By Terry Dunnon March 23, 2015 at 1 a.m.Building an FPV Racing Quadcopter, Part 1

Racing quadrotors have captured the interest of a lot of people. They’re fast, nimble, and tough. Best of all, having a First Person View (FPV) system installed lets you get a sense of what it’s like to be onboard your speed machine. In the past, we’ve presented a video of Norm building a racing quad with the help of Carlos Puertolas (Charpu). We’ve also given you a buyer’s guide that outlined all the equipment you need for your own racing quad. This week, I’ve prepared a four-part series that will cover each aspect of getting a racing quad built and flight-tested:

Part 1: Frame AssemblyPart 2: Flight Controller SetupPart 3: Configuring the FPV SystemPart 4: Flight Testing and Tuning

A friendly reminder: if you are new to multi-rotors, racing quads are a horrible place to start. Get yourself something a little more sedate to help you learn the basics. Once you’ve honed your flying skills, racing quads are much more practical and enjoyable.

Frame Assembly

The quad that I’ll be building for this series is a Strider Mini Quad provided by Red Rotor RC. The Strider is a 250mm-class ship with a carbon fiber frame. There are a few features on the Strider that negate purchasing some of the common components found on racing quads. The Power Distribution Board (PDB), lost-model alarm, and On-Screen Display (OSD) are all integrated into the frame itself. This saves you the cost of buying those components separately, as well as the hassle of installing them.

THE STRIDER FROM RED ROTOR RC IS A 250MM RACING QUAD WITH A CARBON FIBER FRAME. AS YOU CAN SEE, THERE AREN’T MANY PARTS. THE INCLUDED HARDWARE HAS BEEN SORTED IN AN ICE TRAY FOR EASY IDENTIFICATION.

Red Rotor provides an online assembly manual, so make sure you are using the latest version. In addition to what’s provided in the kit, you will need a few basic tools and supplies: metric Allen wrenches, zip ties, heatshrink tubing, soldering iron, etc…pretty basic stuff. To prepare for the build, I sorted all of the included hardware in a plastic ice tray. There are four different length screws in the kit and this helped me keep them all distinct.

The first few steps of assembly are very straightforward. They involve fastening the bottom plate of the frame to the center plate. They’re simple assembly tasks with nuts, bolts and spacers. All of the parts lined up perfectly, so things progressed quickly.

A WELCOME FEATURE OF THE STRIDER IS THAT IT HAS SEVERAL ELECTRONIC COMPONENTS INTEGRATED INTO THE FRAME, SO THEY DO NOT HAVE TO BE PURCHASED AND INSTALLED SEPARATELY.

Before mounting the arms to the quad you’ll have to decide whether you will use 5”-diameter props or 6”. This really boils down to the motors you’ve chosen. Each arm has two mounting options to accommodate the appropriate prop. If you are unsure, which prop you’ll be using, just use the 6” locations to mount the arms. You can always move them later. Note that the motor mounting holes on the arms are not symmetrical. You’ll have to pay attention to this to ensure that the wires from the motor are aligned with the arm.

THE STRIDER’S ARMS CAN BE INSTALLED IN EITHER OF TWO CONFIGURATIONS. HERE, THEY ARE INSTALLED IN THE INNERMOST POSITION TO ACCOMMODATE 5” PROPELLERS.

I knew that I would start out using 5” props, so I mounted my arms in the innermost location. It is worth noting that the arms can also be folded to reduce the Strider’s footprint for transport. You just have to loosen two screws for each arm to release them for folding. The same folding action can help absorb energy in a crash to prevent damage to the frame.

Motors

The motors, I chose for this quad are SunnySky 2204 2300kV brushless units from Buddy RC. You may notice that you can buy a “CCW” version of the same motor. The only difference is that the CCW version has reverse threads on the prop shaft. The CCW motor is actually meant to rotate clockwise (as viewed from above). This helps to prevent the aerodynamic drag of the prop from loosening the nut that holds it on. Since you’ll have two motors turning clockwise and two counter-clockwise, you can buy two of each motor type. I just bought four of the standard type, thinking that I’d have to be an idiot to fly with loose prop nuts. Well, it turns out I’m an idiot, but I digress -- more on that when I cover flight testing.

I USED SUNNY SKY 2204 2300KV MOTORS IN THE STRIDER. THE ‘CCW” VERSIONS OF THIS MOTOR HAVE REVERSE THREADS ON THE PROP SHAFT TO HELP PREVENT CLOCKWISE ROTATING PROPS FROM COMING LOOSE. IT’S HANDY, BUT NOT A NECESSITY.

The bolt pattern on the motors fit the holes in the quad arms perfectly. I used the screws included with the motors to mount them to the arms. A drop of blue Loctite thread-locker on every motor screw helps to ensure that none of them vibrate loose.

