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Q2G2 goes off "explosively"

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ScrapDaddy

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I heard that the continuicy tests from other launch controlers could set these babies off. So I was inside and I layed everything down on a concrete floor so I had my trusty 6v electron beam with me (I figured my interlock would deffinetly set it ofF on the test) so I inserted the safety key in (I didn't press the launch button) and the Q2G2 went off..... Explosively not like the estes solar igniter where it would light up the Q2G2 went off with I big bang Is this supposed to happen? The quest controler was a 9v and the estes was a 6v so how did it set it off?

Rocketry is an exact science...... But not exactly!
 

Chrisn

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This thread is a 1/4 of an hour old and you expect a reply so soon?, Thats rare at this time of the day. The continuity check with the safety key provided enough current to the Q2G2 to set it off.
 

JAL3

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One of the electrical people may need to clear me up on this but the problem is not the voltage, its the aperage that flows through when the clircuit is completed. You may not be pushing the launch button but some current IS flowing through the continuity light/buzzer/(whatever the electron beam uses for continuity). That device, probably a lamp, draws more current than needed to set of the igniter.

I'm not familiar with the Quest controller but suspect that it uses a low current LED or maybe a buzzer. I would guess its a low current LED though.

I hope this helps and I hope I haven't steered you wrong.
 

Johnly

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I've been busily collecting igniter firing data with an oscilloscope, current probes, and a programmable electronic load for my NARCON presentation on igniters, so I know exactly what you observed. G2Q2 pop like an electric match, they don’t sizzle like an Estes igniter.

The G2Q2 igniter firing time under the conditions you described are in the area of 5 ms, which is about 10x shorter than Estes igniters under similar conditions. When things happen that fast, they make noise.

Come on up to NARCON and I’ll be presenting the results of instrumented firings of over 50 igniters at different firing currents and clustering configurations.

John
 

Micromeister

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it's not the voltage that activates igniters its the Millamps. In order to make any controller Q2g2 safe the continuity check circuit needs to have a lamp, led or buzzer with under 25ma draw.

Our Club has various 6, 9, and 12Volt controllers that are all Q2g2 and e-match safe. All we did was change the continuity lamps to leds with resistors configured for the specific controller conditions.
 

shreadvector

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http://www.rocketryforum.com/showpost.php?p=12107&postcount=5

I heard that the continuicy tests from other launch controlers could set these babies off. So I was inside and I layed everything down on a concrete floor so I had my trusty 6v electron beam with me (I figured my interlock would deffinetly set it ofF on the test) so I inserted the safety key in (I didn't press the launch button) and the Q2G2 went off..... Explosively not like the estes solar igniter where it would light up the Q2G2 went off with I big bang Is this supposed to happen? The quest controler was a 9v and the estes was a 6v so how did it set it off?

Rocketry is an exact science...... But not exactly!
 

GuyNoir

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Come on up to NARCON and I’ll be presenting the results of instrumented firings of over 50 igniters at different firing currents and clustering configurations.
Sounds fascinating. I'll be there!
 

tquigg

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I've been busily collecting igniter firing data with an oscilloscope, current probes, and a programmable electronic load for my NARCON presentation on igniters, so I know exactly what you observed. G2Q2 pop like an electric match, they don’t sizzle like an Estes igniter.

The G2Q2 igniter firing time under the conditions you described are in the area of 5 ms, which is about 10x shorter than Estes igniters under similar conditions. When things happen that fast, they make noise.

Come on up to NARCON and I’ll be presenting the results of instrumented firings of over 50 igniters at different firing currents and clustering configurations.

John

John, for those of us who will be unable to attend NARCON this year, would you be willling or able to provide your presentation on the Internet after the event? I woudl REALLY like to see it!

