best quadcopter racing

How to Build the Best Quadcopter for Racing

In Basics, Build by FlightClub27 Comments

How to Build the Best Quadcopter for Racing
Let’s build the best quadcopter for racing.  When I first started this site, I made a post on How to Build an FPV Quadcopter in April 2015.  It was an intro on how to build a quadcopter using good parts, at that time.  The quadcopter industry is advancing so fast.  Just 18 months have past and parts used in that build were considered good at the time seem obsolete now.

It’s time for an update on my first quadcopter build.  In this post I’ll be building the best quadcopter for racing at this time.  I think I may have to do one of these posts every year just to stay up to date!

I’ll be using a 200mm X pattern frame, the Armattan SCX 200 frame.  Now keep in mind this build method can be applied to nearly every quadcopter frame.  It can even be applied to my QAV250, QAV210, QAV-R and QAV-X builds.  The build method is essentially the same but just without the OSD.  Since this will be a quadcopter for racing we won’t be using on screen display.  All the voltage, RSSI and time info will come from the Taranis telemetry.

Parts used in this build:
Not Needed but I love these
  • 2.5mm 110 degree FOV lens – I love this lens.  It makes seeing cones and gates so much easier.  The default HS1177 comes with a 2.8mm 87 degree FOV, which in my opinion is way too narrow.  I get lost on tracks because I can’t see the next gate.
  • 12v Pololu – save your FPV gear by powering them off a regulated 12v source.
  • 35 Degree GoPro mount
Tools used
  • Weller WESD51 soldering station – if you’ve never soldered before, have not fear!  It’s easy and fun.  Check out this soldering basics post.
  • Soldering Vise – gives you a hand when you are one hand short.
  • Wiha Metric Hex and Philips screwdrivers – can’t emphasize the importance of having the right tools for the job.  No more stripped heads.
Build Kit

I’ve put together a build kit that that include all the parts used in this post.  It comes with all the miscellaneous parts (12v Pololu, buzzer, cables, silicon wires, heat shrink…etc) that you’ll need to complete the build.  It also includes the Taranis program file that has all the switches, telemetry, voice prompts and timers.  The cheat sheet and KISS backup file is included also.

Testing

best quadcopter racing

Once again I’ve built two identical quads with different motors, T-Motor F40 2300kv and EMAX RS2205-S 2300KV motors.  I heard a lot of good things about the T-Motor F40 2300kv motors so I decided to give them a try.  After flying both motors I’m going with the EMAX motors.  Both motors feel really good with lots of power but on the T-Motor I found myself at 100% throttle more often than the EMAX.  On the straight aways the T-Motors seem to lack the top end speed I wanted whereas the EMAX I felt like I had some power in reserve if I wanted.  The new EMAX RS2205-S are stupid fast.  Another plus is the EMAX motors are $20 less a set than the T-Motor.

Build Schematic

build best racing quadcopter

Let’s Start the Build!

I can’t tell you how many ESCs I’ve had killed by the props striking them.  If you experience a weird twitch after a crash and your motors and props are fine, there’s a chance a tiny component was knocked off your ESC by the props.

It’s a little more time consuming but I’ll be mounting the KISS 24A ESCs on the bottom of the arms.

Install the arms on the frame.

best quadcopter racing best quadcopter racing

Start by pre-tinning the motor, power and signal pads on the ESC.  Then solder on the power and signal wires on the ESC.  If you are using the EMAX RS2205-S 2300KV motors, you can go ahead and bridge the motor reverse pads on the KISS 24a ESC for motors 1 and 3.

best quadcopter racing

Slip on the big arm heat shrinks and mount the motors with the wires pointing away from the quad.  Thread the motor wires through the holes going under the arms and solder on the ESCs.  No need to cross any wires.  Solder the motors to the ESC straight on.  Slip on the ESC heat shrink.  Pull the power wires on the ESC until there’s no slack and solder on the PDB.

best quadcopter racing

Solder on the 12v Pololu for the FPV gear.  This will give you a clean regulated power source.  You could directly solder the FPV gear on the PDB and it will work but that’s not good practice.  It will work at first but the voltage spikes from the ESCs will eventually kill your VTX and/or camera.  Do it right the first time!

best quadcopter racing

The easiest way I found to surface mount a Pololu without holes is to lightly tin the 4 pads on the board.  The put solder on one hole on the Pololu.  The align the holes to the pad and tack the first hole.  If you do it right the solder will melt through the hole and bond with the pre-tinned pad below.  Next just add solder to the rest of the holes.  (watch the video) Solder on the battery cable and check the output of the Pololu with a digital multimeter to make sure it’s outputting 12v.

best quadcopter racing

Cut and install the VTX and camera cables on the regulated 12v pad of the Pololu.  Directly soldering the wires on the pad eliminates the need to splice, solder and cover the tiny wires with heat shrink.

best quadcopter racing

Next is to install the KISS fc.

