I've tried to think of my non-US visitors throughout this whole Shopping List. This page is one where I'll struggle with that. Most of these supplies, I source locally or from U.S. Amazon. And I won't recommend a potentially-inferior product that I can't vouch for. If you're not from the U.S., I hope that you can find local equivalents. If you know of international dealers for any of these products, please contact me.
3M Super 35
I've tried a lot of different electrical tapes and this is hands-down my favorite. It molds snugly to the object it's wrapping almost like heat-shrink. It sticks securely to itself and seldom comes loose. It's perfect for taping ESCs to quadcopter arms, and that's the main thing I use it for. (Incidentally, don't use electrical tape for covering wire splices, except in a pinch. Heat shrink is the right material for that.)
I'm showing the red tape above, but it's available in a bunch of different colors. The purchase link takes you to a search results page that shows them all.
double-sided foam tape
Foam tape has two uses. The first use is (obviously) to stick things together. The other use is for vibration isolation and padding. I always put this tape underneath my ESCs so that they're not directly against the quadcopter arms, where they'd get knocked around. I also commonly use it to stick my receiver on top of my flight controller. Finally, I'll sometimes make a little stack of this tape to help snug something loose up against a zip tie.
I prefer the 1-inch wide version of this tape.
BCP Polyimide High Temp Tape
Kapton tape is like translucent, non-stretchy electrical tape. Technically, its defining characteristic is that it isn't affected by high temperatures, but that's not why I use it. I use it basically any time I want to protect something electrical, but I still want to be able to see it. A great example is the receiver, which has LEDs and buttons that would be covered up by regular electrical tape.
If you're well-prepared, you'll use clear heat shrink instead of Kapton tape, but here's why I don't: because you have to know what size heat shrink to order before-hand, and I never seem to have the right size on hand. With Kapton tape, I can wrap up whatever I need.
SUPER STRONG MOUNTING TAPE
4011 is commonly referred to in modeling as "servo tape". It's so strong that you can mount a servo with nothing else and it'll hold basically forever. 4011 is so strong that it can be used to mount bathroom mirrors to the wall, if you have enough of it.
4011's strength is also its weakness. It's so strong that I've had it literally pull parts off of a circuit board when I was trying to remove it. In fact, if you're going to use it on electrical parts, I suggest using it sparingly so that you can safely remove the tape later if you need to.
The other disadvantage of 4011 is that it seems to refuse to stick to certain surfaces. I've never really been able to figure out the common link between what it will and won't stick to.
110 foam tape is my primary go-to for mounting. But I always keep some 4011 around for times when I want to stick something down and know for sure it isn't going anywhere.
Best battery pad
Kyosho 3mm Sheet
This stuff is sold for vibration absorption. It's great at that, but that's not actually how I use it. See, the adhesive that it comes with isn't secure enough for the rough life that a mini quad experiences. In fact, the adhesive pulls off pretty quickly after application in my experience.
So what's it good for? It's a heck of a good battery pad for quadcopters where the battery is mounted on the bottom of the frame. These quads land (and crash) right on top of the battery. The battery slides loose from the strap and goes flying about.
The brilliant thing about Kyosho gel is that, even after you've peeled the adhesive off, it remains incredibly sticky and tacky. Put it between your battery and your frame and the battery won't slide out even in the hardest crashes. It picks up dust over time and loses its stick, but just clean it with a bit of water and it goes right back as good as new. In addition to mounting batteries, it's good for securing a GoPro or other action-camera to some frame. And in this case, its vibration isolation is actually beneficial!
Kyosho gel is the best battery pad for bottom-mounted quadcopter frames because it's inherently sticky, and infinitely reusable. The listing above is a 145x45x3mm sheet that you can cut into several battery pads.
Solder comes in several different blends, also known as alloys. 60/40 solder, which contains 60% tin and 40% lead, is the most commonly used. The newer 63/37 alloy is hands-down superior for the type of soldering we're doing, and that's all you'll find on this page.
All of the solder on this page is also rosin-core. This means it contains a tiny bit of flux in its center so that you don't have to apply any flux separately to the joint. You can just tin the pad or wire and know that the joint already contains the right amount of flux.