Best Regards
 

blackjack2564

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For simplicity's sake, you can always get a Quest launch controller. It's 9volt but designed for them.
 

kullas

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I just got the micro max launch set from quest. It came with the quest controler, launch pad, rockets, engines and igniters. i got it all set up and gave the controler to my little girl and when she inserted the key off the rocket went. My first thought was she was holding the button when she inserted the key so i told her not to do it then i gave it a try and did the same thing. What gets me is that quest would put out a controler that will set off one of there igniters just by inserting the key. someone is going to get hurt
 

jadebox

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I just got the micro max launch set from quest. It came with the quest controler, launch pad, rockets, engines and igniters. i got it all set up and gave the controler to my little girl and when she inserted the key off the rocket went. My first thought was she was holding the button when she inserted the key so i told her not to do it then i gave it a try and did the same thing. What gets me is that quest would put out a controler that will set off one of there igniters just by inserting the key. someone is going to get hurt
Have you contacted Quest about it? I suspect the controller is defective.

-- Roger
 

kullas

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Have you contacted Quest about it? I suspect the controller is defective.

-- Roger
No i havent contacted Quest about it yet but i plan on it. i am going to buy some more MMX motors from them so maybe they can send it out at the same time
 

tomar

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One of the electrical people may need to clear me up on this but the problem is not the voltage, its the aperage that flows through when the clircuit is completed. You may not be pushing the launch button but some current IS flowing through the continuity light/buzzer/(whatever the electron beam uses for continuity). That device, probably a lamp, draws more current than needed to set of the igniter.

You are exactly correct. The light bulb is draws more current than is necessary to fire teh igniter and since that current is flowing through the igniter wired in series, it caused the igniter to fire. This is why I use high intensity LEDs in my controlers (very low current draw - about 20 t0 50 mA).
 

ScrapDaddy

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would the aerotech interlock or pratt hobbies go box set them off?
 

kullas

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I just got of the phone with quest with the problem with my controler and i now have a replacment on the way
2 thumbs up to Quest :clap:
 

luke strawwalker

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I heard that the continuicy tests from other launch controlers could set these babies off. So I was inside and I layed everything down on a concrete floor so I had my trusty 6v electron beam with me (I figured my interlock would deffinetly set it ofF on the test) so I inserted the safety key in (I didn't press the launch button) and the Q2G2 went off..... Explosively not like the estes solar igniter where it would light up the Q2G2 went off with I big bang Is this supposed to happen? The quest controler was a 9v and the estes was a 6v so how did it set it off?

Rocketry is an exact science...... But not exactly!
It's more about amps than volts...

The Estes controllers use a light bulb, which is low-impedance (low resistance). Plug in Ohm's Law (amps= volts/resistance) and you'll see how the three factors work together. What it boils down to is, the light bulb in the Estes controller allows more current to flow to the Q2G2 than it needs to ignite. The Quest ignitors only need about 100 MILLIAMPS to fire-- and that's not much!

Now, the Quest controller uses an LED continuity indicator. LED's have resistors wired in series with the LED to protect the LED's semiconductor bridge so that it doesn't burn out. Therefore, the LED only passes a few milliamps, FAR less than is needed to set off the Quest ignitors. That is why Quest ONLY recommends using THEIR controller for the Q2G2's... because of it's high impedance design.

When you press the launch button, the LED is essentially 'short circuited' (more like bypassed, actually) and the power is then allowed to flow unimpeded to the ignitor, which is what happens in EVERY controller-- the unrestricted power heats the ignitor and it burst into flames, igniting the motor.

Now, it's a simple fix to get around the 'continuity light" problem... there have been a number of threads in the last month or so about rebuilding Estes controllers, and IMHO ANYTHING you do to an Estes controller is a distinct improvement!

The simplest "fix" is to install an LED bulb in place of the regular old flashlight bulb the Estes controllers are equipped with. These are available online from various sources, or from local big box/camping stores. The LED bulb 'chokes back' the current going to the ignitor and reduces it to a safe level that can show the continuity without heating the ignitor up. Use the "Search" box above and look for the "launch controllers" threads-- there's a LOT of good information in there. (some from yours truly:))

It's actually a VERY good thing that the Quest ignitors are low-current and a bit more energetic when they fire-- the lower current requirement means they are MUCH MUCH easier to ignite, even with low batteries, small wire, etc... and they are ESPECIALLY useful for clustering where you DEFINITELY WANT EVERY IGNITOR TO FIRE VIRTUALLY INSTANTLY. Estes ignitors with their high current requirements are WAY INFERIOR in this regard. They take a LOT more wattage (volts times amps= watts) to heat up and ignite, which means they need larger wire, more current, and higher voltage definitely helps as well) and getting several of them to all ignite simultaneously can be a daunting task...

