The first step of wing rib preparation involves straightening the flanges and fluting the ribs to remove any curvature along the length. Rib flanges need to be at 90 deg. to the web, and rather than using hand seamers and a square to get the flanges to the correct angle, I decided to build a Rib Flange Straightening tool that I found referenced on VAF.
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| Materials needed to build the rib flange straightening tool |
For mine, I used the following
I ripped the 2x2 oak plank in half to make a handle, and rounded over the edges using a handheld router and 3/8" roundover bit. I then cut one end to a 22.5 deg. angle (than will help clear any raised lightning hole edges when bending flanges).
Next I ripped the MDF to a length of 16", and the 2x6 oak plank to a width of 4" and a length of 6". I also cut one of the 4" sides of the oak to an 11 deg. angle. This will ensure that when the rib flange is pushed against that side, the spring back of the aluminum will leave the flange at 90 deg. to the web.
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| Handle, anvil and base cut to size with the appropriate angles as required |
I then marked and positioned the oak anvil 9" back from the edge of the MDF as shown below, ensuring that the 11 deg. face was oriented correctly. With clamps to hold it in place, I drilled pilot holes through the bottom of the MDF, and then glued and screwed the anvil to the base.
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| Anvil positioned on base, glued... |
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| ...and screwed from below |
Next, using a 1-1/2" wide piece of scrap wood, I centered and marked the position of the hinge on the handle, again making sure that the hinge was placed on the correct face where the 22.5 deg. angled face would be in the correct orientation. With the hinge positioned correctly, I marked and drilled the screw holes and then screwed the hinge to the handle.
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| Marking the hinge location on the handle |
Finally, I positioned the handle on the anvil, marked the hinge hole locations, drilled pilot holes and screwed the hinge to the anvil top.
Initial tests of the rib flange tool with an old horizontal stabilizer rib showed that the bottom of the handle was only about 1/64" higher than the web of the rib when holding the handle vertically. This caused the flanges to be bent beyond 90 deg. due to interference with the bend from web to flange. To fix this, I trimmed the bottom of the handle angled surface so that when held vertically it just cleared the bend. This corrected the issue, and now the flanges were right at 90 deg. to the web after bending.
I may do a few further tweaks before working on straightening wing rib flanges, but for now I will put the tool aside until I hear back from Van's on their plans for laser cut parts.
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| Completed rib flange straightening tool. Works well after some initial tweaks. |
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| Bottom of handle was sanded away using a sanding disc in a Dremel so that it clears the bend in the rib web to flange |
Jumping ahead a little, I fabricated the W-1029C angles, and W-1029D and W-1029E spacers. After deburring the edges, I marked the spacer alignment lines as per the plans.
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| Fabricated wing rib angles and spacers |
Build Hints
- If building a rib flange straightening tool,
- use a hardwood for the handle and anvil to ensure solid contact and bending of flanges
- Round over the handle edges where the handle will be held, especially if the handle is wide, otherwise it is not comfortable to hold. For me, 3/8" radius worked well. I would have gone to 1/2" radius, but the bit did not fit my mini handheld router.
- Ensure that the bottom of the handle clears the bend in the rib web to flange. This will result in better flange bends
Dates: August 27 - August 30 2023
Wing Ribs Total Time: 3.7 hours
RV-10 Build Total Time: 455.2 hours
Priming Total Time: 47.2 hours (not included in build time totals)
