First 1LB BP Rockets

[ibizon]

Greetings, fellow pyros! I have been mostly a lurker until now, but must say that I have learned a lot from reading about all of the experiences those new to BP rockets have, and I contribute much of my success to learning from their mistakes. Here is my story thus far.

 

I began by reading as much as I could about what it takes to make a good BP rocket, and luck for me, I also belong to a local pyro club and I was able to talk to another rocket builder about his experiences. After being invited to his place to press a few strobe and whistle rockets, I really thought that I wanted to start making my own. He gave me a list of items I would need and another list of places that sold the tools. A few days later, I ordered a set of 1lb universal tooling from firesmith, some NEP tubes, and the required chems for my own BP. I figured if I was going to make my own rockets, I wanted to be making my own fuel as well.

 

My initial process for making the fuel was to screen together a basic 60-30-10 fuel, then mill it for 3 hours. Here is where I made my first mistake though. I added dextrin to the mix and then used a 75/25 mix of water/alcohol to wet and screen the mixture. I read that this helped to keep the dust down, and it did a great job of it. My initial static tests seemed a bit weak to me, so I made a couple more batches, 65-25-10 and 70-20-10, but again added the 5 parts dextrin to the mix.

 

At our first club shoot was the first time that I got to fire them instead of just the static test. I was convinced that none of them would fly, because during the static tests they seemed like they did not produce enough thrust to lift it from the launch tube. Well I was correct that they would not fly, but they didn't burn in the launch tube ether. As soon as the lit fuse hit the fuel, BOOM! No whoosh that a good rocket is supposed to make, just a big boom. Upon inspection of the remains, the motor tube itself was still mostly intact, it was the header that was blowing up. (I was using a small amount of flash for a header.) After firing the remaining 7 rockets I made, they mostly did the same thing. A few would reach a height of about 30-50 feet and then blow up.

 

After many walks of shame back to the crowd of spectators, I did some thinking and decided that I needed to take a good look at what I was doing. The following week, sitting in my chair at work, I was thinking about how they looked after I rammed them. Looking inside after ramming them, I noticed that you could still see where there had once been hard granules of the BP fuel. I can only describe it as a reverse honey comb pattern. I started to think that since I was ramming, and it was granulated with dextrin it the mix, I wasn't able to put enough force into it to completely close those gaps. The result was the heat traveling up those tiny cracks and reaching my header before the rocket left the launch tube. After some more reading here on the forum, I saw where someone mentioned that they will still wet the mixture to keep dust down, but will not add the dextrin. My theory was almost confirmed after reading that, so I decided to test it.

 

With the next club shoot 4 weeks away, I started mixing my fuels exactly as I had before, but did not use the dextrin. After ramming the first rocket I immediately noticed a difference. The honey comb pattern was not there. It was nice and smooth, much like the whistle and strobe rockets that I had pressed looked. I was feeling more confident about this. As added assurance I added a bulkhead to them, using a method that was recently shown in the PGI bulletin. Out of curiosity, I did make a few without the bulkhead so I could see if it was the fuel that was the problem, or the lack of a bulkhead.

 

Fast-forward to this past weekend. I walked to the line again and lit the first rocket, took many steps back and waited. Whoosh! Problem solved; the rocket flew. Tested a few more, with and without the bulkhead, and they all flew just as they should. Great height and a nice tail when it hit my D1 delay, followed by a nice boom. Since I was so confident that I had solved the problem before showing up, I actually had a dozen rockets to shoot that day. 10 of 12 flew, the remaining two just burned on the launch tube and then blew up. This turned out to be a weak fuel that I had added aluminum to. I plan to make a faster fuel and then combine the two to see if that helps. If not, I will use it at the top right before my delay until it's used up.

 

I mostly wanted to share my story with everyone. The whole process was actually much easier than I had expected. While I still have a few things to iron out with them, I am more confident with my building style and now I can focus on adding some new effects to them. I picked up some 36 and 80 mesh charcoal to add a longer tail, and I'm still going to figure out how to get my Aluminum tail to work for me.

 

Feel free to ask questions or make comments about anything. Many of you are way more experienced than I.

