Making Extra 300 80" totally composites
 

I was learning too much here at RCU, so one year a go I'd start my first composite proyect.

It's an Extra 300 wich I get plans at the web.

This plans are for 1/3 Extra, so trying to learn more first before invest all that amount of money
I reduced plans to 80" wing span....

I'd take AutoCad and reduced it.

Plot plans and start to scratch first prototype, to be sure it will fly OK.

The designer say at the web that plane fly better than many kit there are outside (but at 1/3 scale)

so I take it slowly and make all very simple just for test.....

I'd scratch built first plane, cover with "moneykote" and put an OS BGX on it....

First flys were better I expect, and the guy who help me is a very good flyer, so with that in my mind I'd start
this project...

Please excuse my english, but I'll try to explain the best I can

RE: Making Extra 300 80" totally composites
 

First I must make a plug, so start with some door ply (cheapest)

I'd cut internal formers without any hole on it, weight will not matter

I'd buy some blue foam at isolation store and some polyurethane resins to fill the plug and get some stiff

RE: Making Extra 300 80" totally composites
 

The polyurethane foam works great (Thank's Mike for your web site)

The fuse jig I must make was taken from here RCU, take some time but it's cheap and easy to make

It's similar to Gator RC fuse jig, and I'll search threat for post here to thank's the guy who share it.

Here are the thrust line and cowl shape... thrust line is at fuse too...

RE: Making Extra 300 80" totally composites
 

Blue foam is a great material, sands easy and take little time to shape.....

Spinner is 3.25", and it's line is visible here

RE: Making Extra 300 80" totally composites
 

Because this is my first project this kind, I must asume will be making many mistakes,
but that is the lovely art of learn.....

I'd not take many pic's about process, so will explain what I do

RE: Making Extra 300 80" totally composites
 

When plug was totally shape, was cover with glass and epoxy
4 or 5 oz wave (don't remember) was used;
when cured wave holes was filled with car filler and sanded to smooth

It takes some days, so then was when I'd think about foam cores.....

RE: Making Extra 300 80" totally composites
 

I must say the Extra is my girlfriend's plane, she fly very good and make me start with the prototype,

but when I'd start can't stop with the project.....

So search the way to make the wing, stab and rudder cores with no luck here at my country; then
I decided to make some for cut it....

I'd get some electronics with the guys at some web page and start the cutting machine... it take me about three
months to finish and tune but works great.....

I'll post some prototype and cnc pic's tomorrow..... time to rest.

Merry Christmas

RE: Making Extra 300 80" totally composites
 

Marco

You are to be applauded for your tenacity and effort. This is a huge project and you seem to have it well in hand. Good luck and please continue to share the process with us.

Mike Luvara had some information in the Pylon Racing Forum on a composite hollow core molded wing build. I 'll see if I can find the link for you.

If nothing else email me, I can provide some insight on our methods.

RE: Making Extra 300 80" totally composites
 

Thank's mglavin,
all about the project is learn to me, so the hollow wing system is welcome....

This is CNC cutting machine, very easy to make with industrial trash and some step motors (trash too)

The program was cheap, about 40 Euro, so it was ready for cutting cores...

I'd buy white foam 12Kg/M3 (I don't know about what imperial density it is) and start to cut cores for wing, stab and rudder

RE: Making Extra 300 80" totally composites
 

At previous pic's you can see the fuse jig and over the CNC's table you can see some prop's too, the first Dynatrust 22x10, the second Mejzlik 22x10 and third is a test I'd make with a prop mould 22x10

RE: Making Extra 300 80" totally composites
 

With CNC cutter, now it's time to make vacuum....

Get some parts at industrial trash like freezer compressor and an old car diafragm...

Some conectors and presure lines.... some time later.....

vacuum system

RE: Making Extra 300 80" totally composites
 

After vacuum system, I need a wing cutting hole system, and that was made with a great idea from Scott Smith (really thank's).

It's a good idea and works great, so I get some material and make de hole cutting jig...

