Power Kite Forum

Buggy metal

BeamerBob - 7-8-2008 at 05:18 AM

I posted this on the hampton kiter meet up thread and decided it was too much of a hijack so I started this one for the discussion. They were discussing making buggies out of aluminum and the possibilities of using titanium for lightness. Maybe the use of aluminum has another appeal other than lightness, such as it's laying around in WG's shop?

I've never said anything, but isn't the pursuit of lightness counterintuitive to buggying? That expensive high end buggy from europe has places to attach weights to "add" weight. Seeking lightness seems along the same lines as wanting to design a race car that has lift to reduce downforce and therefore reduce traction. It is my understanding that weight is what causes the tires to grip when the kite is loading the buggy from the side. You have reached your max speed when the tires start to slip sideways. More weight gives you more traction and more speed before you start to slip. Am I off base here? Is your goal for lightness or the use of aluminum motivated by other factors?

silvereaglekiter - 7-8-2008 at 05:30 AM

You do have a point their :( for Wg Al is what he had handy. The Green Machine is heaver then my Rockvill.

BeamerBob - 7-8-2008 at 05:34 AM

He certainly does a nice job working with it. Beautiful welds and cuts.

acampbell - 7-8-2008 at 05:40 AM

Ya huh. With added weight comes some stability, too (but weight is not all of it) The buggies at NABX that were comfortably doing 50- 60 mph were the ones around 90-100lbs and over.
I hit over 40 mph in my little bitty 36 lb PL Comp XR+ and I was floating/ rattling/ shaking accross the top of the playa and I have to say I was more than puckerd with the thought of my feet bouncing off the pegs.
I remembered seeing Brad's (from Texas) big homebuilt with a camera mounted on the axle. I asked him how the camera handled the vibration and he smiled and said "What vibration?". The axle was solid steel, he explained.

jellis - 7-8-2008 at 10:28 AM

IMHO A buggy should be strong enough to take punishment, and still be able to lift it for loading and handling, then use add on weights in the right areas to handle more power.

coreykite - 7-8-2008 at 10:52 AM

Hey Sailors,

If you don't make the buggy so blazing heavy you don't need to fly overpowered.
Lighter weight buggies accelerate faster.

Heavier buggies (mass) once going (momentum) roll longer and further (inertia).

You can make both work.
Heavier is nice for long runs and lighter is nice for maneuverability and tricks.

The issue of convenience is also important.
If the buggy is a hassle to haul around and lift in and out, we'll probably play less and less over time.
Nothing is slower than the buggy in the garage.


Safen Up! Buggy On!

"Often wrong... Never in doubt"

the coreylama

_____ - 7-8-2008 at 12:25 PM

When I was talking to Donny about his bug, I believe he told me it weighed about 60lbs. Not too sure if thats with or without the rocket launchers on it.

BeamerBob - 7-8-2008 at 01:27 PM

I bet 60 lbs of aluminum buggy would be very strong and heavy enough as well. There is a balance point of compromises.

WELDNGOD - 7-8-2008 at 02:05 PM

YOU RANG? allright every one, I will tell ya all about it. I build alloy buggies cause:
1) I have constant access to scrap aluminum
2) a pound of aluminum is 2 1/2 times stronger than a pound of steel.
3) aluminum is easier to drill, grind, cut,machine etc.
4)aluminum is cheaper than stainless.
5) aluminum doesn't contain Hexavalent chromium (extreme lung carcinogen)
6)I never said my buggy was lighter than other buggies.( it weighs a little over 67 lbs., without the luggage rack and rocket launchers) And when the wind gets about 25-30 ,I can feel the rear end slip sideways a little, and thats at like highway speed!(really creepy feelin)And I got dualies on the rear! So adding weight in high wind ,overpowered conditions is something I have considered.
7)I love to TIG weld aluminum and have access to some of the best aluminum welding equipment available, Between my day job and the family welding service ( HOT WORX INC.) :D
8) Nobody else is doing it! Except those chrome plated pieces of aluminum crap I saw on the internet(I think they made em out of lawn chair tubing:lol:) Anyway that's my story and I'm stickin to it:yes:

clintopher - 7-8-2008 at 02:35 PM

Quote:
Originally posted by WELDNGOD

4)aluminum is cheaper than stainless.


Really? That's good to know because I priced SS tubing today and about fell out the chair.

WELDNGOD - 7-8-2008 at 02:59 PM

I didn't say it was a whole lot cheaper! Get ready to fall out again :lol:

awindofchange - 7-8-2008 at 03:54 PM

I think you'll find that good quality aluminum like WG is using is going to be pretty close to the cost of stainless. Better put your seat belt on when checking prices.