 

 

 

Rocket Details:

 

Tooling: Firesmith 1lb Univeral Tooling 6.25" length

 

Tubes: NEP Tubes

 

Fuel: 60-30-10, 65-25-10, 70-20-10

 

Airfloat from Hobby Chemical Supply

 

 

 

Build:

 

1.5 tsp Bentonite Clay for nozzle

 

BP 1tsp at at time to approx 1.25" from top of tube

 

3/8" D1 Delay

 

3/8" Bulkhead w/ 2 pieces black match (if used)

 

Stick: 3/8 x 36" square poplar dowel

 

Fuse: J-Hooked 3mm visco

[Peret]

Dagabu probably knows some better aluminum tail compounds, but this one I've used is from Hardt:

 

Potassium nitrate 60

Charcoal air float 22

Sulfur 10

Aluminum coarse flake 8

 

Ball mill the first three ingredients, or the rocket won't fly. These are the proportions I use for 1/2 inch rockets, they may be a bit hot for 3/4 inch. Add more aluminum to slow it down.

[dagabu]

Dagabu probably knows some better aluminum tail compounds, but this one I've used is from Hardt:

 

Potassium nitrate 60

Charcoal air float 22

Sulfur 10

Aluminum coarse flake 8

 

Ball mill the first three ingredients, or the rocket won't fly. These are the proportions I use for 1/2 inch rockets, they may be a bit hot for 3/4 inch. Add more aluminum to slow it down.

 

I too have stayed below 10% Aluminum in rockets and have found that depending on the mesh, Aluminum can add power or take away power. Static test your fuel before launching a rocket with a changed fuel. The Universal Tooling should burn all fuel off in under 2 seconds, if your rocket burns for longer, you will need to spice it up a bit.

 

Be really careful with dark aluminum, dont add water to keep the dust down and stay below 3% and add more incrementally.

 

-dag

[ibizon]

I too have stayed below 10% Aluminum in rockets and have found that depending on the mesh, Aluminum can add power or take away power. Static test your fuel before launching a rocket with a changed fuel. The Universal Tooling should burn all fuel off in under 2 seconds, if your rocket burns for longer, you will need to spice it up a bit.

 

Be really careful with dark aluminum, don't add water to keep the dust down and stay below 3% and add more incrementally.

 

-dag

 

Thanks for the good reference time to use for how fast it should burn off. The ones that stayed on the launch tube were definitely burning much longer than 2 seconds. I'm using the Alcoa 120 atomized aluminum they have on hobbychem and I'm right at 10%. I'll try mixing it with a slightly hotter fuel and then do some static tests.

 

I know everyone loves videos too, but I got frustrated the first day and did not get video of anything. This past weekend I left without my camera. I'll make sure to get some next time.

Edited June 7, 2011 by ibizon

[dagabu]

Thanks for the good reference time to use for how fast it should burn off. The ones that stayed on the launch tube were definitely burning much longer than 2 seconds. I'm using the Alcoa 120 atomized aluminum they have on hobbychem and I'm right at 10%. I'll try mixing it with a slightly hotter fuel and then do some static tests.

 

I know everyone loves videos too, but I got frustrated the first day and did not get video of anything. This past weekend I left without my camera. I'll make sure to get some next time.

 

FWIW- Try your new fuels without a clay nozzle first. The fuel will burn out approximately the same time but you will get a feel for the "power" the fuel has with very little possibility of CATO. That way you can try the fast fuels with headings with no worry about blowing the rocket up. In fact, you may like the nozzleless design better. I know that I do

 

-dag

[ibizon]

FWIW- Try your new fuels without a clay nozzle first. The fuel will burn out approximately the same time but you will get a feel for the "power" the fuel has with very little possibility of CATO. That way you can try the fast fuels with headings with no worry about blowing the rocket up. In fact, you may like the nozzleless design better. I know that I do

 

-dag

 

I actually made one without a nozzle for this past weekend using the 70-20-10 fuel and it worked great. I was considering doing this from now on. The BP would be easier on my tooling and I don't see a reason to complicate a process by adding a nozzle if it works fine without one. I have gotten all of my plain fuels to work, but I was thinking of using the 70-20-10 as my primary, since it worked with and without a nozzle and it says it's a universal tooling formula. I'm also considering dropping the bulkhead. Is there a certain situation that would cause you to use one?

[dagabu]

I actually made one without a nozzle for this past weekend using the 70-20-10 fuel and it worked great. I was considering doing this from now on. The BP would be easier on my tooling and I don't see a reason to complicate a process by adding a nozzle if it works fine without one. I have gotten all of my plain fuels to work, but I was thinking of using the 70-20-10 as my primary, since it worked with and without a nozzle and it says it's a universal tooling formula. I'm also considering dropping the bulkhead. Is there a certain situation that would cause you to use one?

