v6goose

Gentlemen...

I thought you might be interested in a project I have been heavily involved with over the last few months.

To help celebrate 100 years of flight in Canada, I volunteered with six others to design and build a stand-off (a long way) scale replica of the Silver Dart for the Canada Aviation Museum here in Ottawa.

A brief history...

Silver Dart, the first powered, heavier-than-air machine to fly in Canada; designed and built by the Aerial Experiment Assn (Oct 1907-Mar 1909) under Alexander Graham Bell, a flight enthusiast since boyhood. After several successful flights at Hammondsport, NY, early in 1909 the Silver Dart was dismantled, crated and brought to Baddeck Bay, NS, the Bells' Canadian home. The "aerodrome" (Bell's preferred term) had a 14.9 m wingspan and an all-up weight of 390 kg, pilot included.

J.A.D. MCCURDY was the principal designer and pilot; Glenn H. Curtiss developed the water-cooled engine, an advance on the association's earlier experiments. Pulled on to the ice of Baddeck Bay by horsedrawn sleigh on Feb 23, the silver-winged machine rose on its second attempt after travelling about 30 m, flying at an elevation from 3 to 9 m at roughly 65 km/hr for 0.8 km. Over 100 of Bell's neighbours witnessed the first flight of a British subject anywhere in the Empire. The Silver Dart flew more than 200 times before being damaged beyond repair upon landing in the soft sand of Petawawa, Ont, during military trials in early Aug 1909. The engine was later retrieved and restored and is now on display at the National Museum of Science and Technology in Ottawa. A full-scale model of the Silver Dart may be found in Ottawa's National Aviation Museum.

v6goose

Several meetings were had and tasks assigned. I was to produce the working drawings, calling on my many years as an engineering draughtsman in AutoCAD.

Reference drawings and information was scarce, so together with less than a dozen photographs and one drawing, the project took off so to speak.

Nigel Chippendale hosted the early meetings and directed the project ensuring concensus with the design decisions, of which there were many. How big? What materials would we use? Power plant type? etc

A short time later the working drawings were distributed for a 7' (84"), ~7lbs electric powered replica utilizing spruce, ply, balsa, carbon fibre rod, various rods, tubes and wires.

We did deviate slightly in places where deemed necessary for the good of the end result, like developing a full airfoil section wing instead of the originals single sided structure, but by and large as the head of construction (a job I was to inherit) I wanted to maintain an as scale as practical approach to the model.

v6goose

As you can see, the Silver Dart was typical of the earliest flying machines in that it was a biplane configuration with a carnard arrangement - the stabilizer out in front.

It was constructed of hardwood, probably spruce or similar and a lot of bamboo. Interestingly, the black sections featured on much of the bamboo areas is hockey tape - used to reinforce the joints that were suspect or had failed during construction and/or flight.

The wings curve towards each other and have triangular ailerons, top and bottom, at the tips.

The biplane stabilizer arrangement is an all-moving affair and the rudder is atypical.

The tricycle undercarriage is modified motorcycle parts and is frighteningly close together given the wingspan.

Like the full scale aircraft, we intended to control all the surfaces via pull-pull arrangements and were successful in doing so... on the ground thus far anyways!

v6goose

We elected for an electric motor for power given that the model would be flown on the anniversary day of the original - February 23, 2009.

Those of you who live in the Ottawa area (Canada) will know that this is winter, very cold, snowy and the weather is less than cooperative for flying rc planes!

None of us voted for gas or glow as starting such a beast in this weather, even on a clear day, seemed like an exercise in futility.

You will note this is a pusher configuration as well.

I will be posting construction pictures in some kind of order shortly.

Enjoy!

Goose

codiddley

My Feedback: (4)

Interesting project! Looking forward to some construction pics!

v6goose

Thanks Codiddley...

That it is, for several reasons over and above the historical one outlined above.

This is my first foray into electric, first biplane, first canard etc.

