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Paul Williams

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Everything posted by Paul Williams

  1. Paul Williams
      Thanks PatMc I can see your logic though you have brought me another equation I had not thought of. If I read your script correctly the optimal ESC would have variable timing for differing power demands? Is there a setting that will give me more torque at lower RPM and another setting to increase RPM with a loss of torque? Or are the options provided so one ESC is commonly used for differing motor types. I will do the tests again and record more factors like RPM I just assumed the RPM would increase with the amps gain. Erfolg You have hit the nail on the head, what is the optimal setting and why are we given options? One concern for me; is it possible to cause long term damage to other components should I chose any of the timing or PWM settings. I have noticed that whiist programing the ESC it gets very hot strange it does this not running the motor. Edited By Paul Williams on 04/08/2009 18:05:05
  2. Paul Williams
    I have been following the thread with interest,  a lot here is going over my head but just in case this should help I have conducted the following tests. 12 pole out runner Motor run up to max RPM on four different timing settings  1 deg = max amps 19 7 deg =max amps 25 15 deg= max amps 25 30 deg =max amps 29 I have not tried to measure any difference in RPM or power but that’s a big difference in current draw, the default setting was 1 deg. Leaving the ESC set at 30 deg I then move the PWM from 16KHz to 8KHz with no difference in current draw. The instructions are vague they say set at 15deg for 10-12 pole motors then state set at 30deg for 10-12 pole motors high RPM (when does a rpm figure become high? 10000 or 20000)
  3. Paul Williams
    I have to say the onboard glow system I bought of Timbo has made my ASP sweet as a nut on tickover I was looking at your video and though its hard to assess the RPM seems very high for a 4s tickover, This leads me to think you may have a problem with fuel getting to the carb without the exhaust pressure being quite high. Has this set up ever run correctly? Is the tank mounted at the right height. This being ok try removing fuel line from carb and blowing very gentle into exhaust pressure line you should get ample fuel with a gentle blow. If your not using proper four stroke fuel get some I would never run a 4s on 2s fuel.   Hope this helps.
  4. Paul Williams
    My fantastic Deuces Wild is now pride of fleet but I am concerned my landing abilities have still a lot of room for improvement! Has anyone seen for sale a tricycle kit that is sprung in any other manner than the usual coil wire system? Its 10lb weight is begging for some thing to absorb the impact before it will due the damage I know will happen shortly.
  5. Paul Williams
    Thanks Scott that makes good sense.
  6. Paul Williams
    Sorry I shall go out into the garden and eat worms, When I said knowledge I was refering to what the timing does on a technical basis in other words how it works.
  7. Paul Williams
    Please you guys, the subject matter!! looking through the threads I have read the effects of timing don't really make any difference to it is critical, are we saying test every set-up or forget we have options. I see the point of reducing the amp flow so a useful flight time is acheived but is this causing long term damage would you not be better off sourcing the correct power to weight ratio in the first place. One thing I do agree with is the need for some knowledge so choices can be made with a better confidence.
  8. Paul Williams
    Thanks Guys
  9. Paul Williams
    I am confused, although my knowledge base has increased largely regarding electric flight one thing still confuses me. The timing options on ESC and motor poles. Can some one explain how I can tell which option I should use and how to find out what my motor poles are please. What happens if its not set correctly?
  10. Paul Williams
    its the social aspect mate, since joining my club last year I have been threatened with divorce because there is always some one holding a sim and chat night or similar event. made loads of good friends who stop me making silly purchases. It get boring on ya own.
  11. Paul Williams
    If your looking for some thing different and a little more than your standard electric jobbies look no more,     When I first mentioned I fancied a twin most guys in my club said "more trouble then fun mate" or "they are difficult to fly as a model" that was enough for me to start looking for one. Always up for a challenge I was on the phone and internet reviewing what was available. Surprisingly this was little in the ARTF range but then I was recommended the Deuces. I was nearly put off with the £158 price but then when I priced up the electric side of things from that cheap place with a fish in its name it all began to make sense. I waited 10 days for the model but when I opened it I was not disappointed. All the usual weak points ARTFs employ have been sorted probably to the other extreme leaving the model weighing in at a beefy 9lbs all up. Solid 3/8” thick mounting points for undercarriage and with motor mountings a similar thickness it left me confident this was built to last and will survive all but major crashes. Impressed with the build quality I pushed on to see how it would fit together, no problems here either (being a machine tool engineer by trade I am very often disappointed with factory tolerances and quality control) it went together like a dream.     Its 62” wing span equalled by its 62.5” length adds up to one very impressive looking aeroplane. No need to worry about transportation or storage because it takes seconds to split the 3 piece wing section and even the tail components are bolted on. I was worried about the power needed to pull all this around. The nacelles are another brilliant design, sturdy with ample space for motor, ESC, battery and ubec. I chose a power set up that would give me 556 watts per side using a 12x6 prop, 4 cell 2800Mah li-po and 60amp ESC the total power being 1112 watts  beating the standard 100 watts per pound aerobatic performance figure. 556 watts x 2 / 8.5 = 130 watts per lb.
  12. Paul Williams

