an electronic system that remotely operates a charge of black powder but which would be located under the piston?
In example, for rockets with a booster. If the second stage motor don't start, i must push a button on my hand to eject the parachute. Did anyone ever see that?

upload_2019-5-21_22-9-47.png
 
So you would put a charge well at the base of the piston?

Your system would only work for lower altitude flights, because if you can't see it has reached as apoge, you risk a zipper.

Most electronic systems trigger a drogue deployment charge at apoge, you could then set up the main charge as your backup.

Else, if your that worried, use a redundant system.

William
 
You right but i use this system if the second stage don’t start.
 
Check out the Eggtimer Rocketry site.
https://eggtimerrocketry.com/home/altimeters-av-bay/

They have several flight computers that do all the work for you. The computer can qualify the launch and make sure the rocket is where you want it to be before the second stage is ignited. If there is a problem, the computer is smart enough to recognize apogee, and that the second stage didn't light... and deploy the chute.

I have seen these work both successfully, and scrub an air start due to the rocket not being vertical or high enough for ignition. Both times, the chutes were deployed as required, and all parts were recovered undamaged.
 
The sustainer should never be dependant on "motor deployment".

It is best to use altimeter based electronic deployment in the sustainer.

In addition to altimeter deployment... you could add "remote" deployment using a button in-your-hand for added safety.
 
If you're simply asking if you can locate the drogue ejection charge below the piston, the answer is yes. You'll have to figure out how to do it, though. I suppose you could locate the altimeter in the piston itself with the requisite vent holes going through the airframe into the side of the piston.

If you're looking to do this with a two-stager, you could still do this too, but it's going to be a lot more complicated because you have to figure out how to get the electronics to light the sustainer motor and fire the drogue, and there has to be some kind of break between the wire that goes to the airstart igniter and the electronics. Get out a pencil and notepad and start sketching, and sketch what it's going to look like after it fires... you'll see what I mean.

Remote control of a sustainer is unnecessary and is not really a good idea, and unless you're doing your two-stager with small motors for the size/weight of the rocket it's going to be so high when it fires (or doesn't...) that you may not even be able to see the rocket to determine if you need to press the button. That goes for remote control of parachutes if you don't see the drogue either, because the rocket may be so high up that you can't tell. If you're doing an HPR airstart for the first time, you will be hard pressed just to get it to work properly without any fancy stuff added on.
 
Just use an altimeter and set it up for either dual deployment or single deployment. Use the motor as backup for the apogee event. That’s the least expensive and most reliable way to do it. I would never recommend a manually operated remote control for primary recovery. Backup for the main? Maybe, but not for the apogee event.
 
I have seen manually triggered recovery events used effectively on some relatively high flights. A DTMF tone over a normal radio was used. It worked.

I prefer altimeter deployment personally.
 
OverTheTop said:
I have seen manually triggered recovery events used effectively on some relatively high flights. A DTMF tone over a normal radio was used. It worked.

I prefer altimeter deployment personally.
Click to expand...

Yes, once upon a time when rocket electronics weren’t as commonplace as they are now people repurposed Radio Shack personal paging Systems to do that. After reading about that in HIgh Power Rocketry Magazine I stumbled across such a system marked down for clearance at a Radio Shaack and bought it. I never did use it.
I also remember seeing a friend futilely mashing the button on a non-responsive WRC while his rocket plummeted to earth.
I agree about preferring altimeters.
 
scsager said:
The sustainer should never be dependant on "motor deployment".

It is best to use altimeter based electronic deployment in the sustainer.

In addition to altimeter deployment... you could add "remote" deployment using a button in-your-hand for added safety.
Click to expand...
You right but my rocket is build since many years and does not have any electronic system
 
This would be the time to figure out how to add them. Or even better would it would be a handy excuse to build anew, then you can build what you want.
 
The OP is asking about adding a backup ejection system to an already-built rocket. He wants it to be manually activated by radio control, in the event that his upper stage does not ignite, as a "fail-safe" to prevent the rocket from streamlining in. Obviously, his upper stage is using motor ejection and not electronics.

As I see it, the biggest problem would be ensuring that the transmitter has sufficient range to be reliable at a considerable distance. A "Spektrum" RC system should be able to handle that task.

I am no "RC guru", but the combination of these items might work (The E-Match would have a "plug" soldered to it to fit the servo pins in the receiver.

https://www.horizonhobby.com/produc...smitters/ttx410-4-channel-slt-system-tacj2410

https://www.horizonhobby.com/produc...ivers/ar410-4-channel-sport-receiver-spmar410

https://www.horizonhobby.com/radios...0mah-2s-66v-life-receiver-battery-spmb300lfrx

https://electricmatch.com/rocketry/see/6/6/mjg-firewire-initiator

Dave F.
 
Ez2cDave said:
The E-Match would have a "plug" soldered to it to fit the servo pins in the receiver.