It is also the shortest time frame I have had to squeeze a scratch-built model into and that has been quite a challenge!

Michel and I have just crossed over 200 hours on the project.

Cheers

Goose

v6goose

Rick (left) and Michel (pic 1) seen here working on the first pair of Dart wings, constructed them in a jig built to include what we figured to be a very important aspect... washout.

We chose an Aquila airfoil section after discussions with an expert and because they were plotted in AutoCAD, it was a fairly simple task to prepare a laser cutting drawing (seen bottom right of CAD drawing) and was sent to [link=https://mraerodesign.securicom.ca/]MR Aerodesign[/link] here in Canada.

I began by constructing the carbon fibre forward fuselage frames and a jig to represent the critical dimensions of the the fuselage core.

Chris (seen with Michel in pic 3) was a volunteer in the early days and lent a hand to the build effort.

v6goose

Once Rick and Michel had constructed the wings, no easy feat mind you, the LE was laminated spruce and had to be hand carved in the jig to set the curve and washout, it was off to the spray booth at the Canada Museum of Aviation on a wet and windy Saturday morning.

Fortunately, Marc had completed the covering and was well setup to dope all the flying surfaces with silver dope. He did a great job and the wings look quite authentic.

v6goose

Meanwhile back in the workshop, construction of the forward fuselage continued. Carbon fibre rod is quite difficult to work with and many experiments were undertaken to establish best practices.

Scallops were cut in the ends of all CF rods with a carbide rotary bit in my drill press and hardwood dowels were inserted in both ends. This gave me much more gluing surface and a better chance at it all staying together.

JB Weld became the glue of choice for CF rods despite taking a long time to set.

Michel worked on the spruce spars and all three of us (incl. Rick) assembled the wings in the jig.

More to come...

Cheers

Goose

v6goose

The biplane stabilizer was next on the construction list and this is version II after version one (built by Brad) didn't stand up to the pull of the dope and warped so badly it couldn't recover (not Brad's fault, mine).

I redesigned the construction, basically resorting to spruce instead of balsa and all became well.

I wasn't very happy with this version and as it turns out we managed to install the support pivot upside down. Version III is a sexy beast and 1/3rd lighter!

The rudder was built from CF rod and was braced with .5mm rubber thread. This allows the bracing 'wires' to stay taught but not break everything when you knock it, which happens a lot.

Rick supplied our pilot and spent some time giving him plastic surgery to more closely resemble J.A.D McCurdy before having him sent away for a clothing refit.

v6goose

Yours truly caught during the construction of the rear fuselage frame. All joints in the CF tube in the vertical plane were pinned with a 40mm long, 4mm music wire pin and JB welded. All the supporting struts in the horizontal plane were JB welded and bound with kevlar thread, finished up with a little CA and some acrylic paint (Tamiya).

With the wings assembled, I went about adding all the functional bracing wires of which there are plenty! 40 separate wires, 40 turnbuckles (hand-made) and 80 connection point crimps. All the wire in this model is 0.18 control line wire and is crimped with short brass tube pieces.

The brackets like most things on this project were designed and built for the job by hand. I had to redesign them 4 times before they both looked good and were functional, much to Michels chagrin...

Next up was the fitting of the ailerons which have a pushrod between top and bottom. Controlling them is achieved via an intricate pull-pull system and 4 pulleys per wing (single servo).

Hinges are CA type, folded into an 'S' shape and inserted into slots in the CF tubes created with a Dremel and a cutoff wheel.

More in the next couple of days...

Cheers

Goose

v6goose

With the job of constructing the fuselage core being handed back to Michel and I, it was quickly included in the late night building sessions.

Michel ripped all the spruce used in this project from a large 6"x6"x4' length with a table saw down to some very accurate requirements.

This was to replace the jig as soon as possible and it started to look like the intended model.

We did discover a couple of issues.

