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14. Getting horny

12/02/2012

Although the Scout is generally made up from parts that are easily made up from flat metal sheet and tube, there are a couple of exceptions.

We’ve already seen how we needed to squash the wire ferrules into an oval shape.

Here’s another part that also needs squashing, but it’s altogether more fun.

It’s a control ‘horn’ – a little lever attached to a movable control surface to which you attach the wire leading to the controls in the cockpit.

The photograph is of the Sopwith Pup, but by now you’ll have got the picture that the Scout is pretty much the same.

If you look closely at the photograph, you’ll see that it’s a natty aerofoil shape – pointed at the front, bulging in the middle, and tapering to nothing again at the back.

If you made it of solid metal it would be much too heavy, so you make them from two pieces of thin metal which is dished to give it the bulge. They are then welded together.

The Scout horns are a bit more complicated, having a fancy crescent  shape, so we decided to make patterns in thick steel which we would use to do the forming.

Tool for making the horns.

The shapes were waterjet cut in 25mm thick steel, and we had two of each made.

As you can see from the picture, we bolted the two female pieces together with the workpiece clamped between, and we shaped a piece of wood to give the correct form was matched to the male cutout piece.

Then we put the wood in on top of the workpiece followed by the male cutout, and used a 10-ton car jack in a home made frame to press it down.

Actually, we did it the other way up, with the male bit in the bottom, so that we could watch the sheet metal as it formed. It was very successful; we could get pretty precise control over the depth of forming, and the metal seems to have formed a perfectly even curve, without any lumps or bumps.

Pressing the Horns

The formed horn still in the press

 

 

 

 

 

 

 

 

 

And now we have to get the two halves welded together to make a complete horn.

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From → Building, Technical

2 Comments
  1. escapade1 permalink

    Excellent Blog – you have caught my attention!

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