BBA/Winter Build 2017/18 - Top Flite Corsair

willsonman

Builder Extraordinare
Mentor
Years ago, I had my doubts too. I used to only enjoy the sport scale kind of stuff and then I fell in love with the detailing. Different things at different times. I just got to the point where I really loved building I wanted to be in my shop more so I tried new things that I had seen elsewhere.

There were many times at FF this year that I saw an airplane, not nearly as detailed as this one, and thought "that is soooo cool!" Just because it does not have all the intricacies does not make it any less inferior. It is always a reflection of the builder.
 

willsonman

Builder Extraordinare
Mentor
Finally unpacked tools and all from FF and dig into the tail gear. Again, I built this light but seeing as I ended up nose heavy I’m going to beef things up a bit.

I will add a shock absorber to relieve some of the energy of bumps and the strut along the ruler here is where it will go. It will be a tight fit with the pull-pull lines for the steering but a necessary evil.
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This picture shows the weak spots. The carbon did its job on the top piece but I’ll end up with metal here as this is the second or third break of this part. I laminated some brass with mechanical solder but may just end up with thinner steel. The other plate will be reinforced with carbon tow and still be able to flex once the shock is installed.
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willsonman

Builder Extraordinare
Mentor
After scratching my brain cells and moping about how to do this, I had a bit of inspiration from browsing through the Lowe's website. I was searching for springs and stumbled across those spring rods for curtains. Eureka! I knew I had one stashed away in our storage room so I made a straight go for it when I got home from work.

The problem I faced was with the spring. The smaller diameter of wire the less spring resistance there will be. So, I knew I needed something substantial but not too big given the clearance of the steering arm. If you go too large of a wire then you run into compression length. I had to then make a compromise and design the shock with the spring on the outside. Not scale, but functional. Remember, this needs to dampen the tail end of a 13-pound airplane.

Taking some hardened brass tube I had laying around I gathered some other odds and ends to start assembly using mechanical solder. This is sort of like brazing but not exactly.
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There is no mechanical piece to keep the shock tubes together other than the form of the assembly itself. However, there is 8mm of overlap between the inner tube and outer tube and that takes away my worry of things ever binding.
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Then I had to fabricate the piece that kept breaking. I had previously made it from two layers of brass sheet soldered but it was HEAVY and overly strong. I opted to hack up some scrap steel. Drilling out the holes and then final shaping got the full gear assembled again.
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At this point I'm nearly ready to put this back in and give it a test. I'm confident that it will handle the weight but I'll do some extensive taxi testing before I'm fully convinced. As many of you know, I have a very rough runway at my club. I'm hoping this will alleviate some stress there. Also, I'm not too concerned about the bit of weight added from the metal. I was sitting nose-heavy still. This is even after removing an entire row of jugs from the dummy radial. I'll check the CG as well before the next flight.
 

willsonman

Builder Extraordinare
Mentor
As a mild update, for those curious, after the previous update I did attend another event that was local... just 30 minutes down the road. Had another 2 flights that were pretty spectacular. I did lose the bombs but that is why I made them printable! Fast-forward to now, I finally got the Corsair out to my home field yesterday afternoon. My concerns with my field are always the roughness of the runway (old farm field) and the shortness of the runway (~300ft). The great news to report is that her sortie was exceptionally good. This was also my first flight with her on the Horus radio and the trims did not seem to have transferred over. So, after some elevator trim, she was right as rain and flying as predictably as usual. The landing was a complete non-event and frankly, my best landing yet. Full flaps slows her down well and the grass field helps her slow much faster than the paved runway at the prior event. Absolutely fantastically pleased with this one now. I can fly her anytime I please and I seem to have ironed out all of the failure points.

I did get some video from the cockpit again but I've covered enough of that IMO so, unless there is a large demand for that footage I'll keep it for myself.
 

RipSmith

Member
I know I am coming in late on this build, however do you have a broken down view of what is on the inside of the brass tubes beside the ball of the ball connector. I am repeating on my TF Corsair some of what you have done here on this one. The sliding canopy being one of those things.