Step by step build – DC130

To show the versatility of the Atto design we wanted to put build a DC130 with a traditional vertical antenna and a large pigtail VTX instead of the usual horizontal setup. The build shown here is just one way to put the DC130 frame kit together and works perfectly on the D130, DC165 and X210 frames as a tidy and efficient way to wire a lightweight quad.

The Layout

Lay out a tidy work surface with all your parts, wires and tools where you can see them. Obviously your build list and tactics might differ from ours. You can build any way you wish, this is just how we do it.

Our build kit:

  • DC130 frame kit, 35mm standoffs, 1.5mm Nano plate
  • SPF3 Flight controller
  • Littlebee Pro 4in1 20A ESCS
  • Emax RS1306 4000kv motors
  • Matek Micro BEC
  • HS1170 camera
  • FX668T 25mw pigtail VTX
  • Menace Raptor antenna
  • Lemon RX satellite receiver
  • Kingkong 3030 props

Build weight 170g

We’ll also need:

  • A temperature controlled soldering iron
  • Fine solder (1 or 2mm)
  • Small cable ties
  • Heat shrink of various widths
  • Helping hands or similar clamp (useful)
  • Circuit/continuity tester

We’ll start by planning our build, if we know where everything has to go before hand it’s easier to avoid mistakes and having to fix them.

Start with power in. The XT-30 connector will be attached directly to the 4in1 ESC. The Littlebee 4in1 provides a 5V supply which we will use to power our flight controller. The flight controller will provide a 3.3v supply for our DSMX satellite so now it’s just the VTX and camera to worry about.

Without a full PDB you won’t be getting the 12V and 5V BEC that you might be used to if you haven’t done a build like this before. To provide a clean 12V signal we’ll use a Matek switchable BEC. Set to 12V this will provide more than enough power for the VTX and camera on the same circuit.

First put everything on the frame as a dry run and decide where all the components go. This is our setup for this build.

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Starting from the bottom we have nylon bolts through the frame secured by 2.5mm nylon hex spacers to keep the ESC’s clear of the frame. The the 4in1 ESC is mounted upside down to get it closer to the base. Next are 5mm alloy spacers followed by the flight controller. With a full size FC the props will overhang the rear corners so it’s important we keep to this ‘2 stack’ height unless we want to use the included motor risers.

Think carefully about which way round you mount your FC. Ports and connectors that are right on the rear corners can get in the way of props. Here we’ve actually removed the UART3 plastic port to make sure the props will be unobstructed as UART3 is still accessible for direct soldering.  If you’re not sure, bolt on a motor at this stage and swing a prop on it to check your clearance. The SPF3 is about the worst board for this with ports everywhere. You can mount your FC any way up and facing any direction so most boards don’t present a problem at all. Don’t worry that your props overhang the corner of the flight controller. If your props are bent enough to hit it, you shouldn’t be taking off anyway.

On top of the flight controller sits the VTX with 90° pigtail through the top plate. This will be secured via sticky foam or a a cable tie to the stack. The Lemon RX satellite will be attached to the rear of the top plate behind the SMA connector. All this leaves plenty of room for even the most serious camera angle and leaves the battery connectors neatly out back.

Prepping for assembly

Time to start soldering. We’ll be directly soldering to a new board but if you’re using an old board the time to pre-tin it would be now. If like us you’re using new gear you can move on to preparing the individual elements for assembly.

We’re using the Foxeer Arrow V1 camera for this build which requires a bit of extra soldering to use the in built voltage OSD. It’s a fiddly solder job but worth it to get voltage on screen without a dedicated OSD unit. Remember, lightweight is key.

When soldering it’s good practice to use a continuity tester throughout. Checking to see if you’ve created a short is much less time consuming and less expensive than plugging in your quad and being met with magic smoke. Every time you solder something, unless you’re certain you know what you’re doing check it.

If you’re not using this camera you can skip this section but we’ll include it anyway. For those using the Foxeer Arrow V1 only…

Unscrew the rear panel of the Arrow camera and remove then board by gently pulling it out of the casing. Be very careful not to damage the sensor glass which is now exposed. Take the included red wire and solder from the rear to the front through the header marked ‘+’ as shown. The wire should be on the same side as the rear connector.

If you wish you can solder the black wire to the ground header but the camera has a common ground so there is no need. The voltage OSD will work fine on just the positive wire. Leave this wire long for now and re-assemble the camera, passing the red wire through one of the slits in the back of the casing. Secure with a little hot glue for strength and leave the wire long for now. That’s it. atto-dc130-pigtail-build-21

Wire your BEC

The Matek BEC can be switched between 5V and 12V output via a solder bridge on the back of the board. Start by connecting these two pads with a small amount of solder to choose the 12V output.

Next grab some unneeded wires from you FC loom and solder one to the ground and one to the 7-24V in pads. We need the 12V out for two things – the camera and VTX so resist the urge to solder a single wire now and have to split it later. Measure the length of cable you need from the inside of your stack (or wherever your BEC is going) to your VTX and camera and cut the cables from the wiring harness of each to size. Twist the two positive wires together and solder to the 12V out pad. Do the same with the negative wires and the ground pads. Here we’ve twisted the ‘V in’ wires together so we can tell which is which in a minute. This whole process is much easier if you remove the wires from the camera and VTX harness. Do this by easing back the tab on the connector with a pin or blade tip and gently pulling the wire straight out. Don’t force it, if you’ve done it right it should be easy to remove.

