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Bob Denny

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Everything posted by Bob Denny

  1. Goran, you are doing a great job on a great project. Thank you! It amazes me how ungrateful, and sometimes downright mean, people can be when they think they are so much smarter and/or more capable than others. Guys, back off and enjoy flying!!
  2. For your enjoyment. I accidentally turned the autopilot on and off during takeoff since I had just wired up the buttons for heading hold. Also I know I left max power on for 2 minutes. It's within limits but probably not needed even with the rising terrain. The washed out look is my fault, it looks much better on the 56" monitor running full 4K at 60fps!
  3. Hi again.. I can't get the left engine to feather button to work at all, and yes, once the pitch reaches 88 degrees, the pressure rises and interrupts the current to the magnet that holds the button in causing the button to pop out. They can stick, so part of the shutdown checklist is to feel the button when the propeller stops rotating, to make sure it has popped out. Left stuck in, the propeller will unfeather, then feather, then unfeather, etc. Also, the LES DC-3 has its propeller levers set up to feather when pulled all the way back, so you can feather both engines. This isn't accurate though because the engine run up includes cycling the propellers by pulling them all the way back to pull fresh warm oil into the domes. If you do this on the engine will feather very quickly. I ran out of time after working out the autopilot stuff, but you can look for the commands to feather each engine and bind it to a key or button. Goran will need to fix the button action. It may be "too difficult" to duplicate the stuck button failure mode though ha ha.
  4. Hey Douglas49 see this post for a way to assign keys or buttons to turn heading hold on and off in the DC-3. If you have FlyWithLUA installed, you can install this little LUA script which will cause heading hold to be the default mode when you turn on the autopilot. Then when you turn it off, both heading and altitude hold are both cancelled. Useful because you can't tell if either mode is on or off :-) SperryAutopilotDC3.lua
  5. Learning more... enabling heading hold is a command not a dataref. Since you already have the heading wheel in the Sperry wired to the autopilot heading selector (nice work!) all I had to do is hook up a joystick button (or a key in the Keys tab!!) like this, and now the DC-3 has heading selector that works as the real Sperry did. If you wire another key or button to sim/autopilot/heading_hold (Autopilot altitude select or hold) it will toggle altitude hold (current altitude) on the Sperry (but that's definitely not realistic :-)). Since this is not a mod using Plane-Maker, but just a button or key assignment, I hope this is OK to post. Note that if you have turbulence, this autopilot hunts like the real one. When the turbulence got moderate in the DC-3, the real guys shut off the autopilot and flew by hand, including using their feet to keep people in the back from getting sick. I was beaten as a child for not using my feet :-) :-)
  6. I won't post anything more like this. I apologize, Goran has to support this aircraft.
  7. Hello Goran -- I publicly apologized for my Plane-Maker posts, and removed the specifics from Engine Behavior Issues. I am sorry. I really understand the support problems. I am a professional developer with over 1000 astronomical observatories as customers :-) My company is called DC-3 Dreams, SP (!!!) and has been in business for 19 years. 

    Anyway, I am a real DC-3 pilot so I know how the engines should be, what the limits are (at least for  the P&W R1830-92 which I assume you modeled, not the Wright R1820). I worked more on the engine behavior yesterday, specifically:

    • sluggish throttle response (turn off FADEC)
    • Governor not working to keep the RPM constant when the throttles are changed (this is really unrealistic, they are "constant speed propellers")
    • Inability to ever reach max RPM (2700), even in flight
    • Inabiity of the propeller levers to bring the RPM below 1700 on the very important run-up propeller governor check
    • Idle cannot go below 800 rpm (should be 600)

    I was able to make adjustments that resulted in first three. The odd  thing is that I had to "cheat" in Plane-Maker on the max RPM and red-line. But the results, as you will see, are that it correctly governs at 2700 as the MP moves from 35" to 45" (slowly, it will overshoot if the throttles are moved too quickly and this is correct).

    Anyway, here are settings that will provide much more realistic engine behavior. You will notice a distinct performance improvement. Acceleration, which I found to be sluggish compared to real, is also more realistic, and the single engine behavior is better. You will also notice that the engines can (barely) reach 2700 RPM at max power even standing still. Give this a try, I think you will be surprised.

    I wish I knew how to fix the low-end and idle issues. I suspect that will involve some "deeper" changes beyond my knowledge and understanding. I also don't like the fact that I had to set the limits 200 RPM below what they should be. I can only say that the result is much more realistic behavior and limits.

    Snap3.jpg

    Snap1.jpg

    1. Goran_M

      Goran_M

      Hi Bob
      There are still things in X Plane itself, that are not perfect.  That's why it's constantly being updated.  Sometimes things need to be heavily modified or hacks put in, just to get things to work how we want them.  For example, The Saab has it's own engine model that operates outside of X Planes engine model.  

      I will take a look at what you posted here and do some tests.  After I post an updated acf, I will be sure to credit you for the fixes.

      The DC3 was never meant to be as popular as it is.  It was only meant to be a small side project to give me some pocket money.  It turned out to be a pretty big seller, and I regret not putting more detail into it.

      I do look at everything people suggest.  Paticularly you and "Douglas49" (the other guy in the forums).  But some things will just take too much time to add for an XP10 version update.  
      In saying all of this, please stick around.  I may get you to be a tester for the XP11 V2 upgrade.

    2. Bob Denny

      Bob Denny

      Thanks Goran. I definitely intend to stick around. I just made a 1:40 flight from Battle Mountain Nevada to Salt Lake City, starting at evening twilight. I navigated solely by the lighted airway beacons and the Four Course LF Range (and its fan marker beacons). I have all of the roads and cities turned off so it becomes a black as ink experience except for the stars, the beacons, the "acetylene blinkers" and the airports which "appear out of nowhere".