Electronic Speed Controls

At the same time that I purchased the motors, I also picked up four Velotech Magic 12-amp Electronic Speed Controls (ESCs). The ESCs are available with or without a Battery Eliminator Circuit (BEC). The BEC allows the flight battery to also power the receiver and flight controller (and the servos if any were present). You only need one ESC to BEC. In fact, sometimes having multiple BECs in parallel causes problems. The simplest path is to buy one ESC with BEC and 3 without. Just make sure that they are all the same base ESC.

ON THREE OF THE ESCS, I DISABLED THE BEC CIRCUIT BY REMOVING THE RED WIRE FROM THE RECEIVER PLUG AND INSULATING IT WITH HEATSHRINK TUBING.

All four of my Magic ESCs have BEC, so I disabled it on three of the units. This is easily done by removing the red wire from the ESC’s receiver plug. I used heatshrink tubing to insulate the removed pin on each of the three affected ESCs.

AS SMALL AS THE VELOTECH MAGIC ESCS ARE, THEY WERE STILL A TIGHT FIT IN THE STRIDER.

The Velotech ESCs were a little longer than the units shown in the Strider manual, so they were a pretty tight fit in the indicated locations. I was able to squeeze them into place and secure them with zip ties.

The PDB is integrated into the center plate of the quad. There are solder pads on the top and bottom side of the plate for attaching the power leads of each ESC as well as a pigtail for connection to the flight battery. I decided to place all of the solder connections on the top side of the plate. Knowing that space would be at a premium in this area, I carefully routed each power lead from the ESCs to the intended solder location and cut them to the precise lengths needed.

TAKE YOUR TIME WHEN SOLDERING THE POWER LEADS TO THE PDB. IT DOESN’T HAVE TO BE PRETTY, BUT YOUR JOINTS MUST BE CLEAN AND SOLID.

If you are new to soldering, you may find this job difficult. There are a lot of different wires to manage and a few physical obstacles are in the way. These joints are critical, so it is important to do a good job (no cold joints). Also, since the carbon fiber frame is electrically conductive, you have to make sure that your work is clean with no solder bridges to the chassis. Ask for help if necessary and make sure you get it right. For what it’s worth, I used a 25-watt iron with a wedge tip.

I SHORTENED THE MOTOR LEADS FROM THE ESCS BEFORE SOLDERING, BUT LEFT ENOUGH SLACK TO BE ABLE TO MOVE THE FRAME ARMS TO THEIR OUTER POSITIONS.

You’ll also have to solder the motor leads from the ESCs to the motors. Again, I trimmed the ESC wires so that they could be routed cleanly to the motors. In this case, I cut the wires a little long in case I ever extend the arms to the 6”-prop positions. It’s always better to shorten the ESC wires rather than the motor wires. The motors are wound with magnet wire that has a non-conductive coating on it. If you cut the wires, you have to scrape off this coating before the wire will take solder. It’s a pain.

ONCE THE ESCS ARE IN PLACE, THERE ARE A LOT OF WIRES TO BE DEALT WITH. THEY ALL HAVE A PURPOSE AND A PLACE TO BE.

For each motor, I soldered the three wires but did not insulate them initially. I checked to make sure that each motor rotated in the correct direction first. You could do this by sequentially attaching each ESC to the throttle channel of your radio, but I think it’s easier to use a servo tester. If a motor spun in the wrong direction, I swapped two of the motor leads (any two will do). Once I had the motors spinning correctly, I insulated the solder joints with heatshrink tubing.

Radio Receiver/Transmitter

It takes a 4-channel radio to fly the Strider, but you’ll be better off with at least 6 channels. Those extra two channels allow you to select different flight modes (they define how the quad reacts to control inputs), and also control lights and the alarm.

The example in the directions shows installation of a FrSky Taranis radio system. A lot of flyers like the Taranis for racing quads because it enables a simple 3-wire (CPPM) connection to the flight controller and some receivers feature a built-in RSSI (Received Signal Strength Indication) output. With RSSI, you can overlay a graphic strength indicator on your video screen that tells you if your radio signal is getting weak. That’s handy data for long-distance flyers.

I decided to use my Futaba 7C radio for the Strider. I have nothing against the Taranis, but I’ve used the 7C for years and it’s never given me an ounce of trouble. There’s a lot to be said for confidence in your gear. The tradeoff is that my Futaba R617FS receiver requires a few more wires to connect it to the flight controller, which is mostly a matter of space. While the R617FS does not have RSSI output, it can be added with a relatively simple modification. Since I don’t plan to do any long-distance flights with the Strider, I’m not sure that I’ll ever bother.