Dave F.
Click to expand...

That absolutely will not work.

If you choose to go the remote route, you would need an electronic switch or relay module going to the receiver to fire the initiator.
 
Ez2cDave said:
The OP is asking about adding a backup ejection system to an already-built rocket. He wants it to be manually activated by radio control, in the event that his upper stage does not ignite, as a "fail-safe" to prevent the rocket from streamlining in. Obviously, his upper stage is using motor ejection and not electronics.

As I see it, the biggest problem would be ensuring that the transmitter has sufficient range to be reliable at a considerable distance. A "Spektrum" RC system should be able to handle that task.

I am no "RC guru", but the combination of these items might work (The E-Match would have a "plug" soldered to it to fit the servo pins in the receiver.

https://www.horizonhobby.com/produc...smitters/ttx410-4-channel-slt-system-tacj2410

https://www.horizonhobby.com/produc...ivers/ar410-4-channel-sport-receiver-spmar410

https://www.horizonhobby.com/radios...0mah-2s-66v-life-receiver-battery-spmb300lfrx

https://electricmatch.com/rocketry/see/6/6/mjg-firewire-initiator

Dave F.
Click to expand...
You right Dave. I want just not crash my second stage IF the motor not start ( Sorry, i speak french ), this is not for start the second stage.

My accufire from PML will start the second stage, if the second stage not start, i push button for black powder explosion for eject the parachute. That it : - )
 
20333,
If you’re thinking of adding a receiver and ejection charge beneath the piston, just do exactly the same thing except use an altimeter instead. The work will be almost exactly the same. I would build it into a coupler and split the airframe.
I would not build either into the piston. Pistons take a beating.
 
Steve Shannon said:
20333,
If you’re thinking of adding a receiver and ejection charge beneath the piston, just do exactly the same thing except use an altimeter instead. The work will be almost exactly the same. I would build it into a coupler and split the airframe.
I would not build either into the piston. Pistons take a beating.
Click to expand...
Good, it seem that it's the best solution, Altimeter with ejection charges beneath the piston
Thank's
 
20333 said:
Good, it seem that it's the best solution, Altimeter with ejection charges beneath the piston
Thank's
Click to expand...

PML has instructions for adding their CPR 3k to their kits. After watching a rocket lawn dart due to what I considered a bonus delay, I converted all of my motor deployment rockets to dual deployment using the general method shown in their instructions. It worked well.
Good luck!
 
Steve Shannon said:
PML has instructions for adding their CPR 3k to their kits. After watching a rocket lawn dart due to what I considered a bonus delay, I converted all of my motor deployment rockets to dual deployment using the general method shown in their instructions. It worked well.
Good luck!
Click to expand...
Yep the retroKit 3000. I check also that : - )
 
Ez2cDave said:
The OP is asking about adding a backup ejection system to an already-built rocket. He wants it to be manually activated by radio control, in the event that his upper stage does not ignite, as a "fail-safe" to prevent the rocket from streamlining in. Obviously, his upper stage is using motor ejection and not electronics.

As I see it, the biggest problem would be ensuring that the transmitter has sufficient range to be reliable at a considerable distance. A "Spektrum" RC system should be able to handle that task.

I am no "RC guru", but the combination of these items might work (The E-Match would have a "plug" soldered to it to fit the servo pins in the receiver.

https://www.horizonhobby.com/produc...smitters/ttx410-4-channel-slt-system-tacj2410

https://www.horizonhobby.com/produc...ivers/ar410-4-channel-sport-receiver-spmar410

https://www.horizonhobby.com/radios...0mah-2s-66v-life-receiver-battery-spmb300lfrx

https://electricmatch.com/rocketry/see/6/6/mjg-firewire-initiator

Dave F.
Click to expand...

Spektrum rc radios operate on 2.4ghz and have horrendous range. If you get 500meters if reliable range your lucky. If doing this, you rlly need to be on 900mhz or 433...even classic 72mhz radios would be superior.
 
Some clubs will not allow use of radio control for recovery unless it is a system specifically design for that use. This stems from very poor performance from generic R/C systems and historic crashes.

Personally, I would not recommend R/C for deployment other than a back up to a recovery controller.
 
Steve Shannon said:
Yes, once upon a time when rocket electronics weren’t as commonplace as they are now people repurposed Radio Shack personal paging Systems to do that. After reading about that in HIgh Power Rocketry Magazine I stumbled across such a system marked down for clearance at a Radio Shaack and bought it. I never did use it.
I also remember seeing a friend futilely mashing the button on a non-responsive WRC while his rocket plummeted to earth.
I agree about preferring altimeters.
Click to expand...

Steve, Do you know if a post mortem was done on that particular flight and whether or not there was an installation issue. Stuff like broken antenna or battery wires due to G forces can be an issue.

