has anyone ever built a frame out of round tubing what im thinking of using is 2.5" o.d. .095 wall 4130-N tubing it would be rails about 100" long with the axles hung out the ends on perches "suicide" style im shooting for a period 1949 build....or somewhere close and i want it to be pretty high tech looking for that time but still something someone could have built in their home garage with a bit better equipment then the average guy box tubing is out of the question anyone have any experience thanks Zach
i have seen pictures of some early cars built with black pipe frames but most looked kinda funny where the crossmembers meet.
the Rodders Journal # 33 has a killer round tube frame roadster in it.The Salt Shaker:Return of the Ramblers Roadster.The car is a fine example of a round tube frame.The car won competition class at the 56 GNRS and best constructed car at the 57 GNRS.This is the standard by which a round tube frame could be judged.
Shelby small-block cobras of the early 60's were built this way although they had independant rears.....The early ones even had a transverse front leaf spring.....The way they were designed is that chassis flex became part of the suspension and racers of that time said that they handled better than the later big-blocks which were made with larger diameter and thicker wall tubing......Most of the replica cobra's are designed with round tube frames
The last two months issues of street rodder are covering a build of a tube framed build. I would check it out, the guy has some cool ideas and you e-mail him any questions
thanks guys sounds like it oughta work out then i was just concerned with the strength really i guess being chromoly it shouldn't have any problems i have some ideas for the ends of the rails and attachment of crossmembers...shouldnt look too bad thanks Zach
Zach... check Fabien Valdez's chopped sedan he built with a tube chassis. His Co. name is Vintage Hammer. Great guy! Think he hangs tight with the Bean Bandits and most of the guys out at Muroc. He also races a cool roadster called "Rockabilly Boogie" a few times a year. I'll see if I can dig up a pic...
thanks, i just found a pic of his sedan he has a double row of tubing i want to just do one....pretty much just like a box tube frame but round instead
the chromoly is a bad idea IMO. just use DOM or HREW. the chromoly will most likely crack where you weld the crossmembers etc. it just does not have enough flex in it for a single tube frame. Randy
really? hmmmm what about wall thickness and whatnot if i go with the DOM keep the same .095? anyone else know anything about this? i know i built alot of bicycles out of chromoly and i saw alot of bikes that had cracked beside the welds... so it is a concern thanks Zach
You may want to look into both cracking, and buckling issues. The easiest way to visualize the buckling, is if you were to choose a thin wall tube as main frame rail, and then join the center crossmember and/or x-members to it. All the stress arrives at the joint...and "tests" it. There are formulas that predict buckling. If I recall correctly, the cracking can happen, if it is either too hard material or there is migration of certain material due to welding. Best example depicting migration might be the rust "corona" that you see around a weld on a stainless tube (the chromium leaves(?) the heated area). Maybe Brianangus or Squirrel have some good advice here, and there are some fine chassis builders too (Scotty?). Good luck on it. P.S. Bike frames use double or even triple butted tube, where the thickness increases as you move toward the "ends". They also use lugs, to strengthen the joint regions,
I would suspect that any tube frame from this period would have design directly based on WWII period aircraft stuff...many planes were tubular, though the fighters and newer stuff had moved on to monocoque type builds. I seem to remember that up into the '50's PBY wing struts from surplus were considered prime material for the main rails...used in bellytanks and such. Lots of different aircraft derived thinking came out of the war--I was just reading an old HRM story on a car built by Issagonis (Mini, minor!) from stressed aluminu, covered plywood...rubber landing gear suspension!
Here's some pics of what I was told was a drag roadster. The owner - original builder I believe - set it up for street running, engine setback and all. Nice car, well thought out . . . and these are the only pics I hve of it. Somewhere - God only knows - I have a pic or two of a 29 A on double main frame rail round tubing with angled round pieces between the two long horizontal tubes. Built somewhat along the lines of a Deuce framed A in that the double tube frame is exposed all the way. Nicely done solid axle car fwiw A little classier, sorta sporty/Indy car looking frame as compared to the drag racing style frame seen in the pics. At a guess, the drag race roadster is running 2 1/2" tubing and the double tube framed A roadster was running 2".
Chromemoly is well covered in Circle track type books...from memory, I think it needs reheating at welds to prevent cracking there. I think on a decently designed frame not required to survive 5,000 pounds flipping at 200 MPH, the extra strencth is wasted.
thanks guys sounds like DOM might just be the best bet and save me a little money also! anyone know what year box tubing was introduced? the earliest i can find is 1954 on an MG race car but it had to have been sooner then that??? thanks Zach
these are the guys to talk to about chromoly: http://www.gamblersprintcars.com/Contact_Information.html but DOM should be fine, the words gusset, gusset, gusset come to mind
Do it! I've always thought Buttera's space tube frames were awesome. Not sure if he was mentioned in this thread but, there's a guy named Beck that is building an A sedan with a 409 that was covered in Street Rodder a couple years back. The project is called Beck's Bomb. Anyone have that article? Tube frame, traditional suspension (with some tricks). He moved the rear axle back and UP. Also, he relocated the rear fender arch likewise. Anyone seen this one finished? If you can find it, use THAT as inspiration!
I believe It's not how much steel you use but how you use your steel. That said, the advantages of 4130 are all wasted if appropriate welding and design are not used. Mild steel is a lot more forgiving and cheaper.
on the chromoly, the key is to tig weld it. from someone who raced midgets, I can tell ya the difference in requirements from mild steel tubing to chromoly were 1/4" in diameter and between 30-60 though in thickness bigger thicker tubing was required when building a different frame. also, chromoly has some memory if it flexes where mild steel seems to bend and stay bent much easier.
Zach, This is one of my favorite sites. Front page features a tube frame. http://www.pauzasfd.com/ His products are very intesting too. I know he will answer your specific questions is you email him or post them on Metalshapers.org Check out his photo albums. He is very willing to share and provide quite a bit of help.
Since you're up north, finding a desert racer is kind of out, but you can likely find a rock crawler enthusiast to bend and weld up a DOM frame for you for pretty cheap. Nothing says zoot like a TIG welded frame with dimple died sheet metal gussets like a trophy truck. If you want a pro to do it, start hitting up the local off road fab shops, and talk to them. I'd guess that someone would take it for the challenge and fun factor of something different. 1.75" .120 wall DOM is pretty much a standard building material for many Jeep and rock buggy chassis and cages. Look at some of the rock crawling fab shops for some neat brackets and solutions for your suspension and body mounting. Also, pick up an AA Manufacturing catalog (it's free from their website) they cater to the dirt track and roundy-round folks, but it's a treasure trove of neat brackets, plugs and creative solutions.
Davidfe nailed it there. Rich Pauza is one of the good 'uns. If you call him mention this place. I'd love to see him on here. Also Rooman is a good to ask. Also I was looking at the Bob Dron duece at the GNRS. It's a space frame. Lots of good ideas on that one too.
thanks guys for all the input and help im really leaning more towards a frame similar to the salt shaker car in Rodders journal #33 a bit more simplistic then the "space frames" remember im shooting for more of a home built late 40's racer tig welding and all that isnt a problem....just a matter of knowing what tubing will have enough strength... im still thinking that the 2.5od .095 will be plenty with some added bracing here and there I'll be sure to post pics along the way thanks alot Zach
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