dkshema
rrMaster
Location: Cedar Rapids, IA
My Posts This: Topic Forum | Interesting what some down time will do for a fellow... I think I've made a discovery that explains the EP's habit of rolling out of loops and rolls!
The EP is waiting for parts from RC Heliworks. I took the occasion to whack the plastic balls off the swashplate and replace them with metal balls. It's a bit dicey, but with some patience, it can be done using a sharp X-acto knife, a pin-vise, and a very sharp drill bit. I used T-Rex balls. I think I need to use Kyosho balls, as the T-Rex balls have the same amount of slop in the plastic links as the original plastic balls did. Oh well, live and learn. I can replace the balls another night.
BUT, in the process, I discovered a very perplexing phenomenon. Early in this thread, perhaps the first page or so, I posed the following question:
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| Flybar question: Meanwhile, I was taking a closer look at the heli this morning and noticed that the flybar travel (the amount that it can tilt) is limited by the presence of an aluminum collar at the base of the main rotor hub, and the Jesus bolt goes through it. I assume this is a limiter to tame the heli down for novice flyers. The part doesn't seem to show up in the manual anywhere.
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Ozace quickly replied
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| I made that comment about the flybar tilt very early on an was told by the guru's here that is makes no difference and was not a problem.
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Several posts later, Dwight Schilling added:
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| I removed the collar on the yoke and flew it. There did not appear to be any difference in the control rates. Like you the weather in Chicago is cold so I have not had the chance to do extended testing to be positive but it looks like there is no difference. This reminds me of a thread long ago about flybar travel and in many cases the flybar never moves as far as you think. To see this you need to use a high speed video camera that can stop frame to see this.
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(I added the bold face type in this post)
Where is this going? In my last post, I noted:
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| What I DID notice is that the heli seemed to have a habit of wanting to roll to the left at high speed when turning from downwind at a high rate of speed and going back upwind.
When attempting loops, heading into the wind, as I pulled back on the stick the heli had a nasty tendency to roll to the left, and ended up corkscrewing out of the loop. This happened repeatedly. At first, I thought maybe it was related to the wind I was flying against. As I continued to fly and pull up hard, the heli would do the corkscrew thing. That made me start to wonder if I had some kind of problem with phasing -- but that's not adjustable on the EP.
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Well, after getting the heli all back together, and having no TR blades, and the MR blades removed, I plugged in the battery, and fired up the heli. I left it sitting on the table, about half throttle, and began to slowly feed forward cyclic into the controls. The flybar did what I expected it to -- tilt down in front. BUT -- beyond a certain amount of FORWARD cyclic, the flybar carrier bottoms out on that collar. When it does, the entire tilt of the flybar plane changes from forward, to forward and LEFT. When I put in REAR cyclic, the flybar tilts down in back. To a point. Then, the flybar carrier bottoms out on that collar, and the plane of the flybar changes from pure down in rear, to rear, and RIGHT.
Thinking back to yesterday's flight, as I pulled BACK to LOOP, the heli began to loop. BUT, as I fed in more "up", the heli quit flying straight through the loop, and rolled out, ending up doing a real bad corkscrew and flying out of the bottom of the loop at least 90 degrees out of the original flight path. I attributed this behavior to a phasing problem. I believe I have found the culprit -- it's not exactly a PHASING ADJUSTMENT problem, but it's the fact that the flybar bottoming out on the MR hub reinforcement collar actually radically changes the plane of rotation of the flybar. This is some SERIOUS control input that's neither expected, nor wanted!
This also explains the poor rolling ability. Beyond a certain amount of roll cyclic, the flybar carrier bottoms out on that collar, and feeds either forward or rearward cyclic into the mix depending upon if you've put in left or right cyclic. BAD BAD BAD!
Per Dwight's earlier post, it may be that the flybar doesn't move as much as we think it does, but I'd like to think that no matter how much it moves, that it shouldn't get a mind of its own and start adding its own inputs!
Until the new parts from Chris and RC Heliworks arrive, I'll spend the next couple of nights trying to figure out if this collar is necessary, and what happens on the bench with it removed.
Dave |
