The 43% Carden was build by Trevor Poots and is being flown by many times UK Imac Champ, Matthew Poots, the other 35% Carden was built by Kees Blokland, just because he likes to build nice perfect flying planes.
Matthew has clocked up a few more wins, Kees only got the plane flying last year due to the fact that he moved countries once again.
The server crashed a few weeks ago, some parts are still in the dustbin, once everything settles down a bit I’ll clean things up around here. Since this is not a high traffic site, I’m also trying out bit and pieces here .
note to self: not all the posts appear to be in the correct order?
Just before covering began, my dad added the control horn for the ailerons (and elevator), this is the same method he has used on all our larger models and it has worked flawlessly.
A neat slot Is removed from the aileron leading edge extending into the foam. This matches a plywood plate to which the control horn is attached, the control horn itself is a 5mm stainless steel countersunk bolt available from www.Modelfixings.co.uk, a plywood plate is cut to about an inch square and the bolt is threaded into the wood and a
countersunk hole drilled to recess the head. The plywood is then 30min epoxied into the slot cut in the aileron, being careful that it sits at the correct angle. After the epoxy had set two 6mm dowels are drilled and epoxied into the ply plate and on into the foam at an angle to ensure the ply plate can’t pull out, in fact the dowel touches the other side of the skin so the dowels also transfers load to it, distributing it more evenly. After the epoxy sets all is sanded down nice and smooth and it’s ready to cover! Once you cover the control surface you then place a nylock nut onto the bolt to prevent flex in the bolt at the ply plate.
As previously mentioned the baffling on the DA200 is critical. The theory worked out and prefected over 8years of development by Desert Aircraft Engineers is to place a plate on the same plane as the C/L of the engine. You then block of the cowl intake below this plate, so the air, only enters the cowl above this plate, the plate is cut to be as close to the engine all round as possible, a gap of 1/8th all round, means that the air comes in and can’t go anywhere but be forced onto the heads and down the channels between the fins and then straight out the bottom of the cowl, a simple concept that works so well.
The baffle plate was a real tricky and fiddly job to fit, ply supports were goop glued onto the cowl, then a fitted light ply plate fixed through the supports with the use of a few captive nuts and bolts. You will see this from the pictures. It will be covered in some Monokote to reflect the heat and remove the need to fuel proof it.
After all that weight saving ( I wish I could lose a few lb’s!) it’s back to the Airframe.
Some pictures here of the fuselage in a finished state. At the point these pics were taken, the Canopy hadn’t been glued in place, it now is, the cowl was only placed in this picture for scale, it is now fitted and ready to be painted. More pics of the Hatch/Canopy and Cowl will follow.
The pilot is a foam helmet head from Aircraft International, very light and looks well. You might have saw some people on other Carden Builds have cut the sheeting on the Fuse rear and Rudder in a triangulation form, we decided not to do this on this Extra (we did it on our previous model) the reason was that with the DA200 in the front, you don’t really want to take weight out of the rear of the fuselage, a bit pointless taking out structure to possibly add lead at a later date. The other reason is that the weight saving would be in the region of 2oz, every oz does count but it will make the covering nicer and make the airframe quieter as there is less of a drum effect.
The DA engineers are always working on perfection, after over 8years of development the DA200 hit the market. A true masterpiece and simply the best IMAC Engine available for your 41-45% model. Over many years of testing DA knew that it was possible to machine the standard DA50 head down slightly, multiply that by 4 creates a significant saving in weight which for us an option that we wanted to take up. We wanted to counteract the 1.5lb increase in weight in our choice to use a Cansiter Exhaust Setup over the more common Stock Mufflers, so with the option to save over a pound on the nose we went for it. DA also do a magnesium Case for the 200, which saves a further pound, but this is a lot of coin!
As you can see from the pictures, a weight saving in total terms of 1lb 0.6oz or 471g.