It’s always a good idea to flash the flight controller before you start soldering.  But for the sake of this post I’ll show installing the KISS flight controller then do the flashing.  But really I’m going to flash first just incase there’s an issue with the board I won’t have to redo the whole install.

Pre-tin all the pads on the KISS fc for signal, rx and buzzer.  Add the VBAT wire so you can solder it on the PDB later.  Add the buzzer.

Solder all the signal wires from the ESCs to the KISS.  Make sure you install the correct motor/esc signal to the correct pad on the KISS fc.

Cut the wires and install the XSR rx to the KISS fc.  The yellow wire is the Telemetry wire.

best quadcopter racing

Taranis Setup

At this point we are pretty much done with the build part of the race quadcopter.  To setup the rest of the quad you’ll need to program the Taranis first.  For the sake of keeping this post short, refer to the QAV-X part 2 for setting up the Taranis.  The setup on this quad is exactly the same.  See the video HERE.

The only thing different I’m doing from the video is setting up a 2 minute race timer.  This timer will give you a haptic and verbal notification at 30 and 20 seconds left in the race.  Then countdown from 10 seconds to zero.

Timer 1 is just an overall flight timer with the minute call set.  This will say the time every minute.  Using THt will only start the timer when you give it throttle.

best quadcopter racing

Timer 2 is the 2 minute race timer.  Set countdown to Voice.  This will be the verbal prompts.

best quadcopter racing

The rest of these screens are how I have the Taranis set.  See part 2 of the QAV-X build for an explanation of the screens.

best quadcopter racing

best quadcopter racing

best quadcopter racing

If you don’t see Vfas or RSSI you many need to do an extra step.  On this Taranis firmware 2.1.8, bind the XSR to the Taranis with the battery plugged in, go to page 12/12 and hit Discover new sensors.

best quadcopter racing

KISS FC Setup

Next see this KISS fc setup post on how to get the KISS configurator and flash the KISS with the latest firmware.

best quadcopter racing

The PIDs here are tuned for this Armattan SCX200 running the KISS 24A esc and EMAX RS2205-S 2300kv motors.  You can adjust the rates to your liking.  If you want a smoother flight, lower the rates.  If you want a twitchy cracked out quad, crank up the rates.

Watch the the video HERE on how to test the motors in the KISS configurator.  Since we are using the KISS fc with KISS ESC, ESC calibration is not needed.  Make sure the correct motors are spinning for the correct outputs and that they are spinning the correct direction.

Finishing the Build

The SCX200 has a really smart way for mounting the VTX.  It uses a small carbon fiber plate, o-ring and rear plate to lock in the SMA.  Place the SMA into the square hole of the carbon fiber plate with the longer side facing up.  The slide on the o-ring and put the SMA through the back LED plate.  When you screw on the antenna it will lock the SMA in place and take the impact off the solder joint.

best quadcopter racing best quadcopter racing

Conclusion

best quadcopter racing

best quadcopter racing

The all up weight of the SCX200 is only 300g without battery or GoPro.  Compared to the QAV-X which is 340g and the Alien 5″ is 405g, the SCX200 is a one of the best quadcopters for racing.  A 40g weight reduction is huge for such a small quad.  You really feel the weight difference when you punch the throttle or whipping through the turns.

The SCX200 feels really good in the turns.  It’s very balanced and has plenty of punch.  There were times where I found myself going much faster than normally fly.  There’s something about this quadcopter that makes you want to push it harder and harder.  It’s like a good controlled chaos.  The SCX200 is one of the best quadcopters for racing.  I highly recommend it!

If you found this post helpful, it would be super cool if you purchased the components from my store or purchase items from my Amazon links.  These posts are expensive and take a loooong time to make!  The purchases make it possible for me to keep making them.  Thanks in advance, I greatly appreciate it 🙂

 

Comments

  1. Adam

    You have to love the scx, it is my favourite frame
    Good job mate, have you seen foxeer arrow v2? If all you want from an osd is voltage and timer this does in in a hs1177 cam format, although doesn’t quite fit one the scx as the back is slightly deeper, I would suggest runcam swift (similar price, better osd connection for changing cam settings) with a gopro2 lense,

     
  2. Larry

    Nice build. I’m not a fan of those kids ESCs for the simple fact that they are overpriced. I have a similar build using a qavx and use the Aikon SEFM 30A ESCs. These are just as capable as the kiss ESCs sans the telemetry (which I wouldn’t need). One other FC that I’m experimenting with is the Raceflight Revolt. I’ll let you know how that goes but I’ll be definitely running at 32khz!

     
    1. Author
      FlightClub

      I’ve got a Revolt sitting here just waiting for a build. Seems like hot new products are coming out every week. It’s hard to keep up!

       
  3. Eth4n

    I was wondering. Would this build be able to fit a power osd v2 rather than the built in pdb? Are the arm bolts go through the pdb as well as the frame?