      I took Araneus' lighted airways, made some fixes, and enhanced it to include uncorrelated slightly varying rotation periods for the beacons and morse coded course lights on the towers. I also moved some beacons around to match the 1940s sectional charts I have.

      The LF Range Experience is something I also developed.

      Why? This is me when I was 2 years old, in 1948. Note the DC-3 on weeds, an unimproved landing field in Wyoming. My Mom put me in that crib, closed the top, loaded it into the DC-3 and off we went. I just bounced around in there. So many hours in the jump seat ad a young boy, and some time in the right seat too.N66699BruceCrib.jpg

       

    3. Bob Denny

      Bob Denny

      PS if someone wants a "modernized" DC-3 they can get the Heinz one. I think it is bad. A DC- that has Cessna instruments. The panel looks totally bad. But they have the colored AI, compass card, all the "newer" stuff. Bah!!

       

  8. Goran -- I apologize, and will not post realism adjustments from now on. I totally understand your support concerns, and I feel bad for not considering that. I just love this airplane, and I was struggling with some serious realism problems, found a way to resolve some of them. I will communicate privately from here on out. For the record though, We didn't communicate well. It was not the curves on my controller, it was the FADEC being on (the DC-3 has no FADEC :-)). Once I disabled the FADEC, as I reported in the Engine Behavior Issues thread, the throttles now have the dynamic response like they should. I should mention that Douglas49 reported the same issue in that thread as well: so it's not just me. I have removed the specifics and screen shot from that thread. I will no longer post realism adjustments. I do have some suggestions for the other engine issues after I worked on it yesterday for several hours. I am a real DC-3 pilot (well not for almost 20 years, but back then I did!). I will send these to you privately. Also, please feel free to delete anything, including this thread and the Engine Behavior Issues one as well.. It's your project after all, and of course you have to support it.
  9. Real World Taxiing of the DC-3 When taxiing the real DC-3, you have only brakes and differential power to work with. The tail wheel is not tied into the rudder pedals. In addition, most DC-3s have "expander tube" brakes (older ones have what they call "truck brakes"). They are very sensitive. Using brakes to steer the DC-3 is frowned upon by the real pilots. The brakes heat up very quickly. If you apply the parking brake with a set of hot brakes, the heat conducts from the drums into the shoes and then into the expander tubes, causing the static hydraulic pressure to increase and sometimes the expander tube can explode. SOme DC-3 operators prohibit the use of the parking brake - chocks only! If you have (1) dual throttle controls, and (2) pedals with proportional brakes, you can taxi the DC-3 like it's supposed to be taxied. At present, the ground friction seems way too high and I am going to work on this today. I'll add to this thread if I find something (new PlaneMaker user here). Meanwhile, to decouple the pedals from the tail wheel you can make the changes to the "n-w steering, slow and fast" in PlaneMaker as shown below. You should only do this if you have dual independent throttles and pedals with proportional brakes. (Goran, this would be a nice option for the new bird). Tail Wheel Retraction In the real DC-3, the tail wheel does not retract. You can fix this in PlaneMaker as shown below for the "retracts" checkbox.
  10. Oh, OK. IT was the axis assignment in XP settings that is backwards here. When I move my left throttle, I have to make the setting in XP that it is "throttle 2" for the left throttle to move in the DC-3. I'm unsure how that works in XP.
  11. Once I got my Thrustmster controller hooked up, and I have separate throttles, I found that throttle 1 is the RIGHT engine and throttle 2 Is the left. In airplanes, the number 1 engine is the left, etc. These seem backwards.
  12. I've been flying this wonderful bird for a while maybe 25 hours... and I just noticed that the elevator trim wheel runs backwards. When you command nose down trim, the wheel rotates with its top edge going rearward. It should be the other way around. Push the top of the elevator trim wheel forward to give nose down.
  13. Playing with design tools (I am a newcomer to this), I can see that the autopilot's heading selector is already hooked up to the relevant /autopilot/... DataRefs. So it is already capable of telling the AP the desired heading. I played with DataRef Editor to try to force the autopilot into heading hold mode, but some DataRefs that have attractive names for this seem to be read-only. I'd be pleased to find DataRefs that will turn on heading hold... I would hook it up via LUA and FlyWithLUA.
  14. Goran has rightly asked me to check with him on aircraft changes before posting here, for support reasons, which I completely understand. With a couple of minor changes to the model, the throttle response and engine behavior can be made more realistic. I have removed the specifics here even though he didn't specifically ask me to do it. I'll send my discoveries to him privately.
  15. I decided to try my hand with PlaneMaker today (never used it). This is what I did to add the rear nav light.
  16. Please preserve the old cockpit as an option. Some of us fly this aircraft for its old school operation.
  17. When advancing the throttles, it seems that the response is minimal until the throttles get half way open, then the engines start to respond. I have linear curves set, and I checked it with two different controls. On takeoff, if I set power to say 42 inches MP, then as the aircraft accelerates the MP will creep up to 45 inches or more. The RPM never gets above 2500, it should be able to reach 2700 at takeoff power. The RPM also changes a little with MP changes, as though the governors are not working right.
  18. Thank you Goran!! I won't say anything more.
  19. The "some issues" thread reports this as well. I hope for the autopilot heading hold to be implemented. The AP's artificial horizon isn't so important at least to me.
  20. Since Goran is watching I am bumping this for near release. Sorry if this isn't allowed. Sometimes it's against the rules.
  21. Excellent news! Happy to support your continued work on this wonderful aircraft.
  22. Of course. The pitch, roll, and even yaw are working
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