It looks like spring is finally coming! I brought my running gear in to work and was able to sneak out for a quick 2.9 mile run after lunch. It was a balmy 41 degrees, overcast, and starting to sprinkle- but it felt great to be outside.

I was hoping that I'd be able to bike into work tomorrow, but since I'm visiting our injection molding vendor that won't happen. I might get lucky and be back in the office early enough to allow me to swing home after the vendor visit and ride in for the afternoon.


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P-51BL Upgrade & Tricopter Update

Parkzone P-51BL structural upgrade
Over the life of my Parkzone P-51BL I've gone through two fuselages, and I'm now on my third. The previous two had failed multiple times just forward of the leading edge of the wing. I think they broke as a result of wildly overpowering the airframe, vibrational fatigue, and repeated impacts from hard landings. So, before I started flying fuselage #3 I thought I'd add some additional reinforcement. Next time it'll fail somewhere else... Part of the problem might be to fit the larger 2200 mAh batteries, I had to carve out a fair amount of foam.

I glued in several pieces of 1/8" liteply to the bottom and sides of the battery compartment. I also moved the velcro battery straps rearward and placed them under the plywood. So far, the modifications appear to work well. No breaks yet and the battery is securely held in place.

Tricopter Update
The wiring harness is almost done... I just finished the wiring harness to allow the main battery to first initialize the gyros via a UBEC, then once they are running the second switch will supply power to the ESC's for flight. Next step is to build a wiring harness to connect all of the gyro gain controls together. (the JST connector is for the UBEC)

Multi-Camera Angle Video

This was my first try at a multi-camera angle film. You can see how motor vibration increased from the first to the last run. By the final runs- with the rear-ward facing camera- the vibration was bad enough to turn most of the field of view into "jello". I believe the issue is linked to the Hobby-King 10x5 APC clone prop. I'll be switching it out with a real APC and see if it rectifies the issue. I'm planning on using those HK 10x5 props for the Tri-copter, so I'm going to have to try and balance them to remove any vibration.

Also, during the final camera run the camera was ejected and fell several hundred feet down into the snow! This happened at the farthest distance away from me in the pattern I was flying. I saw a dark spot leave the aircraft, and initially I thought it was just my eyes playing tricks on me. When I brought the aircraft back, I noticed the camera was missing. It only took me an hour and a half searching on Saturday and another hour on Sunday to find the camera. ;) When it impacted the snow, it left a perfect rectangular hole, then penetrated down to the ice. Luckily I found it Sunday afternoon, because later in the day it started snowing. If I wouldn't have found it when I did, it would have been lost forever.

Tricopter Inches Closer to Completion...

After work tonight I was able to finish up the drive mechanism to tilt the "tail" rotor of the tricopter. I must say, the du-bro ball links are sweet. I re-used one from last summer's ill-fated "speedwing." The parts are all machined out of scrap delrin. The servo is taped to the bottom of the swiveling motor mount with some 3M VHB tape.

The entire motor / motor mount / servo assembly rotates about the aluminum spar. The black delrin piece at the end of the spar is fixed rigidly to the spar. So, when the servo actuates, the entire assembly rotates and the tail rotor will slew from side to side- hopefully providing a nice yaw rotation of the Tricopter.

Once this was working properly, I started mounting the gyros. This Tricopter will use 4 Hobbyking 401b gyros, one to control every axis of rotation. Everything I've read online says these gyros are very sensitive and negatively affected by vibration. I decided I'd mount the gyros on plywood daughter board, isolated from the main chassis through some rubber grommits. I'll also mount the gyros to the daughter board using double-stick tape. Hopefully both of these steps will help. If these steps are not enough I'll tear apart the gyros and tweak them as shown many places online.

Daughter board mounted

Gyros and Receiver Mounted

Lots 'o' wires

Next steps:

• Build wiring harness for gyro gain control
• Build wiring harness for initial gyro spin-up and ESC arm, then final flight power