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.

I still like the jet. It reminds me of a spaceship. I would like to have one some day.

First off, let me say that the Diamond is a fantastic model! I love it! It flys amazing!! Eric did a fantastic job on this model!

The very first thing I encountered were the cheap plastic servo frames. One broke in my hand. Do not use these! place them in the appropriate land fill!
I made my own carbon servo frames before Oly came out with his, but I would have bought his if they were available.

8711 wont fit in them either. chunk them. Im sure Eric could provide them in the kit and raise kit price $210. Just pretend like he did, pay the extra money and get them from Oly.

FYI, the diamond will glide forever without flaps!! I had a flameout at takeoff and made it all the way back around and landed safely the opposing direction.
Scott

I got some more work done on my diamond past weekend. Just some final words on the plastic servo mounts: If you want to use them and plan to install servos like he JRDS8811 or Futaba 9156 / 9157 you have to work on the servos to make them fit. It is necessary to narrow the servos by cutting down the brackets. It does really hurt to do that to a new servo and i still believe that it is just wrong to supply such crap in a high quality kit. Doesn't change my attitude towards using them in the plane. May sound stubborn, i know.

Used BVM vpoxy to glue the control horns in place. They do fit really nice. The fuel tank plumbing is also done. I 3D printed a rack to support the futaba 6014 receiver with a cortex on top.

http://www.rcuniverse.com/forum/atta...mentid=2017931

As you can see. Servo won't fit by design.

http://www.rcuniverse.com/forum/atta...mentid=2017932

Installing the retracts is a joy. They fit very nice and everything left to do is the wiring.

http://www.rcuniverse.com/forum/atta...mentid=2017933

This is how i am going to install receiver and power supply. Turbine equipment in front of the fuel tanks. The 3D printed rack will support the cortex gyro. Sometimes i switch receiver / gyro combos between planes and with the rack its real easy to do.

oh man, Tuggs!! You did that to brand new servos to fit a plastic servo frame :eek: :(

I did break my heart, indeed. :mad:

Maybe I will regret it one day, but at least future diamond buyers are aware of these little problems. Don't get me wrong. I love the plane, but this is just one thing that doesn't feel right about it.

My Diamond will be shipped on Friday. Ordered the aluminum servo covers on Saturday and got message
today that they will be in the box :-) I really don't understand why you choose to use these plastic ones. I would
never feel good flying my Diamond with the plastic covers.
I think Aviation Design should do something about this!
From what I understand I will receive 8 aluminum covers but only need 7!? Because they are sold as pairs. I can only hope that they come as 4 left and 4 right.
Looking so forward to receive this amazing modell.

OMG! that's not a good idea!!

I also don't like your flap setup!! clevis on a bent all thread with a plastic servo arm? That's a huge flap that need tons of throw! lots of stress on that
Scott

Scott,

Yeah, the servo arm won't stay like that... I didn't receive the aluminium arms I ordered in the right size yet. I wasn't really worried about the clevis and the threaded rod, but now that you mention it. The thing is I want the rod to be vertial to the arm in flaps up position to have zero slop in the flap. I only get enough throw on the flap like that without having to mill a slot in the wing for the pushrod - I hope its clear what I mean

/T

I'm with Scott on that linkage, threaded rod is so brittle too, one slight bend and its on its way.

Never seen the Diamond close enough to understand the servo issues but Oli is the master when it comes to linkage calculations and design, a shame the 'standard' hardware is not quite up with the rest of the kit which looks to be superb.

For those who have not come across these guys yet - some well designed and fantastic clevis/horn products for all rc planes, Y ended servo arms so the ball clevis is not subject to a twisting loading, they also do a matching horn range to match up (only issue is the site is in German only!)

http://www.gabriel-stahlformenbau.de...rvohebel-25-55

marcs

Marc: Have you tried the Y- ended servo arms? They look solid.
From what I understand it is a mix of nylon and 43% carbon in them.
And they have them in 14mm length as the Diamond need. They also have suitable ball links for 3mm rod. The only thing missing is double control horns on the Diamond.

Christian they do a range of horns too in the double range with a ball link pre-fitted (you can change them over)......

http://www.gabriel-stahlformenbau.de...l?dataoffset=0

I have used them on my Orion, found them superb, easy to fit, strong and well designed. The process is as I understand a carbon reinforced plastic which is pressure and heat set to give a very strong product. The horns are easy to mount as they have pins so a hole is required which is easier to do than a neat slot IMO.

Here's my Orion......

http://www.rcuniverse.com/forum/atta...mentid=2018202

Build thread link, see #34 for horn and linkage pics detail...

http://www.rcuniverse.com/forum/rc-j...-thread-2.html

marcs

Just a quick update. I wrote an email to Eric yesterday explaining the situation and my thought about the mounts again, now that I started building the Diamond. He agreed and will consider to ship the aluminium mounts in future diamond kits. I think its great when manufactuers listen and adapt to customer feedback. Thumbs up for Eric and Aviation Design. :rolleyes:

http://www.rcuniverse.com/forum/atta...mentid=2018312

Marc: I think I will use these on the control horns
A 3mm threaded rod with a carbon tube outside.

They are quiet bulky and the clips are not handed so one ends up the other way round which can make removal a PITA - I know as have them on a 2.5M Extra....

marcs

See what you mean, but if you insert clips from right side or left side it will change from up to down. I have used them before and liked them a lot.
nice and tight, no travel. I have had some similar with separate pin and E-clips.
Think I order all three kinds and see what I like best.
Thanks for input.