Hope this helps! OL JR :)
 

luke strawwalker

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would the aerotech interlock or pratt hobbies go box set them off?
Depends-- if they use a light bulb, then yes.

If they use an LED, probably not. Some controllers (interlock IIRC) uses a piezo buzzer-- piezo's generally are low current, so it'd probably work, so long as it's not passing too much current. Try it and see.

Not sure what the "Go Box" has for continuity.

Most of your better controllers have LED's instead of bulbs-- for one thing, LED's draw MUCH less current from your batteries, meaning your batteries last a lot longer. Secondly, low current LED's make the controllers 'safe' for most low-current ignitors (flashbulbs excepted, IIRC, but I don't know of anybody using flashbulb ignition anymore since the thermalite fuse isn't available anymore) and of course "regular" (high-current) ignitors have no problems with the low-current continuity circuit. Some folks prefer piezo buzzers but I always find them annoying and prefer continuity lights.

Here's my rebuilt Estes controllers-- A Solar Controller and a Pola-Pulse controller... both over 20 years old, both powered by an external 12 volt jumper pack, and use regular extension cords for low-resistance easy to store firing leads-- the extension cord plugs into the controller, and the clips plug into the extension cord.

Later! OL JR :)

polapulsesetup.jpg


solarcontrollersetup.jpg


polapulsemod.jpg


solarcontrollermod.jpg


launcherwiringdiagram.jpg
 

luke strawwalker

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Here's a hand-drawn "picture" of the guts of an Estes Solar Controller-- this is what you'd see if you open the case on the one I rebuilt.

The brass contacts are the factory parts, the wiring with ring connectors is what I added, and you can see clearly how it's wired-- from the external "battery charger" battery clamps for use with your car battery (or preferably one of those really cool jumper packs that are at every auto parts store now, and which have TONS of power and are eminently portable!)

You can also see the "plugs" installed in the firing leads that the extension cord plugs into, along with the 'clip whip' that plugs into the end of the extension cord to connect up to the ignitors...

Hope this helps! OL JR :)

solarcontrollercomponents.jpg
 

MarkII

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The Pratt Hobbies GoBox and their new FullBoost handheld 12v controller both use buzzers to signal continuity, and both are advertised as being safe for use with flashbulbs and electric matches.

MarkII
 

ScrapDaddy

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Wow thanks guys this helps alot:) TRF has lots of info I can't imagine what this looked like before they reset this in 2009
 

ScrapDaddy

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Use the "Search" box above and look for the "launch controllers" threads-- there's a LOT of good information in there. (some from yours truly:))



Hope this helps! OL JR :)
I just ask good questions:D and then when people reply i feel obligated to say something stupid then they counter and well....... its a gift and a curse :D
But when i searched for launch controlers i found nothing:confused:
 

JoeG

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would the aerotech interlock or pratt hobbies go box set them off?
When I was using the Aerotech Interlock it was flashbulb safe (back when we actually used flashbulbs) . It had/has an audible continuity check.

It would also work on 24 volts for those stubborn igniters. ;)
 

ScrapDaddy

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The only truly stubborn ones are the copperhead and the firstfire
 

BEC

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The Pratt Hobbies GoBox and their new FullBoost handheld 12v controller both use buzzers to signal continuity, and both are advertised as being safe for use with flashbulbs and electric matches.

MarkII
I just got a FullBoost and the first thing I did was measure the continuity current. Less that 12 mA for the electronic "buzzer" that it uses to indicate continuity on the supplied batteries. So it is clearly Q2G2-safe.

Just to restate what others have said - the light bulb in the Estes Electron Beam will draw more current than the all-fire current of Quest Q2G2s. I just checked two - the newer one - one of the new yellow sealed ones - drew 210 mA. An older one was just under 160. Both have slightly used sets of batteries.

The little Quest controller uses an LED and a pulsed beeper for continuity indication. The one I just checked was a little under 13 mA. This of course was an average since the meter didn't respond fast enough to show the pulsing of the beeper.
 
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