RE: Pushrod Geometry
If the push-rod is free to move, for instance if it's a long piece of balsa rod, then the rod should be arranged so that it's perpendicular to the hinge line. At neutral the rod should also be perpendicular to the servo arm and should be parallel to the chord line of the control surface. The shape and rake of the control horn don't matter, what matters is that the attachment point of the rod to the horn is perpendicularly "below" the hinge line of the control surface. This will give equal throws and remove the tendency for the control rod to rip off the horn. If you're using Bowden cables or "Gold'n rod", then the cable needs to be attached to the servo so that at neutral it's at 90 degrees to the servo horn. At the surface, the cable needs to be perpendicular to the hinge line and parallel to the chord line for best effect.
Posted on: 11/24/2011 5:05 PM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10827610

RE: Wing Joint Reinforcing..need advise
[quote]ORIGINAL: RONSTERMONSTER 1 layer of tape and oxpoxy will be enouph . Ron [/quote] yup. Most hobby stores will do a "Wing reinforcing kit" with epoxy and bandage in a pack. I'd recommend getting one because the epoxy will be the correct viscosity to saturate the bandage and grip the wing skin. Beware of over applying the epoxy! Weight is the enemy. Once epoxy sets it has to be ground off, so don't over apply it, just enough to saturate the bandage, and no more. I'd recommend applying some electrical insulation tape as a mask to give a nice clean line to the end of the epoxy. Apply the tape just a few millimetres outside the edge of where the bandage goes. Don't use painters masking tape: it can pull off the wing covering veneer. As soon as you've finished stippling the epoxy into the bandage, paint the epoxy up and over the edge of the tape then remove the tape immediately. Don't do this in the cold; the epoxy will ruck up the bandage and the tape won't stick to the wing. Prepare somewhere to support the wing after epoxying, before you start! Finally, once you've finished, walk away and leave it. Coming back to it to "improve" the finish will just give you endless grief. Smoothing the hardened finish with wet and dry will allow film coatings to stick better, but beware of over sanding the glass fibre: it's what gives the join its strength.
Posted on: 9/16/2011 9:59 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10719530

RE: Something Learned Today, Magnum Engines!!
[quote]ORIGINAL: Gray Beard What he cleaned the case in I haven't a clue but it's turning a dark gray. [/quote] My guess is some form of kitchen cleaner or oven cleaner. Caustic Soda dissolves aluminium very agressively and even a trace of pH positive on your engine will cause it to darken. (Don't ask me how I know!)
Posted on: 7/18/2011 9:09 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10626765

RE: saito-dubro soft mount-edge 540 query
Whats the model of the Edge 540?
Posted on: 7/13/2011 3:50 AM by Author "psuguru" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=10618949

RE: SOMEBODY STOP ME!!!
[quote]ORIGINAL: rye O!!! YEAH [/quote] Giggedy Giggedy
Posted on: 6/28/2011 7:36 AM by Author "psuguru" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=10596110

RE: camera trickery......
I thought it was just an aliasing effect of the tail vibrating and the scanning rate of the camera.
Posted on: 6/28/2011 7:26 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10596093

RE: Starter Current
The stalled current of the starter is determined only by the total resistance of the battery, leads, brushes and windings. Because the starter isn't rotating, there's no back-EMF to reduce the current. If you absolutely must know what the current might be, you can use a multimeter to measure the total resistance of the starter and leads. Current =12/(resistance). It will be a big number, but the actual current won't be more than that. My starter set-up is limited by lead resistance rather than the battery performance and I start my big engines (1.20's) by hand. Once the knack is learned, I can get 'em to go, usually on the first flick.
Posted on: 6/1/2011 8:47 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10551651