 

Now try 75:15:10to make the fuel really fast! the nozzleless design takes real hot fuel and gives you a big charcoal tail.

 

The bulkhead (I found out) is for high pressures or short delays. I found that I like a 10% Ti turnings to black powder for a delay and since it burns so fast, I can add a good two ID's of it and get my 2 second delay with no bulkhead.

 

Nozzled rocket without the Ti in the delay:

 

http://www.youtube.com/watch?v=Z-fLoV7gHr8

 

Nozzleless with the Ti delay:

 

http://www.youtube.com/watch?v=2lrYAjp-w6w

 

-dag

Edited June 7, 2011 by dagabu

[guntoteninfadel]

dag,

that has to be the best video ever with ralphs glitter! I too have had issues with the nozzel. I realize that the rocket will carry bunch more payload with the nozzel but my success rate has been less than desirable. I will say that 3 of 4 went skyward this weekend and ALL headers ignited and worked as planned. That would be kudos to dag as he shared his ultra secret, password and clandestine handshake only, method of fusing rockets(read rocket header fusing for dummies, 101). I am really pleased with the backed down (60/30/10) bp with a nozzel. No CATO's and I think my one failure was due to short milling time. Ibizon (sp?) thank you lucky stars you have a club to attend! Wish there was something like that within a hundred miles of here. Oh and if you get the chance let us (me) know of club shoots cause I can make it that far if its a big shoot. Congrats on your success and PLEASE film the failures, they are much more entertaining.

 

later

 

gun

[dagabu]

dag,

that has to be the best video ever with ralphs glitter! I too have had issues with the nozzel. I realize that the rocket will carry bunch more payload with the nozzel but my success rate has been less than desirable. I will say that 3 of 4 went skyward this weekend and ALL headers ignited and worked as planned. That would be kudos to dag as he shared his ultra secret, password and clandestine handshake only, method of fusing rockets(read rocket header fusing for dummies, 101). I am really pleased with the backed down (60/30/10) bp with a nozzel. No CATO's and I think my one failure was due to short milling time. Ibizon (sp?) thank you lucky stars you have a club to attend! Wish there was something like that within a hundred miles of here. Oh and if you get the chance let us (me) know of club shoots cause I can make it that far if its a big shoot. Congrats on your success and PLEASE film the failures, they are much more entertaining.

 

later

 

gun

 

Thanks Gun!

 

There are lots of clubs down south, PGI has a trade directory that lists all of its members, shoot Robin Cleveland an email and she can send you links to them as well. Its a day trip to Canada and back for me so I don't think a 1500 mile trip would be what you want to do for a shoot. Winter Blast is in Nevada, 4F is in Florida, they are nice sized and have lots of good stuff.

 

Glad to hear the rockets are working out, keep learning!

 

-dag

[shagaKahn]

Nozzleless rockets? How's that possible? Do you (carefully) drill a core in the BP? How do you fuse them?

 

(Waaa! I wanna know everything without having to do any homework).

[dagabu]

Nozzleless rockets? How's that possible? Do you (carefully) drill a core in the BP? How do you fuse them?

 

(Waaa! I wanna know everything without having to do any homework).

 

LOL!

 

Even easier then that, ready?

 

Don't press a nozzle in a cored rocket and use hot fuel. No drilling, fuse as normal.

 

That's it.... really.

[ibizon]

Ibizon (sp?) thank you lucky stars you have a club to attend! Wish there was something like that within a hundred miles of here. Oh and if you get the chance let us (me) know of club shoots cause I can make it that far if its a big shoot. Congrats on your success and PLEASE film the failures, they are much more entertaining.

 

 

Gun,

 

MoPyro is the club. We meet 4 times a year in the St Louis area and if you've heard of the St. Louis shoot, that is in addition to the 4 regular shoots. That one is definitely worth the drive. It's the last weekend in September each year. Let me know if you haven't heard of it and I can get you more info. I actually do have one video of one of my failed rockets. Forgot it was taken, and I even uploaded it.

 

When I started this rocket building, I thought it would be something I would struggle with for a bit and then have it down. While I could just settle for my rockets working the way they are, there is just so much you can do to modify them. I see now that while I will have a handful of reliable rockets at each shoot, I will also have a handful which I am trying new things with. I'll be working on my tails for the next shoot; both with the Al and larger mesh charcoal.

 

Enjoy!

