Design ideas?

[terryg]

I picked these up for free at club swap meet. They were to neat to pass up, but I have no idea what they were made for, or how to utilize them.
One is 72 mm wide by 78 high
The other is 72 mm wide by 87 mm high. Any ideas?

 

[jmasterj]

Use them as nose cone "tips," and 3D print the rest.

Cut off the tips and use them as tail cones.

 

[Rschub]

 

[Rob Campbell]

They look like carbon fiber spinners for rc airplanes minus the backplate and method of attachment.