You are very astute my friend! Driving the alternator using that method is option number two, for sure. I have the cover in the illustration with the Potvin logo cast into it and I really like it and would like to use it unmolested as it will be visible through the track nose, so that's what's holding my back. I've ran an alternator off the driveshaft on another car and it worked fine, though that car had a mag, lights, and that's about it. This car is going to have more electrical components than the typical traiditional roadster (fuel pump, electric fan, electric water pump, EFI, etc.) so we shall see if it will work. Worse case scenario, i can just keep adding batteries! LOL
I am making the Potvin fuel pump drive right now. you have to make the drive yourself using oil pump drive gears from a flathead. the other issue is that the drive turns at 1/2 crank speed
I am a little late to this discussion, but am I mistaken to believe there is a 'middle ground' between 'pipe' and DOM tubing. I am thinking of the very common 'welded seam' tubing, round, square and rectangle. DOM is, I think, the primo of tubing, but also may be overkill in many applications. Am I missing something here? btw, I loved (as usual) the @Ned Ludd post on the matter. Ray
Here is the deal when you use a water pipe description everyone is going to think water pipe. Some of us are hard asses and we expect someone to say what they mean. As for your use of tubing, if you properly engineer is you can build a chassis from exhaust pipe. It has been done and done well, all the sanctioning bodies have out lawed it not because it is unsafe but because it is unsafe when not properly engineered. I cannot recommend it this is just for an example. Here is the what I do, I am mildly educated in structural design. That said I am lazy and know that the sanctioning bodies have already figured a lot out for me. If I am building a tube chassis I build one that will pass tech and the easy way to do that is to see what sanctioning bodies like the SCTA or NHRA is passing. I got an NHRA and an SCTA book in the shop packed away in a box. Have I mentioned that I am lazy? If you do not want to order one for yourself I'll just about bet you can find either book on line. A safe bet is .125 to .3125 wall thickness is what you are after. The later if you are not a design wizard and a little extra weight is not an issue.
In the lightweight, low horsepower application of your project, DOM would be great, but .120 wall ERW will do the job just fine. I bend and mix DOM and ERW (Electric Resistance Welded) tube all the time.
A new trend in the 2020s amongst us. Deep analysis, metallurgy, chemical composition, historical fact finding, SAE test results, govt regulations, health warnings and personal protection. All to find out if "...is this tubing overkill for...". Can you bend it? Notch it? Got plans for smaller supports and cross members? Then fuck it, run it. Show of hands, who wants to analyze that?
Without some ongoing analysis (evaluation) of materials and processes, we might be building hot rods with rough hewn tree limbs held together by pegs…. Ray
I learned FEA software years ago, can't use it anymore. We did a project as part of the training - design a structure to support mass with intermittent known shock loads. Then redesign with different materials, steels, aluminum, wood. There's structural specs for different wood types. I learned a lot.... then only used it for a short time
Over kill. Too much welding. Too much time on my hands 15 years ago. No time to finish now but the #525 is done.
This is what they called a st reched midget back in 1950. 1.75 OD x .120 wall. DOM. A 7/8 x .095 lower truss. 4130. Not yet installed. And a T bucket chassis I built In 1970.
DOM or 4130 depends on your frame design. I use EWST always on hot rods. When building race cars I always used very thin wall 4130. LOTS of lead ballast for a low center of gravity. These are preliminary sketches for the front and back of T sh irts I am having made.
FEM software Featured snippet from the web Finite element analysis (FEA) is a computerized method for predicting how a product reacts to real-world forces, vibration, heat, fluid flow, and other physical effects. Finite element analysis shows whether a product will break, wear out, or work the way it was designed. A rich man goes to college, a poor man goes to work. FEA? I had to look it up. I had no clue. Once again saved by google. I tell my kid, it doesn't always have to be what was actually intended for use, as long as it serves the purpose while being used. Give a bunch of kids a long rope, one tire, point them to a tree branch. One of those kids will do what kids do. The rest, they will figure out a reason why not. Did you know, the top speed record on a bicycle is 183mph. Would have been faster but he let go the rope. You guys worrying about tube pipe molly dom seamless and drawn, most of you won't go that fast. But I do like fancy and cool to look at from a design stand and viewpoint. What didn't I read was how long it took him to get to that speed? Maybe it was all downhill? I'm sure with pipe it would have been an effort. Chrome-moly, not as much. Maybe it's me, but I'd say it's traditional to use pipe. It was available. Affordable. Then again, it's an opinion not a fact.
My question is whether a properly braced tube/pipe frame will be any stronger or lighter than an original stamped frame with added bracing in a lightweight roadster if the heavier stuff is used.
