More Mailing Tube Rockets

[Neil]

As some of you know, I am making rockets out of mailing tubes. I just thought I would share the idea, and get some feedback on the designs. I have several 4" ones, a 3" one and a 1/2 scale of the 4" one. All the tubes are mailing tubes, including the motor mounts. The 4" kind will cost $35-$45, the 3" one will cost $30-$35, and the 2" one will cost about $20.I am making some kits that are2" diameter, but they will be better, with Kevlar cords, pre-glassed airframes ETC. With these I am just making these for me.

One question: Does anyone know where I can get fiberglass by the roll? Thanks. -Neil

 

[jetra2]

Neil,

Sounds very cool man. I have been doing some research of my own for a project I am looking to build, and I have found that US Composites carries fiberglass, carbon fiber, kevlar, expanding polyurethane foam, epoxy, and many other items - this place seems to me to be a one-stop shop for HPR reinforcing materials. BTW, the fiberglass is offered in different widths, I think it comes in rolls, but I'm not sure.

Hope this helps,
Jason

 

[BlueNinja]

One thing about carbon fiber: coat it with something thick. I learned this the hard way when I was shooting arrows, one of my cf arrows was splintering. it hurts for about a week.

 

[jetra2]

Giant Leap Rocketry's Kevlar sock needs to be covered with a layer of fiberglass also, because the Kevlar is NOT sandable. More people know more about that stuff than I do...I'll let them talk.

Jason

 

[BlueNinja]

Yep... that happened more than once. You can shoot an arrow pretty darn far with a rubber band... loop it around index finger and thumb, nock arrow onto both sides, pull back, hold with fingers, throw. I tried that with my splintery one... "Darn! I can't get this adjusted right!" I got it adjusted, then it slipped, driving a nice painful cf spike into my thumb.

Nope, dont know anything about kevlar except it's fireproof and can be used as epoxy filler.

Or you can Quasi-glass: use pantyhose and varnish.

 

[Neil]

Fiberglass it is then........... I know how to use that.....

 

[daveyfire]

OK, here's my two cents on composites, professing to know *something* considering I've sent rockets into the ground at mach 2 and had the fins stay on :

1. Fiberglass: excellent stuff to start with. I still use it almost exclusively. Strong, cheap, and easy to work with. Not too many bad points. You can also finish it without a veil (well, duh, most veils *are* made of fiberglass ). Price is usually $4-10/yard for virgin cloth.

2. Carbon fiber: great cloth, looks cool, very light and STRONG. But it's expensive, and harder to use than glass (you can't see when it's wet out as easily). Price is usually $20-30/yard for virgin cloth.

3. Kevlar: fun to work with but I wouldn't use it exclusively. Kevlar has many of the same properties as Carbon, except it's more flexible and you can't cut it without Kevlar shears. This is easier to see when it's wet out (turns a darker "banana yellow" from its standard "bright yellow" color -- hard to explain but when you use it you'll know what I mean ). It also provides some degree of zipper protection, however it's harder for the fiber to do anything when it's constrained in the matrix with resin. Priced similar to carbon but a little cheaper ($15-25/yard).


So... yeah. Also another thing to keep in mind -- you need to put a light layer of glass over either Carbon or Kevlar to keep it from fuzzing when you finish it. Yeah, yeah, the composites guys say "you don't need a veil because you shouldn't sand the fabric anyways". But believe me, your sandpaper will nick ONE fiber in the Kevlar and it'll be impossible to get it out of the paint job. Been there, done that Remember that you'll need a high quality resin (e.g. Aeropoxy (nb: my favorite -- it's CHEAP!), West System, System Three) to hold it all together, epoxy based filler to finish dings and imperfections (and fill the overlap), and high build primer to fill the weave (trust me, it's hard without it -- scraping filler over the WHOLE airframe then sanding it off, then again, and again, ad nauseam).

One more thing... Enjoy working with it! I love working with composites.

 

[astrowolf67]

I just happened to notice, while looking at a small lathe on eBay, that this seller also has a lot of rolls of fiberglass cloth for sale in various weights.

Summitcentral.

It might be worth a look

 

[sandman]

Neil,

i have 3 done so far.

The balsa I got is as hard as pine!

But...my fingers got numb so I came in...almost half done.

sandman

 

[Neil]

Those look great! On the one in the middle, is that just the camera, or is the tip of the cone bent? I like the sounds of this super-hard balsa..... I think you made the right choice buying that stuff! Make sure you get a good supply of the stuff! This wont be my last order, you can be sure of that!!!