Fiberglass... why?

[Kevin Huddleston]

Yeah, I'm full of questions. What can I say? I'm 44 years old and still thirsty for knowledge! :p

So, fiberglass kits are considerably more expensive than non-fiberglass. What are the qualities associated with fiberglass that make it so desirable?

[Jerry Irvine]

Yeah, I'm full of questions. What can I say? I'm 44 years old and still thirsty for knowledge! :p

So, fiberglass kits are considerably more expensive than non-fiberglass. What are the qualities associated with fiberglass that make it so desirable?
Fiberglass not.

http://v-serv.com/usr/kits/easyrider-38.htm

That's a kit that is also offered in fiberglass or similar kits from other vendors in FG. Not needed. That kit has experienced NO power limit. People have tried.

The same airframe has been tested to the limit of 54mm and 75mm.

http://v-serv.com/usr/kits/sonic3100.htm

Just Jerry

[luke strawwalker]

For high power rocket motors, capable of much higher airspeeds than regular black powder model rockets, fiberglass is capable of sustaining much higher aerodynamic loads than can be sustained by standard cardboard tubing and balsa or basswood fins... (although thicker cardboard tubing and lite ply fins can also work, to a point... usually combined with improved construction techniques like through the wall fins and often with more substantial adhesives, like epoxy). However, plenty of high power rockets have been built and flown perfectly well using only thick balsa or basswood and thick cardboard tubing using regular wood glue... Fiberglass is NOT, by definition, REQUIRED for high power construction-- it's simply an option, like many other things-- another tool in the toolbox and useful in certain applications... depending on what you're trying to do...

Later! OL JR :)

[jadebox]

Another advantage is that fiberglass rockets are very easy to build. There are no seams to fill; tubes and fins are easy to cut; tubes and couplers fit together very well; fiberglass retains its shape better; and fins are usually smooth without sanding, sealing, and filling.

A large fiberglass kit can be built and painted in a single afternoon. I've been building (and rebuilding) my large cardboard rocket for the past three years. :-)

-- Roger

[UPscaler]

Fiberglass not.

http://v-serv.com/usr/kits/easyrider-38.htm

That's a kit that is also offered in fiberglass or similar kits from other vendors in FG. Not needed. That kit has experienced NO power limit. People have tried.

The same airframe has been tested to the limit of 54mm and 75mm.

http://v-serv.com/usr/kits/sonic3100.htm

Just Jerry

While that is a cool kit, if you really wanted extreme altitude out of 38mm minimum diameter you would want a shorter airframe. For and additional $25 you can get the Wildman Blackhawk 38, which is carbon fiber (I believe).

That being said I am not big on extreme altitude.


One of the biggest things I like about fiberglass is the fact that it is simple to use in construction. Don't get me wrong, I like a typical paper/wood rocket, and I like laying up fiberglass myself, but as far as ease of use, putting together a fiberglass kit is almost as easy as an Estes E2X model. And paint goes on smooth as silk as well.

Edit: I get my glasses next week. I didn't notice that the kit is 3 inch with a 38mm mount. My bad!


Braden

[PaulK]

In addition to the items Luke points out, some folks like fiberglass simply because of its durability. Some fiberglass builds can withstand a very hard landing with no damage.

When not required due to airframe stresses, the main downside is weight, requiring more expensive motors.

[Jerry Irvine]

While that is a cool kit, if you really wanted extreme altitude out of 38mm minimum diameter you would want a shorter airframe. For and additional $25 you can get the Wildman Blackhawk 38, which is carbon fiber (I believe). I have one. 29mm.

But:

http://v-serv.com/usr/kits/sonic165f.htm

http://v-serv.com/usr/kits/payloader.htm

My point is fiberglass is overkill. In MOST situations. Here's a clear exception:

http://v-serv.com/usr/kits/sonic100f-s.htm

http://v-serv.com/usr/kits/sonic100.run.txt

Just Jerry

[UPscaler]

My point is fiberglass is overkill. In MOST situations..

Just Jerry

I wouldn't argue there! I've seen a 100% Stock LOC Caliber ISP fly on a K550 and do just fine.

I didn't know you had fiberglass kits! Looks pretty cool.



Braden

[luke strawwalker]

Here's another benefit...

I was feeding cows at Shiner a week or so ago... something caught my eye from the tractor in the area where I was feeding-- someone lost a rocket in that general direction from the launching site a year or so before, and I've always been curious as to where it actually landed. I rolled out the bale of hay and then went over and looked to see what it was... turns out it was a rocket... completely pristine-- not a scratch on it. Even the decals and paint were still in good shape. I picked it up and cleaned off the clinging dirt/grass bits from it laying out in the pasture for a long time, stuffed the shock cord back in it, and popped the nosecone back on. No motor casing, and the parachute was some distance away and the ripstop was badly sunburned and faded and disintegrating, but the rocket was in fine shape... it was fiberglass... Turns out it had been laying out there in the pasture for most of the fall and winter... luckily no cows stepped on it and I didn't flatten it out with the tractor driving through the weeds, but the exposure to rain, sun, and cold had virtually NO effect on it. I put it up for the owner to retrieve from its storage place at the next launch out there...

I was chopping weeds with rolling choppers yesterday afternoon at Shiner, on the front hill... something caught my eye about 20 yards away, so I stopped and jumped down from the tractor to go see what it was... turns out it was an Estes Stormcaster. A buddy of mine had said he'd lost one at the last launch he attended up there a few months back. The rocket was basically toast-- the tube was wet and collapsing and smooshed/warped, the fins were broken and turning loose, the plastic nosecone had either taken a hit or been stepped on by a cow and broke the shoulder off it, so even the cone wasn't salvageable... (sometimes the plastic nosecone is all you'll ever find of a crashed paper/balsa rocket after a few months on the ground... everything else eventually disintegrates almost completely...

Course, I don't like the WEIGHT of fiberglass... and the strength means its non-frangible, so if it malfunctions, whatever it hits gets perforated, because the fiberglass is NOT going to crumple like a paper body tube or balsa fins... and with the additional weight, impact energy increases substantially compared to an identical rocket using paper and balsa construction... plus as weight increases, larger motors become necessary to loft the heavier fiberglass versus that needed for the same size rocket using lighter paper tubing and balsa fins....

There's tradeoff's to it... not a simple "X is better than Y" type argument...

later! OL JR :)

PS. Thank goodness that fiberglass rocket didn't hit a cow... it would likely have killed her... (or hit anybody or anything else for that matter...)