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BP rockets lifting capabillities


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Posted (edited)

Hello everyone, i couldnt find any dedicated topic for how much can a BP rocket lift, so i decided to start one.

My reason is to know how much can core/end burnning BP rockets can lift. Lets say,have anyone done any testings on 1" (25mm) end burning rockets,about how much can they lift?

I have only tested my 16mm ID rockets,with 8mm choke,that are corer burners,and they did lift 70gr payload easily.

Thanks in advance!

Edited by millhouse
Posted
16mm bp coreburners can lift a 3'' shell easily. I don't know much about the lifting capacities of end burners though.
Posted
I use 18mm coreburners for lifting 2,5'' and 3'' shells and works great. My biggest goal now is to get a really consistent BP. The BP i use has willow charcoal, and milling for one hour is sufficient. If i use 12 hrs milled BP (for lift) it is way too strong for my humble purposes. After dissection of Chinese made rockets, i learned that a firmly rammed delay charge (green mix) above the actual motor is enough to get the thing done. I don't use any endplug anymore. This method needs a lot of testing and tweaking, i use casings 15mm longer than what i used before. (85mm) But, as i like to mass-produce rockets, it is an improvement for me, because the top clay plug doesn't need to be drilled and filled as there is none. It saves time. No, i am not one of the guys chasing the biggest/fastest/most powerful rocket possible. I just want a consistent traditional produced motor to launch small shells, and don't make a study out of it. They just need to work and produced easy in large numbers. My 2cents
Posted

Thansk for a fast reply guys!

I would appreciate more info on endburners,as i plan to use some end burning rockets for my 2" shells. Anyways,i think i will have to make a study my self:D

Posted

Talking about endburners:

how long do you usualy make the motors?

Just to get an idea of what is reasonable. RTS proposes 10x id long tubes, that seems very long to me. Estes Engines are much shorter.

Posted (edited)

Thansk for a fast reply guys!

I would appreciate more info on endburners,as i plan to use some end burning rockets for my 2" shells. Anyways,i think i will have to make a study my self:D

 

I will post a video of my endburners tonight now but for the record, they hardly lift a 10 gram report to apogee.

 

http://www.youtube.com/watch?v=FA2CtnJa160&feature=youtube_gdata

 

-dag

Edited by dagabu
Posted

I will post a video of my endburners tonight but for the record, they hardly lift a 10 gram report to apogee.

 

-dag

 

Just for the science, just for the science... to compare, test and get it better together as a collective source of info. That's what i like about internet forums! Keep up the good work.

Posted

I will post a video of my endburners tonight but for the record, they hardly lift a 10 gram report to apogee.

 

-dag

 

 

I think I can help with that ;)

Posted

Thats what i achieved from endburners in a shortterm. Anyways,it wasnt a 3" rocket,as long as i remember,it was a 40mm rocket. It was a simple endburnner with a 3" shell. But the nozzle choke was a way too big,with a smaller choke it could of been much better!

Posted

I will post a video of my endburners tonight now but for the record, they hardly lift a 10 gram report to apogee.

 

http://www.youtube.com/watch?v=FA2CtnJa160&feature=youtube_gdata

 

-dag

 

You need a shorter fuel length in the motor. I reckon this would have been better with a 5 second burn rather than the 9 secs or so this rocket burnt for. In a 16mm endburner motor I have a 40mm fuel length. (Just over 3 x the ID), After this they arc and lose height. That is with a 3mm choke. Willow BP riced.

 

Otherwise a great rocket. Naturally you may need to tweak for your particular fuel.

Posted
Looks a bit weak:/ I think a little too big choke was used. I plan to make some more testing on end burnners next week,as i have to many tasks this week. I use my wooden tooling to make rockets,thats why i preffer enburnners,as the tooling design is way more simple.
Posted (edited)

Looks a bit weak:/ I think a little too big choke was used. I plan to make some more testing on end burnners next week,as i have to many tasks this week. I use my wooden tooling to make rockets,thats why i preffer enburnners,as the tooling design is way more simple.

 

That's the specified nozzle size for a 1# EB millhouse, the powder is fuse and burns slightly slower then 75:15:10.

 

Here is a 3/4" nozzled BP rocket lifting a 500g canister shell. I don't know why YouTube cuts the video off like that...

