"A First"
An Electric Ducted Fan Event

2007

Kyle Normberger thought it was time for such an event and so he made it happen.  With the support of his fellow Ocala R/C Flyers, they hosted about 30 entries at their "picture perfect" club field just off Interstate 75 in Ocala, Florida.  Kyle topped his day with a flight on one of our factory demo Electra's.

This happy group flew these BVM "E" Jets many times during the one day event enjoying the 80°F warmth of December in Central Florida. 

L-R David Plaine, Chuck McClellan, BV, John Banner, and Bob Fiorenze.

(4) Electra's and (1) F-86 - all EVF and EVO powered.Flight Power, Director of Marketing, Colin McGinn and Steve Rogers (technical support) attended the event to observe the state-of-the-art in electric ducted fan propulsion (EDF).

A significant part of the "State" are the new 30c 2p 6400 mah Saddle Cells. Shown here as (2) 5s 2p packs in series in the Camo Electra.

For a 12s setup we use (2) 5s 2p and (1) 2s 2p packs in series.  This combination was flown for the first time in Bob Fiorenze's EVF 5012 powered Electra Jet.

The performance and flight times were awesome and the after flight battery temps are the coolest we have seen at just over 100°F on an 80°F ambient day.

Sleek looking and efficient, this BVM Electra Jet logged several flights at Ocala with the EVF and EVO batteries for power.

More info on these and other Lipo battery combinations for the EVF soon.

Liberty Bell 2007

At the Liberty Bell event, we shared the use of a Honda generator with the Malchione "E" pilots to power the IOTA converter unit. A pair of BVM Cool Trays definitely helps to shorten the turnaround time. A single Thunder Power 1010C charger and balancer will handle the 10S system while the 12S requires 2 units.

Some Battery Numbers

We did field charge a few times at 1.5C after the "Cool Trays" did their work. It is important to note that the outer cells in the pack will cool faster than an inner cell. This is not an issue with the BVM 5S1P Saddle Cells™ but the 6S1P Saddle Cells™ will require a few minutes for the pack temperature to normalize.
The cycle time in this hot weather is about 1 hour; 15-20 minutes of cooling time and 40-45 minutes of charging time.
Be sure to check that the Saddle Cells™ are within .1 volt of each other after charging and prior to flight. We keep a volt meter handy and always check each pack prior to installing them in the model for the next flight.
If you have multiple sets of Saddle Cells™ it's a good idea to label them such that you can operate them in pairs.

    Sometimes there is a stubborn cell or two that requires more time to balance. We have found that if the maximum difference between the cells in a pack is .02 or less, it is ok to fly if the flight profile does not push this pack to the limit.

NOTE: The Thunder Power charger/balancer allows you to read each cell voltage accurately to 3 decimal places.

Slower charging (1/2C) in your shop will allow the balancer to complete its work.
In summary, the BVM EVF products allow you to enjoy high performance electric jet flying in August which is usually hot anywhere in the U.S.A. Just follow the guidelines presented here as you gain some experience.
My thanks to Chris True, and the technical assistance people at Flite Power and Thunder Power for guiding us through this learning process. We will keep passing along this kind of operational info as we continue to gain experience.

Bob Violett

EVF Powered BVM Jets at the '07 Liberty Bell Jet Rally - Electra Jet's, F-86's and the F-16. The blue impulse Sabre and the Thunderbird F-16 were flown by the Malchione "E" team. More on these "reborn D/F models" in a later post.

Dave & Pete Malchione with there EVF F-86.