You'll also notice that all of the solder on this page is leaded. Lead-free solder is harder to work with and produces worse results than leaded.
Is leaded solder bad for you? NO. Soldering temperatures are far, far too cold to vaporize lead. The fumes you see when soldering is the flux burning off (don't breathe that). The main risk of lead exposure from soldering is lead particles on your hands. You can mitigate this simply by washing your hands after soldering. And don't lick the solder.
if you only need a little
BNTECHGO 63/37 Rosin-Core
This is a fine solder, but it's neither the highest quality nor the cheapest per gram on this list. So why is it even here?
Because sometimes you'd rather pay $10 for a 4 oz roll than $25 for a 1 lb roll, even if the 1 lb roll is a better deal.
And hey: it ships with Amazon Prime.
The product listing above contains several different sizes and amounts of solder. The 0.8mm thickness is great for basically everything you would want to do on a quadcopter.
HIGH QUALITY, BULK PRICING
KESTER 63/37 ROSIN-CORE NO-CLEAN
Kester makes high-quality soldering products, used by huge manufacturers and hobbyists alike. This solder has a no-clean rosin core. Normally, after soldering, you're supposed to clean flux residue off the board with a Q-tip soaked in alcohol. No-clean flux is safe to leave on the board, which saves a step. (To be honest, many hobbyists skip this step anyway.)
This flux comes in a 1 lb roll, which means it's way cheaper per gram than 4 oz rolls, but it's more expensive up front.
Great For Rework
Chemtronics CW8100 Flux Pen
Flux is essential to a good solder joint. That's why the recommended solder on this is rosin-core. For most joints, the flux that's built into the rosin-core solder will be sufficient. But for re-work, you'll often do best to add a bit more flux.
That's where this flux pen comes in. Imagine that you're putting a new set of motors onto your quad, and the ESCs have left-over solder on the pads. If you just try to solder the new motor wires to the old solder, it'll try to stick to the soldering iron tip and form pointy peaks when you remove the iron from the joint. Put a little dab of flux onto the joint from this pen, and that problem is solved. Smooth, shiny, perfect joints.
Protects Against Moisture
MG Chemicals Silicone Conformal Coating
Silicone conformal coating paints onto your solder joints and dries to form a waterproof coating. If you ever land in dew-soaked grass, or if you might crash in the snow, you need this stuff. The beauty of silicone conformal coating is, if you ever need to solder over it, it burns off cleanly, so rework is a breeze.
HEAT SHRINK TUBING
Heat shrink tubing covers electronic components and keeps the electricity from going where it isn't supposed to go. A well-stocked quadcopter builder will have several different sizes on hand. My recommendation is that you start off by buying an assortment and then figure out which sizes you use the most of, and buy a 100' roll of those sizes.
Heat shrink comes in different shrinkage ratios. So a 1" pre-shrinking heat-shrink would be 1/3" if it was 3:1 shrink raito, and 1/2" if it was 2:1 shrink ratio. When you buy heat-shrink, the post-shrinking diameter is what you care most about. So make sure you're buying what you expect.
The best assortment
SummitLink 415 pcs
I was so thrilled to find this heat shrink assortment because it covers sizes up to 30mm (a little more than 1"). Every other assortment I could find stopped around 3/8", which simply isn't large enough for everything you might want to heat-shrink on a quadcopter (most notably, ESCs).
Please note that this heat-shrink has a 2:1 shrinkage ratio. So the fully shrunk size will be between 0.5mm and 15mm.
SwitchMe 198 PCS
This heat shrink assortment includes equal parts red and black. Lots of people like to use red heat shrink on their positive wires, although having a red wire with black heat shrink isn't the end of the world. Another good use for red heat shrink is if you use all the same color wire on your build, marking the positive wires with red can help prevent you from accidentally wiring things up wrong.
The disadvantage of this kit is that it's 3x the price of the Summitlink kit, for about half as many pieces. So it's way more expensive. But hey... you want red? You got red.