 

http://www.youtube.com/watch?v=6khHL6gb3e4&feature=youtube_gdata

 

-dag

Edited by dagabu
Posted
The last video looks really nice, it would be great to achieve such results with an en burner:) Whats the size of a choke on the last video?
Posted
But are you sure its 500g? I understand that its 500gr,which is 0,5kg? But it is very very heavy,are you sure about the weight?
Posted

Talking about endburners:

how long do you usualy make the motors?

Just to get an idea of what is reasonable. RTS proposes 10x id long tubes, that seems very long to me. Estes Engines are much shorter.

 

 

You need a shorter fuel length in the motor. I reckon this would have been better with a 5 second burn rather than the 9 secs or so this rocket burnt for. In a 16mm endburner motor I have a 40mm fuel length. (Just over 3 x the ID), After this they arc and lose height. That is with a 3mm choke. Willow BP riced.

 

Otherwise a great rocket. Naturally you may need to tweak for your particular fuel.

 

 

 

I don't know if there are standards in the literature for end burners, but there seems to be a standard from the tool makers. Ben Smith is the same dimensions.

 

http://www.wolterpyrotools.com/?page=cc_catg&cat=rocket

 

With those dimensions, the standard fuel length is probably around 4.5-5x ID in length. This sounds like a close approximation to Estes rockets. If you're losing thrust and arcing, it sounds like you're enlarging your nozzle or getting casing burn through. End burners should largely accelerate the more fuel is burned as weight is lost.

Posted

The last video looks really nice, it would be great to achieve such results with an en burner:) Whats the size of a choke on the last video?

 

It was made with Thunderr1's tooling, a copy of the Universal Hybrid design.

 

But are you sure its 500g? I understand that its 500gr,which is 0,5kg? But it is very very heavy,are you sure about the weight?

 

Yes, I am quite sure, we routinely launch 500-700g headings on BP rockets with a nozzle and with VERY fast BP, use nozzlleless rockets to launch similar headings.

 

300g headings on a 1" nozzleless on fuse powder..

 

http://www.youtube.com/watch?v=QVcOWq9QF9g

 

 

-dag

Posted
fuse powder

What's that? Can you give a formula and processing?

Posted

What's that? Can you give a formula and processing?

 

I am told that it is 69:18:10, ball milled, pressed to pucks, granulated to 7FA in size. I purchase it by the bag and use it straight in rockets. It provides a good middle of the road fuel for end burners.

 

-dag

Posted
where can you purchase fuse powder? this seems like a new appearance in the market, am I correct in this? also what's the cost?
Posted
I get the impression that fuse powder, among the other bulk packaged things there, cannot be shipped. It rather explicity states that "sporting powders can ship Fed Ex". The sporting powders (fg's), are designated as such in the package size. The blasting powders and such come in 25lb bags (or 22 in the case of fuse powder). If it can be shipped, it may have to go via freight. Everyone who I know who's gotten that kind of stuff from them, picks it up in person or at PGI.
Posted

I get the impression that fuse powder, among the other bulk packaged things there, cannot be shipped. It rather explicity states that "sporting powders can ship Fed Ex". The sporting powders (fg's), are designated as such in the package size. The blasting powders and such come in 25lb bags (or 22 in the case of fuse powder). If it can be shipped, it may have to go via freight. Everyone who I know who's gotten that kind of stuff from them, picks it up in person or at PGI.

 

I will stay away from making statements about legality, give Jon a call, he will tell what is allowed and what is not.

 

-dag

Posted
I wasn't saying anything about legality, just company policy. It clearly states that sporting powders can be shipped via fed ex. I would think it's an odd distinction to make if everything can go that way. I'm close enough that the hazmat fee plus shipping costs make it more cost effective to drive over and pick everything up in person anyway. I was mostly bringing it up as a potential snag.
Posted

Gotcha, sorry for the toe stepping 2huh.gif

 

-dag

Posted

my endburners can lift 1.5" canshells weighing 35g they are 10mm id and the fuel grain is about 4.5 to 5 id's,

i dont believe endburners accelarate as the fuel burns they get lighter but the internal volume is decreasing meaning less pressure and lower thrust than when it took off,

if the fuel grain is too long they can come back.

for lifting 2" shells you probably need at lest half inch rockets up to 16mm 3/4" will be overkill.

 

dan.

 

 

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