RE: Making Extra 300 80" totally composites
 

Now I'd cut core for fin and rudder and was sheeted with 1/16" balsa ....

Glue was 24h epoxy like many guys here at RCU sugested....

When sheeted, cut fin and was addeded to plug, totally aligned....

After that, all was cover with glass cloth and epoxy resin....

Some car fill compound and sanded....

Two heavy coats of K-36 primer and sand to get out the imperfections....

One more primer coat and it was ready...

Canopy was made with polyurethane foam and sanded to shape, some light wall fill compound and two heavy glass cloth with epoxy resin... Two K-36 heavy coats, some sand and ready too....

The chin cowl was separated of the nose, the same cloth and resin, K-36 and ready...

Pic's was made yesterday, too much time after mould was made, so plug are a little damaged...

RE: Making Extra 300 80" totally composites
 

Now it's time to make partition board and make the female moulds....

Apply wax 6 times and buff every one very good.....

The gap between plug and partition board was sealed with plastecine....

Two more wax and buffing .....

24 hours later two PVA light coats and let it dry 24 hours...

Mould layers was:

- Two heavy epoxy resin coats; it was colored with polyester resin black pigment
- three 6oz glass cloth
- one marine grade glass cloth

All epoxy was black tinted (I'd like it)

RE: Making Extra 300 80" totally composites
 

Some more mould pic's...

Pic's was taken some time after first fuse was layed....

RE: Making Extra 300 80" totally composites
 

I'd have not hot box, so somebody tell me It was not necesary "just let the piece to sun light".... I did it.....

BIG MISTAKE!!!!!!!!!!

a little part of mould get too much heat and deform about 1/16" in a 2" sq in at the tail part (just one halve)....

I don't like it, but learn is hard and take it with philosophy..... ok, next time first ask to RCU friends.....

OK, plug was taken off, the halves get wax and buffing 6 times....

Two PVA lilght coats, 24 hours to dry and it was ready to layup....

Layup was made next way:

- One K-36 light coat; let it totally dry
- One more K-36 light coat and before it dry start layup (Ola Fremming suggestion, thx for the tip)
- Some carbon tow for reinforcement at corners
- One light epoxy resin coat to get bubbles off
- One 5oz glass cloth
- One 5oz carbon fibber cloth
- Many time getting extra resin out with paper towels....

8 hours later I'd join halves and fuse parts with carbon ribbon...

Now I'd learn, and I'd make a hot box with cartoon box and electric heater...

After 24 hors, first fuse was done.... well.... all the work look well... but there are a little imperfection at the tail.... I'll work on it...

After trimming and sanding edges, fuse weight was 1,024 gramms (about 36.12 oz)

Fuse #2 will only have 1 layer carbon cloth, because fuse was very stiff and I can get it lighter.....

Stab and wing cores was made, but I decided to enlarge wingspan to 81.5" because I only have a G-62 at hand, and it is a heavy engine to get at least 30oz/ft wingload.... I'd expect a totally weight about 17-18 lb so with a light engine, it will be at 15-16 lb range

I prefer paint over plastic film, but since it will be my first paint attemp, all work is a test for me......

Wing and stab was sheeted with 1/16" balsa, holes was cut and was time to tube sockets....

Stab sockets was made 5oz glass cloth... wing socket was made 5oz carbon cloth.... aluminum tube was dural type... 1" OD for wing (may be 1 1/2" or 2" will be better but I'll try) and 5/8" OD for stab...

Wing and stab root was made with 3/32" balsa and one carbon layer... looks beautiful and it's durable....

Sockets was glued, wing and stab was aligned with fuse, ailerons and elevators was cutted and all surfaces was covered with 0.75oz cloth and polyester resin (old system). Cloth holes was filled with resin and microballoons....sand and sand.....when all was OK a heavy K-36 primer coat and more sand.....

RE: Making Extra 300 80" totally composites
 

Canopy mold was made same way than fuse's mold...

Canopy piece was made one layer 5oz carbon cloth...

It's very stiff, 1/8" balsa was used at both ends formers, and at botton two balsa ribbons to stiff...

