Skip navigation

Helicopter Build - Minicopter Diabolo 700

Post

Helicopter Build - Minicopter Diabolo 700

Helicopter Build - Minicopter Diabolo 700

Alright, ready the the skids. Things are starting to move quickly, but again there is so many things to do still! OMG, why do I do this to myself!!! Skids - In the picture you can see the carbon fiber landing gear, and skid tubes. These parts I bought as an upgrade from the aluminum parts that came in the kit stock. I chose these because if you know aluminum only bends once, and then they break. Landing gear takes some punishment so I think this will be a wise investment. There is a vendor in the US that stocks parts for this but in the event that I have to order straight from Germany these might hold up better to avoid an order. If anything I will have the original skids as replacement for later. I can't say that I've seen carbon fiber tubes this big and with a curved end like this before, and I'm very impressed. I installed blue tape where the end of the tube needs to be to the first mounting strap so each side is even. This was a lot easier than measuring , and adjusting and remeasuring again… and again. These is a metal strap that goes around the tube and a single fastener that attaches them to the landing gear strut. Then the you may notice that there is a front and read strut too. the front strut is a lot shorter than the rear to get a nice rake to keep the tail rotor up high out of harms way. Then the tail fin was mounted only to help keep the heli upright to work on it further. Cyclic servo installation - Here you can see the the swash plate, anti rotation guide, servo links, servo spacers, and yes more fasteners. I installed the front aileron servos first and got the SAB servo horns installed. For sure not all servo horns are created equal especially for helicopters. These will be strong for flight but will break during flight to save very expensive servo gears in a crash. Then I set the kit supplies swash leveler to set zero degree pitch under the swash. This tool makes things easy to setup later with the flybarless controller. Its important to keep the arm at 90 degrees at zero pitch to keep the geometry even as it goes through positive, zero, and negative pitch. I'll cover more of the technical setup when I start programming, and setup later on. The link from the servo to the tail were made up so the servo is at 90 degrees, and the swash is setting on the leveler. I just got it close to make it easier on myself later. Then matched the length on the other 2 links to each cyclic servo. Again, I'll go through the theory of how helicopters work later when setting up, and things will get a more interesting. For now we will just get the mechanics built. Lastly, you can see the anti rotation guide for the swash. Its starting to look like something now, and it makes me want to tread further. I know that better and have to stop for the day. It doesn't look like it but this took a major portion of the day when I should have been doing other things. With summer almost half gone I really want to get this thing in the air especially with work being more demanding through the summer months. So the dumby that I am, I tread forward a little more! [br][br][br][br][br][br][br][br][br][br][br][br][br][br]
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Last post for the night! I went forward to head, and I ran into a few issues that I'll take care of later after some more research. The head ended up really soft and I might have to take it back apart to stiffen it up a little to avoid a boom strike under heavy load. There is Dampening in the head to allow the main blades flap, or in other words suspension like in a car in sorts. When the suspension gets too loose the blades can lean a little low on the back elevator and actually hit the tail boom. At lower head speeds a loose dampening is need to allow flapping, but too much can end in a horrific fashion. I look into it later. Main Rotor - In the picture you see the parts for head. There is an illustration showing how all of it goes together and it looks like a lot but really isn't. The first thing to be installed are 2 O rings that actually do the dampening followed by a rigid stiff plastic insert. There is a shaft that goes through this that attaches the blade grips and this allows movement(flapping). Next is a thin spacer, to a normal bearing, to the attachment piece for the blade grip, to the thrust bearing to allow outward force, to another spacer, to another normal bearing, and to two washers for the bolt to hold everything together. This is where my problem lies. I need to add more spacers into this packing to squeeze the O ring a little more to make the head stiffer. I'll add more when setup starts after some reading up on the forums. You can see in the picture how it looks like in person. The blade grip will then slide over all of this and bolt into the black aluminum pieces you see in the stack. This is very unusual, and I'm not sure why they did it this way. Usually you assemble the stack inside the blade grip itself and the end bolt holds everything on… Now with the blade grip on you notice the screws going through the grip and into that stack inside. Leave it to the Germans to make something more complicated that needs to be. So now that the head is assembled its time to put the rest of head together. I made up the links from the swash to the spec'd length, but they are always only close. This will be fine tuned later in the head setup portion of the build. The installed the swash driver into place which are the little arms that attach to the swash. All these parts are vital to making a helicopter fly and I'm currently looking for an illustration to easily explain how this all works without trying to explain it in text. So I seriously wondering why I enslaved myself to do this build about now. This is a lot of work to do, and then type it, and keep track of pictures to post about. Its really an eye opener for me for how long of road its been getting into this hobby. I've been pretty much on my own to figure all of this out, but worth every moment. I'm going to try to get the mechanics on this mostly done this weekend, and to have more time in the coming weeks to work on the wiring, and setup. Enjoy Anthony [br][br][br][br][br][br][br][br]
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Something to lighten to mood during a long build. Here is a video of Tareq Alsaadi which is one crazy pilot from dubai. https://www.youtube.com/watch?v=7TIWaZExGeI
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