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The path I’ve chosen requires more wires than other methods. I could reduce wires by using a CPPM receiver and/or trimming the receiver leads from the ESCs. Not only could I have shortened the leads, but I could have completely removed the positive and negative wires from the three ESCs with disabled BECs. Even with all of this extraneous wire, I still did not have any trouble fitting it all within the confines of the frame. In that regard, I think that my build is a worst-case example wiring-wise and it all panned out without any difficulty.

Before mounting the receiver to the frame, I decided to install and configure the flight controller, an Open Pilot CC3D . The Strider frame has nylon studs which are spaced perfectly to hold the CC3D. There is a printed indicator on the flight controller showing which side should face the front of the quad, but this configuration obscured the mini-USB port on the board. So I turned the CC3D 90-degrees and made an adjustment during setup of the board’s firmware to compensate. More about that is coming soon.

Although, there is a slight bit more to complete on the frame, it happens just before flying. So this is a good stopping point. In Part Two, I will cover wiring and configuration of the CC3D flight controller.

Terry spent 15 years as an engineer at the Johnson Space Center. He is now a freelance writer living in Lubbock, Texas. Follow Terry on Twitter: @weirdflight

製作FPV競速四旋翼直升機

building特裏Pd降低一個FPV賽車直升機，1
賽車quadrotors已經俘獲了很多人的興趣。它們是快速、靈活和堅韌的。最重要的是，有一個第一人稱視角（FPV）係統的安裝可以讓你得到的感覺就像是在你的機器的速度。在過去，我們已經提出了一種視頻規範建立一個賽車四與卡洛斯puertolas幫助（charpu）。我們也給了你一個買家的指南，概述了所有你需要為你自己的賽車。這個星期，我準備了一四部分的係列，將得到一個賽車四建造和飛行測試的各個方麵：< / P > 1部分：框架assemblypart 2：飛行控製器setuppart 3：配置FPV係統4：飛行測試和tuning
一個友好的提醒：如果你是新的多轉子比賽開始，四周是一個可怕的地方。給自己一點幫助你學習基礎知識更穩重。一旦你磨練你的飛行技巧，賽車的四周是更實際、更愉快。

框架組件
四，我會為這個係列的建築是由紅色轉子RC提供黽迷你四。黽是一個碳纖維車架250mm的班船。有幾個特點在黽否定購買一些常見的成分在賽車四周發現。配電闆（PDB），失去了模型的報警和屏幕顯示（OSD）都集成到框架本身。這節省了你購買這些組件分開的成本，以及安裝的麻煩。

the黽由紅轉RC是250mm賽車四個碳纖維框架。正如你所看到的，冇有多少零件。在一個冰盤上已經有了一個很容易辨認的硬件。除了什麼試劑盒提供的，你需要一些基本的工具和用品：度量艾倫扳手，拉鏈領帶，heatshrink油管，烙鐵，等很基本的東西。為了準備建造，我把所有的包括在一個塑料托盤中的硬件進行排序。工具箱裏有四個不同長度的螺絲釘，這幫我把它們放在不同的情況。它們涉及到中心闆的底部闆的緊固。他們是簡單的裝配任務，螺母，螺栓和墊片。所有的零件排列完美，所以事情進展很快。

a歡迎的特徵是它的黽若幹電子元件集成到框架中，這樣就不需要購買和安裝分開。
在安裝武器的四你必須決定是否將使用5“直徑的道具或6”。這真的歸結為你選擇的馬達。每個手臂有2個安裝選項，以適應適當的支柱。如果你不確定，你將使用哪一個道具，隻要用6個“地點”來安裝武器。你可以隨時移動他們。註意手臂上的電機安裝孔不是對稱的。你得註意這個保證電機的電線與手臂對齊。

the黽的武器可以安裝在兩配置之一。在這裏，它們被安裝在容納5“螺旋槳最裏麵的位置。
我知道我會開始使用5”的道具，所以我裝在裏麵的位置，我的手臂。值得註意的是，武器也可以摺疊以減少運輸Strider的足跡。你隻需要放鬆兩隻手臂，釋放他們的摺疊螺釘。同樣的摺疊動作可以幫助吸收碰撞能量以防止損壞的幀。

電機
馬達，我選擇了這四是華科2204 2300kv刷單位從好友RC。你可能註意到了，你可以買一個“同電動機正版”。唯一不同的是，CCW版本有反嚮螺紋的傳動軸。CCW電機實際上是意味著順時針轉動（從上麵看）。這有助於防止支柱的氣動阻力，從鬆動的螺母，認為它在。既然你有2個馬達，順時針和2逆時針，你可以買2個馬達的類型。我隻買了四的標準型，認為我必須是一個傻瓜飛與鬆散的支柱螺母。哦，原來我是個傻瓜，但我離題了，更多的是當我蓋的飛行測試。

i在黽用晴朗的天空2204 2300kv電機。“公約”這一運動的版本有反嚮螺紋的支撐軸順時針旋轉的道具來幫助防止鬆動。這很方便，但不是必要的，“汽車上的螺栓模式適合於完美的四臂上的孔。我用的螺絲，將其安裝到手臂的螺絲。一滴藍色的樂泰螺紋鎖每個電機螺釘有助於確保他們冇有振動鬆動。

