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#41
06-27-2013, 05:52 AM
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If you can't overcontrol at high speeds or in turbulent conditions then you'll get sweet F-A control at low speeds.
Terms to look up are Maneuver Speed and V-Speeds. Going from flight sims in the past, maneuver speed being the fastest you can pull full stick deflection on ONE AXIS is about 240-250 mph for the P-51. By 360 mph it's -probably- not safe to pull half way, I leave it to someone else to guess why. Note that in WWII fighters the pilot can't take what the plane can. They had feel and were less prone to trying things that gamers who have no feel take for granted. Also that IL-2 is a simulation. When some G-limit (like 12 G's) is reached even momentarily it is bye-bye wings. Pilot blackout though seems to have a time element. BTW, I just came across FreeChecklists.net. Here is the P-51 page: http://freechecklists.net/Resources/.../P-51+Mustang/ And from the 1944 manual on page 19 under Maneuvers Prohibited: "It is impossible to do a good snap roll with the airplane and most attempts usually end up in a power spin." 
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#42
06-28-2013, 06:54 PM
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It is just silly to require the Player to click the elevator trim three or four times for every speed variation of less than 20kph indicated (plus a couple of clicks of rudder trim to compensate for nose angle immediately afterwards) for aircraft that history (and multiple current examples) shows (1) didn't require it and (2) will be constantly varying in speed and angle of attack with no accurate on screen display to indicate vector/trim state. That this group is composed almost entirely of aircraft that exist in large numbers that fly to this day leads me to wonder if their FMs are a bit too detailed for the game engine or that there might be some kind of common mathematical error somewhere, possibly as a result of the conversion from Imperial measurements to metric. Most of the aircraft instrument panel displays are hard to read at best (always in Wide View, and often in 'Normal' view) and far too many of them are grossly inaccurate; artificial horizons that are indistinct or offset to an exaggerated degree, climb indicators that are slow and frankly, lie much of the time (when you have an indicator that measures feet of climb in feet per minute, and one deflection division mark is supposed to represent 100 feet, you shouldn't be able to change heights by 60 or more feet in less than 3 seconds with the needle just above the '0' mark, and I experienced this routinely in a great many of the aircraft I've tested so far, the notable exceptions being the Soviet and the IJA fighters). Two changes seem obvious to me; first, the addition of a temporary trim state display similar to the ones we get when we adjust throttle, prop pitch, supercharger or radiator settings. I'd like to see something along the lines of x% up Elevator Trim, x% Right Rudder Trim, and x% Right Aileron Trim with full trim deflection being 100%. Second, make the cockpit instrument displays consistently accurate to exactly the same standard for every aircraft; currently, there seems to be a great deal of variation in instrument accuracy and readability from inside the cockpit. I understand that unless there is one common conversion error that is easily detected, major changes in FMs is way more work than can be fairly asked of TD, in the near or far term, but the community shouldn't pretend that the inaccuracies aren't there. cheers horseback
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#43
06-28-2013, 07:29 PM
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The pots that CH used for my old yoke are all 270 ohms, but they use only the 'middle range' of the pots because that is where the change in resistance is most consistent; the resistance between the 10th and 11th degrees is almost exactly the same as the resistance between degrees 45 and 46. This allows them to use less expensive pots and still give you pretty good precision across the range of movement that their mechanical setup allows. Since little Joey only cracked the plastic case and one of the Yoke handles (it was only a drop of about six feet!), I was able to recover the CH control circuit card as well as the five axes and the 12 buttons plus POV hat; this means that when I plug the USB into my computer it sees a CH Yoke and automatically puts me into the CH Control Manager software, which allows me to combine it with my other CH controllers into one or two (rather than four or five) controllers for Il-2, which I'd rather not lose. I was able to cut out the throttle/prop pitch/mixture levers' mounts so those three axes are intact, while the X-Y axes are now mounted in the box as twist knobs, with that short range of movement I was complaining about; I'm wondering if rather than putting another potentiometer in series, it might be better to put one in parallel to get that fine control. I'm also still looking at those gear kits that Tamiya makes for robots and RF controlled vehicles with an eye to adapting one of those to my needs with something along the lines of 20:1 ratios. I'm not very familiar with programming (one course in Basic back in college 25 years ago), so tossing the little CH CCA is something I hesitate to do. cheers horseback
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#44
06-28-2013, 07:56 PM
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Two more charts and data tables; USN/USMC fighters at 100m/330ft, and Mid-War Soviet Fighters @100m/330ft.
