mattsimis

A demo of the vacuum pod arms I designed and printed to replace the defective Audi original. You can see the pods demo the vacuum over the rev range, thereby opening up different air intake tracts over the power curve. Making them at home saved some $$ and the Nylon I use likely will outperform the plastic Audi chose over the long haul.



Had them installed for a month now as a trial and they have performed perfectly.


Ive also designed and 3D Printed the bushings for the Anti Roll bar, which was a bit tricker to get correct. Installed various versions for over a month now.. finally got it quiet with no knocking. I ended up printing these 5 times at different infill settings and slightly diff shapes to get the right rigidity. On a normal ARB install this would be easier, but since Audi wants the arm held rigidly (originals are bonded) it somewhat more difficult.

Albatrossboss

This is very interesting. Are these prototypes that you plan on selling?

richard-tx

I make the vacuum arms out of metal. The metal arms will never crack like plastic.

mattsimis

Netiher will Nylon, outside of specific strong acids, which (along with water on metal) would also attack metal. But to clarify, Im not presenting this as a superior option to Metal, merely something to replace the existing brittle/broken black plastic arms.

haggisuk

Great stuff, will you be sharing the models with the community so we may make our own?

GradecEngineering

I'd like to say bravo for attempting this. I've done a lot of prototyping and can appreciate a person doing things on their own.

One thing to note is that except for high-end printers, the 3D-printed parts are not solid, but contain many air pockets and other irregularities. This causes the material strength to go down. Additionally, most any plastic component in our cars is fiber-reinforced, giving it superior strength properties. As of current technology, 3D-printers are not capable of this. Only injection-molding can create a type of plastic part. The fibers are especially important to the rigidity of the part in cases of hot environments in which the plastic becomes less rigid.

If you're confident in your design you may consider contacting an injection-molding manufacturer and putting this on the market.

richard-tx

I used to sell the metal arms. There just isn't a large enough market for them to make it worth making and selling. If anyone is interested, I will sell my remaining stock of parts to make metal arms at cost assuming I can find them.

If anyone is interested I can tell you where to get the parts.

richard-tx

My problem with white nylon is that it gets brittle over time. It is worse with UV and heat exposure. Seems that the plasticizers disappear and then the nylon becomes brittle and fragile. Black nylon is less prone to UV damage. Heat is what causes the original plastic arms to break down over time.

Audi, like every other car manufacturer, is using any method possible to reduce weight. Every gram is counted. Years ago Dodge used plastic front fenders on their Intrepid cars. Audi went with aluminum for the body and frame to reduce weight.

haggisuk

I think what has been said is indeed true about the plastics degrading in that environment, but If you already had a 3d printer the cost to make these would offset the negatives of a possibly earlier failure would it not?

richard-tx

Agreed