Some of you might be thinking but where’s the catch, what about cooling? Well this is always a concern, but after DA’s research over many years, the baffling system that has been developed is hugely efficient and the DA200’s actually run cooler than 150’s or 170’s even with the heads machined down. For many years, Chip Hyde, Mark Leseberg & Frazer Briggs have been testing/using prototype DA200 with the heads turned down.
A massive thanks to Dave and his Team for all they do for my Dad and I and they turned this round for us really quick as always.
We picked a different brand to Dubro for our latest model, Air Manufacturing Wheels the reason, lighter, stronger and better looking! They come with a Dubro tread, so it’s the best of both worlds.
The saving in weight over a Dubro Wheel is 7oz over a pair (198g)!! Yikes!!
A big thanks to Rex the owner of AMW for his superb service.
You can see what I wrote on my own website click here
Here is the text,
These Beautifully Engineering Wheels are going to find their home on our new 43% Carden Extra 300. They are engineering is the USA by Air Manufacturing and are a very high quality and lightweight option for your large model!
My dad was on the search for a lighter option to the Dubro Wheels we have used on all our previous large models, after a quick search on Flying Giants he came across an article by TOC Pilot Bill Hempel, he had a similar theory to ours and wanted to save some weight. The wheels in question are manufactured by Air Manufacturing and are CNC machined by a RC Modeler called Rex Chapman. After some research and a good look at them on the net, we decided to go for them. My Dad called Rex who was very helpful and after a good conversation we had two 4 3/4″ Polished Wheels on the way, within two days they had arrived at our door, now that’s service that you can’t even expect from many of our UK shops.
On arrival it was clear to see these wheels are a true work of art, CNC Machined hand polished Aluminium rims with a Dubro tread, so we still have the high quality tread that we know works and wears well. The rim has a roller bearing which houses the pre-installed axle, the wheel spins on the axle so so smoothly, they are simply quality! The major bonus of these wheels are the weight savings, the Dubro Tire and Axle, weighs in the region of 9oz (thats per tire), the Airman wheels are 5.5oz including the Axles per tire, so a saving of 3.5oz per wheels, 7 oz in total, so nearly 1/2 pound, that I can tell you is a lot!!
We will get a few shots of the wheels on the plane in a few weeks when we have the model finished, but I for one will be buying more of these wheels as saving 7oz for no building effort or effect on the airframe is a huge incentive.
On the same theme as the undercarriage, hardware of all types carries some weight and it is interesting to see what you can save in weight when you look whats on the market.
We purchased a 64oz in capicity tank as many of the Carden Builders State side are using with the thirstier DA200, not really thinking about it at the time, we received it and thought that’s a bit “chunky”. After some searching and research we found an alterative.
Below are some pictures to show the saving, the two tanks are the same capacity 64oz (1.89l) and are minus the fittings, which we can’t really change.
Again you can see this a notable weight saving just under 6oz (170g). The tanks are a different shape but the same capacity. They also have similar screw sealed end.
Firstly may I aplogise it’s been over a month since my last update, things have just gotten away from me and it seems like I’m always doing something else.
Well the build has been progressing if the blog has not and it has been a hectic month with all the final bits and bobs arriving and the last of the building work is all but done. The airframe will be ready to cover in a matter of hours.
As you all know weight is the killer of any airplane, from a small foamy right up to our 43% Extra. You can be as careful and detailed in the construction of airframe, making it as light as possible and then you come to all the bits on you have no control off, such as engine, undercarriage etc etc, when you begin to add them up you soon realise that the airframe itself is a very small part of the overall weight of your plane and this is why it’s important to look at the whole package.
One area of hardware many of our fellow Carden builders on the Flying Giants Build forums, have saved some weight is on the UC. Carden supply an aluminium undercarriage which is very strong and for 99% of modellers would be fine, but for the mad hardcore competition folk it can be lighter. You have two options, purchase a lightened Aluminium UC which is machined down and this saves some 6oz, the other option is a Carbon Fibre UC from Graphtech which saves 14oz, that’s nearly a pound!!
You can see this in the pictures below and the choice we made.
You can see from the pictures that this is a large saving! And worth it in my opinion!