A few notes: 1. The Soviet fighters really shine at this altitude (this means that I said "Holy *&^%*&%$%!!!!" a lot when I reviewed the data and had to slow the track down to half or quarter speed to catch the speed changes in time); compared to the 3000m data, they are far more impressive. The La-5FN is indisputably 'king of the hill' at this level, although I have yet to do the Seafire LF III. 2. The Soviet fighters also tended to drop their noses as speed increased, generally around the 360 to 400 kph range, but it was only about half the radius of the gunsight circle in WW view. I started taking screenshots at certain intervals to confirm this, so I am certain that it is happening. 3. The USN/USMC fighters are mostly 4.11.1 versions that I had already completed before the patch was released; after three comparisons to 4.12 runs, it became obvious that there were no changes. 4. I haven't had a chance to do the same sort of screen shot comparisons with the Corsair and Hellcat that I did with the Soviet fighters because the idea didn't come to me until I was doing the Russian runs; I have started a folder labeled 'nose drops' and will use it for fodder on another thread, I think. 5. Using Max' suggestion of applying 50% filter to my ailerons, elevator and rudder axes made some difference; still, very tiny movements in elevator or rudder when I attention wandered from the climb or alt indicator or artificial horizon (and when these instruments are obscured or widely separated, I had some real issues) resulted in big swoops and climbs in a matter of two or three seconds, often well out of proportion to the indicated displays (as mentioned in an earlier post) Enjoy, discuss, debate. cheers horseback
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#45
06-28-2013, 09:16 PM
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#46
06-28-2013, 10:48 PM
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The Soviet aircraft all have a 'drop' of around a quarter of the WW gunsight circle's diameter, and it generally takes place between 370 to 400 kph ias, varying somewhat from Yak to LaGG to La. It also appears that the drop is not as great when the aircraft is in a constant speed compared to when it accelerates and that some aircraft have little or no 'drop' with acceleration or greater speed in general. My impression so far is that aircraft like the Lightning, Corsair, Hellcat and P-47 have much greater 'drops' and that at certain speeds the nose will suddenly rise again somewhat at higher speeds. I haven't fully quantified it yet (as I have said, it takes about 45 minutes to actually make a 4 run track and at least the same amount of time to replay it and transcribe the raw data) but I think that these aircraft's noses raise and lower (and sometimes raise again) by nearly the full diameter of the WW gunsight circle, possibly more. At 100m, that puts the 'pipper' well below the horizon, while the Soviet fighters' gunsight center is just a bit above it (and at considerably higher speeds in many cases). I contend that it is way too much variation, and plan to create a separate thread about it, but only once I have my ducks in a row. Right now I'm struggling to maintain level flight and have noticed that my key visual references are either unreliable in the case of my cockpit instrument displays or are changing on me in the case of the view of the horizon, which I could normally 'set' at a certain point in my cockpit framing to keep level. I need to (a) fly a reasonably level course while accelerating through the speed range and (b) take a series of screen shots from the track after doing so to confirm what are so far just impressions. If I'm wrong I will say so; it won't be the first time. cheers horseback
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#47
06-29-2013, 02:10 AM
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Series resistance will give you linear changes.
Rtotal = R1 + R2 Parallel resistance will give you curves and the total will be less than the smallest resistance (pot adjustment) and relative to it. (1/Rtotal) = (1/R1) + (1/R2) A microcontroller can use a lookup table to correct non-linearity of the sensor. There's room in a Teensy 2.0 to adjust _every_ step of all 12 10-bit analog inputs and still have room for useful code. The most accurate stick I ever had used optical encoding. That wasn't analog at all. When the new hardware came out something changed and it wouldn't work so I sent it off to Rookie from the old Delphi FSF.
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#49
06-30-2013, 11:01 AM
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Horseback, you are complaining exactly about what on trim, that it requires too much touchs to reach the desired position, that it is not working as it should, or both?
On the P38, you must be carefull with what you read. The P38 may not need rudder trim, as most other single engined, and bi motors whithout counter rotating engines did. But elevator trim may be assumed as allways needed. In game trim management will be far better if there was a x10 adjustment, at least for those people that don't have a free axis for trim on thier joys.