Total weight after paint, clear coat and buffing: 100 Gr (about 3.5 oz)

RE: Making Extra 300 80" totally composites
 

Some more canopy's pics....

I'll be layingup fuse #2 tonight, so I'll show you more pic's about.

RE: Making Extra 300 80" totally composites
 

Now I need an undercariage, so I'd take the idea watched here at RCU and some web pages....

Desing it with clearance enough for 22" prop, so make a wood base, glued some formica, make balsa lateral walls and
it was ready for layup....

Carbon tow was used for it....

RE: Making Extra 300 80" totally composites
 

Main gear was reinforced with some carbon wave at axles area and fuse area...

Totally weight was 157 Gr (about 5.5 oz)

It was divides at two pieces for fuse fix....

RE: Making Extra 300 80" totally composites
 

Tail gear was made same way, but carbon clth was used.... very stiff and for my surprise when attached to fuse,

it make the same movements than a spring or car trust...

RE: Making Extra 300 80" totally composites
 

Great work Marco!
Keep the pics comming!

RE: Making Extra 300 80" totally composites
 

Now was time for spinner....

I'd try to get a good mold from aluminum spinner, but prop holes don't let me do it good enough....

I decided to make a solid metal spinner shape and then make the mold....

Spinner is 3 1/4" diameter.... After mold was made, start layup next way:

- 6 wax and buffing
- 2 light PVA after 24 hours
- One light epoxy resin coat (for mirror finish)
- After 8 hours, one 0.75 oz glass cloth and paper towels for get most resin off
- After 12 hours, one layer 5oz carbon cloth, cut it 2 pieces overlaping each
- One carbon ribbon to reinforce aluminum base
- some chopped carbon tow with resin for central hole reinforcement

I'd take idea from a staudacher page.... I'll search it and post... Thank's that guys for share

Base plate was machined from dural aluminum to shape.....

RE: Making Extra 300 80" totally composites
 

Thank's 3de,

It's a very long travel but delicious...... make all this is enjoyable.....

Learning curve at this point is very complex and long, but since I don't mind to make bussines with it (It's my hobby only) I like to share all my learning process and mistakes too....

Hope all you enjoy it like me....

Some more spinner pic's

Weight was:

-cone 20 Gr (0.70 oz)
- back plate 47 Gr (1.65 oz)

RE: Making Extra 300 80" totally composites
 

At this point I'm yet testing make carbon prop's, I know about the danger side if a prop explode at lead and many carbon parts fly all around, so I can't say it is totally finished system, but I'm trying and learning....

Take many ideas from many web sites (one I remember is David Fee web site.. really thank's for share) and many other good people who share their knowledge.....

I'd take all about prop's very carefully......

First I made the mold with fast cast resin.... it is very dificult to make a good mold since there are some areas (hub area) that are not rigid enough to close and open mold many times...

Shape and balance must be closed to perfect....

There are many variables I must to take in count....

Here is where I am now:

Prop is Mejzlik 22x10... there are a Dynatrust 22x10 too but only for engine test.... the third with epoxy flanges is the first prop I'd made....

It was rigid enough but with some estructural problems between hub and tip..... I'm now changing layup to make it better and get good performance....

RE: Making Extra 300 80" totally composites
 

OK, It's time for firewall and engine....

firewall is 1/4" ply and one carbon 5oz layer....

Since plane's nose have 2 grades right thrust and 0 grades down thrust shape from plug, it was a little simple to get firewall position...

Engine holes was other history, but using some balsa little blocks and incidence metter, holes was allocated and drilled....

G-62 has Bennet cup mount and muffler, and that horrible phenolic carb isolator..... ok, the isolator helps to make servo instalation, but there are too many troubles incoming with it....

Thank's to RCIGN and some more friends here at RCU for help to know the piece have a trouble and to fix it with some epoxy... new piece is incomig....

At this time I'm trying to learn all about gas engines, this are beautiful beasts and after some bench test I'd loose some apprehension I'd have....

