Drewculous - 29-4-2009 at 11:00 AM
I was talking about power kites with a customer that happened to hang out with some kite fliers years ago in Oregon... he runs a metal fabrication
shop here in town. We got talking and he started asking about buggies. He looked over some books i had around and suggested aircraft aluminum as a
frame. He said its extremely strong, very lightweight, and that they use it in dirt bike frames.
Any opinions on aircraft aluminum as a frame material as compared to stainless steel?
edit:
I've further read on the forums and noticed a thread on aluminum frames, but didnt know if there was a difference in "aircraft" vs. generic aluminum
Looking_Up - 29-4-2009 at 11:19 AM
I have a bug in the works right now and i am using polyurathane pipe it is verry strong and still light weight
DAKITEZ - 29-4-2009 at 05:25 PM
Light weight is not necessarily key. I'm sure weldngod and screwyfits will be along shortly to explain better.
SCREWYFITS - 30-4-2009 at 01:00 PM
Hello Drewculous,
I'm by no means an expert on the subject...
I'm in a collage welding class now and learning, and have just completed an aluminum race style bug that I can comment on my experiences and
opinions...
First off I love aluminum everything, it's just "COOL"... but my experience with my Alum project is full of opinions...
I think aluminum for buggy building should "not" be considered based on building a light weight bug (unless it's a freestyle type, my opinion varies
here also)... The reason I'd recommend it would be so you can add the weight to the bug (that it needs) where it's beneficial to the bugs stability,
basically low and to the outside, as close to the wheels as possible... This helps with stability, how much, that's the question
I haven't seen many issues with the top manufactured race style bugs and stability... in fact, they are made with stainless, and are heavy, and they
still add weight, a lot of it too!!!
I think as far as production goes, aluminum is probably not a good choice... I don't think there are many consumers that are looking for aluminum,
that know what they are looking for...
I think there is a possibility for aluminum to be superior for bugs but I haven't put my finger on it yet, I'll say again it will not be for weight
(light weight) but to benefit from creative strength with more material and not be outrageously heavy...
I think the average cruiser or freestyle bug might benefit more from the weight reduction and still the cost offset will not be beneficial...
Great subject though!!!
MMMMMMMMMMM ALUUUUNIMUMMMM!!!!!
Drewculous - 30-4-2009 at 03:51 PM
good info screwy!
Just kinda throwin that out there, didnt know how feasible or benificial somethin like that would be. My concern with alum is the use of steel
parts.. if memory serves, they dont mesh too well...
No, if you wanted a slick @$$ buggy, two words: carbon fiber.
:shocked2:
feasible, no. expensive, yes... at all effictive, ?? idk
krumly - 30-4-2009 at 06:24 PM
Weldngod knows more about welding tahn most of us ever will. But I do know welding most aluminum seriously degrades strength at the weld zone unless
it is a heat treatable alloy where strength can be restored through artifical aging (usually in a heated solution bath). Many aluminum alloys cannot
be heat treated at all, like the 5000 series often used in boatbuilding. The option if you can't heat treat and artifically age is to overbuild by
adding gussets or using thicker walled tubing.
Aluminum also tends to have a cycles to failure curve where strength gradually drops off after many flexures, even under the smallest bedning loads.
Most steel, and carbon fiber composite laminates, will flex almost indefinitely below a certain bending load, but will then yield (steel) or snap
(carbon) when a certain point is exceeded. This means aluminum structures generally have to be designed around service life along with maximum
anticipated load.
Aluminum is about 1/3 the density of steel, but can be 1/2-2/3 as strong and 1/2 -2/3 as stiff. Weight savings can be achieved by using a larger
diameter tube than you would use with steel, but with a thicker wall to keep the larger diameter tube from buckling. Aluminum can accept stainless
fasteners, but it's still best if they are insulated .
Carbon fiber needs to have any metal fasteners insulated with plastic bushings, an epoxy bushing, or a layer of fiberglass/epoxy cloth; otherwise
electrolysis is guaranteed. Despite it's superior physical properties, hand layups with carbon fiber can be well underneath the calculated maximum
properties. The slightest mis-orienetation or waviness in the fibers. combined with minute air bubbles and over or undersaturated layups lead to
unpredictable results. The use of pre-preg laminates or pre-cured forms will generally insure stronger structures. Bonding to aluminum is dicey
unless it has undergone mil-spec etching and priming specific for epoxy bonding. If not treated this way, your joint will fail over time due to
oxidation at the aluminum at the aluminum/resin interface.
krumly
Drewculous - 1-5-2009 at 06:26 AM
wow krumly... good call!
FYI i really wasnt goin to attempt a CF buggy, just thought it sounded cool.
But it sounds to me like youve looked into this and gave aluminum and carbon fiber both a shot, in the books, at becomming a buggy.
Very interesting stuff... off to google to find some obscure building material that may/may not fly... no pun intended
awindofchange - 1-5-2009 at 11:26 AM
Joe Hadzicki from Revolution has a carbon fiber buggy. 
Looks pretty sweet!
popeyethewelder - 2-5-2009 at 05:21 AM
I rode probably the world first fully composite buggy, including the forks in Dubai, it was a big desert buggy for traversing the dunes, it handled
superbly and only weighed 14kg