Dave Patrick Ultimate 120 ARF

(link to build images)

This bipe was a must-have for my client. To make it work, I needed to put the plane on a major diet. Diving right in, off came the covering and the surgery began. I pulled out wood every place I could without sacrificing the structural integrity of the airframe. At this point, I could have probably started with a kit and ended up with the same number of hours, but I was knee deep and needed to continue. We have a proven design and in the end this will make a great electric bipe.

The rebuild started by finding a home for all the electronics to make proper CG. With the motor mounted and the batteries up against the firewall, I needed to mount the dual elevator and rudder servos in the middle of the fuse. I ended up making the servo access a rear air vent.

The assembly of the cabain and wing struts is a timely event at the field, so an external battery access was a must. The structure of the fuse enabled me to create a battery access in the side of the fuse without cutting any holes. I framed up a removable panel to allow the access. Next was the battery tray, I designed and fabricated a sliding tray on two stainless rails for CG adjustment.

I was able to remove about 5-6 oz’s by remounting the 4 wing servo mounts and covers. I cut a carbon fiber rib that held the servo. The covers were vacuumed formed styrene.

The idea for the graphics came from a logo designed by a friend. The “American Winner” idea was a blend of a checkered flag, from auto racing, and the American flag. Cutting vinyl for the stars and stripes and painting the fiberglass parts, I was able to create a piece of art. Applying the logo to the airframe was a challenge but worth every moment.

The maiden flight was eventless and needed only a couple clicks of trim. Unlimited vertical performance with about 2/3 throttle to hover made the plane a joy to fly. All of the hard work making this a light airframe was worth the effort.

 

Here are the specs: