Park Pilot, Fall 2021
by Greg Gimlick
Now that you’ve gotten a park flyer or two, it’s time to start thinking about the things that will make your life easier at the field and in the shop. How many accessories do you need? The common answer is “N+1” where N is the number you have now. That means, you’ll probably always be adding more “just because.” It’s easy to get headed down the accessory rabbit hole, so look at what others have at the field and see what would make your experience better. I’ll try to highlight the items that I think are “must-haves.” Battery checker/wattmeter: These are “must-have” items. The terms are often used interchangeably and that confuses a lot of people. A true wattmeter will tell you the voltage, current, and watts under operating conditions. It connects between your battery and ESC for testing. When connected, you can run the throttle up and it will tell you how much current your setup is pulling.
When simply connected to a battery, it will tell you the total voltage, but not individual cell values. A battery checker won’t connect into a system the way that a wattmeter will, but it can connect to the balance port of a battery and tell you each individual cell’s voltage, along with the total pack voltage. It is invaluable to see how balanced the pack is. You can check before and after a fl ight to see how much you have run the pack down. Almost every RC vendor carries a variety of these, and most are inexpensive. Some will claim to check internal resistance too, but that’s a stretch when it comes to an accurate measurement. More on that later.
Battery checkers are a “must-have” and come in all sorts of sizes and capabilities. Be sure to find the one that fits your application
The Astroflight Wattmeter shows volts, amps, and watts under load
Servo drivers: They might not be “must-haves,” but servo drivers are very handy accessories to have when setting up a new airplane or replacing servos. A driver allows you to power a servo and run it through its range of motion—along with proper centering as you’re setting up the airplane— without the need to have a radio connected. Powered by a battery, you just plug in the servo and use the dial or touch controls, depending on the device, to run the servo and center it. The Spektrum XBC100 Smart Checker is great for this! Not only do you have a great battery checker, it also functions as a servo driver/checker. This gem kills two birds with one stone and doesn’t break the bank. This is my number-one pick.
Servo drivers are great for setting up a model without needing a radio. The Spektrum XBC100 doubles as a battery checker and servo tester/ driver!
Servo connector clips: You might argue that these aren’t absolutely necessary, but you must use some method to ensure that servo extensions don’t disconnect in fl ight. Admittedly, tape can do the job, but it leaves a sticky residue when you remove it and can end up weighing more. These clips snap on (you’ll notice in the photo that I didn’t push the one end all the way down) and remain secure until you pry open the tab and remove it. My scale goes down to 1 gram, and these do not register on it, so they’re extremely lightweight. Even with my quick mistake in assembling this for the photo, it’s on far enough that it won’t allow the connectors to come apart. These clips are great little items that can save an airplane and are musthaves.
Servo connector clips are super lightweight and effective to keep your wires connected in flight.
Glues and fillers: This category pretty much goes without saying, but what you stock depends on the materials of which your aircraft are made. With an eye toward newcomers and the number of foam models, I focused on two excellent foam glues: odorless CA and Foam-Tac (beaconadhesives.com/ product/foam-tac). Both work equally well to repair foam, but the Foam-Tac will also repair or make hinges. Either glue will get a broken wingtip or piece glued back on at the field and have you flying again, instead of having to pack up for home. Foam airplanes end up with some dings from landings, hangar rash, etc. over time. These materials will fill those dents and have your model ready for touch-up paint in short order. I use water-based fillers that sand easily and don’t attack any of the foams that I’ve used. Beacon Foam-Tac adhesive is excellent, but at a slightly higher price than home-store alternatives. It also seems to be more forgiving of surfaces that might flex during use.
Foam-safe glue is a must for modern foamies.