I'm back for the last time for awhile. I covered the tail blade assembly, and canopy installation in this post. In the picture you can see all the parts to the tail rotor. Everything went well expect one item. One tail blade grip was slightly warped and enough where it wouldn't go on. It was easily filed, and a final buffing with a dremel to get it to go on smoothly. After this everything went well. I didn't take a picture of the bearing stack since it looked almost exact as the main rotor's. In the last picture of the tail you can see the blades on and how big the rotor actually is. Turned out the tail disk size is over 12" diameter. Next items I got done was the tail linkage guild, and boom struts. You can see them in the picture with the canopy on. Lastly, I got the canopy mounted which only consisted of mounting 2 front brackets, and inserting the back 2 grommets. Pretty easy stuff. I only have a few things to do to the air frame to complete that I probably won't bothering covering the build thread since its been pretty lengthy already. So as the thread is considered the airframe is complete. The next thing I'm going to do is go back and hit points that are a problem like the dampening of the head, and a few other little things. Then the wiring will begin As a refresher, the electronics can be quite a bit of work to get everything ran. I'm going to be running a 2s 2250 mah rx pack to run all the servos like my other helicopters so all the harnesses will have to be made to fit. As soon as the wiring is done the programming can be started. This is the part that I hate the most of a build so this is going to take me some time to finish. Enjoy Anthony [br][br][br][br][br][br][br][br][br][br][br][br][br][br]
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

That Dubai pilot is incredible. Dunno about flying next to a road, but holy cow he's amazing. I need to know how in the heck a heli can sustain flight on knife edge or nose up or down. Also, can you explain the head speed thing.
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

I agree he is a very talented man. He usually flies at night because of the heat of the day in Dubai is way too hot. I think that video was a 2:00 am, but it doesn't make it any safer flying next to a road. The main thing to under stand about a helicopter is how the main rotor works. These are all collective pitch controlled by a swash plate. With the swash plate level and center you have zero pitch on both blades. If the swash goes up level you get positive pitch (up), and if it goes down level you get negative pitch(down). Then if the swash tilts forward, back, left, or right the heli rolls in that direction. Also you can give both pitch (+/-) and aileron/elevator together. Headspeed is the speed of the rotor spins at a constant rate while the amount of pitch that you give the blades is variable with the swash. Thats how you can control the heli which is important to to understand how they can do crazy things. A sustained knife edge is can be achieved a few ways that Tareq demonstrates in the video. The first one is by what is called a tic toc that can be done on aileron, or elevator. Only way I can easily explain it is its similar to tossing a ball between your hands. You toss the ball from hand to hand, but instead of your hand stopping the ball, the pitch control is stopping the model. Also ail/elevator creates the arc of the ball's path. If you do it fast enough it looks like its sustaining a knife edge. The other one Tareq does in the video is really no different than a banked turn, but he can do it every quickly. Same concept as the Tic Toc. It looks like he is flying all over the place on his side but using momentum to keep him in the air bouncing back and forth just like the ball toss between hands. Headspeed is another hard one to put into words. A ceiling fan is a good example maybe. On low (low headspeed) not much air is moved for lift. So the helicopter with low lift will not move around that quickly, or with much power. Now with a ceiling fan on high and lot more air movement is made. So more air movement or lift is created so the helicopter would be fast & powerful. You use pitch to control the model, and the throttle is preset.
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