 

Edited June 8, 2011 by ibizon

[shagaKahn]

Really stoked to try this. And that extra half-inch or so of fuel's gotta be a sweet treat for the rocket.

 

Think my current stinger fuel is 70/20/10. Maybe give it a shot in a static rocket tube. (Got to where I can almost tell by the roar whether it's gonna fly or not).

 

Anybody tried a nozzleless stinger?

 

Thanx dag

 

LOL!

 

Don't press a nozzle in a cored rocket and use hot fuel. No drilling, fuse as normal.

 

[shagaKahn]

Rammed two quarter-pounders nozzleless and mounted them with bamboo sticks. Flew straighter and truer than any rockets I've rammed so far.

 

Thanx Dag for the nudge on this; now I'm gonna see if I can speed up the BP a bit. (Tried the same fuel in a couple of stingers and they barely flew at all).

 

 

Don't press a nozzle in a cored rocket and use hot fuel. No drilling, fuse as normal.

 

That's it.... really.

[RocketTony]

not a reply but a question:

 

I am trying to make estes type e motors for some rockets i have built. I seem to be having trouble producing the needed power to lift the rocket. The rocket is roughly 6 oz. Here is the process flow i am using. 75/15/10 kno3/air-float/sulfur ball milled for 3 hours, screened through a 100 mesh screen. I then add 10% water to the mix, and the bp is screened through a 30 mesh screen and left to dry for several hours. i then pack the tube with bentonite clay and add 24Grams of bp while using an end burner tool from wolter pyro tools . when i ignite the rocket it only wants to lift about 6 inches. Any help on this matter would be appericiated.

Thank You

[dagabu]

not a reply but a question:

 

I am trying to make estes type e motors for some rockets i have built. I seem to be having trouble producing the needed power to lift the rocket. The rocket is roughly 6 oz. Here is the process flow i am using. 75/15/10 kno3/air-float/sulfur ball milled for 3 hours, screened through a 100 mesh screen. I then add 10% water to the mix, and the bp is screened through a 30 mesh screen and left to dry for several hours. i then pack the tube with bentonite clay and add 24Grams of bp while using an end burner tool from wolter pyro tools . when i ignite the rocket it only wants to lift about 6 inches. Any help on this matter would be appericiated.

Thank You

 

I think you hit on your own answer there Tony. I can get some endburners to work very well and lift a very meager payload but at 170g, your rocket motor is really heavy. Question back at you: What is the ID of the motor and how long is the tube?

 

With a dead weight of 146g, I am not surprised that you dont get lift off. Also, let the BP dry longer, several hours is not nearly enough time to let it dry. Depending on the humidity, it can take three days to get dry BP. The only real way to tell is to weigh the comp before you add the water and weigh the comp as it is drying. A few percentages of water can actually make BP faster but just one percent more can make a good powder slow.

 

In a rocket like this, a nozzle throat only needs to be 1/2 ID so dont add any more clay then you need to and dont even bother to add a bulkhead, its a waste in and end burner.

 

-dag

[nater]

 

With a dead weight of 146g, I am not surprised that you dont get lift off. ...

 

-dag

 

I know there are a few variables, but what is the average weight of a 3/4" traditional BP core burner motor?

 

I just made a few, each motor has about 2 oz of fuel and weighs 90 grams.

[dagabu]

I know there are a few variables, but what is the average weight of a 3/4" traditional BP core burner motor?

 

I just made a few, each motor has about 2 oz of fuel and weighs 90 grams.

 

I would have to make one with my BP tooling to give you a pretty close number but since I make mostly UT motors, I will just post this picture again (sorry for the repeats guys).

 

http://www.pyrobin.com/files/100_2351.jpg

 

-dag

[SjeefOne]

I know there are a few variables, but what is the average weight of a 3/4" traditional BP core burner motor?

I just made a few, each motor has about 2 oz of fuel and weighs 90 grams.

It probably depends on the weight of your tubes but for the tubes I use (Convolutes from PS) they weigh 90 to a 100g.

 

Also the type of C matters in weight too, I pressed a pair of motors recently

1 contained fuel made with Willow C and weighed in at a 100 and 1 contained fuel made with Seqouia C (FASTT!) and it weighed 90g.

Variables,variables..

[shagaKahn]

 

Don't press a nozzle in a cored rocket and use hot fuel. No drilling, fuse as normal.