Fillers are handy for repairing hangar rash or landing mishaps that dent your foam
Tape: Various types of tape are musthaves. The good news is that they’re also cheap. I always have some Blenderm medical tape for repairing hinges, along with some double-sided mounting tape to secure servos that might come loose. Foam wings can often fl ex more than intended, and a strip of fiberglassreinforced packing tape down the spar area on the bottom of the wing can often cure that. If you have a stickbuilt airplane covered with UltraCote, MonoKote, etc., it’s good to have some clear packing tape to patch any holes at the field. This is a temporary repair so that you can keep flying. The sparkly tape that is shown in the photo below can be a lifesaver if you’re flying small gliders or any small airplane with which it might be hard to distinguish orientation at altitude. This is available from most places that have sailplane supplies. A small piece on the bottom of a wingtip, or wherever you think it will help you maintain orientation, works wonders. It catches the light and gives instant help in telling what is pointing where. It doesn’t take much of this to make a huge difference. It saved me many times on my little Radian sailplane.
Tapes of different types are a musthave
This sparkly tape is great for visibility on small airplanes. A bit under a wingtip will catch the light and clue you in to its orientation
Battery connector adapters: I try to standardize my connectors, but even with my best efforts, I end up with several types. I make a lot of my own adapters, but more are becoming available from hobby vendors. Try to minimize the types of connectors that you have and reduce the number of adapters that are necessary. It also helps to have a few of the common ones in case a friend at the field needs to use your battery, or vice versa. I’m a believer in organizing cases. As you can see in my photo, the number of adapters that I’ve accumulated throughout the years has grown beyond the point of just tossing them into a pocket. I found a plastic fishing tackle organizer in which to sort and store them.
Battery adapters are handy to make maximum use of your gear.
Charge adapters: I do a lot of parallel charging and that requires special parallel adapter boards that match my batteries. For single-cell packs, that’s an easy setup, but multicell packs require a bit more. They will also have the main battery connectors and a balance tap. If you’re using a small charger, be sure not to push the limit. When I go to the field or an indoor venue for a full day of flying, I’ll toss the small packs and adapters into another fishing tackle organizer. This is not for long-term battery storage, but it is good for a day trip to keep everything together.
Greg Gimlick’s fishing organizer keeps a lot of adapters organized and sorted
Parallel adapters to charge multiple packs are handy.
This box is an organizer for small packs and adapters when Greg goes out for the day
Battery storage: Safety is key when it comes to storing your LiPos between flying sessions. Do not leave them in plastic cases for short trips to the field. For maximum safety, both at home and at the field, you should have a selection of LiPo-safe bags. These contain the flames as much as possible and can prevent catastrophic results should the worst happen. For home storage, I believe in a bit of overkill. I keep all of my battery packs at storage-charge levels, inside of a LiPosafe bag that is stored inside of a steel ammunition can. Those ammo cans are stored inside of a steel truck box on a rolling stand. There is a smoke detector mounted directly over the rolling stand. Never leave them in your car! LiPo bags are a “must-have.”
This is Greg’s long-term storage scheme for maximum safety
This ammunition box holds a firesafe LiPo bag for double safety
ESC programming cards: Almost all ESCs come with instructions for how to program them using the transmitter and receiver connections, but I fi nd them cumbersome and difficult to remember. Most brands have programming cards that are inexpensive, usually $10 or less. These require no great feats of memory and can be connected at the field to tweak settings. Another feature of most is that they’ll tell you what the present settings are. This is especially handy if you’ve acquired a used airplane and don’t know why the motor isn’t acting right. Most of us have a smartphone of some sort, and that can come in handy for storing your instructions. Shoot a photo of your manual or save a PDF to your phone for reference when needed. If you don’t like the programming card option, some also have USB adapters and programs for laptops to see and change settings.
ESC programming cards are cheap and easy to use at the field to tweak settings.
Hot glue guns: These are great for some repairs. I have two versions, as seen in the photos, but the cordless version always makes a trip to the fi eld for those moments when a fi eld repair is needed. There are all sorts of cordless hot glue guns on the market, and some will connect to your 3S LiPo pack, if needed.
Hot glue guns are popular items for park flyer repairs. Greg takes a cordless one to the field.