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#50
06-30-2013, 09:01 PM
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On this specific group of aircraft, it almost seems as though the trim is not applied until I have clicked the button a certain minimum number of times and then it is all applied at once. It is quite similar to the visual effect of applying trim; you apply four or five clicks, and only then do you see the rudder or elevator move slightly. As for the P-38 comment, let me say that I am almost 60 years old, and that my father retired from the US Air Force just before my 18th birthday. I have been interested in WWII’s air war since I was about seven, when we were transferred to Great Britain just after the 20th anniversary of the Battle of Britain (it was kind of a big deal over there). I’ve met a great many pilots who flew Warhawks, Lightnings, Thunderbolts, Mustangs and the naval fighters during the war over the years (strangely, only one admitted that he flew a P-39—and by the way, being curious about the aircraft your girlfriend’s Dad flew can make a big difference in what time you have to get her home), and most of them were happy to talk about flying them if not always about combat. I also read everything that I could find about those airplanes, their pilots and the air war in general once I mastered the printed page. I made hundreds if not thousands of scale models of every major fighter type that could be found in 1/72nd and 1/48th scales (including paying ridiculously high prices for the crude east of the Iron Curtain stuff that gave the only semi-accurate depictions of Sturmoviks, Yaks and LaGGs). Back to the pilots’ testimonies: P-40 drivers always mentioned that it was like an unruly horse that had to be tamed every time you got behind the stick (with the implication that you had to be a ‘real’ man to fly it well) and a couple mentioned the constant manipulation of the rudder trim. Thunderbolt pilots talked about how safe they felt in it and how smooth it was (the turbosupercharger gave them all of the engine’s power at any altitude, so they never felt that they had to compensate for more or less power as they climbed or dove (and their dive stories were full of superlatives), and Mustang pilots tend to go on about how you just felt in control of every little thing and how you almost automatically knew what you could get away with (one guy said that it wasn’t just that it was responsive so much as it told you how responsive it would be and let you know exactly where the limits were). The P-38 guys talked climb, acceleration (according to the comparisons on pages 603 and 604 of America’s Hundred Thousand, at sea level the P-38F accelerated from 250 mph at 2.30 ft/sec/sec (roughly 70.7cm/sec/sec) and the P-38L would do 4.13 ft/sec/sec (or about 1.27m/sec/sec), this was about 0.15 ft/sec/sec faster than the early P-47D models or the Allison Mustangs for the F and the L was about 0.11ft/sec/sec faster than the M model Jug and 0.28 ft/sec/sec faster than the P-51D; the -1 and -4 Corsairs were well back from that among US fighters) and firepower. Like the P-47, the Lightning had the GE turbosuperchargers, which gave them all the engines’ power at any altitude. If the Lightning guy served in the Pacific, it was THE airplane; if he flew the later models in the European or Med theaters, it was a cold and unreliable SOB at high altitudes. They all said the P-38 didn’t use a lot of trim unless you were going up or going down; one guy said that it was a good thing it didn’t, because the elevator trim wheel was so hard to get at (America’s Hundred Thousand says that the 1944 Fighter Pilots’ Conference voted the P-38’s cockpit arrangement the worst of the US fighters and that the flap and landing gear controls were particularly hard to reach). From what I’ve seen, if you were wearing gloves thick enough to allow you to avoid frostbite, everything except the yoke and the rudder pedals was hard to manipulate at high altitudes in the P-38, so constantly grabbing and adjusting that tiny little knob on the wheel right next to your left knee in gloves with any precision would be hard. See the attached photo; the elevator trim wheel is that little thingie with the little wooden knob on the side of the black box; from other photos I have it seems as though the thing would be digging into your knee all the time. All of these details have been confirmed in dozens of books, magazine articles and in some cases, the training films I’ve been able to view over the years. Only the P-40 was ever described as being hard to keep up with in terms of trim in level flight, and that is consistent with the recognition that it was an early design and that it was an adaptation of the radial engined P-36 (which is universally praised as a well-balanced fighter, if a bit slow post 1939). Every other aircraft was designed for a specific range of speeds and the idea that trim should be convenience rather than a necessity. When trim tabs are referred to as sensitive, there is usually a line about how you only need to add or subtract it in small increments in the pilot manuals. Given that Il-2 ‘46’s trim model gives you 160 clicks of trim from stop to stop, it seems to me that two or three clicks from ought to cover any need for trim for changes in speed up to 35-40kph or of 10-15% throttle/rpm in all but the most extreme cases in either rudder or elevator. What I’m seeing is five or six clicks nose down, then two up, then a couple of clicks of rudder one way, then one or two the other direction; then wait a couple of seconds to settle and begin the whole process over again for normal level flight for this specific group. When you look at the external views of these aircraft in normal level cruise trim, the elevators are all visibly deflected down. Compared to the dozens of in-flight photos I have found of these same aircraft in apparent level flight it looks as though these do not have any appreciable deflection up or down. If you look back from the cockpit at the Il-2 ’46 Spitfire’s elevators while in flight, most of the time the balance horn is sticking up well past the upper surface of the stabilizer. Find a video on YouTube where a guy from The Guardian is learning to fly a Spit in a two seat conversion of the Mk IX (there appear to be several): the in-flight shots of his face while he flies clearly show the elevator balance horn flicking up occasionally (without the immediate bouncing up and down that Il-2 ’46 depicts), but generally it is not constantly above or below the stabilizer while in level flight. So trim demands for these aircraft seem to me to be excessive and at the same time, trim is impossible to track, excessive in axis form and much too small and unintuitive in button form. cheers horseback
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make it easier than ever but I say that already knowing C since the 80's. Your mileage may vary, learning to code from zip may not be worth what you get. There's a lot of help available from Leo for his products (already coded) and on the Arduino forum for those.
Linear Mode
