[munter]

Agree with all previous posters. 
If you are racing on Scalextric sport plastic sectional track then stay with plastic chassis and investigate adding weight and front/rear balance.

As an aside I have hosted a few proxy events on my wood track where most of the cars were plastic chassis cars with a few being scratchbuilt brass and wire and steel chassis....the top place getters were the metal chassis cars but there wasnt much in it.

[chrisguyw]

A lot has changed over the years in our hobby..........years ago most raced on large commercial type tracks, with long straights and wide radius corners, with cars with much grippier tyres (sponge/traction additives), and much more powerful motors. In this environment, nothing beats a brass/wire/steel chassis, as the cornering speeds/torsional chassis loads require (still do today) a much stiffer motor box, and a stiffer (both longitudinally and torsionally) chassis. 

The type of racing most commonly done today  (home/club,...plastic/wood tracks) utilizes smaller/tighter tracks with relatively less grippy tyres and far less motor torque, so a softer flexing chassis and a flimsier motor box (plastic chassis) suffice with the  lower cornering loads and motor power used most frequently today.  (A stiff motor box area is still very beneficial to todays plastic cars, but that is for another thread). While most current plastic chassis' can certainly benefit from a few modifications, they largely do a very good job. 

So, with that said, a very well designed and built brass/wire/steel car in todays hobby can compete and out perform a plastic one, but, the margins are very very  small, and while I do encourage everyone to try making their own chassis, please do not despair if your first few efforts do not outperform the plastic stuff on your shelf. Again, it does take a well designed/built metal chassis to rival todays plastic offerings

I have seen many high tech chassis designs that were not particularly well executed being out performed by some simply designed but well built chassis.

In any chassis the two most critical elements are that it be flat (both axles absolutely horizontal) and square (both axles absolutely parallel).....all the rest, weight/weight balance, torsional flex, guide lead, etc. are important, but without being flat and square, they just don't matter.

Cheers
Chris Walker

[Mr Modifier]

There is a distinct advantage with 3D printing IF you have a printer and can get to grips with a design package.

The cost of printing a chassis is literally pennies so any design mistakes can be easily remedied.

Once you have a design you can easily change the wheelbase and track and engine mount if you take a modular approach to your design.

The other day I decided I wanted to make my front axle mount height adjustable and about 30 minutes later it was designed and digitally welded  to my chassis. 50 minutes after that the chassis came off the printer.

A chassis can use between 5g and 10g of material and the material costs GBP16 per kilo.  That makes the chassis between GBP0.08 and 0.16 and a penny or two for power.  The printer costs GBP150 but that spreads pretty thin over the hundreds of thousands of things it will print.

I get the appeal of brass chassis but as I run exclusively SSD digital any metal close to the rails is a potential race killer (shorts either corrupt SSD data packets or safe mode and that means race over).

[Tamar]

Nice topic but very similar along the lines of mag vs magless, resin cast vs vacform, analoge vs digital etc, etc.
I fail to understand how somehow although we're all united in our hobby these topics tend to split opinions along the lines of a choice one vs choice two.
How they tend to polarize. 

Ok I'll stop my rant

For me all of the desired properties low CoG, squareness, rigidity and flexibility apply to all chassis, brass and plastics are just some of the materials available for fabrication.
A good well designed and build chassis is a work of art, regardless of the material used, but the real beauty is the mind of the designer/builder.

with kind regards
Tamar

[Gordon Steadman]

the real beauty is the mind of the designer/builder.

Hmm....doesn't say much for my mind then. My chassis are, shall we say, somewhat utilitarian!

[Tamar]

What can I say Gordon...if the shoe fits.

Maybe the beauty of your mind is more into bodies  

with kind regards 
Tamar

[Gordon Steadman]

What can I say Gordon...if the shoe fits.

Maybe the beauty of your mind is more into bodies  

with kind regards 
Tamar

I feel I should not make the obvious reply

[Kevan]

We race allsorts in 1/32 with rubber tyres (not foam or silicone or urethane).

The fastest anyone can get round our club track with a plastic chassis is 5.8 seconds

Fibreglass Allslot f1's can do 5.6 seconds with 14mm wide rears

Mack chassis (or modified Eurosports with front wheels) can do 5.5 seconds

That's why we classified all plastic chassis in our Standard classes and everything else in the Scratch/Open classes

Basic Falcon powered JK X32 with fresh dry ungooped foams can get round in 4.8 seconds

...I wouldn't like to guess how quick a proper BSCRA car could get round with fresh dry ungooped foams

[KensRedZed]

I'm reading through this from the beginning and there is much wisdom contained here about brass vs plastic.

And then there's aluminum... 

[mickey thumbs]

This discussion confirms my observations over the past several months as I try to build a brass-piano wire chassis that will outperform a modern, tuned plastic one on my home wood track. One section has wide turns connected by a 10 foot straight and the other has tight turns, esses and short straights. The metal builds hug the high speed turns much better, but the plastic ones are more nimble through the tight bits, resulting in near equal lap times with the edge so far to the plastic because of the quicker acceleration of the lighter material. Great fun building unique cars trying to beat the RTR cars.