OME's Lawn Dart Build

[old man emu]

A tad more done today. Half a wing.

 

To get the corflute to fold back on itself without splitting, you have to cut the inside of the bend. This means cutting the surface. To do this, you use a pair of hook-blade cutters attached to the sides of a piece of plastic to get the width.

 

The next step was to fit span-wise strips of corflute to act as stoppers when the corflute was folded over to form the airfoil shape. The plan calls for a strip of balsa to be glued in as a main spar, but I couldn't be bothered hauling out my balsa supplies, so I used a bamboo garden stake.

 

Then I folded the corflute over, and stuck the folded half to the span-wise strips. This created the airfoil shape.

 

[ClintonB]

A tad more done today. Half a wing.

 

To get the corflute to fold back on itself without splitting, you have to cut the inside of the bend. This means cutting the surface. To do this, you use a pair of hook-blade cutters attached to the sides of a piece of plastic to get the width.

[ATTACH type=full" width="234px" alt="1589182304523.png]53116[/ATTACH] [ATTACH type=full" width="230px" alt="1589182332603.png]53117[/ATTACH]

 

The next step was to fit span-wise strips of corflute to act as stoppers when the corflute was folded over to form the airfoil shape. The plan calls for a strip of balsa to be glued in as a main spar, but I couldn't be bothered hauling out my balsa supplies, so I used a bamboo garden stake.

[ATTACH type=full" width="255px" alt="1589182662090.png]53118[/ATTACH]

 

Then I folded the corflute over, and stuck the folded half to the span-wise strips. This created the airfoil shape.

 

[ATTACH type=full" width="261px" alt="1589182798881.png]53119[/ATTACH]

That section looks aerobatic, your’e gonna need a bigger motor now.?

[old man emu]

I think it's supposed to be a Clarke-Y. I made the other half of the wing today, and before I closed it up I took a photo to show how the shapers and the spars went in.

 

 

If I made these wings again, I think I would use the printed aerofoil shape to make template from wood, then make a stack of rectangular pieces of corflute and cut the aerofoil shape with my bandsaw. I'd get a more accurate shape.

[old man emu]

That method sucker, big time. Because the corflute for the shapers was cut with the columns going up and down, there wasn't enough surface area for the glue, so the sheet did not glue down. Also, they did not have resistance to sideways moving, so bent to the trailing edge when the sheet was pulled down. That's why the Clark-Y looks like a symmetrical one.

 

I've decided to go back to scratch and cut ribs. I'll still cut them from corflute, and with the columns vertical, but before I glue them down, I'll put a strip of masking tape along the top and bottom edges of the ribs to give the glue something to stick to. It makes it easier, too, to glue ribs as there's not much room to get a glue gun into the shapers after the first one has been glued. Ribs can be glued one at a time. Considering the weight of the plane when built, I don't think that it needs wing spars. This plan is the first I've seen where a spar is used in a corflute wing. The columns run horizontally from root to tip, and that's a pretty strong structure.

[onetrack]

OME - Use some Soudal or Parfix Urethane adhesive/sealant, instead of the hot glue gun. Sticks just as well, and you have the advantage of being able to lay a ribbon of adhesive/sealant on the edge of each rib, and then just clamp the corflute to them.

[old man emu]

I didn't like the symmetrical wind that following the plans produced, so I decided to go the wing rib route.

 

First I cut two templates from MDF, and drilled matching holes through them to take a bit of fencing wire. Then I cut rectangular blanks of corflute and put them between the templates.

 

I used my band saw to follow the edges of the templates to cut the ribs. That's one good thing about getting old - you finally have the tools you wished you had when you were younger.

 

 

Cutting the ribs with the channels running from top to bottom give the greatest resistance to vertical crushing, but doesn't leave much surface for glue. So I ran masking tape over the top and bottom edges to make a gluing surface. The result is not pretty, but who looks at the ribs inside a wing?

 

[onetrack]

Wings held together by masking tape?? Sounds like Bubba's and Homer's workshop!

[Bootstrapper]

OME; Have you checked out the build videos at Flite Test? Their method of building wings is tailored for "maker-foam" (only available in the U.S. unfortunately) but the technique looks like it could translate to Corflute or (Australian) Foamboard successfully. The CF or FB wing would be heavier than a MF or Depron wing but would be stronger. Maybe make the fuselage and empennage out of CF and the wings from foamboard?

[old man emu]

That project has stalled while I build my sandblasting cabinet. SWMBO won't let me start anymore projects until the already started ones have been completed. So the Son came around last Friday night and told me that I was going to help him build a speaker box. He reckoned he only wanted me to hold stuff. Yeah! Like the handle of a saw, a rule and square and a glue pot. SWMBO is not a happy lass - again.

[Marty_d]

SWMBO is not a happy lass - again.

You wouldn't be Robinson Crusoe there, OME.