You can't just grab any old copper wire for use on a quadcopter. Quads are subject to massive amounts of vibration, shock, and handling. Regular copper wire will quickly work-harden, stiffen, and break off. For use on quads, you want fine-strand, silicone-insulated wire--commonly referred to as "silicone wire". The fine strands allow the wire to flex without hardening. The silicone insulation can take the heat of soldering without melting.
For Low Current and Signal Wire
Striveday Silicone Wire Assortment
This assortment of thin-gauge silicone wire is great for nearly anything you want to do on a quadcopter. The box comes with an assortment of colors so you can color-code your applications.
Ultra-thin and light 30-gauge is best for very-low-current applications like signal wires, FPV cameras, and receivers. 26-gauge is better for applications up to about 2 amps, such as higher-powered video transmitters.
Thicker wire is necessary for ESCs, motors, and battery leads, because of the high current that they carry. 14-gauge is commonly used for battery leads. 12-gauge is used on high-performance quads that will draw LOTS of current, but be aware that it's thicker than many components, including XT60 connectors, are designed for. It can be made to work, but it's a little tricky. 20-gauge is almost universally used for ESC power wires and motor wires.
GLUES AND SUCH
You know this adhesive as SuperGlue (TM) or Krazy-Glue (TM). Its generic name is cyanoacrylate. Cool kids in the RC hobby just call it "CA".
We recommend Mercury Adhesives CA because it's top quality. But I won't ask you to take my word for it. What if I just told you that the bottle and cap are designed so that they won't clog up?
If you've only bought CA from the hardware store, you might be surprised to learn that it comes in various viscosities, from so thin that it wicks into hair-line cracks to gel-thick. Links above are to thin, medium, and thick viscosity. Medium is most similar to what you're likely to be used to. Thick is for when you want to put a blob in place and not have it go anywhere. Thin is for when you want it to spill out of the joint and go all over your carpet, leaving a crackly spot that's still there a year later ask me how I know.
The BEst For Removing CA
Mercury Adhesives M68DB Debonder
If you're the kind of person who can use CA without gluing your fingers together, then ...
... well, good for you, you jerk.
How do you do it?
For the rest of us, there's CA debonder. This stuff dissolves CA. Useful for cleaning up messes, repairing mis-aligned joints, and yeah... un-sticking your fingers from each other.
The Best Thread-Locker
Mercury Adhesives Brush-In-Cap Blue
Thread-locker is an essential part of building a quadcopter. It's especially important on motor screws, but any screw can back out under the constant vibration of a mini quad's motors. Mercury Adhesives blue thread-locker is unique because it comes in a bottle with a brush under the cap, so it's easy to apply.
These standoffs are most commonly used in the flight controller stack. Having a variety of sizes on hand helps you get the spacing between your stack components exactly right. The Female-Female version takes a screw in either end. The Female-Male version has threads on one end and a screw receptacle on the other end. (And no, I'm not being dirty. That's how screw threads are designated.) For smaller quads, these might be strong enough to act as frame standoffs, but for larger quads that take bigger hits, metal standoffs would be better.
When you've used up these parts, don't throw out the case! It makes a really nice tackle-box style case for miscellaneous other things.
The Amazon and Banggood listings above are not for exactly the same assortment of sizes and types, so check the listing carefully before ordering.
M3 Screw Assortment, Button-Head
Almost all screws on mini quads are M3 size, so you'll get a lot of use out of this assortment. The screws are in sizes from 4mm up to 20mm. A set of standard nuts is also included, although I prefer Nylock-style when I can get them. These steel screws are a bit heavier than aluminum ones, but my experience is that aluminum ones shear off in crashes, and the heads strip too easily, so I prefer steel.
M3 Screw Assortment, Cap Head
The big advantage of cap head screws is their durability. It's common to go to change a motor and find that button-head screws have been scuffed to the point where they're essentially stripped. Not so with cap-head screws. The disadvantage of cap-head screws is that they're not as low-profile as button head. Cap head screws are especially appropriate for holding motors onto arms, and for the very front and back-most bottom standoff screws, which get the most abuse.