A Build: AD Diamond
 

Hello RCU Folks,

Its been quiet around the Diamond lately. I expected it to be one of the most anticipated airframes of the 2013/14 season, so its a little surprising that the internet isn't full of videos or threads about the plane (at least it is surprising to me). Anways. A friend and I ordered 2 complete airframes directly from Aviation design past fall. The communication with eric has been great. He was very patient with our impatience to say the least. ;) The planes finally arrived in late June.

My buddy had a little head start on his diamond which is basically ready to fly now apart from the paint job, as I was busy with other projects I had to finish first.

The setup:

Behotec E-Tract landing gear
Behotec 180 Gold or evojet 170VX (not sure yet)
Servos JR 8411 & 8811
AD Fuel cells & clear canopy

When we unpacked the kits, we had mixed feelings. On the first look the fiberglass work is top-notch "super light and strong more" :D:D However, some parts suffered due to poor packing. We had some scratches and dents on wings and stabs since those parts laid on top of each other in the box without sufficient bubble-wrap or the like. There are also quite some chippings in the gelcoat, maybe from demoulding? We thought what the heck, since they will be fillered and painted anyways - still not 100% convincing for the first date.

I will document relevant steps of the build mixed with photographs from my buddy's diamond and mine. I can tell you already that mounting the servos and the turbine is a real PITA! Why? I'll tell you soon enough. What really impressed us is the landing gear installation which takes not more than 20 minutes. Of course, only if you use the recomended behotec retracts, which fit perfectly.

http://www.rcuniverse.com/forum/atta...mentid=2016452

Both kits were packed in one huge box. We unpacked them at the TNT depot and left the box there.

http://www.rcuniverse.com/forum/atta...mentid=2016453

Its huge!

http://www.rcuniverse.com/forum/atta...mentid=2016454

All slots for the carbon fiber control horns are precisely pre-cut. You notice the big dent right of the slot.:(

to be continued

/T

We believe the wing tubes were sufficiently designed.

http://www.rcuniverse.com/forum/atta...mentid=2016455

http://www.rcuniverse.com/forum/atta...mentid=2016456

There are pre-drilled holes on the underside of the wing to fix the wings before flight. You still have to drill a threaded hole in the wing tube though.

Very nice project! looking forward to seeing how these turn out :)

Mine is coming first week in August. So it's nice that you started this thread.
Always nice to see what others do.
I will have a Behotec 220 for power.
Do I need to order some servo covers? I see ADjets is selling some nice aluminum ones.

There was one flying at Kentucky Jets with a JetCat 180. Awesome

My Diamond has now 15 flights and I am very happy with it.
Performances are very good with a Jetcat 180RX which I think is more than enough.
Dry weight is 17.6 kg ( I've not installed transparent cockpit, seat and pilot )
I also used the aluminium servo covers not only because they are nice but because with the plastic ones you cannot install servo arms longer then 12mm and that is not enough for the Diamond )

Thank you Alsacian. I guess I will order the aluminum ones.
But where do I use all eight? Would think seven is enough?
Any other things I should know? How long servo arms do I need?
I like to use as short as possible to keep the strength and full travel of the servo. I think it is better to shorten the control horn than to have longer servo arms

Seven is enough but I think AD only sells pairs...
I've built the jet exactly as written in the manual...
On all commands the distance servo axe / clevis axe is 14 mm
I've not modified the control horns

Thanks for your input Alsacian. I kind of agree here. I was reluctant to use the plastic servo covers at first because they didn't look very trustworthy. On the other hand i thought that the manufacturer wouldn't put them in the kit if they were not up to the job, so i decided to use them....

First of all, its not possible to install the servos as per manual with the plastic covers, because as alsacian already pointed out, the control horns won't fit. It is necessary to rotate the servos. Now the linkage is too short for 2 cleviss. If you would shorten the servo arm below 14mm you wont get enough throw.

I really don't understand why the manufacturer doesn't deliver those aluminium covers with the kit and just raises the price accordingly. Its really annoying to do trial and error with supplied accesoires.


http://www.rcuniverse.com/forum/atta...mentid=2017033

For sufficient rudder servo throw it is necessary to mill a small slot in the fin.

http://www.rcuniverse.com/forum/atta...mentid=2017035

Elevator servos finally in place.

I will see how the servo covers work for aileron and flaps and then decide whether to order the aluminium ones. I already imagine that the flaps will be troublesome.

The fuel cells are well made. They come with hardware and tubing, which is nice.

http://www.rcuniverse.com/forum/atta...mentid=2017036

With those two wooden "stoppers" the fuel tanks fit very nice and tight.

http://www.rcuniverse.com/forum/atta...mentid=2017037

One big bummer on both of our diamonds are the canopies. Luckily we are using clear canopies.... Here is why:

http://www.rcuniverse.com/forum/atta...mentid=2017038

There is a good 2 mm gap between fuselage and canopy. Before the frame was milled out, it was even worse. Luckily we had some CARF hooks left which are used to install the Eurosport canopy. Will post pics tonight.