We now have a mini 12V power supply for the cam and VTX, find a place for it to go on the quad. If you’re economical with your cables you can fit it between the ESC and FC for a really tidy build. Once you’re happy, cover the whole BEC in a layer of heat shrink for protection and if you haven’t used the wires with connectors make sure you have some way of telling which is ‘V in’ and which is ‘V out’.

Heat shrink your Antennas

We’re using the Lemon RX DSMX satellite for this build as it’s light, small and has great range. Unfortunately the antennas themselves are perilously thin. Cut some heat shrink to the right length and use a pair of needle nose pliers to open up the end enough to fit over the plastic arm of the RX and heat. The shrink does not interfere with the signal and allows us to pose the antenna in any direction we wish as well as providing much needed protection. To repose the arms just heat the wrap for a second or two and reposition.

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Time to start permanently attaching your components.

Stop. put a kettle on.

Work everything out one more time and check you haven’t cut something too short or mixed up a wire.

Right.

Remove your 4in1 and flip it over so you can access the battery cables. Our micro BEC needs a connection to positive and ground and you can solder directly to the ends of the battery cable. At the same time, connect another positive (red) wire that leads out to the front of the quad. Later we’ll connect this to the camera’s voltage sensor. Even if you’re not using a Foxeer Arrow like us you’ll want to connect this to your ‘VBAT’ pin on the FC. Try to solder to the side rather than the top of the battery connection so as not to raise the height of the solder. Check when you’re done that these solder joints are not touching your frame.

When you’re done your Bec should be connected to your battery leads and you should have one extra positive wire up front. Once it’s all in place, check you can still position your BEC as you wanted. In our case, underneath the FC with the cables hidden behind the camera.

Solder your motor outputs

The 4in1 is supplied with a  connector for 5V+, ground and ESC signals 1-4. If you’ve flipped or rotated your 4in1 here’s where you need to stop an think. It doesn’t matter which way you install the ESC as long as the the right motor channels are connected to each corner. In our case we flipped the board upside down so we need to swap channel 1 with 2 and channel 3 with 4. If you get this wrong now don’t worry, you can swap the wires in the connector rather than having to desolder but it’s nice to get it right first time.

The flight controller has a 3×8 block of solder pads labeled +. -, and s1-s8. Solder the red wire to +. the black wire to – and the 4 motor wires to the channels you want to control that corner. We’ve soldered to the underneath of the board by looping the cables so they stay hidden and protected behind the rear standoff. It also looks really tidy.

Solder your RX

Everyone likes a different receiver but for this satellite we need to solder to the 3.3v pin for power and we’re using the UART3 pads for signal and ground. Measure your distances first and make sure you’ve decided on a position for your receiver before you start. If you’re choosing to fit LED lights or a buzzer, now would be time to wire that into your flight controller. We’re building for speed but there’s always room to add these later if needed.

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One of the great things about this build is that the flight controller is not soldered into the quad or to a BEC. If you need to add, modify or swap out components it’s easy to do without the hassle of working around the rest of the quad. With this build you can just pull two plugs and remove the FC completely. If you don’t have an in camera voltage monitor you should connect that leftover wire from the positive battery lead to ‘VBAT’ and fit a 5V buzzer to the ‘Buzzer + and -‘ pads now.

Connect your video

If you haven’t already, place the VTX and camera wires from the BEC back into their connectors. You should now have two plugs with power but no video connection. Connect the two video wires by twisting and soldering then covering the joint with heat shrink. For our build the VTX connection is at the rear of the quad so the video cable will loop underneath the FC, further tidying the cables.

Wire up your motors. 

You may have been wondering why we didn’t start by wiring the motors to the ESCS like many would. Knowing we’d be soldering the the underside of the ESC it makes sense to do it without the motors connected. If we weren’t flipping the 4in1 we would have done this earlier. It’s better to have the stack finished and secure before wiring the motors up even if you remove it from the frame rather than having wires flap about while you’re trying to solder.

We could remove the wires from the ESC and solder the motor wires directly but its such a tight squeeze we’d rather leave it be and shorten both the motor and ESC wires. This also allows a little extra room to work and makes it easier to swap a motor out in the future by having the connection on the arms rather than in the stack.

The order in which  you connect the three motor wires doesn’t matter. The motor direction can be set using ESC software. In our case BLHeli.

You can see that we’ve left the black and white OSD cables attached to our camera. Once programmed to our liking these will be removed from the plug and kept incase we need them again.

Now we have our build we can see where we want the battery connector to end up. Trim your ESC battery cables and thread some heat shrink over them solder your XT-30 in place and shrink the joints. Again, this can be done earlier, we just prefer not to have it in the way during the build.

Thread your battery strap any way you like, we use the method shown so a regular battery strap has plenty to grip with the smaller packs we use.

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If you’ve routed your cables like we have, removing the top bolts should allow you to swing the top plate out of the way to access the components if needed without disconnecting your RX or antenna.

The last connection to make on this build is the foxeer Arrow voltage feed. A quick solder joint and some heat shrink followed by the camera, VTX and Manace Raptor antenna and we’re done.  All that’s left is to choose your props and fasten them down with the included alloy M5 nuts and carbon spanner.

atto-dc130-pigtail-build-36

Time to configure your hardware and test the setup. Fully built it weighs 170g so it’s going to be a riot. For US pilots that’s easily enough to take up a 650mah 4S battery and remain under the 250g registration limit.