A properly braced tube/pipe frame will in my opinion be stronger and lighter than an original frame with added bracing if it's been engineered and designed with such interests in mind. If you equate the materials used, the channel of a old ford is 1/8" x 10" x12" laid flat. A 3" diameter tube is 1/8" x 9.5" x 12". I think the question is, how much can you spend and what the purpose behind spending it. Someone made a joke about bamboo, well crazy as it sounds, why not.
Thats an overly simplistic comparison. The stamped rail is not 10" wide for its whole length and only needs two of them. The tube set up will need 4 tubes that are 9.5" (unfurled) for their whole length. They will also require vertical bracing between the two tubes on each side. I would think that the tubes would be smaller than 3" in diameter though. Not saying lighter frames can't be built with tubing, but it would take a lot of attention to detail and material selection or it could quickly get heavy.
I mentioned the Bamboo, mostly as a reference to Gilligan's Island... however........ very heavy coaches and carriages as well as covered wagons were built on wood chassis.....and were rendered obsolete by wrought and cast iron, both very brittle and heavy. Of course, we're talking about 8hp or so max.....or 20 mules
Have you ever seen a bicycle made out of square tubing...... ever in the 2 hundred years of making bicycles? If there were any advantage in weight or strength to use square tubing those race bikes in the Tour De France bike race would be all over it like a hog on slops. A 4" round tube has a surface circumference of 12.56". To make a square tube with the same amount of surface would result in a 3.14" square tube. Don't even get me started on why submarines are round and not square.
Simplistic it was. “Birdcage” Tipo 60 / Tipo 61 - Post-war Racing Cars | Maserati -And this was exactly what he did: He created a space frame made of approximately 200 small-section tubes, arranged in triangular formations and reinforced in high-stress areas. The result was an extremely light construction that offered exceptional torsional rigidity at the same time. I see it like those contests where they build a bridge out of popsicle sticks. Some get it, some don't. But as far as it goes, once you see the winning bridge, the next one you build is always better.
Let's talk racers for a moment. In the heydays of back half street strip cars 2X3 was plenty strong of properly braced (bridged) by a roll bar and adequate crossmembers where needed. Those who were extra serious about weight reduction, AND had $$$$, went to full round tube moly rear half mods. Full chassis could have been mild 2X3 topped with either mild or moly cages. As time and tech advanced round tube was de rigueur, and eventually double rail round tube as still seen today. Strength? A 200HP flatty or a firebreathing blown Hemi? Are we rock climbing or the occasional stop sign grand prix? I was told monster trucks were moly for weight reduction but mig welded ro reduce the brittle nature of tig welded moly joints. True? I think I researched it way back then and the answer was yes. We all know a moly racer chassis has a "shelf life" don't we? They will crack eventually, and of course depending on use. A modern pro stock won't last as long as local hero bracket racer running mid 8s. If any of this raises awareness and acts as brain food, well, glad to assist. And finally, I'd prefer a braced or boxed OG for the main reason of fits and mounting points. Some pretty smart guys figured that out for us well beforehand. More brain food for your consideration.
I have seen them. Few to none of the bicycles used in the TDF are even made of metal these days. SE Racing still makes the Floval Flyer, that has a floval top tube, bi-oval down tube and tapered rear stays. My point is that the strongest structure for an application is frequently neither round, nore square. Rectangular structures have strength in the path-of-force most commonly experienced in vehicles. Round structures have that, in all directions, which is not needed. Round tube can be harder to fixture, and it often costs more. Sanctioned class racing requires round tube because there is a real risk of actually needing that structure for protection, at high speeds. Street speeds are (or should be!) much lower. As for submarines, that's an apples to aardvarks comparison. I cannot even unpack that. There is no structural necessities comparison between a submarine and a car.
No rope. Flat ground, at Bonneville, on the salt. The rider was in the aerodynamic drag bubble of an LSR car. The bike was almost entirely carbon fiber, so not even metal.
I couldn't agree more. That square or rectangle is a bit simpler to work with, all those flat surfaces. But as unpopular as the opinion will be, if you tell them they need it to play than they have to pay. Your safety and their liability. Yea, but I'm calling it a win for her just the same. I watched her video. It was something. And she was tethered in the beginning. See the 16 minute point start. I think it was around 140mph she cut loose. How This Cyclist Hit 184MPH and Set the World Record - YouTube
Denise Mueller, SHE rode behind a converted RED with a fairing attached. And yes, pulled to speed. But ya gotta have the quads and lungs to stay at that speed!. I actually talked to a couple other fast ladies to see if they wanted to go after the record. Previously John Howard did it behind the Vescos historic Streamliner.
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