Last month, we left our fuel tank filled and in the right place to insure trouble free operation. The tank setup is good, we already know how to set the high and low-speed needle valves and the proper glow plug is in place. Now we just need to get the engine started to have a really great flying day. The first of many.

Modern glow engines are so user-friendly that we only need to make the glow plug glow and then find some way to rotate the engine to get it started. With modern industry and modelers’ imaginations being what they are, there are now about five million tools to perform each operation. Of course, we need some place to house these millions of tools.

Photo 1 – The Hangar 9 field box on the left arrives fully assembled with a power panel cutout. The Great Planes Master Caddy needs more work but has a detachable starting box to permit remote starting at contests, fun-flys and wherever club rules require starting outside the pit area. (Photo courtesy of Hobby Hut, Pompton Plains, NJ)

From 1970 to 1974, I housed all the field equipment I owned, a 2 oz. turkey baster with a fuel line attached, a 1.5V battery with alligator clips, a “chicken stick” and some tools, in a brown paper bag. But the baster took five minutes to fuel a sixteen ounce tank, the battery was always dead, the alligator leads were constantly shorting out against the engine’s head fins and the chicken stick kept breaking the wooden propellers. If everything was actually working, then the bag would rip open, spilling everything onto the ground.

I do not recommend such limited equipment to anyone but, in truth, this is all you actually need to get flying. But there are better ways today, so lets look at some of them. It is a good idea to find a home more permanent than a paper bag for your field equipment and many manufacturers offer these “field boxes” such as the ones shown in photo 1.

Expect a field box to be able to hold all the tools you will need plus a gallon of fuel, full pump, glow starter, power panel, 12-volt battery and electric engine starter. Some field boxes, such as the Master Caddy, are equipped to hold the aircraft during field assembly or repairs, but not for engine starts or runs. Although each field accessory, such as the Thunder Tiger fuel pump in last month’s article, can be powered from its own battery, most model pilots find it more convenient to use one 12-volt battery to run everything through a power panel.

Photo 2 – Gel cell field box batteries come in various sizes and voltages. The larger battery has a 7 Ah capacity while the smaller one rates at 4 Ah. A charger is also required. Power panels range from advanced on the left to basic and inexpensive on the right.

Photo 2 shows a few of the many such batteries and power panels available. Most field box batteries are 12-volt “gel cells.” Gel cells do use common lead-acid technology but in a different form that does not spill or require venting. Motorcycle batteries are also often used, but must be firmly fastened in an upright position and completely vented to the outside.

The most popular 12-volt gel cell battery has a capacity of 7 Ah (amp hours). This is more power than required on most flying days. But sometimes a balky engine, yours or a friend’s, can make excessive power demands on a field box battery that you forgot to charge last night. For these occasions, you may find that a 9 Ah battery is ideal.

If you always connect your starter directly to the battery without a power panel, consider a system that I use for Pattern competition starts where only three minutes, from start to airborne, are allowed (photo 3). Use a heavy-duty starter (discussed later) and a 4 Ah, 12-volt battery wired in series with a 4 Ah, 6-volt gel cell. This setup could probably turnover a big block V8. But always make sure your engine is not flooded as this much starting power could damage an engine hydraulically locked in place with liquid fuel.

Most electric fuel pumps use 12 volts, as do most electric starters. But the average glow plug burns out above 2 volts. If only one battery is used to power the field box, then some sort of voltage control system must be used. The most common is the power panel like those pictured in photo 2.

Power panels range in sophistication and cost from basic to expensive. The Hobbico Accu-Glo power panel in photo 2 automatically adjusts glow plug power based on the plug’s power requirements. This helps a slightly flooded engine (not one hydraulically locked) to start. The panel also indicates the field box battery’s power levels, whether the glow plug is good and has a charging jack for the popular rechargeable single-cell glow igniters. The basic Hobbico panel has the glow igniter’s charging jack, but the pilot must manually adjust the glow plug’s power levels and know that a zero meter reading means the plug connection is bad.