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Alternative rocket casings


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Posted

First cato, I'm so proud!

 

Same hull design with 7/64" x 1 1/4" long core. Dummy payload to bring the weight upto 94g. It lifted off well then at about 8' it let loose. Total case failure. Got it on video!

Posted (edited)
Got them to work. The first one is a cato, blew the end plug out. The second one is the first effect payload one of my creations has carried. I tested them with dummy loads of about 30g. Total weight on the successful rockets has been between 88 and 94g. The shell is an Easter egg, with the holes plugged with hot glue, hot glued seam, and spiked with a couple layers of masking tape. Edited by hillbillyreefer
Posted
I am impressed!
Posted

I am impressed!

 

Thanks dag. Tomorrow it's onto sugar rockets. I'd like to be able to enter your contest. Learning is never a bad thing!

Posted

Got them to work. The first one is a cato, blew the end plug out. The second one is the first effect payload one of my creations has carried. I tested them with dummy loads of about 30g. Total weight on the successful rockets has been between 88 and 94g. The shell is an Easter egg, with the holes plugged with hot glue, hot glued seam, and spiked with a couple layers of masking tape.

These are the best things ever. I love it. You mind if I post a video on them after I get them down myself? I think they're great for people just getting started without the cash for tooling. They would be perfect for many of my viewers to get started with.

Posted

These are the best things ever. I love it. You mind if I post a video on them after I get them down myself? I think they're great for people just getting started without the cash for tooling. They would be perfect for many of my viewers to get started with.

 

Feel free to use whatever you like. Tomorrow when my notebook is closer to the computer I'll post a bit of a tutorial for you.

 

They are working pretty well, but I'm still tempted to play with the core a bit, or just leave it alone and light up the sky!!

Posted

Thanks dag. Tomorrow it's onto sugar rockets. I'd like to be able to enter your contest. Learning is never a bad thing!

 

Everyone is welcome! Lets see you do a two stage shotgun shell rocket!!

Posted

Everyone is welcome! Lets see you do a two stage shotgun shell rocket!!

 

Was that the sound of the gloves hitting the ice? :blink::blink: I may have one flying (catoing) by tonight, doubtful, but possible.

 

I've been getting some pointers from a buddy who is into high power stuff.

Posted
Sounds like a man that knows a little something about cold weather. Thats the sound of my tuque hitting the ice, aye?
Posted (edited)

Toque, we don't need no stinkin' toque, it's only -8C here, eh! Sugar fuel is in the ball mill. Should have something to try by this evening.

 

NHIL

 

Here is the quick tutorial I promised

 

1. deprime hull, I use my loading press, but a punch and hammer should work.

2. fill primer pocket with tissue

3. add bp and ram. for a rammer ATM I'm using a 3/4 bolt. It's a tight fit but works well. I usually take about 5 fills and rams before I get upto the start of the crimp. The BP is standard 75:15:10 with pine charcoal.

4. fill the remainder up with bentonite and ram really well.

5. remove tissue from primer pocket.

6. drill a 3/32"hole 1" from the base of the shell. Should give 3/4" core.

7. wrap at least 10 wraps of masking tape around the outside of the hull.

8. mount on stick, balance. I'm just using 1/4x1/4 sticks 48" long. They usually balance a couple of inches behind the nozzle.

 

I just found the motor from the second one in the video. There is nothing left of the plastic part of the hull, so they are living on the edge. The tape re-enforcement is mandatory in my opinion. Any other questions just ask.

Edited by hillbillyreefer
Posted
Made two sugar motors this evening, using the exact same methods as the BP ones. The first one lit, lifted up about 6 inches and sat there huffed until it settled back into the launcher. The second was on top of a BP, the first attempt at dag's contest rocket. The BP portion worked well, my passfire looks like it worked well, the sugar motor burned but poorly, as it arched over and headed for the ground. The fuel was a bit lumpy when it came out of the ball mill, it must have been a bit damp when put into the motor cases. I will get some desiccant in the container tomorrow morning. The nozzles may also need to be enlarged, according to my research they are undersized by about 50%, that will make a huge difference. I've got video will post it up for a laugh tomorrow. Night all.
Posted (edited)

Thanks for the additional details.

 

I don't know that your sugar fuel will be fast enough without being melted. 2-3% iron oxide will improve the burn significantly as well, if you did not already know that.

 

Your nozzles don't need to be enlarged. If the nozzle were too small the rockets would explode. The smaller the nozzle is the higher the pressure will be that the rocket generates, translating into faster exhaust gases and in turn more thrust. You want the nozzle as small as it possibly can be without causing a CATO. A larger nozzle would result in a drop in thrust.

Edited by NightHawkInLight
Posted

Thanks for the additional details.

 

I don't know that your sugar fuel will be fast enough without being melted. 2-3% iron oxide will improve the burn significantly as well, if you did not already know that.

 

Your nozzles don't need to be enlarged. If the nozzle were too small the rockets would explode. The smaller the nozzle is the higher the pressure will be that the rocket generates, translating into faster exhaust gases and in turn more thrust. You want the nozzle as small as it possibly can be without causing a CATO. A larger nozzle would result in a drop in thrust.

