I already have gussets made for the high stress areas, y'all gotta give me time . Much more to come I love to work aluminum, but it is finicky about contamination. You can't get it clean enough, acetone works best after sanding w/ flap disc though. New pic today

Lookin good Donny

Coming along nicely WG,

Tell me, with with your vast knowledge of aluminium, would
aluminium work as a free style buggy, ie like the Flexi buggy, would it be able to withstand the enormous stresses, that those buggies endure or would aluminium be too brittle? or does it not have the flex needed...?

Just curious, I have never worked with aluminium

Carl

Thanks PTW All I need to say is "they make aluminum bikes and motorcycles don't they?"

I've seen pictures and heard stories about flexi rails sagging in the middle so for extreme abuse, it would need more bracing and/or heavier steel for freestyle stuff with impacts and jolts. Angus says the flexi buggies at NABX that the team guys brought were heavily braced and beefed up. I imagine you can make equal strength buggies in either metal but with aluminum you are going to use more metal with larger dimensions. But you probably don't need to use 2.5 times more metal. I can see an aluminum Dominator working pretty well. It is so triangulated already, an aluminum version probably wouldn't need to be that much different than Popeye's masterpiece. WG is the trick with Aluminum to KEEP it from flexing?

All metals flex, if they don't flex they WILL crack! take a ship for example, as big as it is, when at sea it flexes alot from end to end,if were to not flex it would develop cracks and break apart. Ever been on a big bridge, and had a loaded tractor trailer go by, feel how much the bridge shakes and moves? If it was rock solid, it wouldn't last long!

Aluminum gets a bad rap sometimes, but when properly used it's a great material. But as with any material ,when you cut corners to keep costs down ,you end up w/ an inferior product. Even if it is stainless or titanium! PTW :Ever seen a aluminum tractor trailer frame, 40 ft. long and flexes its ass off. And yes it's heat treated ,like all trailer frames are. But that is still alot of flexing! with alot of weight on it!

Damn thats lookin good Donny. I think I have to talk to you about a small project too

Quote:

Originally posted by WELDNGOD It would take 2.5 lbs. of steel to equal the strength of 1 lb. of aluminum

Sorry WeldnGod, but I call bollocks on this one.
What layman's version of strength are we talking about? Stiffness, yield strength, UTS, fatigue limit, hardness?
Specific stiffness is about the same for steel and aluminum.
UTS and yield strength are going to depend on the alloy and its treatment, i.e. thermal history and degree of work hardening. Try building your buggy out 6061 without PWHT; you would be better off with pasta.
You can cut aluminum with steel. Do you want to try to cut steel with aluminum? Do you see a lot of aluminum nuts or bolts.
Steel cover abroad range of iron alloys with very different properties. The pure metal aluminum is almost never used for anything. It is too soft. As an alloy aluminum has a broad range of properties, but it never comes close to the yield strength of high strength steels.

S

scud , I see racing dirt bikes and mototcycles with an aluminum frame ,all the time. The PROWLER has a chassis made of aluminum. I see flatbed trailers made of aluminum everyday. Bet ya' got an aluminum bike in the garage( if not ,your behind the times) You would be a idiot to use 6061 in a welded application , as you would remove the heat treatment.You are right about the "pure " aluminum. It has no real value in strength ,until you combine it w/ other elements to make an alloy. From a chemical standpoint aluminum isn't even a naturally occurring metal(no one has ever found an aluminum nugget or vein)
Hey, have ya seen a steel or stainless 747 lately?

Dude , do you even work in the metal trade? "Strength through design!"There are alot of ways we measure strength. But I'm talkin' strength to weight ratio here. Sure , aluminum has a shorter fatigue life than steel. But that can be eliminated with good design. It all comes down to application. I'm not talkin about making aluminum bearings or axles,just frames dude. I weld on aluminum boats every day for a living,I'm pretty damn certain I know a bit about aluminum and its properties, and I didn't stay in no damn holiday inn express neither.

