Jump to content
APC Forum

Experimental Rocket Motor


Recommended Posts

Posted

I was was looking for a motor that brings my 3 "balls on a good height, but the flight characteristics of a Endburn Motor ( slow wuuuushing flight ). I think I'm on the right track..........

 

https://www.youtube.com/watch?v=6AWgQRv9nLc

 

This was my firts try with these Motors, so have to do a little work on them. Should be flying 1-2 more seconds to get the shell where i want.

Shell weight about 200gramms + about 50gramms for the stick. With those waxed tubes, i can use a bit hotter fuel i think ?! ( i used 65-25-10 )

 

Greets

VP

  • Like 1
Posted

Nice Rocket, finally someone who tries to get a good amount of thrust out of a endburner ;)

 

You only used 65/25/10? Normally in endburners the hotter the fuel the better...

But it`s amazing how much performance you got with this "slow" fuel :)

 

 

 

Greets

Posted

Thank you :)

 

Yepp i like the way endburners fly, more than coreburner. This is why i´m lookin for some good powered endburners. Yes, just 65-25-10. I think i can go up to 70-20-10. I´m also experemanting with a tool for 25mm Endburner for 4" ball shells.... But this will take a bit time to dial everything in ;)

Posted
Is your end burner tool a normal end burner tool, or does it maybe have a couple cm of core to first build up some pressure.
Posted

And what diameter nozzle?

 

I like to use as hot of BP as I can and then slow it down to the speed you want with a spark producing material. Probably coarse charcoal for this style rocket. A 'nitrated' charcoal might work best with this method?

 

I figure if I'm starting with the hottest BP, I can get the best tail by adding the most extra material. Just a thought.

Posted

Endburners rule, that's for sure.

 

The 22mm Egertubes rule too, unfortunately they are so short...

 

 

I found that I can use hot BP and even a 1/5 instead of 1/4 id nozzle without failures. Without a tool, I just drilled nozzle + 1/2 id into the fuel. No de Laval style shape.

 

 

If extreme performance is desired, one could also consider whistlemix. A german company just brought a new series of model rocket engines on the market, they are based on whistlemix and have a 1/5 id nozzle. A 14mm id motor with 20g of fuel is supposed to cope with 300g AUW.

 

I don't understand why most commercial tools seem to settle on 1/4 id.

Posted

Companies will always go for reliability. While we can afford a CATO they don't.

 

Few years back some British company made some engines that turned out to be "salutes on a stick".

 

I would love to see how the Zink fat motors are actually made: I guess they are made of Al, and are of cored type?

Posted
Well thinking about that, some years ago i had about a hundred whistle rockets from a german company, about 10-12mm i.d. 25% of them where bombs on a stick, you really had to step a couple meters back from them. One year later they stopped producing these
Posted

Ok guys........

 

My tool got a little spindle to get things goin faster at the start. If i used hot BP, these motors blow up at the ground. Here is another motor test with a 3" ball shell. Shell and stick weight about 210 gramms.........

 

https://www.youtube.com/watch?v=v8cgQeAftc0

 

Greets

VP

Posted
So looks like you are giving them a god whack at the beginning to overcome the inertia and then keep em steady going. If don't use your fast powder, what are you using instead?
Posted

It´s 65-25-10 with good charcoal :-) I think i can go up to 70-20-10, but for the moment i have no need for it........

Posted
Sounds awesome, Charcoal your homemade pine?
Posted

No, i used homemade poplar charcoal :-)

  • 2 weeks later...
Posted

Very nice VP! That's the same thing I'm trying to do now. Shoot a ball shell with an end burner. :)

Posted

No, i used homemade poplar charcoal :-)

Allready thought about those too, but never used it as i have a nice source for willow and alder. Do you experience with those and how do they compare to the popplar BP?

  • 2 weeks later...
×
×
  • Create New...