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Speed Runs in Perspective

By: Bob Violett

September 2010

 

   Flying machines that go fast have been a part of my life from the early days of setting control line speed records, to pylon racing, to piloting supersonic jet fighters for the US Navy.  So, it is only natural that my company partakes in the recent interest in seeing how fast E.D.F. jets can go.  E.D.F. jet racing got its start at E-Jets International in 2009.  BVM Electra’s won the top 5 places without any special preparations.

   Some refined ground rules were established for 2010, and again, BVM Electra’s won the top 5 places with EVF units powering the top 3 racers.  This year, we put a little extra effort into the top 2 placing systems.  We believe that Dustin’s 227 mph highest speed and two way average of 218.5 mph is the best yet recorded under similar conditions.  Rob Lynch was just a few mph off this mark.

   So, where is this all going and what benefit does it have to the consumer?

   For sure, the more Watts one throws at the motor, the faster the plane can go.  Using our standard of 3.85 volts per cell under load, this special Electra was propelled by 8,662.5 Watts.  Attention to airframe drag is also important.

   My 3rd place 12 cell, Electra consumed 6,883.8 Watts for a top speed of 208 mph and an average of 197.5.  The relationship between velocity and horsepower (Watts) is clear, to go a little faster, you need a lot more power.

   The top 3 EVF powered Electra’s were efficient enough to make 4-5 runs at the radar and still have plenty in reserve for a few show-off aerobatics and a safe approach and landing.

   There is some value to you in this pursuit when incremental gains in efficiency are accomplished and applied to our products.  But, the average EDF consumer that wants reliability and long flight times, does not want these high amperage, high heat producing motors in there scale or sport jets.  They only spell trouble and expense. 

   Some EDF suppliers will try to sell you systems that consume 140-200+ amps.  These systems will eat the batteries and crash your model when the limited supply of energy is soon exhausted. 

   The BVM EVF (2) 10s and 12s systems draw 110-115 amps installed in a properly designed model.  99% of our customers find that this is quite enough.  They want reliability and flight time.

   Yes, we can sell the special “Race” motors, but only to very experienced users who simply must have 200+ mph performance and fully understand how to handle it.

   Personally, I like this electric stuff, so you will see steady gains in airframe availability and propulsion efficiency from BVM.  It is also important to you that BVM manufactures, owns, and keeps in house, all of the critical tooling, so that what you buy today, can be serviced for many years to come. 

   It is a business model that has worked for BVM for 25 years.