RCU Forums - View Single Post - Balsa USA Force One build
View Single Post
Old 09-11-2016, 10:19 PM
  #61  
mgnostic
 
mgnostic's Avatar
 
Join Date: Jan 2003
Location: Kamay, TX
Posts: 1,576
Received 81 Likes on 69 Posts
Default

MAIDEN FLIGHT! Well, I had a successful maiden flight. It was a pretty short flight, I only burned three ounces of fuel. One problem was that I waited until too lay in the evening to go to the field. The setting sun highlighted the yellow underside attractively but presented some problems with orientation. I may need to add some color to the fins. As noted earlier I am using an O.S. FX .46 engine. It is a well broken in engine in its prime and it produces a lot of power. It felt a little weird holding on to the nose of the airplane as it pushed towards me during the run up. The APC 10-6 pusher prop certainly seems to produce good thrust. The clunk forward orientation of the tank (as shown on the plans) doesn't seem to pose any problems. I probably won't be doing any longs climbs on a near empty tank though. I was a little concerned about clearance for the starter but I was able to reach the prop hub by being certain to orient the starter button so it was anywhere but on the bottom. The O.S. is an easy starter so I may try hand propping it some time. The consensus seems to be that rudders aren't necessary on this model but I did use the rudder servo to control the nose gear. With a few clicks (beeps?) of trim it taxied nicely up and down the runway. I put the flight battery and three ounces of lead in the to forward most compartment to balance the plane exactly as shown on the plans. This brought my all up dry weight to an even five pounds. The manual describes having 1/8 inch reflex on the elevator but doesn't really explain what this eighth of an inch is relative to. so I measured from the cordwise center line of the wing. This is less reflex than indicated by the reflex gauge that came with my Top Flight Holy Smoke. Based on that I pit in a few more clicks of up trim. The prop on this model sits in a slot in the wing rather like the foam F-22s. As a result the prop noise has its own unique sound but it doesn't seem to impair thrust in any way. This airplane taxies and is easier to manage on the take-off run than the Holy Smoke. I will compare these two planes since they are similar in size, both have a delta wing and I have both. The Holy Smoke was designed to have a nose wheel and two skids under the wing. I exchanged the skids on mine for wheels. This leads to a wide track landing gear that has a very short wheel base. I can make the Holy Smoke swap ends by accelerating and then making a sharp turn. The Force One also has a fairly wide track main gear but the longer wheel base, as a result it tracks nicely. The Force One accelerates quickly. Both the Force One and the Holy Smoke are tricycle gear delta wings and both seem to like to have a little speed before rotating. I have read some comments that seem to indicate difficulty with getting the aircraft to take off, basically having to yank the stick back to get the airplane off the ground. Mine sits at about a five degree positive angle on the ground and my take off seemed to go smoothly. I used about 3/4ths throttle for take off. Once the plane left the ground it wanted to pitch up. I had cranked in too much reflex and had to hold forward stick. Luckily I hadn't over done it too much and was able to trim for level flight. I don't think I ever exceeded 3/4 throttle and the airplane is pretty fast for something flying on a 10-6 prop. After making a few circuits of the field I slowed to half throttle. After sorting out the elevator settings the next bit issue is the aileron sensitivity. The roll rate is very fast, especially at speed. The elevator in comparison was, if anything, a little sluggish. Generally the airplane was neutrally stable about all axes and once I dial in some exponential into the aileron function of the elevons it ought to fly like it was on rails. With the light fading I set up for a landing. The first try I came in too high and had to go around. I came in lower the second time around and carried less speed. The airplanes low speed manners seem good. It flared easily and settled in for a smooth landing. I think it lands more slowly than the Holy Smoke. I will have to take both planes out at the same time for a comparison. Aside from the need to tweak the roll rate there weren't any big surprises on the first flight. Sorry there aren't any first flight photos but there was only one other guy at the field and he wasn't comfortable running a camera. I will get some flight photos next time I go out. I will post more comments as I finish tweaking the airplane but this concludes the build. There were a few building challenges but they were primarily due to the relatively unusual plan form of the airplane and most of my challenges were brought on my my modifications to the plane. It is a Laddie Mikulasko design and I have long been a fan of his work. Flying wise this would not be a good plane for a beginner, primarily due to the unusual shape and the speed that it is capable of. That said, I really like the plane so far. I don't know what the current manual looks like but for a seventies era manual it is pretty good with lots of illustrations and helpful guidelines. Building this airplane should not be an insurmountable task for anyone with a kit or three under their belt. One of the nicest things about this kit is that it is still available ​! Thanks everyone for following along with my build.