LocostUSA.com

I've been playing a bit with a couple variants of a mashup of elements from the Midlana and Car9 and figured I would get opinions... Obviously the rear is no where near done but, I'm waiting on some engine measurements before I can get more specific...

Based on 1.5x1.5x.065 steel tube and a 90.3in wheel base 60in (ish) track, based around the published numbers of a Lotus Elise. At it's current length of tubing used and based off of a weight of 1.59lbs per sq/ft I'm at roughly 160-170lb or so of frame steel. I was considering rebuilding it using 1x1x.065 steel since using the same calculation it drops to 95lbs of steel thus far...

Anyway.

Middy V1
https://3dwarehouse.sketchup.com/model. ... 6f0bb2af6d


Middy V2
https://3dwarehouse.sketchup.com/model. ... ab25d652b7

I think 1.25" tube is a reasonable compromise in size and stiffness. That's for the main frame rails, you can use 1" for the diagonals. There is a plus here because the 1" tube joins to the flat part of the 1.25" tube, so the joints are easy to make and weld well. Use 1.25" for the tube crossing the floor under the dash and the tube behind the drivers back at the upper rails. Also the tubes where the suspension attaches. I used 1"x2" for some of those tubes in Car9.

I prefer the first of your 2 diagrams, keeping the top diagonals in the same plane as the frame rails. Maybe you can put a trunk area there under the hood and above the frame.

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Thanks for the ideas. I looked at some of the tubing and the sqft weight of 1.25x1.25 is essentially the same1x1.5 and 1.5x1.5 is essentially the same as 1x2.


I did make a 1x1 version, which I did not measure and calculate for or screen shot but, I kind of like.

https://3dwarehouse.sketchup.com/model. ... 3233e8c355

And then I did a version with 1.25 tube and a mixture of other tubes in other places with the things you mentioned (1x1.5, 1x2, 1X1). and I like it even more. It looks physically stronger and using the 1x2 and 1x1.5 in specific spots looks like it would make mounting other things easier. In the screen shot the the white tubes are 1.25x1.25, the blue highlighted tubes are 1x2, the red highlighted tubes are 1x1.5 and the green tubes are 1x1. I did measure and calculate for this model and without the roll bar it's around 97lbs as it sits, which I think is fairly reasonable.

https://3dwarehouse.sketchup.com/model. ... 0ba6c167c8