Spinning Aluminum (air horns)

[240260280z]

Neat. I always wondered how they "spun" aluminum telecom dishes.

I think this would be an easy way to make custom intakes:

[LeonV]

Metal spinning is very cool, but probably not the "best" method for making air horns. The metal would have to deform quite a bit just to get it to the air horn shape. We CNC'd air horns for our FSAE car back in school.

It's a cool idea though, I wouldn't mind seeing someone try it. I forsee a good bit of post-spinning hand-work though...

[zKars]

Definitely a case of "He makes it look easy" which means its actually very hard to do well, and consistently. You or I could make one air horn, given the right tools, in a day of playing around. But it would take 30 years practice to be able to make 6 the same...

[John Coffey]

I've had a number of air horns spun. Just placed and order for 50 for Solex downdrafts. The spinner can very easily control part thickness and can vary it within a couple thou throughout the part. And there is zero post spinning work required except to trim and drill holes on the mounting flange.

[LeonV]

I've had a number of air horns spun. Just placed and order for 50 for Solex downdrafts. The spinner can very easily control part thickness and can vary it within a couple thou throughout the part. And there is zero post spinning work required except to trim and drill holes on the mounting flange.

Interesting...

How is the mounting flange incorporated? Welding?

That's what I was forseeing: welding on a mounting flange, drilling holes for mounting and for the center airway. The airway hole seems tricky (fixture and milling, or just grind it out by hand?).

[John Coffey]

The mounting flange is also spun on the same piece in a second operation. Holes are drilled in a fixture.

[LeonV]

The mounting flange is also spun on the same piece in a second operation. Holes are drilled in a fixture.

Cool stuff!

Is the flange able to be 90deg to the air path though? Wouldn't you need a sharp corner at the ID on the flange end? I don't see how spinning can achieve that, unless you guys are doing something clever.

Edited April 24, 2013 by LeonV

[John Coffey]

Spinners can do a tight rolled lip like a wire bead, and any angle flange edge from about 5 degrees through 175 degrees. All depends on the tooling and the spinner's skill.

[LeonV]

Spinners can do a tight rolled lip like a wire bead, and any angle flange edge from about 5 degrees through 175 degrees. All depends on the tooling and the spinner's skill.

Wish I could watch your guy make 'em.