 

 

OK finally got out to test some 1/4-pounder nozzleless hand-rammed rockets with hotter BP made with my own balsa charcoal; god almighty these things took off and flew faster than anything I've ever made. One flew straight up and did an almost instant U-turn and came straight back down at incredible speeds.

 

Made me glad I's forgone headers for these tests. Thinking maybe I need to add more stick-length to get a stable flight.

 

Thanx again Dag for the nudge to go nozzleless. Ned Gorski at skylighter calls these "speed rockets" and holy jezus I can see why.

[dagabu]

OK finally got out to test some 1/4-pounder nozzleless hand-rammed rockets with hotter BP made with my own balsa charcoal; god almighty these things took off and flew faster than anything I've ever made. One flew straight up and did an almost instant U-turn and came straight back down at incredible speeds.

 

Made me glad I's forgone headers for these tests. Thinking maybe I need to add more stick-length to get a stable flight.

 

Thanx again Dag for the nudge to go nozzleless. Ned Gorski at skylighter calls these "speed rockets" and holy jezus I can see why.

 

No, Harry Gilliam calls them speed rockets, Ned calls them "DJ's nozzleless rockets".

 

-dag

Edited July 9, 2011 by dagabu

[ibizon]

This thread seems to have taken off since I started it. Now that the 4th has passed, I'm looking to start prepping for my next batch of rockets. I've had good success with several basic types of 1lb rockets so I am hoping to try a few new things this time around.

 

I acquired some larger mesh charcoal from a club member and wanted to try to add a longer tail. I think I have 30 and 80 mesh. I have seen several places that show in place of the typical 60-30-10, I would mill a 60-15-10 fuel, then add the additional 15 of a combination of the larger mesh charcoal. While this will work fine for the basic ones, I was hoping to use one of the hotter fuels so I can lift a larger payload. I've been very pleased with the 70-20-10 mix. Would I still do half airfloat and a mix of the larger mesh for the other half?

 

Also, I am planning to move up to some 3lb motors as well. I have heard that a slower fuel is necessary when you get into larger motors. Should I slow down my fuel for these? Maybe just stick to the 60-30-10 formula?

 

Hopefully all this makes sense.

[allrocketspsl]

This thread seems to have taken off since I started it. Now that the 4th has passed, I'm looking to start prepping for my next batch of rockets. I've had good success with several basic types of 1lb rockets so I am hoping to try a few new things this time around.

 

I acquired some larger mesh charcoal from a club member and wanted to try to add a longer tail. I think I have 30 and 80 mesh. I have seen several places that show in place of the typical 60-30-10, I would mill a 60-15-10 fuel, then add the additional 15 of a combination of the larger mesh charcoal. While this will work fine for the basic ones, I was hoping to use one of the hotter fuels so I can lift a larger payload. I've been very pleased with the 70-20-10 mix. Would I still do half airfloat and a mix of the larger mesh for the other half?

 

Also, I am planning to move up to some 3lb motors as well. I have heard that a slower fuel is necessary when you get into larger motors. Should I slow down my fuel for these? Maybe just stick to the 60-30-10 formula?

 

Hopefully all this makes sense.

 

pillow case charcoal:buy lump hardwood charcoal put some in a plastic bag then inside an old pillow case,take a 4x4 crush charcoal as good as you can,remove from pillow put remainder into coffee grinder,coarse charcoal flots to the top skim off screen,grind some more repeat.Its a perffect coarse size to get great red tails on bp rockets,just a suggestion

[dagabu]

This thread seems to have taken off since I started it. Now that the 4th has passed, I'm looking to start prepping for my next batch of rockets. I've had good success with several basic types of 1lb rockets so I am hoping to try a few new things this time around.

 

I acquired some larger mesh charcoal from a club member and wanted to try to add a longer tail. I think I have 30 and 80 mesh. I have seen several places that show in place of the typical 60-30-10, I would mill a 60-15-10 fuel, then add the additional 15 of a combination of the larger mesh charcoal. While this will work fine for the basic ones, I was hoping to use one of the hotter fuels so I can lift a larger payload. I've been very pleased with the 70-20-10 mix. Would I still do half airfloat and a mix of the larger mesh for the other half?

 

Also, I am planning to move up to some 3lb motors as well. I have heard that a slower fuel is necessary when you get into larger motors. Should I slow down my fuel for these? Maybe just stick to the 60-30-10 formula?

 

Hopefully all this makes sense.

 

Go ahead and try your fast fuel in a 3# rocket, I think you will be pleased with the results

 

-dag

[SjeefOne]

Just shot this