    Paul Williams posted a gallery image in Member Albums

  13. Paul Williams

    Paul Williams posted a gallery image in Member Albums

  14. Paul Williams

    Paul Williams posted a gallery image in Member Albums

  15. Paul Williams
    thanks Bob
  16. Paul Williams
    I am struggling to find a pusher prop 11x7 or 12x6 for use on electric twin set up, however I can find a few IC props which I think will do. Is it madness to fit an IC prop to a motor will it cause damage? Has anyone done this?
  17. Paul Williams
    Thanks guys, sorted
  18. Paul Williams
    Sorry for late reply Tim is correct need to set up twin, Tried the link Shaun thanks but no 12x6 Still not found any !!!!
  19. Paul Williams
    I am really struggling to buy counter rotating props, i need a 12x6 EP any ideas?
  20. Paul Williams
    cheers guys, 3 minutes flight time is not acceptable I will rethink. Some thing I found interesting is the pull I tried the setup with a 3 cell ( I cant believe they reconmend this) I managed 260 watts with the size of prop that suits the plane. testing the static thrust it managed 3lb.(950kv motor)Just out of interest I then tested the thrust with 6 cell 760 watts it pulled 4.6lb ? When you consider the wattaged I would have thought 760w would pull stacks more. I always use to measure setups using Thrust but for ease went to watts save bolting motor onto test rig but I wonder now which would be more acurate?
  21. Paul Williams
    We spoke of this a few days ago and Tim suggested running from one large capacity battery, I can see your point Tim and I was going down that line when I did some testing. The planes flying weight is around 9lb, so I was trying for 1000 watts, If I run a 6s 2800mh 20c battery it should allow me to pull 56 amps but is that divided between the motors? I have two motors that I think are suitable, in tests they pull 38amps each on at 20 volts but together will they pull 76 amps? That being the case it will exceed the C rate of the battery.I can feel a headache coming on !!
  22. Paul Williams
    What a fantastic responce thanks guys that has put a lot of issues to bed, a top class service !!!   Paul
  23. Paul Williams
    I had one that flew simular and after various things were tried all listed above I found the thrust line needed to be altered. Its a good sign if the plane flys ok when not under power, Trouble is when it starts to go pear shaped most people put more power on which of course makes it worse.
  24. Paul Williams
    Ok I have just about got my head round designing electric set ups, but I can't help feeling with twins things are not as simple as they first seem. I dont fancy dropping a dogs at the design stage as this will prove twice as expensive. If I want 125w per lb should I half that amount being as there are two motors?   Will it be ok to turn round a prop and run it in revearse?   Is it really important to counter rotate the motors?   will 1 ESC run two motors?    if I run two ESC's will it be ok on a Y lead from the throttle?   How then can I balance the power output should they differ?   If I run one ESC on a aux channel then mix it to the throttle can I then set the RPMs so they balance?   If anyone has done this or you know of a good article please let me have your thoughts.   Paul    
  25. Paul Williams
    Thanks Ken will try balsaloc then
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