1/8 Scale Race Car Frame

Latest developments.

Okay. Will take a look at coil overs.

Might build them separate on the 'little' car(4 cylinder).

Have coils without shock running through them.

Then shocks on their own brackets.

Just to get the hang of it.

Will get up to speed on the ends they put on coil overs

The might have a little more confidence in them.

Right now sorting out frame layout.

Wide passenger compartment 'floor'. Just wide enough for side by side buckets.

Narrow subframes front and back.

First time around we will use single links for suspension.

Transverse single leaf springs.

Simple but it will work. It will be lightweight little sports car.

Don

I wan't to do this without an extra side to side limiting link.

That's the good part about transverse leaf spring.

Intuitively I say solid single link.

That's the way it's done on Bucket T's.

I think pivoting link would put too much strain on leaf spring shackles at axle.

Hummm.  Question the use of T-type suspension on a four bar frame.  Most sprint cars I have seen with four-bar frames have a much more modern suspension, with pairs of radius rods on each corner.  That allows a relative twist between axle and rods.  And, such rods invariably have heim joints on all ends. 

Whether to make joints articulate may depend on weight of finished car and stiffness of suspension.  If suspension gives any from weight of car, at least some of those radius rod joints would probably have to work.  If you use brass for frame, and heavy materials on body, it will be hard to get suspension stiff enough so that rods won't want to bend.  If all suspension parts are metal, and soldered, you'd probably be okay without joints being able to articulate.

If we weren't having troubles posting pictures, due to problems with Photobucket, I'd show you pics of the 1/8 sprint car I built. It is a two-bar frame, but I faced some of the problems you are talking about.

Don

It's still in the design phase.

The idea is Model T suspension type.

Gettting it down low means putting the radius rods on the side not under.

Transverse leaf spring front and back. Straight axle front.

Have to work out the radius ends at the axles.

Whether to mount them solid or let them swivel on rod ends or heim joints.

What do you think?

Depends on whether you use brass or plastic tubing.  In either case, a jig of some sort helps, but the jig is all important if you use brass and plan on soldering.  You need a good jig that can hold all the joints you have already soldered in place while you do the others.

I often do it like the old balsa and tissue airplane models. I make up the sides, then put them in another jig while I add the cross members.  I find making two jigs, one for the sides and one for the assembly of the crossmembers, easier than one complex 3D jig that holds everything together.

I used to use brass a lot, but have found using plastic tubing and CA a lot easier than brass and solder- cheaper, too.  Also, for stiffer frames I often now use plastic rod rather than tubing (plus, for smaller scales it is harder to find small diameter plastic tubing).  Also, for areas that you have to bend the tubing, rod bends easier than tubing.