RE: AR-6 Construction Thread
 

The core is placed on top of the wing sheeting and the top sheeting is later folded over top of the core.

I pinned the sheeting to the cores in the appropriate location.

The sheeted cores are then fitted between the shucks. Pin parts together insuring that parts fit properly in the shucks. Tape the parts together so that pieces don't move while drying.

Place the wing core on the plastic tarp. Tape a piece of twine down the side of the cores. Place a long piece of paper towel on top of the cores. Tape the vacuum line near the twine.

Apply a bead of latex caulking around the cores. Fold the plastic tarp over and seal the edges by stepping on the tarp to smash the caulking together. Apply a couple quarts of paint near the center to insure parts are straight.

Turn on the vacuum pump and pull about 5 inches of Hg. My pump turns on around 3 inches and shuts off around 6 inches.

The finishing epoxy typically dries overnight, but if it is cool it will take longer to dry.

RE: AR-6 Construction Thread
 

Trim off the outside of the bag and remove the wing.

RE: AR-6 Construction Thread
 

Make sure the wing fits correctly with the shucks and then trim the leading and trailing edges with a razor saw.

RE: AR-6 Construction Thread
 

Trim the leading edge flush to the foam using the razor saw and sanding block.

True up the trailing edge as required. Each tip should be the same width.

RE: AR-6 Construction Thread
 

After trimming the leading and trailing edge the wing is starting to take form.

I couldn't resist a picture with the fuselage on top of the wing.

RE: AR-6 Construction Thread
 

I vacuum bagged a second wing tonight.

This wing is 8.5% thick at the tips. The other one is 11% thick at the tips.

RE: AR-6 Construction Thread
 

I will be curious to see if you can tell a difference between the two wings, either in speed or in handling. According to the Xfoil run, the 8.5% tip wing will be more prone to tip stall and not all that much lower drag. But that's just a 2D simulation and I don't always believe simulations.

The 700,000 Rn is roughly 160 mph and the 220,000 Rn is roughly 50 mph (landing)

RE: AR-6 Construction Thread
 

I glued the leading edges on with Gorilla Glue. You dampen the surface with water prior to gluing. Just use a small bead as this type of glue expands and fills up any gaps.

RE: AR-6 Construction Thread
 

Here's a side view that shows the 11% tip and 8.5% tip.

RE: AR-6 Construction Thread
 

The leading edge was shaped with a pocket knife and sanding block.

I just try to make both sides with roughly the same shape. Try to achieve a more rounded leading edge instead of sharp edge.

The last couple pictures show the 11% wing tip and 8.5% wing tip.

RE: AR-6 Construction Thread
 

The following pictures shows the installation of landing gear blocks:

The blocks are glued in with 30-minute epoxy and micro-balloons.

The gear is temporarily held in place with tape to insure that the blocks are in straight.

RE: AR-6 Construction Thread
 

Here are some pictures showing the installation of the gear.

Each leg of the gear will be held on with four 10x24x1/2" nylon bolts.

RE: AR-6 Construction Thread
 

Here are a few more pictures of gear installation:

RE: AR-6 Construction Thread
 

The wing leading edge and fuselage must be sanded to fit. Take your time, it doesn't take much fitting:

RE: AR-6 Construction Thread
 

Spot the aileron and torque rod locations.

RE: AR-6 Construction Thread
 

Drill some small holes to check the locations for mounting bolts and hardware.

This simple check confirms your figuring is correct (or not). :)

RE: AR-6 Construction Thread
 

Small pieces of 3/4" diameter dowels are glued in the wing with an epoxy and micro-balloon mix.

RE: AR-6 Construction Thread
 

Wing tip blocks were fabricated from balsa, 4 ounce fiberglass cloth, and more balsa.

Adding the fiberglass cloth between the layers makes them more durable.

I glued the blocks on using 6-minute epoxy.

RE: AR-6 Construction Thread
 

The following pictures show more shaping of the wing tips.

RE: AR-6 Construction Thread
 

The Master is at work again !!!

RE: AR-6 Construction Thread
 

Here are pictures on the addition of fiberglass cloth.

1) Begin by tacking on a piece of window sheer over the top surface of the ailerons. The purpose is to provide a hinge surface.

2) Tack a layer of 1.6 ounce fiberglass cloth over the entire surface of the wing.

3) Tack another layer of 1.6 ounce fiberglass cloth over the wing tips.

4) Tack a wide (15.5") piece of fiberglass cloth around the center of the wing.

5) Follow with 3 more layers of fiberglass cloth (each getting gradually narrower) around the center of the wing.

6) Mix about 1.5 ounces of finishing epoxy. Add 10% more 91% alcohol to thin the epoxy. Drizzle this over one side of the wing and use a squeegee to spread out the epoxy. Do the other side the same way.

7) Place the wing between layers of nylon fabric (peel ply).

8) Put the wing in the vacuum bag and apply about 5" Hg vacuum to the wing.

9) It is getting cold at night so the vacuum bag was placed between layers of electric blanket. This warms the epoxy enough that it dries overnight.

RE: AR-6 Construction Thread
 

Scott, Why do you put an extra layer of glass over the wing tips ?

RE: AR-6 Construction Thread
 

An extra layer of fiberglass is used over the tips so that they are stronger and less likely to break. [&:]

RE: AR-6 Construction Thread
 

My grandsons helped me pull off the peel ply.

RE: AR-6 Construction Thread
 

Use a sanding block to trim off the excess fiberglass and smooth the wing surface.

Pieces of fiberglass over the gear hold down blocks were removed.