Jump to content
APC Forum

Recommended Posts

Posted

After a long hiatus from building anything except the smallest devices, I was finally able to get back at it. We're 3 weeks out from the first shoot of the season, after not building much last summer, it will be nice to have something to fire. Video to come.

 

Up first is a 3/4" Hybrid #2 with a FeTi tail and a Firefly heading:

 

2015-04-24%252019.53.25.png

  • Like 3
Posted

Look good. I can't wait to see the video.

Posted

A very aesthetic rocket. What is the burst charge? How is the upper cone attached to the lower one? Am I correct that the casing just consists of a few turns of kraft paper?

Posted

Each part of the cone is 4 layers of pasted kraft. Once dried, the nose cone is simply glued on to the truncated cone body.

 

The header is bulk filled with stars and polverone. There is also a heaping tablespoon of whistle. The result is a soft break with a little more spread than a horsetail. It should look nice with the firefly streamers.

Posted

nater,

 

When filling the header which part is glued on last? What kind of glue are you using for the final attachment?

Posted

nater,

 

When filling the header which part is glued on last?

 

 

The rocket motor. ; )

 

Both sections of the cone are glued together and it is dried as one piece. It is filled upside down and then attached to the motor. On the bulkhead side of the motor, I always press a thin layer of hybrid fuel which spits a huge flame. The bulkhead was pressed and the passfire hole was filled with more hybrid fuel and polverone so the entire empty space in the tube was filled with something flammable. This keeps the header from spilling out.

What kind of glue are you using for the final attachment?

Just a little wood glue on the outside of the motor tube where the header joins. Then a band of pasted paper or gummed tape to hold everything together.

Posted

Nate,

 

So you make these up ahead of time and require time for the attachments to dry. I was thinking about making headers like these with a fused collar that would slip onto a freshly made motor. Most of my rockets are made for club shoots so drying time is important.

Posted

Yes, I make the headings up ahead of time. I typically make them inside on a day when I have nothing else better to do than cut and paste paper. Once the cones are dry, they can easily be filled on site and attached to the motor with hot glue if you want to fire them immediately. I prefer attaching them with glue and pasted paper for aesthetics.

 

I do have some small, punched end disks that fit in the small end. I have an idea to make a 2 break header out of each section of the cone.These would be closed up and pasted more like a cylinder shell and then attached to the motor.

Posted

Nate,

 

Those really look nice on a finished rocket, I have made a couple of the wood formers for making the rocket cone body and nose cones. Might be time to fire up the lathe and turn some bigger ones.

  • 2 weeks later...
Posted

Has anyone seen this plastic piece before? I was given a piece form a friend along with a nose cone that goes with it to make a rocket casing that looks like the second picture. This would make my life so much easier.

 

Any information would be much appreciated.

post-19793-0-87146100-1431285149_thumb.jpg

post-19793-0-76498000-1431285157_thumb.jpg

Posted
I have only seen them on a few commercial rockets. I don't use plastic on anything I build.
Posted

Normally, I wouldn't either but having seen these thing in action I was inclined to inquire about them. The person that had given me this has made a few rockets out of what he had and when I compared them with mine there was a noticeable difference.

 

I usually stick to the standard 2 or 3 inch ball shell mounted on top of my motor and I've been quite happy with what I have been able to achieve.

 

When we went head to head with the same motors made from the same batch of willow BP, the streamlined design of his rockets outfitted with those plastic pieces added at least an extra 100' due to less drag and ultimately made a better looking rocket overall.

 

I was just curious if they were out there but from my research I guess they aren't.

 

Oh well, you cant blame a guy for trying.

Posted

You could turn balsa wood on a lathe and make light weight versions of the top and bottom

pieces for the rocket header. At least the balsa wood would bio-degrade over time. I have made

modular style rocket headers that slip fit onto the motor and everything is made from craft paper,

cardboard tubes, wood etc. The whole idea with being bio-degradable is not having garbage build up over

the years and having the powers to be adopt legislation to clean up the problem. Plastic takes

hundreds of years to totally decompose. Cardboard and wood tend to quickly decompose over several

years.

Posted

You could also make a paper nose cone with pasted kraft around a cone shaped former. Affix the cone to a cylinder shell for a more streamlined header. Another idea would be to use a hemi half to make a domed top shell for reduced drag.

