F3A 2004-2005 Chads Projects
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| Here are some pictures of my new servos (Futaba 3150 slim digitals) installed into the stab of my Enigma. So far it looks like it will work out very well, the servos have very tight gears and give nice smooth consistent movement. I need to construct a new rudder to get the tail weight down for balance, I think this is definately going to be a much tighter, more accurate and more reliable setup than the bellcrank system is. Now if the snow will stay away I will be able to test it and see! |
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Ok got the stab servos installed, with a bit of fancy curve mixing they trace each other through their travel perfectly. Rapidly moving the stick one does move faster than the other, however thats not something that is often done when flying so I dont think it is of any concern. Balance :-) Everything needs to move to the front including the throttle servo, but I can do it without gaining any weight over what I was currently doing (4.5kg, balance at 275-285 mm from TE). On a fresh model that will be built around this system balance wont be an issue. Maybe, just maybe the weather will cooperate long enough this weekend to give em a go. Their are also some pics of the new rudder, a bit of a re-work over the 1/8" sticks on the trailing edge that I did for most of this season. Nothing too fancy just trying to get some extra drag on the back end of the plane :-)
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Chad has been playing with some indoor foamys (Feb 2005). For some pics of his fun, go to this link
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ZN Line Evolution All up weight, approx 6.5 oz. |
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First flights May 8,2005
First the setup: ZN Line Enigma (completely stock kit) Plettenberg Xtra 25-13 Schulze 32.55K controller Apogee 5s2p 4960 packs (2 wired in series to get 10s2p for flight) Apogee 2s 1050 receiver pack, 5.6V regulator Apc 19x12 e-prop Tru-Turn 3.25" FAI LBP spinner, special adapter by Bob O. (thanks Bob!) Futaba 9WC2 Tx Futaba R149DP receiver Futaba 9154 (ailerons), 9151 (rudder), 3150 (dual elevators)
Draw is about 61-62 amps, about 2100W, 3500' asl, 12C outside temp. All up weight of the model RTF with batteries is 10 lbs 2 oz, or about 4600 grams. I have about 2000 flights on my glow powered Enigma so this was a pretty direct comparision between the electric power and glow power models. Mixes, throws etc were all virtually identical between the models for similar flying feel. Lets start with the only negative in the flying of this system that I noticed....it has zero downline breaking! Not sure if this is a setup thing on the controller but the motor really spools up on the way down and the plane picks up a fair amount of speed. Not unworkable by a long shot but a bit surprising when coming straight from a glow Enigma, considering I am using a 3.5" bigger prop.
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The positive.... * Well its very quiet!! In fact you can barely make out the noise from the aircraft in the air. There were a number of birds flying around at the time and they made more noise than the airplane.
* Very consistent power, the airplane is definately not as fast as a glow not even close. There also seems to be a critical throttle setting for a certain attitude where you have enough power to pull at constant speed. I found that increasing beyond this is seemingly pointless as you gain nothing....the model just wont pick up speed like a glow. So running past that throttle point in climbs is only running the batteries harder and drawing more mAh from them. You really need to let the model pull, it has way more power than I perceived it to have.
* Power....big power. Completely different than glow power though...this is more tractor power where glow power is more about keeping momentum. Better? Probably for certain things. It took a couple of flights to get used to though.
* I think the plane felt a little more locked in and solid than the glow version. I guess it feels the same as a glow plane when its new, but over time things wear out...with the electric I guess the feeling will continue for a long time :-) * I do feel that some manuvers are easier to perform, probably due to the larger prop and better wash from it. * All the obvious things like no cleanup, no starting, no tuning etc etc etc.... Anyways, like when changing from a nice fit old pair of shoes to a new pair I had to walk a bit with the plane before I felt comfortable. I felt it was quite a change especially considering my familiarity with the design....but as the more I flew it today the better it felt. I flew 4 flights of increasing duration....on the 9 minute flight I am consuming about 3300 mAh from the packs, and keeping a post flight resting voltage of 3.77 V/cell. I still have big power at that point in the flight. Anyways, more flights coming....feel free to drop me a note if you wish to chat about e-pattern!!!