Thin wall aluminum is pretty cheap. It'll surprise you just how inexpensive it is. When you start getting into sizes thicker than .0875 the price per foot goes up at a very steep angle. .250 has to cost a small fortune.

A quick check on the net for aluminum prices vs. stainless:
T2024 T3 alu 2" x 6' x .120 wall = $228.65
T6061 alu 2" x 6' x .250 wall = $269.85
T304 Stain / welded 2" x 6' x .120 wall = $86.03
T304 Stain / seamless 2" x 6' x .188 wall = $394.94

I'm still very interested in seeing WG's bug once its done. Would love to take a ride in it as well. Perhaps we can work out a time to hook up and do some buggy swappin! :)

WELDNGOD - 7-8-2008 at 04:14 PM

I wouldn't use anything but 5000 series alloy, mil-spec 5086 is my first choice. I never use 6061 cause you weaken it when you weld on it,and it likes to crack(too brittle) And your right about the cost when you start getting into structural grade material.
Kent ,are you in the construction biz?
I think our prices are a little cheaper around here, Norfolk VA is Atlantic Fleet HQ . Ships and shipyards and contractors out the ying yang. So there is a little more supply around here. We also have this one particular scrapyard that has all kinds of material in good supply. You can't use it for govt. work( no certs.),but for commercial use it's the ticket! ya buy it by the pound!(quite a bit more than scrap prices,but alot less than new) and they don't make you buy the whole stick or plate:P maybe I'll make NABX sometime!

BeamerBob - 7-8-2008 at 04:38 PM

The lightweight talk was going on in the hampton meet up thread. I started this thread since this is not a local discussion. Yeah, I slip in there every once in awhile to see what you tidewater guys are up to.

WELDNGOD - 7-8-2008 at 04:55 PM

BBOB, you are always welcome too see what were up to,I don't remember how we diverged into aluminum. But, hey were all kiters talkin about it. This ought to be a good thread for a while. wish I could make the jeckyl island thing. But it looks like that is out of the question for now. I know it's gonna be a blast,Hope ya'll get plenty of wind:thumbup: bob here's a sneak peek

0401081638 (Small).jpg - 28kB

clintopher - 7-8-2008 at 05:26 PM

Quote:
Originally posted by WELDNGOD
We also have this one particular scrapyard that has all kinds of material in good supply. You can't use it for govt. work( no certs.),but for commercial use it's the ticket! ya buy it by the pound!(quite a bit more than scrap prices,but alot less than new) and they don't make you buy the whole stick or plate:P maybe I'll make NABX sometime!


Which place is that?

WELDNGOD - 7-8-2008 at 05:30 PM

Sims

SCREWYFITS - 7-8-2008 at 10:18 PM

Just my two cents...
When I pit crewed on a NASCAR team we built the car (frame and components) as light as we could... NASCAR had a minimum weight that we were always under, so to add weight and be beneficial, we added weight in the corners and low... so to add weight to the tire traction and low to keep the center of gravity down...
I'm working on an aluminum bug that should be light compared to most bugs... but the plan is to make it weigh close the same by adding weights to the corners and low... and hope to give myself a little advantage... we'll see... the weights should be bolt on and removed before transport to keep the convince there... also be able to experiment with the weights to find the sweet spot...
sorry that might have been 5 cents...

BeamerBob - 8-8-2008 at 04:59 AM

Your idea is right on but the benefits will be minimal due to the differences between a buggy and a race car. A Nascar car stands almost 4' tall I imagine, like a typical sedan. You want as little weight as possible up at the roof level. If you have to have weight, you would want it down as close to the ground as you could get it so it doesn't raise the car's roll center (the point the car pivots about when it leans in a turn). In a buggy, all the weight is pretty low to start with so adding weight on the axles won't change its roll center much at all, considering the riders weight. Still, the more weight, and the lower it sits, the more side load the buggy can take before it wants to tip over or slide.

Someone earlier said make it strong first. If you do that and make it out of aluminum for ease of transport, then add weight for stability, you could win on both sides. Heavy when you're riding and light when you are loading it in the car.

awindofchange - 8-8-2008 at 11:36 AM

Quote:
Originally posted by WELDNGOD
I wouldn't use anything but 5000 series alloy, mil-spec 5086 is my first choice. I never use 6061 cause you weaken it when you weld on it,and it likes to crack(too brittle) And your right about the cost when you start getting into structural grade material.
Kent ,are you in the construction biz?
I think our prices are a little cheaper around here, Norfolk VA is Atlantic Fleet HQ . Ships and shipyards and contractors out the ying yang. So there is a little more supply around here. We also have this one particular scrapyard that has all kinds of material in good supply. You can't use it for govt. work( no certs.),but for commercial use it's the ticket! ya buy it by the pound!(quite a bit more than scrap prices,but alot less than new) and they don't make you buy the whole stick or plate:P maybe I'll make NABX sometime!


