I ended up a bit behind on blogging while Greg was here. By the time we were done with the day’s activities and I ensured my slave labor, I mean volunteer help, was well fed, I just didn’t have it in me to write up a post. So in an effort to document what we got done and catch you all up on the status of the Defiant, here is a quick summary and most importantly some pictures.
- Exhaust
- Canard Mounting
- Elevator Actuation
- Betty Check Out
You’ve seen the explanation of what the exhaust scheme is for each engine. Front engine has a 2 pipe exhaust system with an augmenter. The rear engine has a 4 into 1 exhaust system with augmenter. I called in my custom exhaust guy to do his magic. It took him a full two days to get both engines done, and it is exactly what I wanted.
After the exhaust was done, Greg and I moved on to mounting the canard. With the exception of the canard lift tabs being an extremely tight fit between the firewall and the canard mounting bulkhead, it was a mostly straight forward task. The only real challenge was that Brian had already drilled the lift tabs so we had to match drill the fuselage side of those. If they would have been line bored as an assembly it would have been much easier. Of course we measured sweep, vertical position, incidence, and roll many many times before drilling. With digital levels, lasers, and tape measure we were able to get things to within .1 degree on the digital level and approximately 1/16″ for sweep and vertical position. Surely accurate enough for an airplane designed in the bubble level days.
Once we got the canard mounted we also started working on the elevator actuation. As I got them from Brian, they were built long and needed to be trimmed to fit. That was the first task. Once we could install the elevators we started working on actuation. This included carving an arc shaped hole for the elevator actuation to pass through the side of the fuselage. Once we had that done, we could mock up the elevator components and check to ensure we got full travel.
Getting full travel of the elevators proved to be a challenge. There were two factors, or adjustments, that made it challenging. The defiant elevator torque tubes have a disc installed at the root end which locates the pushrod attachment. The rotational orientation of this disc is not easily measured to a high degree of accuracy on the plans nor the actual elevator. A small angle change of that disc seemed to have a large impact on the elevator travel. So before we drilled and riveted it in, we 5 minute epoxied it into the tube to test travels. I am glad we did as we ended up changing its orientation multiple times.
The other adjustment that was elusive until we dug deeper into the plans and arm-rests was the attachment of the push tube on the stick in the cockpit. There are 3 holes to choose from on the stick and 3 on the elevator torque tube bellcrank. Since we didn’t build the stick, Greg and I spent some time figuring out how to easily disassemble and move the torque tube to the lowest hole on the stick for the most linear displacement. Lastly, we also had to remove the stick grips as they were also limiting travel.
Little by little, we found each of these challenges and adjustments and eventually we were able to get full displacement of the elevators. It was kind of tedious and frustrating at times, but the elevators are essentially actuated now. I do have to order proper sized hardware and remake 2 of the push tubes as they ended up slightly too short. But with it mocked up, there shouldn’t be any surprises there.
When Greg offered to come and help, our big goal was to get the Canard mounted. To get the elevators actuated as well was a big plus.
Lastly, its taken 5 years to do it, but we finally got Greg to fly Betty. He has gone for rides in the back, but he finally was able to fly as PIC in Betty. He has tons of Long Ez time, so it really was a non-event for him, but Greg is the first person I’ve let fly Betty. We did a flight with me in the back so I could answer any avionics related questions etc, then he went out and did a solo flight. After his many years of helping me with projects, Betty especially, I am happy he is now checked out and can fly Betty anytime he wants to.
the Garaggio 