Black Powder E motor... Why you kill my rockets?!

Discussions on low powered model rockets using E powered motors and below.

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Lister
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Black Powder E motor... Why you kill my rockets?!

Postby Lister » Mon Jun 22, 2015 9:50 pm

This is the result of an estes E9-6 motor.. I had launched it on a D12-5 a few mins before and the same goes for CC Express I launched on the same pack of E9-6 motors.. and the D12-5 motors worked great, both rockets went up straight as an arrow so i thought ill try the E's..im assuming it was a faulty lot.. Whatever it was the end result was 2 CATO's.not game to use the 3rd in the pack + im out of 24mm rockets :( but on the plus side I had my first CATO :P
Attachments
2015-06-22 21.44.12.jpg
Left -CC EXPLORER
Right - V2
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Lamp
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Black Powder E motor... Why you kill my rockets?!

Postby Lamp » Mon Jun 22, 2015 11:27 pm

Yep, there are limits to black powder motors. The most likely explanation is the bigger they are, the more likely they are to have a crack or other fault in the grain. When the flame front hits this crack or fault you get an increased burn and therefore an increase in pressure that the cardboard casing cannot withstand....resulting in the motor exploding.

Black powder E motors are notorious for this and if you had asked any of the experienced guys at the launch they would have said so. We have had so many failures that no one uses them anymore. They are so big that they are more likely to have a casting fault and they are fragile so all it takes for them to crack is for the packet to be dropped... and this can happen well before you get your hands on them! I told you black powder motors are dangerous! ;-)

For E motors and even D motors you are better off using Aerotech Hobyline APCP reloadable motors.
‘It takes sixty-five thousand errors before you are qualified to make a rocket.’ — Werhner von Braun
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martymonsta
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Re: Black Powder E motor... Why you kill my rockets?!

Postby martymonsta » Mon Jun 22, 2015 11:55 pm

Yeah as Pete said this is a problem with the E BP motors youtube is littered with videos of CATOing E's. I belive ausrocketry doesn't sell them because of their very high failure rate. If you want to fly a 24mm E the AT E11, E18 or E28 are all great options and you wont need disposable rockets. But here are a few more examples of people trying to fly BP Es







And there are heaps more.
Many years ago the great British explorer George Mallory, who was to die on Mount Everest, was asked why did he want to climb it. He said, "Because it is there."
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Lister
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Re: Black Powder E motor... Why you kill my rockets?!

Postby Lister » Tue Jun 23, 2015 12:31 am

Theres my problem. At least I get some practice at repairing rockets :)


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