3D Printed Parts

[Caffeine]

Sounds like SLS (selective laser sintering) which has been around for long time.

[plohl]

UQ have an SLS. It's pretty old. They had to get it serviced a few years ago... it was about $13k for the service. Material is ~$200/kg. It's glass filled nylon IIRC.

Say $70 a pair to cover materials and time. Shipping on top of that.

You have my attention. I might be able to get them 3d printed. If not, I wouldn't be opposed to paying for them. I'll get back to you

[madjak]

After 4 weeks waiting my CNC parts rocked up today for my rear wing project.

So total costs to date are around the $160 mark for a complete rear spoiler, printed out of 12 plastic sections, 2 ali tubes and 8 CNC plates. I'll assemble tonight and see how it all fits and take some photos of it all. Can't wait to see if this actually works or not!

[madjak]

Mounted up my 3D printed rear wing on the weekend. Its made from 12 printed sections and a few cnc cut ally brackets. The wing profile is a low drag to downforce ratio wing from NASA. It all feels pretty solid but the real test will be to see if it holds up at high speed with downforce and drag combining.





Here is a shot of it in parts getting assembled. The 12 plastic sections slot onto two ally rails that then get clamped at the ends with the brackets that mount the end plates. The main support brackets also slot onto the rails and are keyed into the plastic.

[zossy1]

How have I missed this thread? Very nice work, interested to see how it works!

[Rolley]

is it just me or have the pics failed?

[madjak]

There are some issues with the Box.com links I'm using and firewalls I think.

here are the photos again:

[greenMachine]

Great work! is it 3D compliant (sports sedans)?

Care to explain the endplate fitting - I see a plug fitting into the hollow spar, how is this secured? Presumably tapped for the endplate clamp attachment? Any reason you did not use a single attachment for the endplate and endplate clamp? My information is that that endplate is not sensitive to AoA, and can be fixed relative to the wing without detriment.

Have you run any numbers on downforce and drag? Those two spars should hold up to 250kmh I would imagine, unless they are 1.6 wall, that might be a bit light depending on downforce numbers. I use 3mm, but I only have a single spar. You will also need some serious front end aero to balance that.

Look forward to seeing how it works out!



PS as a road car, you might need to put some padding (split hose?) on the leading edge of those endplates, or Plod might take an interest ...

[madjak]

The end plates are separate to the clamps either end. This lets me take off the endplates or adjust their angle without the wing falling apart. There are little tapped plugs in the ends of the spars that are held in with tapped grub screws. The big spar is 4mm tube, the smaller spar is 2.5mm I think. There is a fair bit of clamping force across the wing which is applied by 2 M6 bolts at each end. The endplates are held on with 3 M4s.

The wing itself is very rigid considering its made of separate plastic parts. I'll probably glue them together when I've finished tweaking it.

As for the angle of the end plates... I think its more for aesthetics. In terms of driving on the road I could always remove the end plates for safety, not that I drive it on the road.... it too loud! I also have a home made splitter to balance it out.

The main supports are 5mm ally. I can put all my weight on the wing and it feels pretty solid but thats a static load and directly vertical. If its generating 120kgs of downforce as well as some drag around a long sweeper and the car hits a bump I can imagine the entire assembly shearing sideways. I think I'll make the main supports solid without the cut outs before I track it for the first time.

[greenMachine]

Thanks. Those spars should be plenty strong enough, your only worry would be a failure of the plastic parts themselves. I would also think that the struts would be strong enough at 5mm, if you are worried about sideways movement, I would join the two with a plate strengthener/stiffener just above the bootlid before I made another set. I use 10mm, but I am coming off the bumper mounts.

What is your Vmax at your fastest circuit - that will be where you generate max downforce and drag, and unless you have made it out of brick, the inertia loads over bumps will not be a problem unless it is a lot weaker than it looks! Run the formula for that speed and you will know what you are dealing with.