Engine was totally stock, but after some bench test I'd try CH electronic ignition; iddle was too much better and soft but I can't yet get a good transition.... may be tomorrow....

RE: Making Extra 300 80" totally composites
 

Here is engine at plane...

The wood piece you can see at cup mount is to make incidence changes easily and to get some clearance for installations...

particulary I don't like that cowl joint at fuse's top, so decide to make only a chin cowl (is that the name?) because I saw at PL web site.... their planes looks beautiful without that and nose looks nice and clean.

Cowl attachment was always a problem... the holes at cowl enlarge.... the holes at wood too.... screws are loosing...

RE: Making Extra 300 80" totally composites
 

Starts to look like a plane....

RE: Making Extra 300 80" totally composites
 

Just for rest, here are some shoots of my reduced workshop....

RE: Making Extra 300 80" totally composites
 

Now I need some help to make CF tube (wing and stab)...

Anybody knows how to make it?

I'd see at some web pages they use prepreg carbon and mandreel, then sand to shape....

Is there any way to make it with carbon tow and cloth?

Any help will be apreciated.

RE: Making Extra 300 80" totally composites
 

I'll post how I make wing tube socket for fuse.... I have all fll set of pic's about it...

Again thank's to Ola Fremming ( http://home.online.no/~ofremmi/index.htm ) look under How-to's


Pic #1 shows materials needed:

-plastic for cover work area
-weight scale
-epoxy resin
-waxed paper
-aluminum tube (or what you use)
-carbon cloth 5oz (or what you use)
-rubber gloves
-wood stick
-some container for mixing resin
-brush

pic #2

Roll the waxed paper some bigest than cloth and only one round with 1/4" overlap... you can get it in place with some masking tape but only at ends (not in the middle)

pic #3

cloth with some epoxy on it. weight cloth and make same resin weight

RE: Making Extra 300 80" totally composites
 

Pic #4

Cloth with epoxy is rolled over tube.... be carefully don't let air between tube and cloth...


Pic #5

Cloth end always try to separate (especialy CF) so start to roll plastic film over; that will make a good and shine finish....


Pic #6

All stay appart to cure. You can use vacuum if prefer....


Tomorow I'll post pic's about next steps and results when it cure.

RE: Making Extra 300 80" totally composites
 

I don't like elevator servos at fuse sides, so since start I decided to locate at stab cores....
may be this can make me in troubles with balance, but since it is a test project, I'll take the risk....

Servos are 2 Hitec 5625 for elevator and 2 Hitec 5625 for wings.

Rudder servo is 1 Hitec 5945 at pull-pull system

all hardware is Dubro...

I decided to use Gator RC wing adjuster (one per wing) to help with fine tune....

Now, glue two balsa sticks cover with one CF layer for pull-pull servo..

pull-pull system is Dubro, so I'd made long servo arm with some rigis electronic card board the same size than rudder horn...

(Again thanks to Ola Fremming)

At pic's you can see the wing socket tube at fuse, some lateral formers I'd made with balsa and one CF layer for reinforce,
the sticks for servo, the servo and the servo arm...

RE: Making Extra 300 80" totally composites
 

Simetry at pull-pull will be verified carefully....

I'd make a cross wire system and Ackerman don't lie.... take me about 2 days to get a good quality system....

Some people say CF fuse cause radio interference, some people say it is not.....

I'd read many posts here at RCU and the discussion continues.....

Two guys at Aeroslave ( http://home.comcast.net/~aeroslave/ ) are making carbon pattern planes without issues... just let the antena wire out the fuse.....

I'll take the chance....

The same with radio interference using gas engines... some people attach the throttle servo at engine box and say all is OK when fly......

Other people suggest you let all radio equipment at least 8 inch away the engine or electronic ignition parts (like batteries)...

This time, I'll don't take the risk.... radio equipment will be at least 8 inch away...

RE: Making Extra 300 80" totally composites
 

all i can say about your work is WOW your building skillz are epic

RE: Making Extra 300 80" totally composites
 

Thank's flatlandmike, and all this skill you say is for all the guys here at RCU, all you teach me on line with your posts...

