Specifications

All battery types, especially NiCad and LiPo battery packs, must be disposed of properly. In
the US, go to www.rbrc.org to find the nearest battery disposal site.
More information on R/C batteries can be found at Red Scholefield's R/C battery clinic at
www.rcbatteryclinic.com and also at www.batteryuniversity.com..
30.9.5. Solderless power tube (SPT) battery packs
The endcaps of the solderless power tubes can be damaged in hard crashes when the battery
pack is ejected from the helicopter. These endcaps can be purchased separately from MEC.
My experience with the SPT battery packs is the battery terminals tend to oxidize as the batter-
ies are heated and cooled. This oxidation results in increased resistance and the battery pack
may appear to be weak.
I recommend disassembling the SPT battery packs about once a year and inspecting the bat-
tery terminals. If the positive terminal has a thin film of white residue on it, then this is a sign
the cell has vented. This indicates the cell is probably weak. You should clean the terminal and
write a mark on the cell to indicate it has been cleaned. If this cell requires cleaning more than
once, it should probably be replaced.
30.10. Maintenance and crash repair
30.10.1. Brushed motors w/carbon brushes
After every ten flights or so, the carbon dust should be blown out of the motor with compressed
air and the commutator checked to see if it is clean. If the motor is assembled with screws and
the commutator is dirty, disassemble the motor and burnish the commutator with some extra
fine steel wool or 1000-1200 grit sandpaper.
30.10.2. Main rotor shaft bearings
Some helicopters (ECO, etc) have open-faced bearings. These bearings are not sealed, and
because the ball-bearings are exposed, they can become contaminated with dirt and grit.
If you notice the main rotor shaft bearings grinding or not rotating smoothly, then they should
be removed and cleaned in some good solvent or cleaned with compressed air. If they still
sound or feel funny, they should be replaced.
30.10.3. Tail rotor shaft bearings
The tail rotor shaft bearings may incur damage if the tail blades touch the ground, especially
on the ECO 8/16. They should also be checked periodically and cleaned or replaced if neces-
sary.
30.10.4. Tail belt tension
Tail belts tend to loosen over time especially if the tail boom mount is loose. They should be
checked and retensioned periodically.
30.10.5. Battery retaining o-rings
O-rings will last longer if they are unhooked from the battery mounts when not in use. If they
are left under tension continously, they will develop cracks over time. The o-rings should be
checked periodically and replaced if necessary.
Technical Appendix
210