     
    1. Author
      FlightClub

      Yes you can use the powerosd v2 on this quad for the electronics instead of using the pdb that it comes with but you’ll still need the armattan pdb to hold the arms.

       
  4. Adam

    Actually this is an armattan version of the scx, if you check armattan production you can find the origional which has a carbon plate instead of the pdb, you should be able to just buy that plate, replace the pdb and use whichever pdb of your own you want

     
    1. Eth4n

      If I were to use the carbon fibre mid plate instead of the pdb, would the power osd pro v2 fit into the fc stack without different bolts, stand-offs, etc? If so, what length screws, bolts, etc. would I need in order to do so?

       
      1. Adam

        It could fit it depends on how big your stack is, you would use standard bolts and standoffs, depends what pdb, flight controller, Rx and vtx you use, the scx uses 30mm standoffs, if you see using frsky then one of the new xm Rx would probably reduce the height and fit between boards, it is compact but by no means unachievable, compare it to a v2 shrike which uses 20mm standoffs. It would help to use multifunction boards like a dtfc or kombini flight controller both of which have built in pdb, or frsky have an f3 with a built in Rx

         
  5. Simon Ashley

    Great tutorial and video – thanks! I followed this exactly and it all works! Waiting to do maiden flight. My only query is whether it is possible to hook up the LED board somehow. I would just like fixed white. I have used the KISS FC and ESCs for the build. I tried connecting a 5V output from the FC (near the buzzer pads) to the plus and minus in on the LED board but no joy.

    Any suggestions?

     
  6. Simon

    I understand that to get full telemetry including current and fuel, you need to connect the TLM (telemetry) wire from the KISS ESC to the Trx pad on the FC?

     
  7. Mark Daams

    Great write up! Pololu also sells a step-up/step-down regulator btw. If you use that one instead you can still use 3S Lipo if you wanted to.

     
    1. Author
      FlightClub

      We ship same day priority so it will have it within 4 days depending which state it’s going.

       
      1. Andy Burrows

        Ok. I will be in Las Vegas. Where do you ship from? And have to made any changes to the 250 model kit? Do I need to order anything else? If so, what do you recommend? I bought a taranis already.

         
  8. Simon

    Hi, please note that the only problem I’ve had building exactly as described is slight interference on the video signal with high throttle. This was resolved by removing the camera power and video connections from the pdb and running these directly from the Vtx – I used a Foxeer switcher which clearly filters the power supply to the camera and removes potential “noise” coming through the pdb.

     
    1. Adam

      Hi Simon, whilst what you are saying makes sense I think you will find it is the fact you are running through a second regulator, and thereby a second capacitor has become involved, further smoothing the power than an anctual fikter. Also you do have to be careful with the hs1177, runcam swift, foxeer arrow etc, they generally don’t cope well with 5v if it drops at all which can happen with a 5v reg, there are quite a few people on forums like rcgroups who have reported this.
      Not saying don’t do it, but do be aware and if you encounter brown outs that is most likely the problem

       
      1. Simon

        Hi Adam. Thanks. I considered using an LC filter but they are quite bulky and would have spoiled the build. So far so good running the camera from the Vtx 5V out supply but what other potential solutions are there?

         
        1. Adam

          Tbh other than builds when I use something like an OSDoge I don’t use a filter. As a general rule I run both the vtx and cam from a 12v reg. there are a number of tricks that can help, these include:
          1. Air – electrical interference can be induced, particularly by high and/or rapidly changing currents like those the escs are using, this diminishes exponentially with distance, keeping as much of your FPV wiring as far away from the pdb, xt60 pigtail and esc wiring will help
          2. Shielding – to use the term loosley common methods include using ground shielded cabling (aomway and the longer tbs wires have this, but it is bulky and heavy). Twisting paired wires allegedly helps, wrapping your FPV wiring round a ferrite ring may help but again you are adding weight (other than twisting wires I don’t use any of this one)
          3. Smoothing – most of the electrical jitter comes from the escs, you can smooth this with a capacitor, to be strictly accurate placing the capacitor as close to the source of the noise as possible will make them most effective, this would require low ear capacitors to be mounted across the power inputs of each esc. A second option, which for the electrical purist is slightly less effective, is to put a capacitor across the point where the xt-60 pigtail connects to the pdb. This latter one I do a lot, (most of my quads), you should use 1000uf low esr cap from a good manufacturer such as Panasonic, it needs a decent voltage rating, I use 35v. This approach deals with electrical jitter interfering not only with the fpv kit but also effecting the esc PWM signal although d shot removes the latter

           
  9. Eric strabel

    Do you use the same pids after you’ve changed the firmwares to run dshot? I bought this kit and set it up identically from you, but I’m wanting to switch over to use dshot.

     
  10. Simon

    There have been some posts arguing for and against the ESC ground wire with Dshot. Is the ground wire necessary to use Dshot with this build?

     
    1. Author
      FlightClub

      nope. i’ve never used the ground in the 50+ quads i’ve built.

       

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