EscapeFlyer

My Feedback: (1)

I'm curious. There doesn't seem to be any build threads showing the use of the GP Wing Jig. I am wondering if anyone out there is using this product, in their build, that could demonstrate how to set the center rib at the proper angle (for dihedral) while in the jig? (Pardon my run-on sentence, please.)

Thanks.

Brian

Tony Hallo

If you talking about the jig what supports the ribs with two pieces of music wire, then the root rib would be set at half of the total dihedral angle, just like a miter joint. I has been a while since I have seen a Great Planes jig, the Great Planes kits were one of the finest available in my opinion, only built one, do have a 1/4 scale Tomahawk on the shelf.

EscapeFlyer

My Feedback: (1)

The kits I have built come with a dihedral guage. The issue is setting the proper dihedral on Rib 1 while you build so the wing halves will match properly when you glue them together.

My thoughts:

Cut a block just smaller than rib 1 and drill to holes where the two 1/4 inch steel rods (a bit large to consider to be music wire)will pass, and miter cut the proper angle on both facings of the block for both wings.

My problem here is: If the holes aren't drilled properly to the proper angle of the miter cut, it will not work.

Is there a better way to do this?

Brian

btw: This will be for my Ultra Sport 60. I can have absolutely NO chances for warping the wing. It has to be perfect for good reason- It will be used in Sportsman pattern if my GB Extra doesn't turn out. I don't trust my Extra's wing.

Brian

RICKSTUBBZ

Brian,

If you have access to a decent table saw and drill press you can do what you have mentioned above. Create an appropriate rectangle block with the table saw (keeping everything square of coarse). Say 1” thick X 3” tall X 10” or so long. Something a little bigger than the rib.

Then take and mark and drill the holes for the “DRILL ROD” centered on the block in height and adjust center front and back to match rib.

Now that you have a square (rectangle) block with holes that are drilled square to the face thanks to the drill press you can set up the table saw blade at the appropriate angle to match what you need the rib to be.

However, this method does not truly fix the problem because the holes in your rib will be bored square to the rib and not at angle. However the difference will be small. But you could end up with the rib slightly high or low depending on how the holes in the rib deform as you angle the rib.

This assumes the ribs are square to the drill rod when viewing as a top view. There is a way to cut a compound angle as well but that requires another fixture piece to be cut and a longer post.

By no means is this the only solution just a way to accomplish what you mentioned above with some reasonable accuracy.

Later,

Jim_Purcha

My Feedback: (8)

I made my own from Charles RC website. See link to RCU threadI also used drill rod. www.rcuniverse.com/forum/fb.asp

Jim

landeck

My Feedback: (1)

I built a GP US 40 using a wing jig like the GP one. The jig I have is one I built back in the '80s based on an article in RCM. I have used it on a number of planes through the years and it has always built a straight and true wing. The only problem is that you need kits that have the 1/4 inch holes already drilled in the wing ribs. Trying to drill them true in wing ribs, specially with tapered wings, can be a challenge.

Bruce

EscapeFlyer

My Feedback: (1)

I think the key to any wing would be the centerline (difficult when building a wing with washout) and Spar. If one measures on centerline from the front or rear of the spar on every rib, and drill in incriments to 1/4 inch (at 1/4 you'd want to incorporate a 1/4 inch OD brass tube), keeping every hole on every rib equa-distant (at least 4 inches apart), it should work great on any application that I know of.

Brian

maynardrupp

The GP wing jig works great for the Ultra Sport 60. Because the LE and TE have notches, there is no need to build over the plans. If I were to build another US 60, I wouldn't glue the root rib in at all. I would build both wings then set the dihedral angle. Now glue in the root ribs for each wing. Now back on the jig for sheeting.

EscapeFlyer

My Feedback: (1)

I have purchased 2 GP wing jigs. I have noticed that, when fully constructed, the 2 1/4in rods on both jigs do not touch the center support block.

I was thinking that this may be because the rods need a little weight to them, but after inserting the ribs, the rods still stayed roughly 1/4 inch above the center support block. So I broke out my trust level for a straight edge and found that:

When I weighted down the rods to meet the center block, the ribs were not straight to the straight edge. When I pulled the weight off, I found a 1/4 inch gap between the rods and center support, but the wing was straight.

Is this common?

No biggie, I think I'll simply add a 1/4 inch to the center support.

Brian