Well, my build of the Kharkov R10 is finally complete. And just in time to display the model at the Syracuse Model Aircraft Forum And Indoor Fly In tomorrow morning. Given that I have not yet seen the size of the indoor facility where tomorrows event is being held, the fact that the model needs to be test flown and trimmed, and the fact that I’m not sure that I have the motor configured correctly, this all means that I’m not sure that I will actually attempt to fly it tomorrow. However, I may attempt a few un-powered hand launches depending on how hard the floor of the facility is and how steady my stomach is when contemplating hard landings on that floor!
Since the last build report, I painted the engine cowl, glued all the model components together, installed the motor assembly, and added the canopy, rear gun turret, wing fillets, and trim details. Final assembly of the major model components went fairly easy and I was pleased that I was able to maintain proper alignment of all the flight surfaces during the gluing process. Even though I like the little tail wheel assembly that I worked up for the Kharkov, I ultimately decided to leave it off the model at this point for two reasons. First, the tail wheel is very fragile and would most likely break off during the first landing of the plane. Secondly, like many models, this one proved to be tail heavy. Adding the tail wheel would have made it even more so, thus necessitating the use of more balancing weight in the nose. This would have added even more weight to the plane which is never a good thing in a free flight model.
Speaking of weight, the completed model now weighs in at 50 grams which translates into only 1.75 ounces! Given that the model has a 22″ wingspan, that light weight is some indication of how fragile this plane is! Having said that, with 80 square inches of wing area, the model has a wing loading of .625 grams per square inch which is on the high end for free flight models of this nature. Hopefully the high wing loading won’t have too much of an adverse effect on the flight performance of the Kharkov. It is hard to believe that at only 50 grams, I still managed to build a plane which is ‘heavy’ by free flight standards! The extra weight must have been all that glue I used repairing broken parts 2 or 3 times!
What I found frustrating about this build is that I am a bit of a perfectionist and, for a variety of reasons, this finished model airplane is far from perfect. While the quality of my modeling on this plane is superior to many other really junky looking modeling efforts I have seen (including my own), it is also far from museum quality. On a grading scale, I’d grade the results of my efforts at a C+ to B-.
But, on another level, I’d give the results of this build a solid A grade. It achieves that grade of an A by having successfully accomplished many of the goals I had set for this build. First, it was my first ever ‘official’ free flight model build and to that end I believe that I have achieved building a free flight model that will successfully fly (even though that assumption has yet to be tested). Next, during this build, I learned, and re-learned, a lot of model building techniques that will serve me well on future builds of all kinds. Next, this build also tested my patience which has always been one of my biggest hurdles to successful model building. This model demanded patience and, for the most part, I was successful in overcoming my tendency to rush through things and just ‘get it done’. The parts of this model that came out the best are those parts where I exercised the most patience. Conversely, those parts that look the crappiest (including the rear gun turret and tail cone) are those parts of the build that I rushed thru. Finally, this build was also successful in introducing me to several new building tools and supplies that either were not available when I modeled years ago, or that I was not aware of or could not afford to buy at that time.
The photos below speak for themselves as to the ‘quality’ of the finished plane. Please let me know (good or bad!) what you think of the completed model. I will say in conclusion that I went into this build thinking that this was one ugly plane. And I will state at this time that even after spending more than a few hours building this model of the Kharkov, I STILL think it is one ugly plane! LOL!
Stay tuned for future posts related to the flight trimming and flights of this model once the weather turns favorable. In the meantime, it is now time to move on to my next build…which will definitely be something more substantial than 1/16″ balsa strips…Thank Goodness!
Final Build Photos of the Kharkov R10:
(Click on the photos to get a large image with higher resolution)
I found where all that extra weight is in the plane. It is in that neat cockpit instrument panel and the machine gun sticking out the front of the canopy!