RE: Power Plane Landing Technique Question
The first thing to master is slow flying. Most early pilots rip around the circuit at cruising speed or higher, but when you're in the circuit to land it's already part of the approach and your speed should be appropriate. I recommend swanning around, up high, at low throttle settings, just to get a feel for how the model behaves. You may find that roll control at low speeds requires a degree of rudder input as well as aileron, particularly if you have full-span strip ailerons. I recommend using the elevator trims to keep a neutral stick whenever you want precise control. Once you're happy with flying at approach speed, but straight and level, practice entering the descent stage of the circuit by employing throttle alone to control the rate of descent. Avoid the temptation to allow the nose to drop because the speed will build. If your model is trimmed to fly hands off before you close the throttle (a bit) then it will continue at the same speed but with a descending path. Particularly with 4-strokes, keeping good speed control using pitch allows you to keep the throttle well above idle. This will keep the plug hot and give better response for the overshoot or go-round. When flying circuits, don't allow the speed to build after the climb-out. Bring the throttle back straight away, so that you don't spend all the time in the circuit just getting the speed under control. Remember that your upwind leg should be at least as long as the final leg; many pilots turn straight away after they are level, so that there is not enough distance in the downwind leg. Don't fly the down-wind leg too close in. This will allow a decent base-leg with the same angle of descent as final. Keep the model level unti you have turned onto base-leg. Once the heading is correct, bring the throttle back a little to begin descending. Use the throttle to control the angle of descent. If you are going too high, don't put the nose down, reduce throttle (and vice-versa). if you think the model is too slow, allow the nose to fall, re-trim the elevator and compensate for the higher descent speed with throttle. Flying a square circuit allows you to judge the nose angle and speed much more accurately than in a descending turn towards you. A traditional approach speed is 1.6 x the stalling speed, so for most models this is roughly a fast running speed. A head wind will reduce the speed over the ground so that it can look very slow indeed. The landing phase has three stages: Final approach.:- You are attempting to keep a constant angle of descent at constant speed. Once you can nail this, all you need to worry about is lining the model up with the runway. You might need to make the final turn a longer distance away than you are used to. Round-out: As you cross the end of the runway, you should be at a speed and with enough throttle to be able to bring the nose up and arrest the rate of descent. You're aiming to bring the model into level flight with the wheels maybe a foot off the ground. The pitch change may be very slight. Flare: This is the bit where you transition from being airborne to being on the ground. Having nailed all the other parts of the circuit, when flying straight and level just a foot up, you smoothly but quickly close the throttle fully whilst simultaneously attempting to keep the model level. Once you have reached the landing attitude, you keep on controlling the throttle to the closed position but you keep the pitch steady. The model should settle onto the ground firmly but without skipping or bouncing. The transition from round-out to flare can be very quick, maybe only a second or so, but they are distinct phases of the landing. A good circuit takes just as much practice and the same amount of skill as good aerobatics. Power On. Round again.
Posted on: 6/1/2011 8:35 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10551631

RE: 4 cycle upside down?
[quote]ORIGINAL: ggraham500 IMHO you could always add a Perry pump to give you a bit more flexibility as to where to install your tank. [/quote] (unless your FS is already pumped!) I like Perry Pumps
Posted on: 2/25/2011 5:07 AM by Author "psuguru" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=10362345

RE: Press Release from AMA - Update on Upcoming FAA regulation changes
[quote]ORIGINAL: RTK [We still live in a free country. [/quote] What? You live in Cuba?
Posted on: 2/25/2011 4:57 AM by Author "psuguru" in the forum "AMA Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=10362330

RE: engine mount drilling
[quote]ORIGINAL: bruce88123 Most likely the 4046 refers to the alloy of the aluminum. Not sure what the "L" would be for, if anything relevant. [/quote] I think it's an engine mount for .40 to .46 cu in engine size with long bearers. Edit: D'uh. Should have read the subsequent posts before wading in: sorry
Posted on: 2/22/2011 5:49 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10354869

RE: Dumb question re flaps
[quote]ORIGINAL: dmustangman With flaps fully on It wanted to tip stall without a little power added then didn't want to come down. [/quote] I think you might have a little too much downwards aileron throw when you have flap deployed. Depending on your set you can link the flap selection to a dual rate selection so that when your flaps are in the fully down position, the downwards aileron throw is reduced dramatically. By this, I mean you can assign to the dual rate selection the same switch that puts down the flaps. The other thing to practice, at high level, is to feed in rudder input when you want to turn at low speed. Most models will respond very well to this, more effective in producing a turn than aileron alone.
Posted on: 2/20/2011 8:32 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10349993

RE: Smoke system
There's also the Perry Pump solution. They have a range of pumps and valves that will do the job. I 've never used them for smoke, but I've invested in a few VP20's to smarten up the throttle response on a couple of models.
Posted on: 2/20/2011 8:20 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10349963

