RV-8 longeron bending and twisting

[scsmith]

I'm looking ahead in the plans and instructions for my repeat offense fuselage build. Since my first -8 was a QB, I didn't do the longeron bending.

The plans for the -1 fuselage don't seem to provide a dimension on the lower longeron for the location of the 0°/90° station that gets clamped during the twisting operations. The picture looks like it is at a bend, but there is no drawing or description of a bend.

Does the lower longeron ship with a slight bend in it?

Is there a bend at the location for clamping for doing the twist? And the point where the spreading of the angle stops?

It just struck me oddly that there is a good drawing of the bends in the upper longeron, but not much for the lower.

 

[Lkitson]

Isn't that info shown on the bottom of Dwg 66?

I seem to recall the the lower longeron arrives straight and you have to twist it and smack one end with a hammer to open the angle up a little.

 

[scsmith]

Dwg 66 shows how much to twist and spread the angle, in three steps. But there is no dimension to the station that is fixed at 0°/90° by clamping during those operations.

The drawing looks like there is a bend at that station, but no dimensions or mention of a bend in the instructions that I can find.

 

[bmellis11]

Does the lower longeron ship with a slight bend in it?

Is there a bend at the location for clamping for doing the twist? And the point where the spreading of the angle stops?

I just bent that part a few weeks ago and had the same confusion with the drawings. Yes, the lower longeron comes with a bend where the fuselage floor slopes down from the gear towers to the center section. You put the edge of your vise jaws at that bend for twisting. I was worried about getting this part right, but found that it was pretty easy to get it to fit properly.