Composite plastics...... anyone got info?

[Legacy555]

Hi all,

Does anyone know which thermoplastics are generaly used in construction of B4, XXX, etc etc? And if so, which is best proven in competition for rigidity, strength and toughness?

Is a variant of Ethylene Vinyl Acetate?

All info appreciated.

Regards,

William

[David Church]

Come on Mark Christopher or DCM??? You guys think you know everything!!! Give this guy an answer NOW!!!!!!!!!!!!!!!!!!

[mark christopher]

Originally Posted by David Church

Come on Mark Christopher or DCM??? You guys think you know everything!!! Give this guy an answer NOW!!!!!!!!!!!!!!!!!!

Yes thats right they are! until their not

[terry.sc]

The materials used in race buggies are usually nylon 6 and nylon 6/6, usually reinforced with glass or carbon fibres to give strength and rigidity. Nylon 6/6 has the greater strength and rigidity, but nylon 6 is tougher with better impact strength, although there's not much difference between them. The biggest difference is the methods used to produce them.

As for reinforcements, plain nylon is the 'toughest' as it flexes to absorb impacts, glass fibre reinforcement makes the parts stiffer with greater strength and wear resistance (pivot holes don't wear as fast) but it does make the parts heavy. Carbon reinforcement are stiffest and lightest, but in an impact it doesn't flex so will snap easier in big impacts.

Tamiya use ABS and polycarbonate for their moulded plastic parts in their budget kits such as the the vintage rereleases and the TT01 chassis. These materials are much softer than fibre reinforced nylon parts so not much use in race spec cars where you need the rigidity of the nylon parts, but the softer material means they are more likely to survive accidents as the flexing absorbs the impact energy, although being softer it's easier for screws to be torn out of the plastic in an accident.


EVA isn't stiff enough for r/c car parts.

[Legacy555]

Thanks Terry - have you any blend data? or a source?

[terry.sc]

Sorry Will, can't give you too much help there. I'm a model engineer so can replicate the material properties in prototypes and don't have anything to do with the actual production side of things.

The glass filled nylon used for prototyping parts is 30% glass, 60% nylon. the same mix is usually used for injection moulding. Carbon filled is usually a similar mix with 30-50% carbon depending on stiffness needed.

[dom-dogger]

get a model autoclave and mould your own carbon fibre, from impregnated carbon weave cloth!