What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Section 29 Side Skins — too much crease?

abaden

Active Member
I know they are not bent enough, but I’m worried about the creases where the roll angles were sitting. Those who have made it through this section, what do you think?
 

Attachments

  • 376459CD-C1A9-47FF-8CB0-6438C7B317DF.jpg
    376459CD-C1A9-47FF-8CB0-6438C7B317DF.jpg
    198.8 KB · Views: 215
  • 51091D01-398B-46F5-9C49-5214D3D4F7E2.jpg
    51091D01-398B-46F5-9C49-5214D3D4F7E2.jpg
    250.7 KB · Views: 192
  • 99E11157-9F51-4DCD-9E3E-8F6C67E2C9D2.jpg
    99E11157-9F51-4DCD-9E3E-8F6C67E2C9D2.jpg
    184.5 KB · Views: 182
Crease

If you mean the break along the rivet line on the edge then it does look too much. It will be apparent on the finished painted plane and can detract cosmetically from the appearance. The bend should be almost imperceptible. The blue film should also be removed before working on the part, otherwise it is difficult to see what is happening. Beware of trying to bend it back because the edge can easily become wavy.
 
If you mean the break along the rivet line on the edge then it does look too much. It will be apparent on the finished painted plane and can detract cosmetically from the appearance. The bend should be almost imperceptible. The blue film should also be removed before working on the part, otherwise it is difficult to see what is happening. Beware of trying to bend it back because the edge can easily become wavy.

Yes that is what I was worried about. The plans say:

Twist the F-1070A and B roll
construction angles with the aft vise grip and at the same time push the aft end down and inwards towards the table. Use the extra
roll construction angle which extends aft of the vise grip as a handle for your other hand. The twisting and pushing motion must be
balanced. Twisting too much will create a crease along the edge of the roll construction angles; pushing to hard will create a sharp
bend in the middle of the roll.

I thought I was being pretty careful but evidently I twisted more than pushed. I suppose I can finish the twist, then see how it looks clecoed to the rest of the fuse?
 
I agree it's worth completing the bend to see how it looks once fitted, as the only concern would be cosmetic. Do you have a piece of scrap to practice on first? The 2024 is tricky to curve because of the springiness. I found it would take the curve by bending it gradually and supporting the part at a comfortable working height/position. When curving the similar parts on my -6 I clamped between wood, which had less of a sharp edge than angle. I took my time and it worked out fine, eventually.
 
That rivet line is on the bottom of the aircraft so it won't be seen.
Its a 90deg sharp bend expanding out to a conical bend.
You need to roll and twist simultaneously to get the desired shape.
It dosent have to be perfect as the clecoes/rivets will pull it into place for the last bit.

Have you made the timber bench clamp as depicted in the plans?
Its likely hard to achieve the desired result without it, as you need to twist and bend over itself to get the shape.

Just go at it slowly, creeping up on the final shape. The instructions are good, the only thing I'd add is that it takes more twisting force than you think.
good luck
 
Back
Top