I'm not in the construction biz, I am in the kite biz though. :)

We did design and build the Ivanpah buggy (with a ton of info and help from Popeye, Buggy Bags UK, and others). Weight is a concern but it is not the only thing. Triangulation and stability needs to be built into the bug as well. It also makes a huge difference how the weight is loaded on the buggy. Just making it heavy (or light) won't make the buggy grab in the corners or under power. Balancing the weight in the buggy is what will make it grab. It is hard to compare the buggy to a Nascar because Nascar depends so much on aerodynamics for downforce and traction. With the buggy, you are being pulled upwards by the kite and you have no aero downforce to work with.

As stated above in the thread, weight takes more power to get moving but you gain in momentum. My PL Comp XR+ accelerates much easier and quicker than my Ivanpah but once up to speed, I can hold down much more power with the Ivanpah and I am much less effected by lulls in the wind or redirecting the kite. The buggy is also much more stable and planted, allowing me to gain more power from working the kite harder without the worry of the buggy being ripped out (power sliding). The Ivanpah also has a feature that no other production buggy has in that you can off-set the rear axle for down wind reaches. Think of it as a Nascar team being able to set the right side tires an extra two feet outside the fenders.

bbrex - 8-8-2008 at 12:16 PM

Hey Kent
I have a simular setup on my fullrace rear axle, It telescopes from about 135cm to 190cm in 2 inch intervals and you can set the sides at different lengths. My overall weight is 135 to 145lb depending on the tire/wheel setup I am using. I extend the rear as wide as I can get It and still be able to break the back away to scrub off speed when necessary. Man it holds a line nice. I use a safety system/ harness that is attached to the buggy so I get to use all that extra weight without having to worry about getting pulled out.
Brad

WELDNGOD - 8-8-2008 at 06:06 PM

Yeah ,Kent I concur on that bro', I've been playin w/ the idea of welding a 1/2" bung and plug on my rear axle and downtube .So I can add sand or water for more weight where I need it when wind gets crazy. But I also know that tires make all the diff. Slicks are great when you wanna slide, but ribs and knobs give more lateral traction at the expense of speed which can be compensated for with more sail. It's all a bunch of variables and findin the magic combination is the art of it. I wish I still lived in vegas( I lived there as a teen),but it was all dirt bikes then! P.S. I like the idea of offsetable (is that even a word?) axles :thumbup: If you combined that with adjustable weights down low. OMG what bite you'd have!:yes:

flexiblade - 10-8-2008 at 09:40 PM

One thing I've found out in recent weeks is triangulation is everything - as mentioned earlier in this thread. My homebrew handles fine in 15 -17mph winds with a 13m venom, but as soon as I get over 17 my ass end starts sliding out instead of going faster. Even if I weighted the back end this will not solve the problem of the mass of the buggy (my weight + weight of the axle + 2 bigfoots) that are within 1 and a half feet from one another (I moved the seatback bar a couple of inches to the rear for comfort). I need to extend the connectors from the main seat to the axle at least a foot and a half to help stabilize the side pull into a forward pull. The buggy weighs roughly 60lbs, but I have used lighter buggies that are great at taking off fast in no winds - but get them powered up and you feel like you're riding a 50cc on a mad incline doing 100mph. I prefer stable and fast cruising (30 to 40mph), not having to stress and being able to punch it up a little when I want.

popeyethewelder - 11-8-2008 at 12:00 PM

I am guessing my 150lb buggy, won't beat you lighter buggy guys off the mark.....BUT, you are forgetting one thing, I am about 160lbs....a light weight, if a guy in a lighter buggy weighs 280lb, it kinda even things up a touch...

I have noticed now, for me, with the extra buggy weight, this buggy really is like riding on train rails....it just goes straight, when other are getting dragged all over the place and losing momentum....

for me...the criteria is wide, long, heavy and well balanced, I have been in many buggies, and I have the lighter Wildkat buggy, which is fantastic in the right circumstances, but for long fast extreme beach runs, a big stable buggy wins every time with me.

WELDNGOD - 11-8-2008 at 02:04 PM

The BUGGYGOD has spoken;-)