 

Personally, I tune the motors to get the header to the right height and don't care as much about aerodynamics in a firework rocket. I enjoy making the pasted paper headers more than snapping plastic pieces together. I am also concerned with the plastic debris. One of out shoot sites is a private airport for ultralights and others are cow pastures. Plastic debris needs to be kept to a minimum out of respect for those property owners.

Posted

As far as the lathe goes, I don't have one but its a good idea. I used to work for the Conservation Corps so I do understand about the impact of plastics on the environment. Not to be a jerk or anything but one might argue that the combustion of various comps releases harmful gasses and other such chemical compounds into the environment and produces a negative impact as well.

 

As far as the paper nose cones go, I have yet to either buy or come up with a tooling that could make the shape for those. I was hoping to find an easier way but the paper nosecones look like the best route to go.

 

As far as the base goes, I guess I should just use a paper disk with a hole punched out of the center and glue my motor to that.

 

Thanks for your input, I really appreciate it.

Posted

When I mount cylinder shells to a rocket, I build them like any other cylinder shell except the spolette tube is filled with a few pieces of black match instead of pressed meal powder to transfer fire immediately when the motor delay burns through.

 

If the finished shell is flat enough, it can be secured to the motor with glue and pasted paper strips to anchor it. Another method is to use a section of tube which can slip over the OD of the motor. Center it on the finished shell with then passfire poking through. Then mount the shell with this collar over the motor and secure with glue and pasted paper bands.

Posted
By the way, he uses hot glue to secure the header to the motor... Not because of time, just his preference.
Posted

I have not been able to get them to stay good enough with hot glue. The headings wobble too much for my comfort level.

 

I am not knocking the method at all, I am just not TR or even close to building shells that perfect.

Posted

You could also make a paper nose cone with pasted kraft around a cone shaped former. Affix the cone to a cylinder shell for a more streamlined header. Another idea would be to use a hemi half to make a domed top shell for reduced drag.

 

Personally, I tune the motors to get the header to the right height and don't care as much about aerodynamics in a firework rocket. I enjoy making the pasted paper headers more than snapping plastic pieces together. I am also concerned with the plastic debris. One of out shoot sites is a private airport for ultralights and others are cow pastures. Plastic debris needs to be kept to a minimum out of respect for those property owners.

 

+1 nater.

 

I will not build any device that will leave plastic trash on the ground. I also shoot in a cow pasture, and the property owner did not like the plastic debris from the previous shooter that he gave permission to fire on his property due to the plastic trash from 'saturn missile battery' cakes fired on his pasture.

 

If I can't make it out of paper and the proper glue, I need to research and do better.

Posted

In response to the statement about rolling paper cones, I have had success cutting a perfect circle of paper, then making one straight cut to the center of the circle, then forming the cone in my hand. Diameter can be adjusted by varying the number of "turns" of paper and the size of the circle.

  • Like 1
Posted

Seen from an accident perspective, a pointy stick is a lot more likely ro catch on something, and get dug in. This is why i prefer flat or ballshaped rocket headings. We all know they shouldn't be heading down-street, but if it somehow ends up doing so, i'd much rather see it bounce of someones leg, then dig in, and stay put waiting for the bang.

This is a lot more likely with consumer rockets, with plastic tipped headings, but i prefer ball / cylinders just the same. The kraft paper cone shouldn't have much structural integrity, but... It doesn't really make a difference for how high it goes, so it's not sacrificing performance...

B!

Posted

Those plastic pieces might be produced by a Spanish firm called Plasticos Gamon. They make a lot of molded pyro things. http://www.gamon.es/ I can't get the direct link to work, but if you go to products and click on big rockets, there are some similar looking things in there.

 

There was a company a while ago working on making plastic shell casings from biodegradable plastics. I don't think it ever ended up being financially viable. There may be a European firm offering them to the pyro industry, but I'm not very familiar with the details.

Posted

 

 

Let me fix that for you. There, now this should work.

 

You should be restricted from posting links. I have no idea why it keeps doing like that. I fixed "your" link in my quote as well, but i can of course not affect your post.

 

Cheers.

B!

Posted

It has to be something with my computer or the forum software. I promise I'm copying in good links, but when they get converted, it keeps adding spaces.

×
×
  • Create New...