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Good end burn motor


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Posted (edited)

http://youtu.be/WOhkls7zQNM

 

Model flown on a Black Powder end burn motor. Tube I.D. 5/8" rocket tube 2 1/2" long. Rammed solid clay plug 1/2", fuel 1", delay comp 1/4" ( BP fuel with 10% baking soda added ), about 1/4" bulkhead. The nozzle and pass fire are 3/32" hand drilled, nozzle drilled about a 1/4" into fuel, longer will give higher initial thrust.

 

Fuel: lb. 75-15-10, milled 1 hour, 5 gm. motor oil added. milled additional 15 min.

 

Very easy and quick to make. Also makes great sky rockets!

Edited by kpknd
  • Like 1
Posted

Nice rocket!

 

Why did you add oil to the BP? You don't want to slow down the BP in an endburner at all. What charcoal did you use in that motor? You want to use a very reactive charcoal, Balsa works fantastically for endburners, much better than regular old airfloat and better than black Willow. Try it without oil and press the motors to 9,000-10,000psi on the grain. If you don't have a press you can try hand ramming it as well but you will get the best performance and reliability with pressed motors. What kind of mill do you use? I use an optimized Harbor Freight 6lb mill and run my batches for 6 hours for best results. 1 hour might not make your powder as fast as it could be.

Posted (edited)

The BP I used is the same for the standard rockets up to 3lb. I add oil to keep dust down and help it consolidate better. It is still strong enugh to blow out a nozzel now and then. I am using odinary airfloat from firefox, the tumbler is a Lortone QT-6. It works good enugh for me. I do'nt have a press. I test my fule by ramming a one inch culmn in a tube, about 1/2" dia. and time how long it burns, usualy around 8 seconds. I would be curious to see how long your fuel burns.

Edited by kpknd
Posted

mine burns at around 3 seconds an inch, same as my lift and burst, no additives.

 

dan.

Posted

mine burns at around 3 seconds an inch, same as my lift and burst, no additives.

 

dan.

How long do you mill it.

Posted

Nice rocket. The end burner motor obviously gave a nice flight for that model.

Posted

Thanks, I'm happy with it.

Posted

I mill for 3 hours. I hope you don't think I was rude.

 

dan.

Posted

I mill for 3 hours. I hope you don't think I was rude.

 

dan.

Not at all. Thank you.

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