電子速度控製
我同時購買了汽車，我還買了四velotech魔法12與電子速度控製（ESC）。胚胎幹細胞可帶或不帶電池消除器電路（BEC）。BEC允許飛行的電池也功率接收器和飛行控製器（和舵機如果任何人出席）。你隻需要一個ESC BEC。事實上，有時有多個BEC並行問題的原因。最簡單的途徑是購買一個ESC BEC和3無。隻是確保他們都是同一基地ESC。的ESCS> on三，我禁用了BEC電路由接收堵紅色電線絕緣與heatshrink油管。
我的魔法ESC四都有BEC，所以我禁用它三的單位。這是由ESC的接收器堵紅色線容易做。我用heatshrink油管絕緣刪除引腳在每個三受影響的胚胎幹細胞。

as小的velotech神奇的胚胎幹細胞，他們仍在黽緊配合。
的velotech胚胎幹細胞比在黽手冊所示的單位時間長一點，所以他們在指示的位置很緊。我能擠到的地方，用拉鎖固定。

PDB融入中心闆的四。在頂部和底部連接電源闆的每側導緻ESC以及連接電池引線焊盤的飛行。我決定把所有的焊接連接在闆的頂部。知道空間將在這一地區的地價，我小心地掩飾每個電源引線從ESCs的焊接位置和減少他們所需的精確長度。

take時間當焊接功率導緻PDB。它不需要漂亮，但你的關節必須是幹淨的和固體的，如果你是新的焊接，你可能會發現這個工作很難。有很多不同的導線來管理和一些物理障礙的方式。這些關節都是很重要的，所以做一個好工作（冇有冷關節）是很重要的。此外，由於碳纖維框架是導電的，你必須確保你的工作是幹淨的冇有焊料橋的底盤。如果需要的話，請尋求幫助，確保你得到它的權利。值得一提的是，我用一個25瓦的用鐵楔尖。

i縮短電機引線焊接前的胚胎幹細胞，但留下足夠的鬆弛能夠移動架臂外位置。
你也可以焊接電機引線從胚胎幹細胞對電機。再次，我修剪了ESC線以便排幹淨的汽車。在這種情況下，我把電線切成了一點，以防我將手臂伸到6個“支柱位置”。它總是更好地縮短ESC線而不是汽車電線。電機用電磁線的傷口，它有一個非導電塗層。如果你切斷了電線，你得先把這層塗層刮去，才可以帶焊。這是一種痛苦。

once ESCs在的地方，有很多的電線要處理。他們都有一個目的和一個地方。
每個電機，我焊接三線但冇有使它們最初。我檢查以確保每個電機在正確方嚮上旋轉。你可以通過按順序將每個ESC你收音機的節流通道，但我認為這是一個容易使用的伺服試驗機。如果電機在錯誤的方嚮旋轉，我換了兩個電機的導線（任意兩都行）。一旦我有電機旋轉正確，我絕緣的焊點heatshrink油管。

無線電接收機/發射機
需要4通道無線電飛黽，但你會變得更好，至少有6個頻道。這些額外的兩通道讓你選擇不同的飛行模式（它們定義了四如何控製輸入的反應），並控製燈和報警。

例子的方嚮顯示一frsky Taranis廣播係統安裝。很多傳單像賽車四周的Taranis因為它使一個簡單的3線（CPPM）連接到飛行控製器和接收器具有一個內置的RSSI（接收信號強度指示）輸出。與RSSI，你可以在你的屏幕上的圖形強度指標疊加，告訴你如果你的無線電信號越來越弱。這是長途飛行方便數據。

我決定使用雙葉7C無線電為黽。我不反對Taranis，但我已經使用多年的7C和它從來冇有給我麻煩一點。有很多要說的信心在你的齒輪。權衡的是，我的大r617fs接收機需要幾根線連接到控製器，主要是一個空間。而r617fs冇有RSSI輸出，也可以加一個相對簡單的修改。因為我不打算做任何長途飛行的鳥，我不知道我會不會打擾。

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我已經選擇的道路比其他方法需要更多的線。我可以用CPPM接收和/或修剪接收機的引線從胚胎幹細胞減少導線。我不僅可以縮短這一線索，但我可以完全刪除的