And I use plasma or water jet to cut with. Aluminum oxide melts at around 5000*F ( steel 1800*-2000*) , and is used in sandpapers and cutting grit. Seems to cut and shape steel and stainless steel pretty well too!:D So yeah, I can cut a piece of steel w/ aluminum!:frog:
I want you to go get me a piece of steel angle 3 ft long that weighs one pound.
Now go get a piece of aluminum 3 ft long that weighs exactly one pound.
Now lets bend em'
My money is on the thicker piece of aluminum vs. tin can thin piece of steel you would have to use.
We ain't building a freakin tank here folks! Scud, are you tellin me you know more about when to use aluminum than say HONDA, YAMAHA,SUZUKI. Tell ya what, when you get a motorcycle co. named after you then I'll believe ya'. Until then ... ALUMINUM ROCKS!!
Still friends dude, WG.
P.S. I'd love ta' talk more metallurgy with ya', but this is not the MILLER website ,it's the PKF!!! Back to the kites and etc... WG If it makes ya' feel better , my next bug is gonna be made from stainless! I already got the materials , well mostly.

WG that looks quite good to me! i don't know much about metal so I'll no enter the metal talk I do know that some of the freestylers have been experimenting with plastic rather than steel the idea is flex and shock absorbing over ridgid strengh. I don't know how it works yet. I do like the look f the bug so far!
Nice job.
A

*ahem* would it be profitable (in your eyes) to produce buggy's like this for prices below or near manufacturers?











if so, I GOT DIBS ! HOW MUCH!? :D:singing::duh:

Well what did you think I was gonna say lol? I don't want a Peter Lynn, I want a custom made, hand-crafted, WELD'N-GOD buggy! That would be a cool name no doubt lol

Nice pics keep us posted...

Quote:

Originally posted by TheNotoriousZ28 *ahem* would it be profitable (in your eyes) to produce buggy's like this for prices below or near manufacturers? if so, I GOT DIBS ! HOW MUCH!? :D:singing::duh: Well what did you think I was gonna say lol? I don't want a Peter Lynn, I want a custom made, hand-crafted, WELD'N-GOD buggy! That would be a cool name no doubt lol Nice pics keep us posted...

No one man band in his garage could ever compete with a production line, what you have here is custom made buggies, made to measure, not some average sized buggy that will fit a 1000 different size people...I don't know about WG but I take measurements, leg sizes, weight, hip sizes, unless I know who the buggy is for, in my eyes if you want production prices, you get a production buggy, but if you want something special, different and something that will fit properly, from the masses then you have to be prepared to pay the price.


take production cars and bikes, then take the hand built ones...OCC etc, you will always have to pay more for something special

no, I actually spend time welding my bugs. Each piece is handcut, cleaned and beveled,then I put it all together and weld it . Each one is an individual craft that is unique to itself and its owner. KD , It,s called composites.And it is aerospace tech fo sho! carbon fibre,epoxies,mylar. All cool stuff for construction.

WG I used to build boats... I am now a touch sensitive to epoxies now... anyway I heard that it was some plastic tube that had SS collars and not a composite at all that would allow much more flex most composites flex some but not that much!

Wouldn't I just love a PTW bug... after I win the lotto I'll come and visit Carl and have one built custom for me!

So what is that thing???...some sort of coat rack or maybe a light fixture??? Wait a minute, I got it. It's one of those doodads that you hang bicycles from so they don't take up so much room. :D:D:D

Wish I could weld like that, the kind of welds you DONT want to grind down because they look better, I have to take all mine down to surface level....... And the spatter!!! THE HORRIBLE HORRIBLE SPATTER!!!!!

anti-spatter spray only costs a few bucks, works a charm. But I TIG weld my stuff ,so no sparks or spatter is produced.

I've heard pam actually works fairly well, any truth to that? I haven't welded since I last heard that. Curse you and your fancy welder!!! I'm sitting here with a 110v wirefeed arc

Quote:

Originally posted by WELDNGOD scud , I see racing dirt bikes and mototcycles with an aluminum frame ,all the time. The PROWLER has a chassis made of aluminum. I see flatbed trailers made of aluminum everyday. Bet ya' got an aluminum bike in the garage( if not ,your behind the times)

My point is not that they do not use aluminum in these applications, but whether steel is stronger per unit weight. I asked by which measurement of strength aluminum is 2.5 times stronger steel, what alloys are you talking about?
I have had aluminum bikes, but I do not like ride as it is a bit too stiff and harsh for long distance riding. So both my upright and my recumbent, up to date enough for you, are steel.

Quote:

Originally posted by WELDNGOD You would be a idiot to use 6061 in a welded application , as you would remove the heat treatment.

I guess most the Al bicycle industry are idiots as 6061T6 was the most common alloy used until 7000 series came out. 6061 is used in welded applications you just have to Post Weld Heat Treat, PWHT. If you would like to know all about artificial age hardening, I can bore you for hours on the subject.