There is a large joint where fueslage parts and duct come together, so we filled and sanded the the area. How does this look on the pre-painted airframes?

http://www.rcuniverse.com/forum/atta...mentid=2017039

Those seams will be invisible later :) Black filler and lesonal platinum will do the job.

/T

We only sell our Diamonds in the USA with ultra high modulus pressure molded carbon fiber servo covers. No plastic covers.

These were CAD designed specifically to fit the Diamond application.

http://www.rcuniverse.com/forum/atta...p;d=1386006733

Here is the aluminium mold:

https://fbcdn-sphotos-d-a.akamaihd.n...98920326_n.jpg

And the part:

https://fbcdn-sphotos-b-a.akamaihd.n...80425403_n.jpg

Fitted:
https://fbcdn-sphotos-h-a.akamaihd.n...34305629_n.jpg

Our building manual include the fitting method for the carbon covers and all the flight control computation files with horn and pushrod geometry.

Note that the sport seat that is offered as an accessory is meant to bolt in between the tanks and blocks them laterally. The cushion part of the sit was CAD dimensioned to fit tightly there.

Hey Oli

no offense, but we bought our Diamonds directly from France and with the price tags involved on that model, I expect the supplied hardware to be compatible with the airframe and its requirements. I think it is worth mentioning this to potential buyers. It is nice from you to step up and improve the kits sold in the US, but for me personally, spending an additional ~ 240 USD plus postage for servo covers which should be high quality by standard for such a model is ridiculous to say the least.

On a sidnenote: The plastic covers won't even support servos such as the S9157 which I intended to use. they are too thick. Why don't follow CARF example? Just use reinforced plywood with a slot and a nice over on top of it?

/T

The servo covers are 30 USD each. There are 7 of them. We offer them at cost price with the kit...

That's not my point. I expect any kit in that price range to be delivered with appropriate hardware, especially for such vital parts like servo mounts. Anyways, I am using the plastic ones. We will see if they'll be up to the job. :)

From a bystander's point of view this is a bit confusing.

The manufacturer provides servo covers with the kit which, as Tuggs says, you expect to be, at the very minimum, up to the job yet a dealer of the product with a very well respected engineering reputation says absolutely do not use them.

If is is proven they are not up to the job, ADJets should replace them/redesign them to Oli's specs. It seems daft that only kits sold in the USA can be relied upon? Or do ADJets disagree with Oli and stand by the covers as being fine? I assume Eric has flown several models with these covers???

As I said, confusing.........

Thanks Mark, I agree it is confusing.

I had a discussion with Eric about it and he confirmed that the plastic covers are up to the job. I trust him with that statement, still that was before our installation attempts in the plane which proved to be very complicated as shown above. Apparently he is offering the aluminium covers just because many customer asked for something "nicer". This is absolutely legit in my opinion. Still, I would rather compensate and sell the higher quality mounts as standard in the kits.

It just doesn't seem right to build a multi-thousand dollar plane with 50 cent plastic cover. I know one would say go and get the better ones, but I won't do that. They came with the kit, I use them. Otherwise it would feel like buying a ferrari and hearing the vendor say, look, you have to buy better tyres, the one on the car won't survive 150mph....

/T

Hi Tuggs

I've a factory painted Diamond white gold

The air intakes came ase shown in the images, also pretty good....

http://www.rcuniverse.com/forum/atta...mentid=2017125http://www.rcuniverse.com/forum/atta...mentid=2017126

and here 2 pictures to show the installation i made for the tanks, UAT, ecu, pump, turbine accu.

All these parts are just Under the cockpit so no maintenance problems and the shortest tubing lenght possible

Receivers, powerbox Royal SRS and Etract electronic are just behind the front gear compartment.

With this configuration I have not any gram lead to balance the model and a final weight of 17600 grs dry (But no pilot, no seat and no clear cockpit)

http://www.rcuniverse.com/forum/atta...mentid=2017133http://www.rcuniverse.com/forum/atta...mentid=2017134

Nice install Alsacian.

Good to know that you didn't need any lead in the nose. I think we will end up a little bit heavier with our complex paint jobs.

I did not need any lead in the nose neither with the B220 in the tail. However in that case, the airtrap, ECU, pump and all engine accessories are in front of the cockpit.

Yes i saw that in your thread oli. I think I am going to place my turbine equipment in the same place as you. I am quite sure to use a 180' behotec. Initially i thought i might come out lighter with an evojet 170 though.

I will have the B220 turbine and the large (260ml) CAT air trap,lifepo4 and A-123 batt for all functions: 2×2cell for radio And 2× 3cell for turbine and 1×3cell for gear. So I Will Place it wherever it balances the plane. And I will have the Booma rc intelliswitch version 2 ULTRA for radio and the Booma rc ECU Master switch ULTRA for turbine. Simple and clean install. Servos will be Hitec 7955 TG all around.
I have ordered mine in racing scheme with special color: Electric Orange Pearl. The color from Ford focus ST. Think this will be nice.