Monday, April 11, 2016

New Life for an Electric Glider

Several years ago, I am thinking it has been over 10 years, I had purchased an ARF electric glider with a 60” wingspan. The fuselage was a heavier fiberglass fuselage but the wing was built-up balsa with a transparent covering. There was very little work left to be done, where ever this plane was built the labor cost must have been very low.  

Before Conversion

Speed 400 Gear Drive

Power for the electric motor was first from nicad batteries and later a nimh battery. The motor was the popular Speed 400 but it was geared down to spin a larger propeller. This system was adequate to climb to altitude but only a couple times at the most. Despite the rather heavy weight I had some good thermal flights with it. The real downside was needing multiple batteries and the need to do field charging to get much flying in. At some point it went on a shelf and never converted to 2.4 mhz radio.

Before First Flight of Conversion

Not long ago I thought I really should fly that glider again with modern equipment such as lithium battery, brushless motor, and 2.mhz receiver. The servos were moved way back for balance but were small servos, I thought it might be tough to get the CG located with lighter equipment so I decided I will mount the motor out front of the glider. This might have not been necessary as I am using the rather large 1350 mah lithium batteries that I use in my Radian Pro. 

Brushless Atlas Motor

Slowly I am learning about electric power but instead of trying to calculate the proper motor size needed I just inquired on soaring club listserve. Several people gave me good ideas but someone offered to send me two electric motors to try, Thanks Rich you are the best.  The one motor was designed for a rear mount so that is the motor I used. Before putting much effort into the project I just epoxied a plywood bulkhead to the front of the glider and attached the motor with wood screws. Taped in the battery and went flying. 

Magnetic Hatch, Messy Micro Balloons

This motor seemed to be the perfect match; it easily pulls the glider to altitude. Soaring performance is still not going to be wonderful but it is perfect to grab after work with one charged battery and do a good amount of soaring from a small field. It is working so well that I went to the extra effort of blending the nose to the firewall and installed a magnet system to hold the hatch on.

Now maybe I should look at a couple more old airplanes on the shelf.

Bill Kuhl


  1. Inspired to get a couple of my old soarers back in the air and even a couple that were never designed for electric but fly so well.

  2. Best investment for soaring, perhaps a folding propeller.

  3. Thank you for the comments, I need to get a folding propeller to try.