I know this doesn't exactly fit in with you brass chassis guys but I needed a plastic chassis that I could use to expand my Carrera Gt fleet. Carrera has great cars but in the 1/24 field there is a large gap in what is running out there.
The size of the chassis was determined by the smallest wheelbase car I had in Carrera which was the Cheetah. So that was my starting point. The narrowest width was the Gt40. The chassis adjusts out 3/4" from the smallest which should give me more than enough adjustability. Most of the cars I have there is only 1/2" difference in wheelbase .
The chassis was cut out of 2.25mm Styrene. All I had was 1.5 and .75 so I just glued them together. I wanted something simple and the easiest solution was to use 1/32 parts since I had almost everything. (plus this is for home use, not racing so they should hold up) The only issue I was going to have was 1/24 wheels on a 3/32 axle. I ended up using Scaleauto wheels and put brass tubing inside the wheel to shim it down to 3/32 which worked great. I used adjustable axle mounts for the front and a Devis3D scratch builders pod screwed down in the rear. This way I can still adjust the rear axle height with shims under the pod if needed. I used a B-Nova adapter for the guide mount. The only thing I'm not sure of is I used plastic square tubing for the adjustable length. I'm not sure it will hold up. I may have to go with brass if it flexes to much.
The body I chose was not my 1st choice but it was cheap ($11 shipped) Man I didn't realize how expensive models were. Just finished putting my last coat of clear on it and then a few decals.
Well that's my 1st scratch build even if it is in plastic.
Dave