RE: won't aileron roll?
I have a low wing aircraft that had a poor roll-rate. I re-engined it with an OS FS-91 IIP which was a bit lighter than the original Laser 91. The CG moved aft a little. The roll-response was much improved. So, it may be that your CG position is well forward. This causes a higher angle of attack (because the tail is producing down-thrust) and modifies the airflow over the ailerons, making them less effective.
Posted on: 1/19/2011 8:18 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10273909

RE: Wars over engine starting benches.
[quote]ORIGINAL: lopflyers I really dont know how to start an airplane from the ground, [/quote]
Posted on: 12/27/2010 4:12 PM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10221561

RE: New Futaba 7 channel 2.4 Transmitter, binding issues?
No, That's what Futabas do. If you want the throws and directions to be correct, you have to make sure you have the correct model selected on the TX, because the receiver will work on any model selection. I think it's Spectrum that have the model identifier as part of the binding code so that only the corect model will respond to the Tx.
Posted on: 12/18/2010 5:39 PM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10205249

RE: Futaba 7C Questions?
[quote]ORIGINAL: wazzbat [quote]ORIGINAL: ceecrb1 Its not an "electronics phrase". Its just a posh way of saying "blocked"/disengaged. http://thesaurus.com/browse/inhibited [/quote] That's what I mean. That's why I had no idea what it meant??? [/quote] It's what happens when you let computer geeks from outer space, impressed with their own cleverness, loose on a product without someone sensible checking it over before sale. I've got a 7C and wanted to use mixing in order to use one aileron servo per wing and two elevator servos. Now, you can do that with any two channels for each servo pair but, and I've read the manual umpteen times, it doesn't say anywhere that unless you use the flapperon mix and then only the channels 1 and 5(?) for aileron then the trim only works on one control surface. The net effect is that if you re-trim elevator then you wind up inducing a roll and if you then counteract this with aileron trim it puts in a pitch trim as well etc etc etc. This is a "well known" secret, so well known that it took 6 months before I found someone to share it! The front panel chrome isn't fuel proof either. Mine's come over all bubbly and pustular through having my Tx and fuel bottle in the same box. For setting up dual rates: I'd suggest using the model manufacturer's recommended throws for sport flying as the 100% setting then set the lower rate to 75%. Basically, you do this by getting into the rates menu then you menu along to CH1 say, and select the switch you want to have as the rate control. Flip the switch to the 100% position (decided entirely by you) then using the rotary dial, dial in 100%. Flip the switch to the low rate position and dial in 75%. You should see a representation of the switch on-screen, flipping up and down. THEN, with the 100% rates selected, manually adjust the control throws on the model using different connection to the control horns so that at neutral trim, they are centred and at full stick you have the throw recommended. The Great Planes ACCU-throw is good value for this. Flip the rate switch to the low position with the stick off to one side and you should see the control surface move in a bit to 75% of the throw. If you can't get it centred perfectly because of screw positions, you can play a little with the sub-trim menu that just moves the whole control surface neutral position. Once you are happy with the positions and throws, try setting the "exponential" to -25% for aileron and -15% for elevator. This will give less control movement around the stick-centered position and make life less twitchy for the first flights. This is useful for throttle control too giving finer control closer to idle. This makes the final stages of approaches easier to control. When you are happy that all the controls move in the right directions and have the right throws, write down your settings in a notebook!
Posted on: 12/13/2010 5:25 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10193898

RE: Downwind turn Myth
[quote]ORIGINAL: 67Jag and so, can a UW to DW change in direction be likened to a longer period, steadier gust.? Ray [/quote] No The situations are not equivalent because gusts imply some acceleration of the air. A "steadier gust" is a contradiction in terms. In a simple UW to DW turn, the only thing changing is the direction of the model.
Posted on: 11/22/2010 8:43 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10153060

RE: Downwind turn Myth
[quote]ORIGINAL: rcjets_63 That's it! From now on I'm adopting a [link=http://en.wikipedia.org/wiki/Lagrangian_and_Eulerian_specification_of_the_flow_field]Lagrangian Reference Frame[/link]; therefore wind does not exist and this entire arguement is rendered moot. Regards, Jim [/quote] How will you be able to eat your meals, stuck in a parcel of wind?
Posted on: 11/22/2010 8:39 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10153051