 

The sugar rockets ive been playing with are 5/8 id tubes with 1/8th nozzle and cores drilled almost all the way thru to the top plug. Most have done well, popped the top on a couple. Ive been adding spherical titanium to the top of them to at least see where they go. Ive just been using screened and shaken dry mix and it works fine also in several 3/4 in tubes.

 

Steve

Posted

Thanks for the additional details.

 

I don't know that your sugar fuel will be fast enough without being melted. 2-3% iron oxide will improve the burn significantly as well, if you did not already know that.

 

Your nozzles don't need to be enlarged. If the nozzle were too small the rockets would explode. The smaller the nozzle is the higher the pressure will be that the rocket generates, translating into faster exhaust gases and in turn more thrust. You want the nozzle as small as it possibly can be without causing a CATO. A larger nozzle would result in a drop in thrust.

 

 

I used 63:27:10 for the fuel mix. My iron oxide is too impure (IMHO) to use as a catalyst or anything else. I have no particular reason for using that fuel formula, except it seems to be in the ballpark of what people are using. And I have the ingredients.

 

I misspoke about the nozzle size, I meant core size, my core is 0.094" x 0.75". Going up a couple bit sizes and increasing the depth of the core may make a big difference. One adjustment at a time though, leaning toward larger diameter as a starting point. After watching the motors, they are close to flying, so a tiny bit more surface area may be all that is needed.

 

My first impression when I opened the jar was this stuff is wet. It was lumpy and a bit sticky. I just had to try it, even knowing how hygroscopic this mixture is. After a bit of desiccation and adjusting the core, some success should be achieved. Or a Cato(they are always fun).

Posted (edited)

Here are 2 from last night this is my first feeble attempt at a video with my video glasses. How the heck do I edit out the sound??? My wife is holding an antique miners lamp that i was playing with last night. the second one popped the top. The first on was a nozzleless bp

 

Steve

 

Edited by moondogman
Posted

Sweet moondogman.

 

What are the specifics of the designs?

 

We are going to try a couple more sugar rockets tonight. Can't wait.

Posted (edited)

Sweet moondogman.

 

What are the specifics of the designs?

 

We are going to try a couple more sugar rockets tonight. Can't wait.

 

 

Im using some 5/8in tubes 3.5 or 4 inch long with coffee grinder milled kno3 65gm and 35gm powdered sugar and 1 gm of red iron oxide I put it in a butter tub and shake the crap out of it then run it thru a screen then shake it some more. Im using bentonite clay on top and bottom made on a about half inch peice of dowel stuck in a peice of 2x4 and rammed with another peice of dowel with a bit of a point on it to start then a flat dowel then i gently drill a 1/8th core most of the way thru it. Ive been using some old balsa sticks from an old unfinished model kit. I learned it all from youtube :D hehe. Ive been adding a pinch or two of spherical titanium to either the top (under the clay) or a couple times the whole sugar mix. It really adds some nice sparkles. ive done the same with 3/4th tubes with a slightly larger nozzle hole but the 1/8th core

 

I would have made several more today but my back has had me on the couch all day, work is gonna be rough tomorrow.

 

Steve

Edited by moondogman
Posted

Not sure what happened to my last post. Anyway.

 

I just threw one together with a core the same dimensions as yours moondogman. I still don't have it right for my fuel and cases. She sat in the launcher for a second or two, then slowly chuffed it's way up to about 50 feet, then started to nose over horizontal and made it about 50 yards down range. I wish the lens cover hadn't been on the video camera, it was pretty cool the way it was all in slow moooottttttttiiiiiiiiiiiiooooooooooooonnnnnnnnnnnnnnnnnnnnn.

 

The core needs to be bigger, this failure was a major improvement over the last one.

Posted (edited)

Thanks for the additional details.

 

I don't know that your sugar fuel will be fast enough without being melted. 2-3% iron oxide will improve the burn significantly as well, if you did not already know that.

 

Your nozzles don't need to be enlarged. If the nozzle were too small the rockets would explode. The smaller the nozzle is the higher the pressure will be that the rocket generates, translating into faster exhaust gases and in turn more thrust. You want the nozzle as small as it possibly can be without causing a CATO. A larger nozzle would result in a drop in thrust.

 

You are right NHIL, my fuel isn't fast enough. The best I have achieved is 2 lazy, slow lift offs achieving around 50 feet or so. I need to try the iron oxide trick I guess, even if mine isn't that pure it can't really make the fuel any worse, and if it does it will be better as a delay. I tried a 2 stage bp with sugar as delay today and it seemed to work. If it wasn't for dagabu's ridiculous contest I wouldn't even be playing with sugar. J/K dag.

 

My fuel mix is 63:27:10.

Edited by hillbillyreefer
Posted
I tried adding the iron oxide catalyst you suggested NightHawk. Worked like a charm. The first one I used the larger cores I have been playing with and away she went. It seemed a bit slow so I made the core a bit longer and it cato'd. The third and fourth ones flew like they should. The fuel still burns fairly slow compared to bp, and I don't think it will lift like bp, hopefully testing can begin tomorrow.
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