One: As we had elected to build the top wings as a pair instead of the original one piece (per se) the design of the fuselage could not hold together with the weight on each side trying to pull the fuselage apart... quite successfully I might add!

To resolve this, we added 3 440 rods at strategic places to hold it all together and it works well. See if you can see them.

v6goose

Our pilot was donated by Rick and this is how he started out and how he finished up after Rick did the plastic surgery on his face to match the photos of J.A.D McCurdy, a friend of Nigels refitted his clothing, and Michel and I performed hip surgery on him to straddle the seat.

v6goose

So after 600+ hours of labour, the Silver Dart was finished on time for the unveiling at the January club meeting on the 27th.

I am very proud of this project and happy that it was ready as promised.

We have finished setting up the radio, mixing and throws today and are preparing for ground trials (in a hangar) and possibly getting the model into the wind tunnel at the NRC which would help a lot in determining the C of G, minimum airspeed, takeoff speed, control surface effectiveness etc... all things that noone knows about.

I will add more as it happens, but for now this is up-to-date.

Appreciate your comments.

Cheers

Goose

Pic1: Our model is overseen by the original design and flight team including Alexander Graham Bell (center) and Glenn Curtiss
Pic2: Most of the Dart team (L to R) Michel Carriere, Me, Marc Shaw, Rick Williamson and Nigel Chippendale.
Pic3: Michel (L) and I pose with Gerry Nadon, representing the Canada Aviation Museum and Stetson Flyers club (all)
Pic4: Dart on the floor
Pic5: Dart not on the floor

Super Hot

Congratulation for your fantastic project.

Actually I make a 1/8 semi-scale of Silver Dart, 72" wing span, length of 48 ", weight of approximately 8 pounds and will be propelled by a OS 52 four-stroke engine.

His construction is mainly made of gudgeon, wood and of copper tubing.

v6goose

Hey Superhot...

Great job my friend! Wow, you have really pulled out all the stops in fine detail there.

Where did you get your plans from? Are those the Top Flite wheels that we are still waiting on?

Keep us all up to date with your progress.

Cheers

Goose

Super Hot

Yes Goose

Yes they are wheels Top-Filte.

I have make the plans with AutoCad.

The engine contains servo (4) and the receiver. The dummy gas tank will contain the battery 4.8V and the dummy radiator will be a 14 Oz gas tank.

Cheers

Jean-Jacques

v6goose

Great stuff.

Cheers

PeterC

I watched the test flight of the full sized replia on TV this last week. It flew great, unlike the Wright replica.
Peter

v6goose

Hi Peter...

Thats right, the replica did fly well. There are a couple of better videos of that flight on that site...

[ul][*] http://www.youtube.com/watch?v=bc-0wR6VpTc[*] http://www.youtube.com/watch?v=eKRaM...eature=related
[/ul]

We completed the ground tests of our model successfully and all were happy with the ground performance. It did highlight a C of G issue with it being too far aft which we corrected for flight tests this last weekend.

Interestingly, we contacted the replica team and confirmed the C of G.

Our flight tests did not go so well despite excellent weather (for winter!).

5 flight attempts, 4 small hops with the last hop destroying the scale nosegear.

It will be repaired and displayed statically this coming weekend for the centenial celebrations and attempt at flight will occur in warmer weather and after wind tunnel testing at the NRC facility.

Thanks for your interest.

Goose

Garthwood

vgoose................very interesting. I like your drawings. I watched the video in the hanger (faint sound) it looked pretty good and was off the ground for a second, very exciting I should say.

Garthwood.

Garthwood

Goose....................here's a couple of pictures of the Silver Dart at the Hamilton War Museum.

Garthwood.

v6goose

Hey cool...

It's interesting to see the variance on the replicas.

Like most scale projects there is conflicting information and add to that three versions of the Dart (in this case) and you have many 'interpretations'.

Thanks for that...

Goose

Garthwood

Looking good mate



Garthwood.