RE: Downwind turn Myth
[quote]ORIGINAL: 67Jag Confusing several things here. To get back to the original position of HH: 'A plane turning downwind will not be affected (as closely observed by the pilot), as it is in a sea of air that is moving evenly.....so the plane exactly follows that 'sea' during the maneuver. I.e. a turn within the air will be an exact circle...no slowing or increase of speed, no increase/decrease of lift.' Close enough? Think about it, folks. Your asking that aircraft's mass to undergo no acceleration (change in speed), for if it does, then there must be forces changed (or effects realized) to compensate, since F=Ma. If at HH's 'steady state' (which is NOT same as steady wind), then true....I guess....if SS means no acceleration. But a turn/maneuver is by definition an acceleration and therefore some force is required for equilibrium (more power/more lift/whatever). And, since the mass cannot be accelerated at an infinite rate, there is a time lag...and therefore observable effects (e.g., some temporary loss of lift turning DW...until the aircraft catches back up to the wind). The more inertia or the greater the acceleration, then the greater this effect. Common sense if nothing else...supported by physics. Physics is hardly junk science, HH, simply because you don't observe it. Ray [/quote] The point is that the changes in airspeed are independant of the windspeed. If you apply the same control inputs with zero wind, the model will do exactly the same as it does in 20kts of wind relative to the air. If you were flying the model from a hot air balloon that floated with the wind, the model would always perform perfectly round turns and loops with respect to you.
Posted on: 11/22/2010 8:25 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10153006

RE: Downwind turn Myth
[quote]ORIGINAL: rhklenke Yes, the IAS does react to gusts of wind - that is exactly what is being described above in the article I posted on microbursts. The key here is a *rapid* increase or decrease in wind speed will effect the IAS *until* the aircraft's inertia (which is with respect to the *ground* *not* the air) allows the ground speed to catch up. Now, the point I was working on making when posting that article is that in RC, almost every wind gust is large enough to be considered a microburst. In steady winds, I'll buy the "downwind turn is a myth" argument, but in RC terms, almost no wind is "steady" and the aircraft's airspeed will be constantly varying due to many factors among which is varying wind speeds. In addition, wind gusts tend to not be symmetrical in that they tend to have steeper (faster) increases than decreases. The slower the wind speed changes, the longer the aircraft's inertia has to "react" to the change and the less the impact on the airspeed will be. Therefore, you *will* see some asymmetrical reactions to gusty winds depending on if you are flying into it vs. flying away from it vs. flying across it. Bob [/quote] Inertia isn't relative to anything (in Newtonian physics). It's a property of the object. What occurs is that, because the dynamic equilibrium of the aircraft has been disturbed by a gust, thrust no longer equals drag and lift no longer equals weight. Therefore the aircraft accelerates (or decelerates) and descends( or climbs) until the balance of thrust vs drag and lift vs weight is restored.
Posted on: 11/22/2010 8:13 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10152976

RE: Downwind turn Myth
[quote]ORIGINAL: hugger-4641 (Please don't try this for real by the way.[;)][;)][;)]) [/quote] 55 kts is a bit slow but what's your point?
Posted on: 11/22/2010 8:02 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10152944

RE: Downwind turn Myth
[quote]ORIGINAL: Erik R Highhorse, In simple terms,think of a 3D airplaneflying into a 20kt headwind,and doing a a 3D type push/pull over of 180 degrees.At completion it is now in a 20 kt tailwind.It used thrust/lift to overcome the physics principal described earlier,yet realized a 40 kt loss of airspeed,with a corresponding loss in coefficient of lift.The above is an extreme example,and with the smooth,high energy type flying we do with jets,this effect is usually negligable. Erik [/quote] The change in velocity isn't 40kts. Case1: Model does 40kts into a 20kts headwind and changes course 180 degrees. Speed over ground changes from (+40-20) kts to (-40 -20 kts) ie +20 to -60 kts. Delta V = 80 kts. Case 2 Model does 40kts into zero wind. Speed over ground changes from (+40-0) kts to (-40 -0 kts) ie +40 to -40 kts. Delta V = 80 kts. THE SAME change in velocity. So the forces produced by the wings to create that change in velocity ARE THE SAME. The coefficient of lift is a number used to describe the lifting properties of an airfoil and doesn't change with speed. It changes with angle of attack. Unless the controls are manipulated to change the airspeed with direction (by using throttle or using "G" to wipe off speed) then the model will stay at constant AIRSPEED .
Posted on: 11/22/2010 7:55 PM by Author "psuguru" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=10152924

