Composite racing wing
 

Here's some photos of my latest mold. It's for my composite .60 size Tsunami and I laid the first wing up in the mold today. Final results should be seen Monday. I'm planning on racing this plane at Sacramento in March.

The blue stripe is trim tape used to make a ridge in the mold and the white squares are the servo hatch bay recesses.

Wing layup
 

The mold was prepped with mold release, a coat of primer sprayed on and then layup began. The surface is 2oz glass, then 1/16" balsa, then 4oz glass with some carbon and other reinforcements. Right now, it's waiting to be put in the vacuum bag

wing halves in the bag
 

Here the wing halves are in the bag and I am making sure everything is ok as the vacuum bag sucks all the air out. On top of the glass on the wing panels is "peel ply" which is used to soak up resin. Some paper towels are on top in case the there is too much extra resin and needs soaking up. When the wing is dry in 24hrs, the peel ply is removed and it takes with it excess resin that it soaked up, thus reducing weight.

vacuum on
 

Here, the vacuum system has sucked all the air out of the bag and you can see the peel ply and paper towels sucking up the excess epoxy. Any "white" areas are where there was just enough epoxy and there is no excess being absorbed.

Next up
 

Next for layup is the fuse and tail. These molds have been prepped with mold release and then primer was sprayed on so that it comes out of the mold ready to sand.

how the wing mold is made
 

In case anyone is wondering how the wing mold is made, the next three photos will show you.

This is the wing plug all sanded and polished with a "splitter plate" going all the way around the wing. Mold release is applied and then it's time to start mold making.

Slurry coat
 

After the wing has the splitter plate around it (so that two halves can be made - top and bottom), a surface slurry coat is applied. Here it is epoxy with grey pigment and microballoons mixed in. A good, thick consistency is mixed and then spread all over the wing. A brush spreads it around and it the surface coat eventually smooths itself out. Let this dry and then it's time for reinforcement.

Reinforcement
 

Now it's time for reinforcement. Time and patience is needed here as layer after layer of heavy fiberglass is laid on top of the dry surface coat. In the end, some Aeromat and then a smooth layer of cloth is put on top to finalize this half of the wing. Once this is done, it's then time to remove the splitter plate and do the same process all over again for the bottom half of the wing...

fuse out of the mold
 

Here's a fuselage out of the mold that's under construction. You can see the primer was built in to the model in the molding process and has virtually no pinholes!

Great job!!!!!!!!!!!!!!!!!!!!!
 

Fantastic!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Keep it up. I love this hobby!!!!

Darrin C

Composite racing wing
 

Michael

Your project is very impressive. Obviously your very dedicated to the sport of turning left....

I am in process of building a similar model around Miss Ashley II.
Same basic design considerations, thus far the wing and fuse plugs are complete.

What is the area of the wing and what engine are you going to run?

Look forward to seeing you and your model in March. I have seen you Webra 120 powered version in the air... :)

Composite racing wing
 

Ahh, so you have seen the previous two models. :) The Webra 1.20 ones were fast and had more left in them, but, both of those prototypes were lost (3.75" Tru turn spinners are getting expensive!)...

The wing area is at 555 sq/in (just over the .60/1.20 sizing) and we will be putting four strokes in them this time. My brother's gonna be running an Enya 1.20 geared pump in one and if I can get one done for myself, I will have a YS in there...

Better get out to the garage this morning and get laying up!

Cool - a Miss Ashley II! That is next on my list if I ever get time. What drawings are you working from? What size plane? A gentleman named Tachiro from Japan has a set of immaculate drawings on the pylon1.com site. They are beautiful.

Michael

Documentary?
 

This seems like it is turing into a documentary, but since some of the stuff that I am doing is not something people do every day, I've been happy to be able to share it here. The next few messages are today's progress. I will get to close up the molds tomorrow, but work will probably halt some till next weekend as work and college takes precedence.

Lower wing half out of the mold with the peel ply and breather removed.

Composite racing wing
 

Upper half with peel ply and breather removed

Composite racing wing
 

Stabilizer and wing spar in bags. Wing spar is 3/8" end grain balsa with glass bagged on both sides of it.

Composite racing wing
 

Center panel with retract structure. Spent a few hours laying this out and then making templates for future use. Will glue them in tonight or tomorrow. The main spar will butt up against the rear of the landing gear ribs to tie things in. The balsa near the leading edge is there to keep the "splooge" (mix of epoxy and structural filler material which is laid around the perimeter of the wing) from seeping into the wing when the mold is closed up. This ensures that there is a good bond on the leading edge.

Composite racing wing
 

My stock of Tru-turn spinners for the Tsunami. Racing has its high mortality rate and it hit me at two races. I'm not proud of this photo, but heck, there's $200 sitting there in spinners. The one on the right probably hit the ground at close to 190mph. The 3rd one, on the left, hopefully won't end up like the others!

Composite racing wing
 

Michael,

Thank you very much for posting the photos and descriptions. You're right, this isn't an everyday thing for most people.

A friend and I have been looking at some busted up wings, and the part we're really curious about is the preparation of the halves before they go together. In particular, what is done with the extra material at the mold edges, before joining the halves.

Please continue to update us with additional photos and descriptions.

Composite racing wing
 

Don,
I'll be happy to keep going with this thread till the plane finishes. My new digital camera I bought this winter is helping me document this and it's easy to get the photos right away.

As for the extra material that goes over the edge of the molds, I have heard varying stories. Some cut it off before joining the halves. Others like me (I'm a novice that this stuff - this is my first wing - I've done lots of stabs, etc, but this is my first attempt at a full blown wing) leave the overlap there. If it's thin, it makes no real difference. The overlap will only make the wing thicker if you don't remove it. Some of the aluminum molds for high production stuff probably are designed with this in mind. I guess a good molder has it down pat where very little hangs over the edge. I'll cut off the overlap after the wing comes out of the mold.

Michael

Composite racing wing
 

Okay..... I'm pooped, but final results of the wing will be known tomorrow!

Took advantage of today's holiday and some time off work to finish the wing up. In three days work, a lot was done. Onto the photos...

Main spar and anding gear structure area glued in place. The center rib/wing mount block supports were also installed for the LE.

Composite racing wing
 

Closeup of landing gear area

Composite racing wing
 

Chris's (my brother) neat exit scoop. The real Tsunami used this as an exit door for the radiator spray and heat exit. We're using it as a hatch to get to the servos and put the switch in there. Why the servos in the tail?? Wait till the next photo!

Composite racing wing
 

Well, the reason for the elevator and rudder servos in the tail is because of the huge Enya R 120 being stuck in the nose as is apparent by this photo. That's a lot of motor.

Composite racing wing
 

Close up of the Enya 1.20 in the nose.

Composite racing wing
 

Okay, back to the wing. All spars/supports in wing and a syringe was used to apply a mix of epoxy, milled fiber and some cabosil along all the joints. I was probably too heavy overall with this, but it's the first wing and I don't want to miss any spots. Better to be safe than sorry.