Introduction
Soldering is a non-negotiable skill for any FPV pilot who builds or repairs their own drones. Unlike pre-built consumer electronics, FPV components come as bare circuit boards with solder pads, and you are expected to connect motors, receivers, VTX modules, and power leads yourself. A poor solder joint — cold, cracked, or bridged — can cause a quad to fall out of the sky, sometimes violently. This guide covers everything you need to set up a reliable soldering station, choose the right tools and materials, and produce professional-quality solder joints on every connection.
Choosing Your Soldering Iron
TS100 / TS101 — Portable and Powerful
The TS100 (and its successor, the TS101) has become the standard soldering iron for FPV pilots. It is compact enough to carry in a field bag, heats from room temperature to 350°C in under 10 seconds, and runs on 12-24V DC — which means you can power it from a LiPo battery at the field. The open-source firmware (Ralim’s IronOS) adds features like temperature boost, sleep mode, and detailed temperature graphs on the OLED screen. At around $50-70, it is exceptional value for money.
Key specs: 12-24V DC input, 65W max, USB-C PD compatible (with adapter), OLED display, firmware upgradeable.
Pinecil V2 — The TS100 Killer
The Pinecil V2 takes everything great about the TS100 and improves it. It runs on USB-C Power Delivery (up to 20V/3A = 60W) in addition to DC barrel input, meaning you can power it from a laptop charger or a high-wattage power bank. It heats even faster than the TS100 and costs only $26. The open-source IronOS firmware is the same as the TS100, providing identical features. Unless you have a specific reason to prefer the TS100, the Pinecil V2 is the better buy in 2025.
Key specs: USB-C PD 3.0 + DC 12-24V, 88W max (DC), 60W (USB-C), OLED, RISC-V processor.
Desktop Station: Hakko FX-888D
For pilots who do most of their soldering at a workbench, a dedicated desktop station like the Hakko FX-888D provides more consistent temperature control and a wider selection of tips. The FX-888D is a 70W analog station with precise digital temperature control (±1°C) that has been the industry standard for decades. At around $100, it is a buy-it-for-life investment. The larger handle is more comfortable for extended sessions than the pen-style TS100/Pinecil, and the tip selection includes specialized shapes for every task.
| Iron | Power | Heat-up Time | Portable | Price |
|---|---|---|---|---|
| TS100 | 65W | ~8 seconds | Yes (DC) | $50-70 |
| Pinecil V2 | 88W DC / 60W USB-C | ~6 seconds | Yes (USB-C + DC) | $26 |
| Hakko FX-888D | 70W | ~30 seconds | No (AC) | $100 |
Solder Selection: 63/37 Is the Only Choice
For electronics soldering — which is all FPV soldering — use 63/37 (tin/lead) rosin-core solder. This is the eutectic alloy, meaning it transitions directly from liquid to solid with no plastic (pasty) phase. The result: stronger, shinier joints with virtually zero risk of a cold joint from movement during cooling. Lead-free solders require higher temperatures, produce dull joints that are harder to visually inspect, and are much less forgiving of imperfect technique. For the small pads and fine-pitch components on FPV electronics, 63/37 is the only solder worth using.
Recommended diameter: 0.5mm for small pads (receiver, camera, UART connections) and 0.8mm for larger pads (battery leads, ESC power pads). Using solder that is too thick makes it impossible to control the amount — you will flood pads. Using solder that is too thin means you feed wire endlessly for large joints.
Flux: The Secret to Perfect Joints
If there is one thing that separates amateur soldering from professional results, it is flux. Rosin-core solder contains a small amount of flux inside the wire, but for FPV soldering — especially on oxidized pads from crashed quads, or large ground planes that sink heat — additional flux is transformative. It cleans the oxide layer from the pad and wire, improves wetting (how the solder flows), and prevents bridging between adjacent pads.
Use a no-clean flux pen or a syringe of rosin flux gel. Apply a thin layer to both the pad and the wire before soldering. The joint will form in half the time with a mirror-smooth finish. A $5 flux pen will last you a year of building and is the single best value upgrade you can make to your soldering setup.
Soldering Technique by Application
Motor Wires (16-20 AWG) to ESC Pads
Motor wires carry high current and are subject to vibration. Pre-tin both the wire and the pad separately. Place the wire on the pad, apply the iron to both simultaneously, and feed a small amount of additional solder. The joint should be shiny and form a concave fillet. Wiggle the wire gently after cooling — any movement indicates a cold joint that needs reflowing. Use the largest tip that fits the pad for maximum heat transfer.
Battery Lead (12-14 AWG) to ESC Power Pads
The battery lead is the highest-current joint on the drone and the most likely to fail catastrophically. Use a large chisel tip (3.2mm or wider), set your iron to 380-400°C, and pre-tin the wire heavily. The ESC power pads are connected to large copper ground/power planes that sink heat — you may need to hold the iron on the pad for 5-10 seconds before the solder flows properly. Do not rush this joint. A cold battery lead joint can desolder itself mid-flight when current heats it up — the drone will lose all power instantly. Add a capacitor to the same pads after soldering for additional noise filtering.
Small Signal Wires (26-30 AWG) to UART Pads
Receiver, GPS, and VTX control wires are thin and delicate. Use a fine conical or small chisel tip (1.2mm), set temperature to 320-350°C, and strip only 1-2mm of insulation. Tin the pad first, then tin the wire, then touch them together with the iron for less than a second. Use flux generously — these tiny pads are the most prone to bridging. A helping-hands tool with a magnifier is invaluable for these joints.
Essential Tools Beyond the Iron
- Silicone soldering mat (A3 size): Protects your desk, has compartments for screws and components, withstands high heat without burning. $15-20.
- Brass wire tip cleaner: Far superior to a wet sponge — does not thermally shock the tip, no water splashing near electronics. $5.
- Helping hands with magnifier: Holds boards and wires in position. The magnifier is critical for inspecting small joints. $20-30.
- Fume extractor: Rosin flux fumes are irritants and long-term exposure is unhealthy. A small fan with a carbon filter placed 15-20cm from your work area is sufficient. $25-40.
- Heat shrink tubing assortment: 1.5mm to 10mm diameters. Always insulate your joints. $8-12 for a kit.
- Flush cutters: For trimming component leads and wire ends flush to the board. $5-8.
Inspection and Testing
After every joint is soldered, inspect it under magnification. A good joint is shiny, smooth, and concave — the solder should flow seamlessly from pad to wire with no cracks, pits, or balls. A dull, grainy, or lumpy joint is a cold joint and must be reflowed. After visual inspection, use a multimeter in continuity mode to check for shorts between adjacent pads and to verify that each connection has continuity between the wire and the pad. Power up the drone with a smoke stopper (a current-limiting device) on the first power-on to catch any shorts before they destroy components.
Conclusion
A good soldering station costs $50-100 and will serve you for years of building and repairing FPV drones. The Pinecil V2 paired with 63/37 solder, a flux pen, and a silicone mat is the ideal starter setup. Practice on a scrap circuit board before tackling a $60 flight controller. The skill you develop will save you hundreds of dollars in replacement parts and keep you in the air instead of waiting for someone else to fix your quad.