I apologize in advance if this isn't in the right forum, if so, mods please move it to wherever.

I've been kicking the idea around of a project car something like the KiMini 2.2 thing. It'd be a long-term project, and I'm just in the planning stages now. One of the issues I'm running into is what engine to go with. After looking at some different options, one I'd like to go with is a motorcycle engine. To make that work though, I would require a very light frame/chassis. The question is, anyone have any recommendations for light piping that'd work for a tubeframe design? Safety is my first concern, so while CF tubing might be lightest, it would be absolutely unacceptable.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote"> Safety is my first concern, so while CF tubing might be lightest, it would be absolutely unacceptable.</TD></TR></TABLE>

And also outrageuously expensive. It really depend totally on budget. You could do alot of different things depending on what you are willing to spend and what you want to go through. If your talking ultralight and virtually no monetary limitations, follow bicycle frame design. If your thinking aluminum, they use mostly 7005 aluminum. Super strong, but once its welded it needs to be heatreated to regain strength, which means a huge oven and more money.

Another option would be an airharden chromoly steel or something of the like. Reynolds 853 is super strong, good flexing characteristics, and is airhardened so you can weld it and have no need to worry about baking it.

I would go with the 853 or something like that. CF would be out of the question. You are either talking handlaid molds which aren't that strong, or crazy vacuum molds, or lugs in all different types of orientations. Not in your realm of cost in any way.

Good luck

 

I don't know if you've seen this before, but this guy is doing almost exactly what you're describing.

http://www.dpcars.net/dp1/index.htm

 

Look at some of the Formula SAE cars. My school is building one right now with a suzuki 600cc motor. That thing is a blast when you punch it even with our restrictor plate, I can't imagine how fun it would be without it :D

 

Any idea what the weight difference between the 7005 and 853 would be for the same size shape (a 2-foot long shaft, for example, same diameter, wall thickness, etc.)? Thanks for the numbers though, that's helpful.

I hadn't seen that site either, I've been getting most of my inspiration from kb58's KiMini project (really helpful guy by the way, if you ever have questions, he seems very willing to answer and help however he can ). I do like this guy's design though, although I'd want it in a 2-seater form (it'd be silly to not be able to take people for drive's in such a fun thing). Is this guy on HT at all?

 

well bicycle weight difference. Figure the same size frame. aluminum min is like 2 lbs. steel min is like 3.

will become obviously more dramatic as you get larger materials and segments.

 

Right, but any comparison is a good one. I'll stick with a 1/3 difference for now.