kecskesajt
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Rockets-I have problems.
Yeah.My rockets won't work  .I make a tube,ram BP into it,drill half
way,ballance,put a fuse.It is nossleless. I light it and it makes a bang because it shoots out the clay plug  Can somebody help ?
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greenlight
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Are you using a spindle and drifts to form a hollow cored motor or are you trying to make end-burning rockets?
Are you ramming the black powder in in small increments to get a uniform density through the entire rocket tube? If there are parts that aren't as
compact as other parts of the motor it could cause a faster burn rate in a spot which could cause it to shoot out the plug.
You say that your rockets are nozzleless, I'm pretty sure just about all black powder rockets need a clay nozzle rammed to generate the thrust to lift
off.
Here are two links for black powder rocket construction which may help you compare your design, one on end burners and one on cored motors:
http://www.skylighter.com/fireworks/how-to-make/End-Burner-R...
http://www.skylighter.com/fireworks/how-to-make/4-ounce-blac...
[Edited on 15-1-2015 by greenlight]
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Bert
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Thread Moved
15-1-2015 at 13:19 |
Bert
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There are nozzleless black powder rockets made- simple, not as efficient as could be with well designed nozzle, but very easy and made without many
tools.
Skylighter- Nozzleless BP rockets
I agree with greenlight-
| Quote: |
If there are parts that aren't as compact as other parts of the motor it could cause a faster burn rate in a spot which could cause it to shoot out
the plug.
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Can you measure and report density of pressed fuel grain.
How did you make the fuel.
How exactly do you press or ram fuel, what size is a finished loading increment- It should not be taller than the tube ID, or you can't press or ram
it uniformly in my experience.
If it's not poor pressing: Either your core is too big, you are not putting the forward bulkhead in well enough, or your black powder is just too
fast.
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Hawkguy
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If the nozzle isn't stable enough/ well applied, you'll have an endless range of problems. That was always my biggest problem.
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Oscilllator
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This should solve your problem:
http://www.jacobsrocketry.com/aer/casings_nozzles_headers.ht... and Headers
I especially like the last one with the pvc ring, because it holds the nozzle in place without introducing any bits that stick out from the body of
the engine.
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kecskesajt
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Test for my BP: https://m.youtube.com/watch?v=5PGDLqcVvG4 I ram the BP in small amount.I only use paper casing for rockets.I will buy some gypsum to make a better
and cap.I using a drill to drill my rocket motor.Anyways thanks a lot 4 help 
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kecskesajt
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Quote: Originally posted by Bert  | There are nozzleless black powder rockets made- simple, not as efficient as could be with well designed nozzle, but very easy and made without many
tools.
Skylighter- Nozzleless BP rockets
I agree with greenlight-
| Quote: |
If there are parts that aren't as compact as other parts of the motor it could cause a faster burn rate in a spot which could cause it to shoot out
the plug.
|
Can you measure and report density of pressed fuel grain.
How did you make the fuel.
How exactly do you press or ram fuel, what size is a finished loading increment- It should not be taller than the tube ID, or you can't press or ram
it uniformly in my experience.
If it's not poor pressing: Either your core is too big, you are not putting the forward bulkhead in well enough, or your black powder is just too
fast. |
I make My fuel with a coffe grinder.I grind the KNO3 then the charcoal and mix it with the
sulfur(75:15:12) And granulating it.
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