Sticks, skewers, and toothpicks: I keep a selection of wooden skewers, popsicle sticks, and toothpicks in my field box. The popsicle sticks are great for spreading Foam-Tac on a hinge line that needs reinforcement or to smear epoxy across a surface. The skewers can be used to reinforce a piece being glued back on. I’ve repaired broken stabilizers and wingtips by sticking them into one side before gluing the other piece in place. It goes into both sides and securely holds everything with glue. They can also replace rubber band hold-downs and other hatch pieces that are broken.
Skewers and sticks come in handy for field repairs and reinforcements.
Infrared heat guns: Nothing fancy or expensive is required here, but a heat gun can be a very handy item. I like to do a baseline test when I get a new model to see how hot things get under normal conditions. This can be handy as things age because you can see whether the motor is running considerably hotter. This could also indicate whether bearings are failing, etc. If you’re a helicopter pilot, use the gun to shoot the temperatures of all of the bearings on your aircraft, and periodically do it again to see if any are getting hotter than usual. The same goes for shooting battery temperatures. The generally accepted maximum temperature of a LiPo is 140° F. This is where damage happens rapidly and should be avoided. If your packs are getting hot, look for reasons why. Have they been overcharged, overdischarged, or pushed beyond normal limits? Know what the normal is for your setup and watch for changes.
Temperature guns can clue you into trouble before it happens.
Air and fuel lines: I keep a supply of Robart (robart.com) air line and some regular fuel line in my fi eld box. The fuel line can be cut into small bands to secure the clevises on your control horns. Many come with a small band on them, and they’ll age and break over time. These can slide over the clevis to replace them and last a long time. The Robart air line is perfect for reinforcing antennas on receivers. They usually exit the receiver through a small plastic extrusion and can be bent and crushed against the edge if you’re not careful. Pushing a small piece of air line tubing over the antenna and onto the plastic extrusion will protect them from damage.
Robart Manufacturing air line is great to use to protect receiver antennas
IR meters: This is probably considered a luxury item by many, but I maintain that everyone should have some means to test their LiPo packs for IR (internal resistance). I mentioned that some of the battery checkers claim to test IR, but it’s a poor kludge of true testing. Some chargers will also check IR and they are better suited than the inexpensive battery checkers. The optimal method is to have a device designed to do just that and replicate the exact conditions every time for comparison. If you never plan to fl y things that require more than single-cell or small 2S battery packs, this is probably an item you’ll pass on. The LiPo ESR MkII meter sells for approximately $150. Because I fl y everything from singlecell to 12S battery-powered airplanes, I live by my ESR MkII test results. It allows me to sort packs to match perfectly when they are used in series to get extra-large packs (12S from two 6S packs, etc.). I maintain roughly 30 3S 2,200 mAh LiPo packs and track their IR so that I can adjust which airplanes I use them in. When a pack starts to show that it’s no longer capable of handling a model’s demands, I change it out to one that can. The ESR MkII will tell you the actual C rating of a pack and each cell within the pack. You’ll fi nd that few packs actually match the advertising claims, but this will tell you how much you can expect from your packs without damaging them prematurely. It’s not a “must-have” item unless you’re adamant about data collection and adjusting your use for maximum return on your dollar. My oldest LiPos are 10 years old.
Experienced park pilots might want to look into devices to accurately test IR.
Conclusion: Build your arsenal of accessories slowly as you fi nd out what you need. Everyone is different and no one list will fi t everyone, but I hope this shows some of the things that I’ve discovered have come in handy throughout 30 years of electric flying. Watch what others in your group carry or say that they wish they had. Not everyone likes to repair something at the field and that’s fine, but if you want to repair and continue flying, some of these things will allow for that. You absolutely need a battery checker, tape, glue, adapters, and safe battery storage. Your “must-have” list will develop itself as you continue to expand your hobby. Don’t sweat it— just enjoy it.
By Greg Gimlick | email@example.com