Discussion in 'Low Power Rocketry (LPR)' started by milehigh, Oct 29, 2018.
Has anyone done this with good reliability. Any tricks or tips to pass on?
If you use the Estes controller built for this, it will work.
If you use a high voltage/high amperage system (like a car battery or high voltage tool battery), the bridge wire will melt super fast and not transmit enough heat energy to the propellant face to ignite motors reliably.
I demonstrated the super fast wire "pop" vs the hot glowing wire at our launch yesterday.
I've flown the Quad Runner, both 2 and 4 motor configs, on just Estes starters. No special precautions. Just make sure the head bottoms out in the motor opening before plugging. Also, make sure none of the leads short together. Otherwise, smooth flying on 4-6 flights.
If you use a high voltage/high amperage system (like a car battery or high voltage tool battery), the bridge wire will melt super fast and not transmit enough heat energy to the propellant face to ignite motors reliably. In your experience, Fred, is this typical of only the new Estes starters?
The older Solar Igniters had a pyrogen that would burn when the bridge wire blew apart fast or heated slowly, so they worked with any power source that would either heat them slowly or blow them to bits quickly.
I have seen some composite igniters that pop the tiny bridgewire too fast to transmit enough heat energy to the pyrogen coating when the power source is too much.
It depends on the pyrogen used and if it will instantly start to burn from any tiny heat energy input and if it will continue to burn without more sustained heating.
With Estes controllers, the Solar Starter without the pyrogen will heat up and just keep glowing until it shines onto the face of the black powder propellant long enough to transfer enough heat energy for the propellant to ignite.
Like a wildfire outside your house will "Shine" heat energy through your windows until it ignites your drapes and the house burns up from the inside out.
I've found that the Estes starters can be used with great reliability with a 12vdc system, rather than the 6vdc or 9vdc systems. Obviously, 9 is better than 6, but the reliability of 9 is still poor when used with the starters. With over 300 launches in the last 2 years, you can see the Launch Controller I developed and now use at all my school launches. It's at magmamountain.com There is clearly a sweet spot that doesn't just pop. At my last launch (in August) we launched around 40 times with only one misfire. All with Estes Starters and the Space Cadet controller.
I have a homebuilt launch system that uses three 6v lantern batteries, it reliably ignites my three "D" cluster rocket. I've never checked voltage at the alligator clips, but it works through 50 feet of 12 gauge extension cord.
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