Solder and heat
A temperature-controlled iron, 60-80 W is kinder than a 20 W toy. 63/37 or good lead-free, flux, braid, a helping third hand. Motor wires and XT60 need heat. The FC pads do not need a torch.
Home / Rigger
Dossier 12 / Assembly
Assemble a 5-inch FPV quad
A bench tutorial for a first carbon racer or freestyle machine. The example shopping list uses parts you can buy from MEPSKING - motors, stacks, radios, packs, goggles, and chargers. The steps are ours. Read their listing for voltage, KV, and mount size before you click buy.
What you are building
A 5-inch X-frame with a 30.5 mm stack, four 2207-class motors, a 6S pack, ExpressLRS in the radio, and either analog 5.8 GHz video or a digital HD kit. That is the common fighter of the FPV world. Smaller whoops and 7-inch scouts use the same order of work. Only the screw pitch and the cell count change.
If the names on the board are still fog, open the schema plate first. If you have never held sticks, sit in the trainer before you spend a pack outdoors.
This is not a MEPSKING manual and we are not their shop. They sell the fittings. You are the rigger. Check every part’s voltage, connector, and firmware support on the product page the day you order.
Standing orders on the bench
- Props stay in the box until the last test. Then they come off again for every config change.
- No pack on the aircraft while you solder.
- A smoke stopper or a current-limited bench supply for the first power-up.
- Lipo in a bag or ammo can. A charger that balances. Never a wall-wart guess.
- Safety glasses when the iron is hot and when a motor first spins.
Stores / mepsking.shop
Example parts list (5-inch, 6S)
Treat this as a compatible set, not the only set. Match stack hole pattern to the frame (30.5 mm here). Match motor KV to cell count (1750-1950 KV is a common 6S freestyle pair). Match the video system to the goggles: analog with analog, Walksnail or Caddx Avatar with Avatar goggles.
| Fitting | Example from the shop | Why this class |
|---|---|---|
| Frame | 5-inch carbon X-frame, 30.5 mm stack well, from their frames or accessories | Arms must take 2207 motors. Bottom plate must clear the XT60. |
| Motors (4) | MEPS SZ2207 V2 1750KV or 1950KV, or MEPS NEON 2306 V2 | 5-inch freestyle and racing. 2750KV is a 4S choice – do not put it on 6S. |
| Stack (FC + ESC) | MEPS NEONCORE 60A with a T-HOBBY / Velox F7, or MEPS SZ F7 analog 30.5 mm plus a 60A 4-in-1 | One 4-in-1 under the FC. 60A is headroom on 6S 5-inch. Confirm Betaflight target on the listing. |
| Props | MEPS SZ5145 or another 5-inch tri-blade they stock | Buy two or three sets. You will break them. |
| Radio | Radiomaster Pocket Crush ELRS, TX12 MKII, or Boxer / TX16S if you want bigger gimbals | ELRS 2.4 GHz on both ends. Bind phrase once, not every weekend. |
| Receiver | ELRS RX if the FC does not already have one on a UART or SPI | Read the FC pinout. Many F7 HD boards leave a pad for it. |
| Camera + video | Analog cam + 5.8 VTX, or a Walksnail / Caddx Avatar kit; goggles from the same family (Skyzone, Fat Shark analog, Avatar HD, HDZero) | The goggles must speak the VTX’s language. Mixing analog goggles with digital VTX gives you snow and a refund fight. |
| Pack | CNHL Black 1300 mAh 6S or Tattu R-Line 1400-1600 mAh 6S, XT60 | 1300-1600 is the usual 5-inch size. 150C-class racing packs hit harder and die sooner. |
| Charger | Gens ace iMars D300 or another balance charger they list | Balance every charge. Storage voltage when the pack will sit. |
| Small stores | XT60 pigtail if the ESC has none, low-ESR capacitor, battery straps, soft-mount grommets, zip ties, heat shrink, antenna | The capacitor sits on the ESC pads. It is not optional on 6S. |
Shop the current catalog at www.mepsking.shop – Motors, ESC, Flight Controller, Radio Controller, Batteries, Goggles, Charger, Accessories. They also keep their own build guides. Use those for part photos. Use this page for the order of work and the failsafe.
