Nylon Wheel 1

[ScaleDesign]

Hello,
I am designing an injection molded wheel for an ATV. I am familiar with the conventions of part design for more conventional plastics, but have never worked with engineering plastics like Nylon.

What is the maximum thickness for a Nylon wall? Is Glass-filled Nylon stable enough with regards to cold flow to maintain tolerances around a captured bearing in this application?
Also, do GFN and regular 6/6 vary in sensitivity to mold shrinkage?

The wheels will have a quite a bit of detail,and should support around 300 lbs between two axles (4 wheels).

Thank You Much

 

[patprimmer]

Sprint Cars have used GF nylon wheels for years.

It will cold flow, but not enough to release the bearing.

The properties vary a lot between dry as moulded and moisture conditioned.

Shrinkage will be very dependant on section thickness.

For glass fibre reinforced material, shrinkage will be extremely effected by direction of flow when moulding.

Look at caster wheels to check load bearing capabilities.

Look at power tools to check bearing retention capabilities.

Long fibre reinforced will have better impact, flex mod and creep resistance to normal fibre, but at a cost premium.

Send me a link to an image if you can, preferably a detailed drawing or model.

I have only scratched the surface here. I can give more info if you send me more data.





Regards

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[dwightdixon]

Plastic suspension wheels (with and without bearings) are widely used for snowmobiles. Buy a couple from your local dealers to look at particulars. Dupont offers an excellant design handbook for free which could also help. If your volume is sufficient, Dupont technical service may offer tech support. There are several other material suppliers offering longer glass nylon but have smaller support staffs.
Be aware dry glass reinforced nylon does not have much elongation. Impact modified grades may be required for your application.