DG505 PART 3

Moving right along , the idea here is to keep these posts close together and not fragmented, some long construction breaks are likely up ahead., I would like to fly this beast sometime in the new year, so here is PART 3.

Last post the fin was tacked on (its one of the semetrical NACA foils and not to thin as it needs to be strong enough to support the tailplane)

In this photo a mixture of cotton flox and micro-balloons (paste) is screeded across the gap, once this is dry , it is sanded to a nice radiused contour. I have used LH137 harderner for the filler as it sets rapidly(about an hour) and speeds up building .
The glass cloth with some carbon re-inforcing is now layered on ,this area is greatly stressed on T-tails when landing so its worth making it strong, the leading edge of the verticle fin has 4x 12kcarbon tows which end spread out on the boom .



TIP at this stage if you have mixed a little more resin than required, dont discard it , mix in enough micro-balloons to a thin paste and using a flexable piece of plastic( I use thick mylar)scrape/screed this onto the surface , a little goes a long way and soon with practice you can fill the surface to a smooth shape ,being flexable you can bend the mylar to follow the rounded shapes, unfortunately lots of sanding still lies ahead.

This is were those marker lines are helpfull a set of wing rib airfoil profiles are cut out and tacked to the fuselage , this really needs to be as accurate as possible, once happy some more

light weight filler is contoured across the gap, try keep both sides the same if you dont have a good eye for lines and symetry, use calipers and a vernier to keep track you can also keep track with some light cardboard templates.

Its starting to resemble a DG505 for those who have a Pointy Nose Fetish or PNF , use a cotton flox thick mixture to add material to the nose .This will be shaped to the correct profile and then using cloth glassed in.

The nose is not pointy enough yet ? Well add some more mix and shape, its gotta be pointy aplenty.. (any one know the poem about the Pointy Birds)from a movie with Steve Martin.
I digress , sorry ,the screed is producing a good smooth finish , light weight spray filler is next.
The foam is still inside and the canopy will be cut out shortly.

The posts are now up to date Part 4 later.

DG 505 FUSELAGE PART 2

Summer is comming and summer is for flying, so now we build and build.
The progress has been good so the posts need to catch up while I have some time.

PART 1 covered material selection setting out and shaping about 3 days work.

PART 2

The project glider is large ,so the tube was glassed , cured and then the pod /front cockpit in two sessions , to assist with alignment some red reference lines are taped on and waxed.

Due to a nasty cold snap curing was slow so the fuselage was placed out in the sun to warm up and post cure. The ridges due to the tape edges are now sanded off, and the fuselage blown free of dust.

Even though this looks uneven the aim is to eliminate all the ridges before applying the 2nd layer of glass (163gr straight weave from AMT and LR 20 laminating resin with SLC harderner)

Wear a dust mask and work outside , this is probably the last sanding with this sander from now on its the orbital with 100 grit .

In this picture the boom 2nd layer of cloth is on and is far more even and shiney in finish. It is starting to become more rigid. At this point the aim is to layup about 4-5 layers and add additional re-inforcing to the inside much later. The cloth is layered on in pieces and the edges

sanded after each layer has cured its a tedious process.

The fin was hot wire cut and also taped and waxed .An area of the boom as marked is cut out, this is for controls and wiring. The fin base is hollowed to match the boom and tacked in place and carefully aligned. Note high tech lazer alignment tools with azimuth correction
PART 3 fuselage construction.

Next post to follow

SCALE DG 505

DG 505 ORION GLIDER

There has been a lot of interest in this new project and I was surprised at the response to the 2 x photos posted. Once again it becomes apparent that many modellers are interested in building techniques , so there will be a series of posts demonstrating the methods used.



PROJECT OVERVIEW


The choice of this subject was made based on the DG 1000 which is a state of the art 2 seater designed to compete with gliders such as the DUO DISCUS , after gathering lots of articles on the internet I decided to change to the DG505 as it used a wing planform that better suited my ideas on building a 8mtr plus wing. The intended outcome is a one off aircraft in the
15-20 kg weight class and wings in the region of 8mtrs span (4 pieces) with a fairly light wing loading. As before the goal is not to achieve scale perfection but rather an acceptable stand off scale appearance and good flight characteristics.


GETTING STARTED

If possible a good set of plan views is a must , I chatted to Paul from ETB about his FOX also scratch built and if you can get a set of plans enlarged to the size you want to build this is first prize , this is how Paul set about his project. The alternative is to scale up the drawing you have and mark up the sizes on the project using a calculator and tape measure.


These plan views will be a constant reference.
Some time ago I started collecting materials ,such as polystyrene foam from packaging and the for free part really helped, being resourcefull can lower building costs(to give you an idea a large scale , fully moulded kit of this size advertised in the USA would cost excluding shipping R45000.00 , although this glider is not in the same league , It is a goal to build this craft complete with airborn radio gear RX ,servos and battery pack for under R10000-00)








The foam is shaped out roughly with a hot wire and then moved to the sanding, take care the sander eats the foam at an alarming rate .The denser foam sands the best , after getting the basic shape right the foam is covered with packaging tape and waxed , this will aid removal
later. You will just see a centre line marked on the foam , this aids with sanding the sides the same.


