Battery access in foamies
and 2014 Slope events
by Dave Garwood
After six years of service, a receiver battery pack in one of my favorite Slope Soarers failed to hold sufficient charge to power the onboard radio gear. The first symptom was slow servo response, and pack inadequacy was
confirmed with a volt-meter check.
It’s generally a headache to remove and replace a battery pack in a foamie
because they tend to be buried in foam and glue. In my April 2013 “RC Slope
Soaring” column, I described a method for making the receiver and elevator
servo accessible in a foam fuselage in case they need to be exchanged or serviced.
Here’s a method for making the battery pack more accessible.
Start by digging out the old battery pack, working slowly and carefully, and
trying to preserve the wiring. Unsolder the old pack, solder the new pack, and
press it into place. Add EPP foam to give the new pack a tight fit in the old
Add nose weight if the new pack is lighter. Charge fully and measure its
capacity with a battery tester. Some battery chargers include the capability to
measure capacity while discharging a pack. Installing a pack that does not meet
or exceed its rated capacity will guarantee a short service life.
When satisfied with the battery pack’s capacity, the added nose weight, and
its snug fit in the old cavity, cut an EPP foam plug to fill the slot. Do not glue
the battery or the plug into place. They will be secured with filament strapping
tape. I prefer to use bidirectional filament tape. 3M Scotch Extreme Shipping
Strapping Tape is my favorite.
Before taping the retaining plug into place, mark it boldly so it can be located
under the strapping tape with the covering peeled back. Prominently mark the
edges of the plug so you’ll know where to cut the tape to release the plug in case
your airframe requires another battery replacement.
This method is not as convenient as a hatch secured with magnets, but this is a
Slope airplane, and the airframe must be able to take more of a beating than any
Slope Soaring Events in 2014
Ten national and regional Slope
Soaring events had been announced
at the time of this writing in early
January. Be sure to check event
websites for current information.
1. Cumberland Spring Soar for Fun,
March 20-24, Cumberland, Maryland:
Launch by aerotow, Discus-Launch
Glider (DLG), high-start or winch,
and fly from a mountaintop in big
slope lift on the western face of the
2. The 21st Los Banos Scale Sailplane
Event, April 26-27, Los Banos,
Entering its third decade of Slope
flying and aerotowing of large-scale
modern and vintage sailplane models.
The steep, grassy slopes of the Los
Banos Creek Reservoir provide lift in
several wind directions.
3. North Coast Glider Games, May
Slope Combat and Slope Pylon
Racing on five hills. Altitude Limited
Electric Soaring (ALES) and Winch-Launched Soaring if winds are not
favorable. There will be indoor flying
and a pizza party after dark.
4. Midwest Slope Challenge, May
15-18, Lucas, Kansas:
The 21st running of a venerable
Slope flying gathering. It includes a
At Perry Township Park OH, during the
2013 North Coast Glider Games, the
author flies his 60-inch Magnum Models
MiG- 3 warbird over a wind-whipped Lake
Erie. Photo by Ken Stroud.
123 Model Aviation APRIL 2014