I think I get the headspeed thing now. That's why when Tareq got really wild, he'd stepped up the headspeed. I'm getting more impressed with what it takes to be really proficient with a heli.

Thermals---I need thermals!
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Yes, they take way too much time, effort, and talent. All of which I don't have ! haha Well, the build hasn't really moved since last weekend, and I'm not looking forward wiring this thing. I am looking forward to flying it though. So I think I've found a permanent motor for it though. Not new but a dang new Kontronik Pyro 750-56 for a reasonable price especially being a $600.00 motor(not paying that of course). One step closer!
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Ok, so I received the Kontronik Pyro 750-56 motor today. The motor looks amazing and you can tell its built with high standards. This motor is a top choice for a number of reasons for the Diabolo. One is that the efficiency of this motor can be over 90% that equates to low temperatures especially with a full enclosed canopy(Only 13mΩ of internal resistance). Another is its low weight compared to its output power. Advertised continuous power is rated at 4.5 Kw, but I bet that is underrated. It also has a single stand winding that helps in every aspect of its performance. All in all I don't think there is a motor out there that can compare for its low weight, efficiency, power to weight, and still be able to be ran off of a 120 amp esc. I decided to scratch the castle creations 160 amps esc, and put a YGE 120 (with a heat sink) in its place. It would be a shame to run a castle on this motor. The only thing to see is how the YGE 120 handles the minimal air flow, but hopefully the high efficiency motor will help to keep heat down. If not (see 3rd picture) and heatsink and esc fan might be in order also. Lastly if anyone is interested in the actual specs of the motor. Its stator size is 4425 which isn't huge (44mm x 25mm) but is helped out by the single strand winding. It weighs 15.8 oz vs. the 18 oz of the Align 800mx motor that I was going to use. Then its a 560 kv motor vs. the 520 kv of the 800mx so the gearing for my target headspeed is off with the pinion gear that I have. So I had a 20 tooth but I ordered a 17, and 18 tooth. That way I could gear it down and have some play room for a governor. So my final electronics for the maiden are chosen now, and this coming weekend I can begin wiring. Kontronik Pyro 750-56 motor Yge 120 (heatsink version) esc Jr cyclic Servos Futaba 256hv Tail Ikon/Brain Flybarless Controller Can wait to get this thing in the air! Anthony[br][br][br][br][br][br]
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

That's a honking big motor. I can't believe that they get that kind of money for an electric motor. Yikes. This is going to be an interesting flying machine. Impressive stuff.
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Thank you Merlin. The motor is actually mid sized, but still a larger sized. I haven't had time to take the build much further, but maybe this weekend this will progress closer to a flying machine.
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

What is the actual rotor diameter for the 700? On the minicopter website I don't see the 700 listed.

Thermals---I need thermals!
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

The site has it from 1.56m to 1.68m, or 61 to 66 inches. It can handle up to 750mm main blades. I'll be running 710 mm mains.
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Oh so 710 is the length of one rotor blade, not half the total diameter of the rotor disk?

Thermals---I need thermals!
Back to the top

Post

Helicopter Build - Minicopter Diabolo 700

Interesting way of measurement. It seems the rotor head diameter is included in total disk span.

Onward and Upward.
Back to the top
1 guest and 0 members have just viewed this.