>> As I write this column, New Jersey, and much of the US, is experiencing a very cold spell. It is the time of year when I do the most indoor flying and attend indoor events.
Fishing tackle cases with removable trays come in a variety of shapes and sizes. They can be used to store a number of items in a small space. Shown is a Plano Guide Series with four 3750 trays.
Indoor flying can present a number of unique challenges, especially for aerobatics pilots. Some maneuvers can only be completed in a confined space by getting close to walls, the ceiling, or the floor. An occasional bump can happen—not to mention midairs—because of having multiple airplanes in small spaces, or bumping into basketball hoops or hanging banners.
A well-prepared pilot will have the necessary tools and materials to make repairs. Keeping weight to a minimum is important to avoid adversely affecting flight performance. Indoor aerobatic airplanes are sensitive to weight because increased weight means faster overall flight speed, and the space effectively gets smaller.
Mishaps are hard to avoid when flying indoors, so having some essential items increases the likelihood of being able to make field repairs to keep flying sessions from coming to an early end.
Another challenge of flying indoors can be recharging batteries. For an evening of flying at the local gym, it might be reasonable to have enough charged batteries to avoid recharging.
During weekend events, do you know where the nearest outlet for recharging is? Is an extension cord needed or a power strip to share a single outlet with multiple pilots? Is a power supply required to step input voltage down from 110 volts to 12 volts? Maybe it is easier to have your own power source.
My approach for both challenges starts with fishing tackle trays. Available in myriad sizes and configurations, they are effective for organizing a lot of items in a small space.
I have a field box dedicated to indoor flying. It has four removable tackle trays—each filled with different types of equipment/tools/spares.
The first is the essential flight tray and has batteries, charge leads, and a collection of tools. During a good session, this is the only tray that sees any action.
The second tray holds spare parts for minor mishaps. It is filled primarily with a variety of propellers, propeller adapters, and propeller savers.
The third tray has spares that might be needed for bigger mishaps. It has servos, receivers, speed controllers, linkages, screws, and miscellaneous fittings.
The fourth tray is the crash tray and it has a variety of scrap foam (Depron and EPP) in assorted thicknesses (1mm, 2mm, 3mm, and 6mm), an assortment of carbon fiber (rods, tubes, and flat strips), lightweight fiberglass cloth, wiring, and Kevlar thread. In the top lid compartment of the field box, there is room for bulkier items such as a small cutting board, a propeller balancer, a sanding block, glue bottles, and a small soldering iron.
However it is organized, I would consider the essential items to be:
• Glue: Thin and medium foam-safe CA; kicker for Depron and carbon fiber; Foam-Tac or Welder glue for other foam types
• Tape: 3M Blenderm medical tape
• X-Acto knife; single-edge razor blades (stored in a foam block for safety); cutting board
• Fiberglass cloth and scissors
• Scrap foam and carbon fiber
• Sanding block and old hotel room key card that acts as a building square and straightedge
Crash damage is often easily repaired by simply gluing loose or cracked parts back together using thin or medium foam-safe CA glue (depending on how well the parts fit). Mylar covering tears can be fixed with 3M Blenderm tape. Areas of foam that are weak from being folded or crushed can be reinforced with lightweight fiberglass cloth to restore the integrity of the foam skin.
Severely damaged foam or missing foam can be replaced with new foam scraps. Broken pieces of carbon fiber can be replaced or splinted with a new piece of carbon fiber. Kevlar thread is useful for wrapping joints between carbon-fiber pieces and other hardware bits such as linkages and fiberglass parts.
Many foamies use an X mount to attach the motor to the fuselage. After multiple repairs, the gluing surface between the X mount and the fuselage can become uneven and reduce the amount of gluing area.
This is another situation where 3M Blenderm tape is useful. After gluing the X mount on, a single strip of tape can be placed on the front side of a mounting leg, and then adhered to both sides of the foam. This small bit of reinforcement will keep the motor from coming off the airplane if the glue joint fails.
Even in situations when 110-volt power is available, having your own power still offers a greater amount of flexibility in choosing a pit area. Many chargers commonly used for indoor flying utilize 12-volt input, and some chargers can handle as much as 25 to 28 volts input. A few chargers utilize 6-volt input.
Never alter the input power supply/pathway of a charger without verifying the input power requirements (voltage and amperage) and confirming polarity of the input. A common park flyer LiPo battery is a 3S 2,100 mAh, and it can effectively power many of the chargers used for indoor flying. Larger, high-end chargers that accept higher voltage inputs can be effectively powered by 4S, 5S, or 6S LiPo batteries.
Pictured are two charging setups that I use for indoor flying. The first utilizes a 2S 2,250 mAh LiPo and some homemade adapters. A power meter is used inline with the 3S LiPo to provide information on amp draw (from the LiPo to the chargers), voltage of the 3S LiPo, and mAh drained from the 3S LiPo battery.
The adapter allows up to four 3S LiPo batteries to be used in parallel as the source power, and up to four chargers to be connected using alligator clips. I use this setup primarily for charging 1S ultra micro batteries for airplanes, helicopters, and quadcopters. Roughly 20 ultra micro batteries can easily be recharged prior to the 3S LiPo voltage dropping below a safe level (11.1 volts).
With slight reconfiguring of the foam padding, this JR dual transmitter case easily holds one transmitter and three Plano 3775 trays. Trays can be used for batteries, chargers, and spare parts.
The second charging setup I use is for larger indoor batteries: 2S to 3S LiPos up to 500 mAh for 180- to 300-size airplanes. The same power meter is used with a larger 5S 5,000 mAh battery as the power source. The adapter allows up to four LiPos to be used in parallel as the source power, and as many as seven chargers to be connected using 4mm bullet connectors. This larger charging setup can also be used to recharge a 3S 2,100 mAh LiPo for the smaller charging setup.
With a couple of homemade adapters, a 3S 2,250 mAh LiPo battery is used to power multiple 12-volt chargers to recharge indoor batteries. A power meter monitors the voltage and mAh discharged from the 3S LiPo. When the resting voltage of the 3S LiPo drops to 11.1 volts (3.7 volts per cell), it is time to recharge the 3S LiPo or switch to a freshly charged 2S LiPo.
By Dave Lockhart | davel322@comcast.net
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