RE: thunder tiger pros, help
[quote]ORIGINAL: WindGap 15% fuel, 10x6 prop Definitely a finicky engine. But I'm not giving up. I will tune it, and it will fly. Just need your help :) [/quote] I know it's obvious, but I haven't seen it stated explicitly: you are using tank pressurisation from the exhaust?
Posted on: 9/22/2010 8:40 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=10019299

RE: frequency board design
We used to operate a peg-off, card-on scheme. the peg board has a clip that goes round the antenna with the channel number attached. The flier removes the peg, attaches it to the antenna and puts the club membership card on the pegboard. No transmission without the peg! That way, anyone transmitting should have a peg and if the channel's being hogged, you know who to go to. We don't operate 2.4GHz in the same way, we just put our club cards on the peg-board.
Posted on: 9/7/2010 11:05 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9985909

RE: Downwind Turns!!
[quote]ORIGINAL: hugger-4641 If you really want to learn how this works, get up about 400 feet high and kill your engine as you enter the down wind leg. If you have any skill at all you should be able to make at least one full circuit and be heading upwind again before having to land. By the time you make a couple of dead stick circuits like this, you shouldl have a better feel for what the plane needs from you.[;)] [/quote] I think you are confusing me with someone who is confused.
Posted on: 9/7/2010 10:47 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9985876

RE: Best possible Redundancy
[quote]ORIGINAL: mike109 Lately I have been using Sanyo Eneloop NiMh batteries when I can get them. They have a very low loss rate in storage and do not loose charge over many weeks though I usually top them up before use and cycle them every couple of months. They really are worth the little extra they cost. [/quote] Ansmann Max-E cells are probably even better than Eneloops (I've been working with them professionally), if you can find them with tags. The only thing I'd say about Low Self-Discharge (LSD) NiMH cells is that they don't like high currents. However, R/C duty cycles probably won't trouble them unduly.
Posted on: 9/7/2010 10:43 AM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9985863

RE: Downwind Turns!!
[quote]ORIGINAL: Ben-M The issue stems from momentum; as the longitudinal wind vector switches to a tailwind, the power setting which previously maintained airspeed now needs to increase airspeed. Once airspeed has increased to its desired level, the power setting must be returned to its previous level so as not to continue accelerating the aircraft. [/quote] This just doesn't make sense. A constant power setting is required to maintain constant airspeed, unless you're pulling lots of G.
Posted on: 9/5/2010 8:31 PM by Author "psuguru" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=9982613

RE: FAA under pressure to open skies to drones.
[quote]ORIGINAL: Luchnia Ahhhhh.....The media, yeah, the media...what thoughts I have and it goes so much farther than the media. The dumbing down of an entire nation. Calling evil good and good evil. The generations in our country today cannot even use proper English. I shiver when I think of just how ignorant our kids are becoming! They live and type on these tiny devices and think that is cool while all the while they are losing a wealth of knowledge and just forget about wisdom. The kids think typing sentences is like this: What U up 2 I play w rc plaine U got plaines? CM injins on dem plaines C em? YO day bad Just think about this example: Four kids call each other and say, "Hey, you guys wanna go cruisin?" The others agree. They get in the car and go down the highway and each one of them starts talking on their cell phone to others and don't even communicate with those in the car. [X(] I even know someone that was sitting accross from another person and decided it was best to "text" her instead of SPEAKING with her...this drives me bonkers [:@] Don't get me going on what it means to go outside. When we were kids going outside was a MAJOR part of our day! Ugghhh....I just cannot take it ....whew, mega rant [>:] Sorry, I lost it for a moment with the drone thing. The word drone somehow made me think of just how ignorant our people in this country are becoming [:D] [/quote] I am pleased to announce that you have been voted an honorary member of the Victor Meldrew Association of Great Britain and Northern Ireland (Essex branch).
Posted on: 8/27/2010 8:51 AM by Author "psuguru" in the forum "AMA Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=9963029

RE: most over rated and under rated fighters
deleted
Posted on: 8/24/2010 8:39 AM by Author "psuguru" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=9956186