easy and quick ways to make a large, 12 to 14 inch nose cone besides 3d printing

[Lt72884]

Trying to find some quickish and easier ways to make a large ogive nose cone besides 3d printing it or turning it on a lathe. I am making a LOCIV (sorry, i forgot this important piece of information: 4 inch diameter, 10 - 12 inches length) from scratch as a proof of concept for level 1 and 2 rockets those who want to get into rocketry but may not be able to afford kits, but can at least possibly find parts to make their own.

I have the airframe, fins, rings, and other parts already, just looking for a strong enough nosecone.
i have thought of paper mache covered in epoxy (expensive) foam of some sort etc

 

[Alan R]

Carve it from a dense block of styrofoam?
Use a big battery to make a hot wire.

 

[BigMacDaddy]

This is only 12" tall (maybe 7" across) but maybe you can find a bigger one. Assuming that this is only a mold and that you would cover it with something and/or fill it with something.

 

[OzHybrid]

Shape polystyrene foam to your required shape. Cut with a sharp kitchen knife and finish with a coarse sanding block. Cut triangular strips of fibergalass cloth( choose your preferred weight0 and apply with your favourite Epoxy laminating resin. Sand when finished.
If you want to use FG resin, get spray glue and give the Polystyrene a light coat from a distance that wont melt it...... Cover with aluminium foil and some more sprag glue till it's all flat enough for you. Fiberglass it. If you have ANY exposed polystyrene and get FG resin on it, it will dissolve.
There are plenty of youtube videos on the general technique.
Obviously the tinfoil method could cause radio issues if you cannot get it all out. If you need it all out, make sure you use a release( usually an alcohol based pva release)
Lastly, you CAN cover your polystyrene in 3 painted coats of epoxy lamination resin. That usually guarantees full coverage at a sufficient depth. ( used this on a 4 foot dia globe) Then give it at least 3 coats of Carnuba based wax release, polishing between coats. Use that as a form to laminate FG directly to. If you do it in 2 halves, you should be able to release them and join. If you do it as a full cover, You MIGHT get it to release...

Once set.
Pour petrol on the foam to dissolve it out. (Not going to attempt to justify the environmental effect. It's the easiest way.). Or remove a bit at a time. Painful method.

OR 3d print one and FG it INSIDE. Epoxy or styrene resin based. The advantage of the styrene resin FG approach is it breaks down any binders in the FG cloth and makes it more plyable and it gels before going off. Epoxy has a longer working time, but keeps running for ages.... Painful for a quick job.

 

[PSLimo]

I've found 10" diameter eggs that work well pairing them with a sonotube and then wetting out a fiberglass sleeve over it. Have to look at a few tubes to get a good shoulder/cone match but it's a pretty simple straight forward method.

 

[mtnmanak]

I am wondering if the OP is refering to the length or diameter of the nosecone? Generally, we refer to diameter when referencing a nosecone and a 12"-14" nosecone would definitely qualify as jumbo, but in this post the OP refers to making this for a LOC IV in order to complete a Level 1 rocket. The LOC IV diameter is only 4 inches, so I am thinking the 12"-14" may refer to length?

If this is the case, you may want to just ask around at your club launch. Personally, I have so many 4" diameter plastic nosecones laying around, especially older ones on rockets that are no longer serviceable, I would give anyone who asked one of them for free. I am willing to bet you could find someone willing to part with one for little or no money.

 

[kjohnson]

Foam disks of descending diameter stacked then sanded, covered in fiberglass.

Cardboard tube cut into a petal shape then glued and smoothed over. US Rockets called this Integrated Tube technique and used it in the El Lubbo kit reviewed here: https://www.rocketreviews.com/us-rockets-usr-el-lubbo-by-lance-alligood.html

Here's a guy that used a 2 liter bottle to make a 4 " diameter cone -

kj

 

[Lt72884]

I am wondering if the OP is refering to the length or diameter of the nosecone? Generally, we refer to diameter when referencing a nosecone and a 12"-14" nosecone would definitely qualify as jumbo, but in this post the OP refers to making this for a LOC IV in order to complete a Level 1 rocket. The LOC IV diameter is only 4 inches, so I am thinking the 12"-14" may refer to length?

If this is the case, you may want to just ask around at your club launch. Personally, I have so many 4" diameter plastic nosecones laying around, especially older ones on rockets that are no longer serviceable, I would give anyone who asked one of them for free. I am willing to bet you could find someone willing to part with one for little or no money.

lol, thanks for clarifying for me that its a 4 inch diameter. I forgot to put that in there.

Thats true, those wanting to build an HPR, can see if any club members have a spare nosecone.
This project i am attempting is to help others in my area that want to do HPR, but may not be able to afford the $123 kit, since they need to buy the motor. So i am trying to come up with ways to help them achieve level 1 and 2 like i did with a LOCIV.

So far i have the airframes. Turns out the 4 inch diameter shipping tubes for $7 at the post office are perfect. They are 48 inches in length.

thanks

 

[mtnmanak]

Awesome - I wish there was an easier way to do "swaps" - essentially, shipping costs eat up a lot of the savings even if you try to give away parts, so local swaps are the only real option for cost constraint.

I am only able to attend a few launches a year these days, and those are mostly the bigger East Coast launches like Red Glare and URRF (aka LRDS 42 in 2024!), so, when I get a chance, I am going to try and collect all my excess materials and start bringing them to launches as give-aways.

 

[MClark]

If your time has any value it’s less expensive to use standard commercial components.
Even making a 4” cone with proper tools (lathe) there can be 10+ hours involved. Unless you would be satisfied with it looking like crap.

If the price of shipping is too high you need a different hobby.

 

[Back_at_it]

Only cone I've made from scratch was for an oddball shipping tube I had laying around that was 6". I used sheets of Styrofoam that had a one inch dowel in the center. I stacked the foam sheets together and cut them to the approx. shape then used a lathe to spin it while I shaped with a sanding block. I then laid fiberglass over the foam and let that cure. Once cured it was back into the lathe for sanding.

The process was actually pretty quick and didn't take nearly as long as I thought. All told I think I had maybe 4 or 5 hrs. total working time in it. Of course there was all of the time for the various items to dry but I did it over the course of a couple of weekends.

I'm not sure how you would go about doing it if you don't have a lathe.