But one thing is to read and another to do.... and believe me, this plane have many mistakes and errors I made, but all is part of learning process and I want to show you all for learn together, and the mistakes I did too....

Tomorrow I'll start the paint process pic's, it is a hard work to do with a long way to learn.....

After paint I'll post all real weights I get with this plane, and believeme, I am very surprised with many....

RE: Making Extra 300 80" totally composites
 

Here are the carbon socket finish pic's....

pic #1

Unroll plastic film and start to enjoy the smooth and shine finish...


pic #2

slide aluminum tube easily.... wax paper is at socket

RE: Making Extra 300 80" totally composites
 

pic #3

get off waxed paper... can be made easy...


pic #4

perfect fit..... cut to size you need and enjoy your work.....

RE: Making Extra 300 80" totally composites
 

Paint work is very hard and can make all your work look beauty or ugly.....

Reading many post here at RCU and too many web pages, I understand the only way to make a good work is:

1.- patience
2.- good materials
3.- good equipment
4.- surface preparation is all
5.- try your self or you never learn

This is my first try to paint..... I'm very nervous..... but since it's a project and I want to learn I take the risk....

Here at forum is a great guy who share how to make good paint works and you can get great tip's to afford.....

Name is Jeremy Ferguson, and here is the link:

http://www.rcuniverse.com/forum/m_74.../tm.htm#745346

There are many more friends here who share how to paint, but this is all in a treat....

So I get the polyurethane way....

I'd Get PPG Concept solid colors and clear, catalizer, reducer, sand paper, foam blocks and too much hours of hard work....

I'd buy an HVLP gun and an Passche VL airbrush...... some 3m masking tape (blue and green), frisket film and an old air compressor I have at my work, rubber gloves, cartridge respirator, old tshirt, a girlfriend watching curious....

I then decide the scheme, colors was white, red and black....

Fuse was first, start wet sanding at 600 grid, 1000, 1200, 1500 and 2000

When finished, I washed very well with some liquid dish soap and let it dry at a room dust free...

next day, fuse was cleaned with alcohol and soft cloth..... I'd hang fuse at garage and prepare base coat (white), let it 15 minutes induction time and start with HVLP gun at 30psi and a test surface.... paint try to level so reduce paint flux and move hand faster..

when I feel all was OK start at fuse.... first a light coat... let it flash 15 minutes and second coat to level.... well, not so level, some orange peel start and that must be sanded later...gggrrrrr.... do it better and with many calm.... soft movement.... less paint....more air.... and after 15 minutes white is finished.... I can't believe it... I did it.... many details of course but it was funny....

Next day red starts... some masking tape, plastic film to cancel rest of fuse area and again.... red is hard to paint, you need more paint because it don't get the exact tone with two coats.... let it dry and next day black color... same procedure....WOW it really cover with too less paint....

I want to paint letters, and that's more hard and fine work.... cut "MEXICO" and "AR" symbol for nose at frisket film and use the mask for white letters.... what a pain, airbrush (double action) is hard to drive... after two days of testing I'd start at fuse.... too many errors at both fuse's sides....
well, It's my firs time, and I have the rest of my life to learn how to airbrush better...

Next day totally sand 1000 gris, 1200, 1500 and 2000 to level and get all details out.... wash and dry....

Next day clearcoat.... same procedure... two coats and let it dry at free dust room.... looks great minus some errors... clearcoat paint is very thin...

Next day sand 2000 grid and I don't like glossy is off..... well, it's time to polish....

Sayer Lack polish compound hard, medium and fine....

Here I am now... drill system not work for me so my sister gift me a polisher machine at Christmas ¡¡¡¡ Thank's sister !!!!

After 2 days I discover it's not a polishr machine, it's a grinder with 11,000 RPM.... well, she will return to shop and change what I need but that must be in a few days..... I'd start hand buffing and it's a hard work, but for now plane only need fine compound and finish....

Here is where all plane is at this time, waiting for final buff.....

RE: Making Extra 300 80" totally composites
 

Here are the pic's