The fuselage will be a one off , so the foam will be removed and discarded , due to its size it is not going to be melted out with thinners , but scooped/broken up and removed via the cockpit aperture.








The boom part of this fuselage is not made with foam, trying something a little new, a rigid cardboard tube was bonded into the foam , and a light cardboard rolled into a tube over the inner tube which is for surport and held in place with bits of tape.





A bit of care is now required as the tube is very flexable, it is also covered in tape and waxed,


the first layers of glass cloth and resin will "lock in the shape".

Only one layer of 163gr cloth is applied and it will have ridges in it as it drapes over the uneven packaging tape, I will show you how we handle these in the next part.

DG505 ORION SCALE GLIDER

True to tradition G.B.O.G.H. the large scale DG 505 is slowly taking shape

The Ventus 2cx a baby by comparison is now waiting for its maiden flight on the slope

Blogs new features!

Some of you may have noticed that the Blog looks a little different lately! That is because we have upgraded to the new version and it gives us many more new features to play with.

This also coincided with the BERG Blogs 1st Birthday on the 9th September. Piet wants to celebrate by doing something different, and has come up with some ideas. He has promised us a cake, so that is someting to look forward to!

The options are; we have a Fun-Fly day at BERG with a "Bring and Braai". The fun-fly will entail things like Egg dropping, limbo flying, water drop, Glof etc. Piet has some rather interesting ideas. More later.

Another option is, as a club outing, we all go down to Vloksrust for a weekends Slope Soaring, with the accompanying braai and gathering around the log fire and legendary breakfast at Oom Louis place. You could of course opt to do nothing, but I'm sure that won't be an option!

If any of you have any other suggestion, please feel free to leave your comments!

We want your feedback and with the new Blog features we have the ability to run polls. So to test this we have started one where you can vote on what we should do to celebrate the Blogs 1st Birthday on the 9th of September. If possible, other suggestion will be added.

Even if you aren't a BERG Member and would like to participate, please vote! Everyone is welcome.

The majority vote will decide. So go for it! Have some fun and cast your vote. Or make suggestions at the Comments link. There is even a place to vote if your wife won't let you out to play! The poll will run until Friday 10th August and after that we will start the planning!

BERG-Blog Breaks through 5000 hits Barrier

A Big Thank you to all our contributors and visitors to the BERG blog.
I don’t think I would believe that this was possible 11months ago when the blog counter register only 5 hits in the first week.

BERG - Power, Scale and Tow day.

Like I said before, never a dull moment at the BERG Club. On Saturday the 21st July some of the BERG Club member dusted of their power planes and the pictures below shows all the lovely planes that we flew and some of the action we had. To all that came along many thanks for a fun filled day.

Getting ready for the tow (Evan & Wesley at the glider, Trevor & Len at the tug)

Evan's Tsotsi lifts off from the dolly on tow with J3 Cub from Len.

J3 Cub and Tsotsi on Tow, up and away into the blue yonder.

Len and " Green monster"

Wesley holding the Edge. Here you can see just how big it is!

Trevor and Wesley. Final R/C test before take off.

Piet's Taurus 48“ 60 % scale, 30 glo motor.

Evan's 1/5 scale Super Cub 4 stroke 40 glo motor.

Len's Morrisey Bravo 35 cc Petrol Quadra chainsaw motor.

Final tweeking done. Time to fly!

Straight down the runway and away!

Morrisey overhead!

Len's 1/4 Scale J3 Cub 90 cc glo motor

J3Cub Fly By!

Unpacking and assembling for the days flying.

James waiting for the runway to clear!

Excellent weekend weather greets new BERG member.

This Sunday we had the most fantastic weather that one could wish for with thermals that even a beginner could catch. My first flight was 45 minutes endurance. This was perfect for BERG's newest member who has just joined the club. Welcome Herman. He has many years of free flight experience and the pictures below show him towing his A2 glider (50 meter two line) and on all 3 flights that he had the glider was saved from flying away out of sight by his de-thermal device. After showing us all how free flight works, Evan gave him some stick time on his Tsotsi and it wasn't long before he got the hang of how to interrupt free flight with radio control. As mentioned earlier the thermals were so good and everywhere and he had no problem staying up.
Some of the members enjoying a break in the flying proceedings.

Charl also popped in to show us the latest BERG gear he is organizing, a nice cap and fleece with the BERG logo embroidered on. The fleece will be selling at R200.00 each and the cap at R50.00. If you want please do the deposit into the BERG account and contact Charl charlviv@dmip.co.za with your requirements. He will need to know what size jacket to order for you and quantities and if you want a cap. Evan is wearing an XL and it fits him nicely. Very good quality as well. (That's the fleece i'm talking about!) Exactly what we all need for these chilly winter days.

For more details you can contact me (Piet) at email me


My Gentle Old Lady is nearly complete, only elevator and re installment of RC equipment to do.

More when it is done!