Personally, I think a remote system should be for non-critical events ie. turning on a camera, something so if it failed, wouldn’t affect the safe recovery. Or... As an absolute last ditch attempt to save a rocket as a secondary or tertiary backup. Even then the system needs to be digitally encoded to avoid accidental actuation. I have a 72mhz R/C switch I bought over 10 years ago that I never used and would never use on a recovery circuit.
Why do you say? Well on a high flying rocket, if someone turned on a 72mhz R/C transmitter within 20 miles, could have a nasty event occur. At least it would occur in flight as soon as the receiver got a line of sight signal from the spurious transmitter. Granted, 72mhz R/C usage is not as common as it used to be but I wouldn’t want to risk it with a non-encoded event signal.

The other really big negative with R/C deployment is dependence on having a visual on the rocket. If it is going to extreme altitude, even if one is GPS tracking on a live map, one has to recognize they’re in a major failure situation and either try to get a visual on the rapidly descending rocket or blindly pushing the main chute deployment button and risk blowing the main many thousands of feet up. Mess up the timing and the main chute is going to shred if the button is pushed late. Again the big problem is getting a visual. I’ve had GPS high fliers end up recovering upwind from me due to winds aloft when the crowd is looking 180 degrees from where the rocket is actually coming down as they are assuming the ground level winds. Can’t see the rocket in distress and one might hear the “WHUMP” before it even occurs to them to push the button!

Live map tracking is great but it takes practice to get used to it. Everything said above about frequencies is valid.
Bottom line is it’s best to use onboard deployment circuits and considering R/C as a tertiary backup is dubious due to the narrow window for it to be successful. At best it would be a false sense of security. Kurt
 
Back in the 90's a remote firing system was sold for rockets. I can't recall the name right now.
A local flyer used it for lighting second stages.

M
 
I forgot about that use. If the sustainer fails to fire, at least the electronics could go through the recovery cycle and save the hardware. The problem is avoiding interference the could lead to an accident. In that application, unless there was an R/C field right next door to the launch site, one wouldn’t have to worry as much. In this day 72mhz isn’t used as much for R/C anymore. Kurt
 
MClark said:
Back in the 90's a remote firing system was sold for rockets. I can't recall the name right now.
A local flyer used it for lighting second stages.

M
Click to expand...
Mark, the system you are probably thinking of is the Radio Flyer system designed and sold by Tom Farrand. I bought one back then and used it extensively in my two stage rockets. Compared to modern electronics, is was bulky and heavy but it worked,
 
ksaves2 said:
Steve, Do you know if a post mortem was done on that particular flight and whether or not there was an installation issue. Stuff like broken antenna or battery wires due to G forces can be an issue.

Personally, I think a remote system should be for non-critical events ie. turning on a camera, something so if it failed, wouldn’t affect the safe recovery. Or... As an absolute last ditch attempt to save a rocket as a secondary or tertiary backup. Even then the system needs to be digitally encoded to avoid accidental actuation. I have a 72mhz R/C switch I bought over 10 years ago that I never used and would never use on a recovery circuit.
Why do you say? Well on a high flying rocket, if someone turned on a 72mhz R/C transmitter within 20 miles, could have a nasty event occur. At least it would occur in flight as soon as the receiver got a line of sight signal from the spurious transmitter. Granted, 72mhz R/C usage is not as common as it used to be but I wouldn’t want to risk it with a non-encoded event signal.

The other really big negative with R/C deployment is dependence on having a visual on the rocket. If it is going to extreme altitude, even if one is GPS tracking on a live map, one has to recognize they’re in a major failure situation and either try to get a visual on the rapidly descending rocket or blindly pushing the main chute deployment button and risk blowing the main many thousands of feet up. Mess up the timing and the main chute is going to shred if the button is pushed late. Again the big problem is getting a visual. I’ve had GPS high fliers end up recovering upwind from me due to winds aloft when the crowd is looking 180 degrees from where the rocket is actually coming down as they are assuming the ground level winds. Can’t see the rocket in distress and one might hear the “WHUMP” before it even occurs to them to push the button!

Live map tracking is great but it takes practice to get used to it. Everything said above about frequencies is valid.
Bottom line is it’s best to use onboard deployment circuits and considering R/C as a tertiary backup is dubious due to the narrow window for it to be successful. At best it would be a false sense of security. Kurt
Click to expand...

Hi Kurt,
I don’t recall whether a post mortem analysis was done. I’ll ask the guy who did it. Our ground is very rocky so it’s possible it wasn’t possible to tell afterwards.
I absolutely agree with everything else you said. I especially appreciate the warning about systems that don’t use signal encoding. We live in a rocketry electronics rich era. It’s unwise to take a step backwards in time and make recovery less reliable and less safe.
 
Not being an RC guy, I actually did not realize how many possible variables there were. This is incredibly eye opening. We do happen to have an RC field right next door to our flying field.
 

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