Quote:

Originally posted by WELDNGODYou are right about the "pure " aluminum. It has no real value in strength ,until you combine it w/ other elements to make an alloy. From a chemical standpoint aluminum isn't even a naturally occurring metal(no one has ever found an aluminum nugget or vein) Hey, have ya seen a steel or stainless 747 lately?

You would need to understand a bit about beam theory to understand why aluminum is used on aircraft skin instead steel, but the simple answer is that in this application aluminum's lower density and makes it a better choice. Although aluminum is not found in its metallic form it is considered a natural occurring metal. Technetium is an example metal that is not naturally occurring.

Quote:

Originally posted by WELDNGODDude , do you even work in the metal trade? "Strength through design!"There are alot of ways we measure strength. But I'm talkin' strength to weight ratio here.

25 years as a metallurgical engineer. Which type of strength are you talking about yeild, shear, UTS, hardness, fatique limit, stiffness? Please tell me which alloys you are comparing and give the numbers.

Quote:

Originally posted by WELDNGODSure , aluminum has a shorter fatigue life than steel. But that can be eliminated with good design. It all comes down to application. I'm not talkin about making aluminum bearings or axles,just frames dude. I weld on aluminum boats every day for a living,I'm pretty damn certain I know a bit about aluminum and its properties, and I didn't stay in no damn holiday inn express neither.

I did not stay in a Holiday Inn Express either, instead I stayed five years in a university studying the properties of aluminum and steel and how design around their properties to achieve the required result.

Quote:

Originally posted by WELDNGODAnd I use plasma or water jet to cut with. Aluminum oxide melts at around 5000*F ( steel 1800*-2000*) , and is used in sandpapers and cutting grit. Seems to cut and shape steel and stainless steel pretty well too!:D So yeah, I can cut a piece of steel w/ aluminum!:frog:

Alumina is not aluminum, it is alumina. And the melting point of the oxide has little to do with strength of the alloy.

Quote:

Originally posted by WELDNGODI want you to go get me a piece of steel angle 3 ft long that weighs one pound. Now go get a piece of aluminum 3 ft long that weighs exactly one pound. Now lets bend em' My money is on the thicker piece of aluminum vs. tin can thin piece of steel you would have to use.

Ahhh, stiffness not strength. Actually the way you have set up the bet shows you do not understand how you set the circumstances where aluminum gives a stiffer piece than steel. You have to specify the geometry. Ever notice that you Al tube bike has tubes that are very fat. You have to do this to get the stiffness required

Quote:

Originally posted by WELDNGODWe ain't building a freakin tank here folks! Scud, are you tellin me you know more about when to use aluminum than say HONDA, YAMAHA,SUZUKI. Tell ya what, when you get a motorcycle co. named after you then I'll believe ya'. Until then ... ALUMINUM ROCKS!!

I know exactly the same exactly the same things as the engineers at Honda, Yamaha, Suzuki know: The density of aluminum allows you to make a section that has a greater moment of inertia than you can make with steel. Until you realize that it is the geometry of the hollow cross section that aluminum's lower density allows that gives aluminum a stiffness advantage not greater stiffness or strength per unit weight, aluminum s*cks.

Quote:

Originally posted by WELDNGODStill friends dude, WG. P.S. I'd love ta' talk more metallurgy with ya', but this is not the MILLER website ,it's the PKF!!! Back to the kites and etc... WG If it makes ya' feel better , my next bug is gonna be made from stainless! I already got the materials , well mostly.

I would suggest two fairly easy to read books on this subject: The New Science of Strong Materials or Why You Do Not Fall Through the Floor and Structures or Why Things Do Not Fall Down. Both are by J.E. Gordon and contain some pretty interesting ideas presented so you do not need to fully understand integral calculus and differential equations to understand these ideas. I would be glad to help with any points you have trouble with. Nobody likes to talk metallurgy, even other engineer's eyes glaze over at the thought of talking metallurgy.
Question for bonus points anyone know why austenitic stainless tubing is used in kite buggys?
S

Ok I want to know why? Is it more flexible? I am guessing totally... I don't have a clue really I have a bachelors degree in fine art... I just would like to learn to weld well someday... :singing:

Well I'd have to say because all 300 series stainless is considered austenitic , which covers most available s.s. materials , and they probably used 304 ( most common and cheapest). And because martensitic stainless would crack all to hell. And no s^^%, you have ta post weld heat treat 6061 after ya weld it.If I had access to a heat treat oven I'd use 6061 but I don't ,so I use 5086. The darker gray coating on new aluminum is called aluminum oxide! It has a melting temp of 5000*F , which is precisely why you have to clean aluminum to white metal prior to welding.It is what makes aluminum so tricky to weld. Alumina is what my damn gas cup is made of! You build your buggies , and I'l build mine. What is your beef w/ aluminum? Somebody steal your beer? As far as the statement about strength and steel . That is what I was taught years ago. It is just a rule of thumb like the one about fillet welds that goes "fillet welds should be half the thickness of the thinnest member plus a sixteenth. Anything else is added weight and wasted materials." Maybe you confused my handle "weldngod", and think I'm some "welding engineer". Think not!!! I am a REAL welder! I actually do it everyday. ANY METAL, ANY POSITION, ANY DAY PIPE OR PLATE!!, WITH A MIRROR OR WITHOUT, LAYING IN WATER IN THE BILGE , WITH EITHER HAND! AND STILL GET IT DONE ! X-RAY CERTIFIED when you learn to do this , I'll care what you think about aluminum

And quit actin like a ball bustin engineer! go build your own damn buggy or fly a kite!

Weldngod that is amazing! I can do that with epoxy but welding... that is impressive. I had to make a silver ring once I melted the bugger burned my hand and then scorched my jeans all in 3 seconds flat.

Did you weld an aluminum can to plate.......? How in the........:puzzled: If I blowtorch a can for a fraction of a second it burns a hole in it!


*bows down to weldngod*

yeah I did! I did it, cause I can!! Well ,that and because it is harder than this

Q. How does a pair of 70 ton tanks get to the beach?


A. An ALUMINUM hovercraft!

Who is ball busting? You made a statement; I challenged it and asked you to back it up. Then you start telling me I know nothing about metallurgy, a subject I studied for five facking years. My guess is that the sum of your metallurgical knowledge is how to weld and very little more. You seem to be unaware of the difference between stiffness and strength which are pretty fundamental concepts in metallurgy. I would love to talk metallurgy with you sometime, but you do not seem to know enough about the subject to keep up your end of the conversation, plus when contradicted you get a little touchy.
Instead of contradicting you, I am going to suggest you look up alumina and aluminum oxide. I think you will find that they are the same compound, they certainly have the same formula, chemical structure, etc.
Take care, hope this finds you in a better mood.
S

4Q AWS calls it aluminum oxide when it is on the metal, ALUMINA when they make your gas cup out of it. Either way it still melts at 5000*, and is one of the reasons aluminum is so hard to weld. I wasn't talkin cross sections and all that PWHT CRAP! . Just simple strength to weight ratio , no tempering allowed. And doesn't "lower density" also mean lower weight? I didn't come here to argue apples and oranges, I'm building a buggy out of aluminum. If you wanna make yours outta tempered martensite or lead ,that's your call. From now on I'll check w/ you and the AWS before I comment on anything metallic. Jeez, dude!

Now I see why your avatar looks like A BIG GREEN POMPOUS PR#$K !

weldngod wrote "Just simple strength to weight ratio , no tempering".
We are talking strength right, not stiffness. Go to your AWS book and look up the yield strength or ultimate tensile strength of aluminum then look up the same numbers for whatever steel alloy you want. Strength will depend on the alloy, so you will have to know which alloy you to want to look up. Then divide the aluminum value by 2.55 and the steel by 7.8 that will give the specific strength for each metal. Remember no heat treatments allowed. Write back with what you find.
If we are talking stiffness you have to know the shape of cross section and its dimensions. The stiffness of a structure depends on two things the material it is made from and its moment of inertia. Remember writing "strength through design". That is what strength through design is all about. Read the books I suggested. You might find it interesting and I know you will learn something.
I suggest you look alumina up in a dictionary. Every time you write something about metallurgy, I become more convinced that you know how weld and that is all. You are good welder, no small accomplishment, but a really lousy metallurgist.
Name calling - How old are you ? If you are not under the age of fifteen, resorting to that kind of crap makes you look bad. Do you really hate to be corrected about some archane technical point so much that you revert to adolescence? Get a grip man.

S

I think Scudley and WELDNGOD are both feeling the pain from not enough time in the buggy! :sniff:

Time to ride and stop the pissing match

Ron