Enter keywords or a search phrase below:

1/8 Scale Race Car Frame

6 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2011
1/8 Scale Race Car Frame
Posted by model make on Monday, July 17, 2017 9:33 PM


It is a representation of something we plan to build real world.

It will use a V8. It's what they call a 4 tube frame like a sprint or older Indy car.

Using 1/8" square tubing.

Goal is to keep it simple as possible.

Any tips on this?

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Tuesday, July 18, 2017 9:01 AM

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.


Don Stauffer in Minnesota

  • Member since
    December 2011
Posted by model make on Tuesday, July 18, 2017 12:42 PM


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?

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Wednesday, July 19, 2017 8:48 AM

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 Stauffer in Minnesota

  • Member since
    December 2011
Posted by model make on Wednesday, July 19, 2017 12:39 PM


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.

  • Member since
    December 2011
Posted by model make on Monday, July 24, 2017 11:06 AM


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.


  • Member since
    December 2011
Posted by model make on Tuesday, August 8, 2017 12:06 AM

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.


Our community is FREE to join. To participate you must either login or register for an account.

By signing up you may also receive reader surveys and occasional special offers. We do not sell, rent or trade our email lists. View our Privacy Policy.