Tools
What must be on the bench
Drivers and hex
M2 / M3 hex (1.5 mm and 2 mm are the usual), nylon standoffs if the stack kit is short, thread-lock on metal into metal – not on nylon into carbon. Side cutters, tweezers, a multimeter.
Configurator
Betaflight Configurator and a USB-C or micro cable that actually carries data. Chrome or the standalone app. Props off. Always.
Rigger’s order
Assembly, one fitting at a time
1. Frame dry-fit
Lay the bottom plate, arms, and standoffs with no electronics. Confirm the stack holes are 30.5 mm if that is what you bought. File a carbon splinter rather than leaving it to cut a wire. Fit the battery pad and straps last, after the XT60 knows where it will sit.
2. Motors on the arms
Each motor uses the short screws from its bag – too long and you kiss the windings. Wires toward the stack. Do not tighten until the arms are true. Brushless motors have no lock-in CW/CCW hardware; Betaflight will assign spin later. Put a drop of thread-lock on steel into aluminium if the motor bell asks for it.
3. ESC under, FC over
4-in-1 ESC on the bottom of the stack, grommets in the carbon, nylon screws. The FC sits on the ESC with the arrow toward the camera. Read the silk: USB aft or USB to the side, but the gyro arrow must point forward. Do not over-crush the grommets. A dead-soft mount is a gyro that lies.
4. Solder the motors
Tin pads and wires. One motor per corner as the ESC diagram shows (usually M1 front-right on Betaflight’s default quad X). Three wires per motor. If a motor spins the wrong way in the configurator you swap any two wires – or reverse it in software. Keep strands out of the next pad. A solder bridge on 6S is a fire drill.
5. Battery lead and capacitor
XT60 (or whatever the pack uses) to the ESC power pads. The low-ESR capacitor goes across those same pads, short leads, heat-shrink so it cannot chafe the carbon. This is the part people skip and then wonder why the FC browns out in a punch-out.
6. Radio, camera, video
Receiver to a UART (or the onboard ELRS pads). Camera to the FC camera-in. VTX to a UART if it needs SmartAudio or Tramp, and to the video-out pad. Antenna on the VTX before any power – a bare SMA on 5.8 GHz cooks the amp. Keep the GPS, if you add one later, away from the VTX.
7. Strain relief and top plate
Zip-tie motor wires to the arms so a crash pulls the tie, not the pad. Hot-glue is not a clamp on a racer; a little on a connector that rattles is fine. Fit the top plate, camera bracket, and battery strap. Shake the airframe. Nothing should ring.
8. First power, props in the box
Smoke stopper in series with a charged pack, or a current-limited supply. USB to the computer first is safer for flashing. If you must use a pack, watch the amp meter. A short shows up as heat and a smell. Disconnect. Find the bridge. Do not “just arm it to see.”
Firmware on the bench
Install Betaflight Configurator. Plug USB. Pick the board target the MEPS or T-HOBBY listing names – an F7 is not “any F7.” Flash, then connect. Confirm the setup tab: the model moves when you move the airframe. If it is drunk, the gyro is mounted wrong or the board is set as flipped.
Ports: turn on Serial RX on the UART that holds ELRS. Camera and VTX control on their UARTs. Mixer: Quad X. Receiver: CRSF for ELRS. Bind the Radiomaster in the ELRS Lua, then confirm Channel map (AETR is common). Failsafe: drop or stage. Test it with the props still off by pulling the radio battery. Motors must stop or the craft must do exactly what you wrote.
Motors tab: IDs match the corners. Spin each at a whisper. Reverse in software if a corner is backwards. OSD: pack volts in the goggles before you ever fly. VTX table: legal power and a channel that does not sit on someone else’s race band.
A dump of a working hex is cheaper than a guess. Save the CLI diff before you “just try a tune.”
First hover
- Grass field. No people in the prop disc.
- Angle mode. Rates low.
- Props on, correct rotation, lock the nuts.
- Arm away from your face. Throttle up until it feels light.
- If it walks, land, props off, check motor order and props again.
- One pack. Then home. Logs and a zip-tie check.
Know the rules where you stand. This tutorial is assembly, not a licence. A spotter is still the other crew member when the goggles go on.
Order or check parts at MEPSKING
Betaflight notes
Radio and video