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Paul Jefferies

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  1. Paul Jefferies
    There was a young man from down under whose launching technique was a wonder He managed OK with Certificate A But Certificate B was a blunder!
  2. Paul Jefferies
    There was a young man from Australia, Whose flights often ended in Failure. He couldn't surmise Why his plane wouldn't rise and now it's pushing up dahlias.........
  3. Paul Jefferies
    There was a young man from Kent, Whose model was really quite bent, To stop it going down, (He thought with a frown) Launch inverted n get an upwards descent!
  4. Paul Jefferies
    Posted by Plummet on 27/02/2017 10:30:03 So how about changing the Sharkface into a Hammerhead Sharkface, and installing two motors in the hammerhead extremities. Hmmm..... I like that! They would have to be diesels of course and that might present a problem when one of them cuts before the other...... 'a bit of a challenge on single channel. This requires further thought......
  5. Paul Jefferies
    Posted by john stones 1 on 23/02/2017 22:58:56: It got a lot of down thrust on or is the motor falling off ? No the motor isn't falling off, it really does have that much downthrust. I "tidied up" the nose a bit but the geometry is exactly as per the plan.
  6. Paul Jefferies
    Posted by Phil Green on 23/02/2017 17:19:09: Spot on Paul. And I bet it flies great with the proper sharks teeth doesnt it? (Do you find that beam aerial mounted on the leading edge a bit directional?) Yes of course, how else would it gobble up so much sky. As for the directional aerial, I find it helps with orientation............ on the rare occasions when I have control of it, it must be coming towards me!
  7. Paul Jefferies
    Or you could just buy a small "artists brush" and paint it on.........
  8. Paul Jefferies

    Paul Jefferies posted a gallery image in Member Albums

  9. Paul Jefferies

    Paul Jefferies posted a gallery image in Member Albums

  10. Paul Jefferies
    I had a friend who died three years ago of liver failure and he drank much less than that........... I am not being judgemental, there is no judgement to be made. If you are really drinking that much, you are way over the top and that's a fact! Take a look at this site and make up your own mind....... http://www.drinkfox.com/information/alcohol-metabolism If you choose to kill yourself, that is your decision but if you drive at all the next day you will still be way over the limit and a danger to others. Either admit that you are winding us up or get some help. Sorry, but somebody had to say it!
  11. Paul Jefferies
    For what it's worth, I built a Galaxy Mustang many years ago and it lasted precisely one flight...... I builds into a very nice model and seemed to fly very nicely until it suffered Elevator flutter on it's first flight and that was the end of that! I immediately throttled back but elevator control had been lost and it just continued in a shallow dive into the ground. I had used a bigger, more powerful servo for the elevators but in the subsequent inquiry I discovered that the flutter had caused the servo arm to break. I don't know if other people have had a flutter problem with this model but as an "anti-flutter" measure I suggest that you leave the trailing edge of the elevators at least 1/8" thick, possibly thicker, use a good stiff pushrod and make absolutely sure there is no play in the system. Also, I discovered that there was a bubble in the servo arm moulding which had caused it to break at that point so now I only used disc outputs on controls that could come under high load. OK, I had an unfortunate combination of circumstances but...... for-warned is for-armed.
  12. Paul Jefferies
    I have used different balsa strippers over the years and currently use one similar to the one shown by Peter Miller and have no complaints, even up to 1/4" thick. Sometimes you get good straight strips however sometimes you don't. The trouble seems to be that sometimes a seemingly straight sheet has stresses and strains in it which even eachother out and do not show up in the sheet but when cut into thin strips these stresses are released and you end up with a bent strip........ It is a bit more expensive but when I can, I prefer to buy strips ready cut because if they are straight when you buy them, the chances are that they will stay straight.
  13. Paul Jefferies
    I bought "Weller Thermaboost" a year or so ago and have found it very useful..... http://www.ebay.co.uk/itm/Weller-TB100UK-30-130-W-230-V-Therma-Boost-Soldering-Iron-DIY-ART-CRAFT-Tool-/192025533178?hash=item2cb59d1afa:g:bQ8AAOSwux5YJxsB It is nominally 30W but with a "Boost" up to 130W. The bits supplied are not that big though,  so I would question it's use on bigger jobs as a 130W iron. The problem is getting enough heat into the job without cooling the iron too much so other dodges you can use are to use TWO irons or to "pre heat" the job with a heat gun thereby not taking so much heat from the iron...... Whatever you decide on, try a test joint on some scrap wire first to check that you have enough heat available. Edited By Paul Jefferies on 31/01/2017 10:28:10
  14. Paul Jefferies
    I am pretty sure it is a "Hep Cat", designed by Paul Plecan and dating from 1946. The original was a freeflght model and I have a plan of that, however I think this one was built from a Ben Buckle kit....... **LINK** It looks as though someone has tried to build a second wing with ailerons but I think I would stick with the simple wing and just rudder/elevator control. 'Fraid I can't advise on electric power, firstly because I don't know much about it but mainly because models like this should ONLY be powered with diesels! I would recommend a Mills 1.3.
  15. Paul Jefferies
    A simple way to stiffen an exposed length of wire snake is to melt solder into it...... Clean it as best you can with acetone and since it can still be reluctant to accept the solder, rub some soldering flux into it and use a good hot soldering iron. Be careful not to overheat the plastic outer so pull it out a bit beyond its full movement extention when soldering......... it works a treat! Paul
  16. Paul Jefferies
    FWIW the early Boeing 707 had a bad tendency to Dutch Roll....... I am not sure if it was due to our CAA or BOAC but before it flew in BOAC they added an underfin to try and reduce the Dutch Roll...... though it still had a Yaw Damper. A similar underfin should not be too difficult to add to your model. Paul
  17. Paul Jefferies

    Paul Jefferies posted a gallery image in Member Albums

  18. Paul Jefferies

    Paul Jefferies posted a gallery image in Member Albums

  19. Paul Jefferies
    Could it be "Dutch Roll" I wonder? Dutch roll is a phenomenon of some swept wing designs and is the reason that fullsized jets have Yaw Dampers. Basically, the aircraft yaws and when it does so, because of the swept wing, the airflow on one side is more across the wing whereas the airflow on the other side flows more along the span of the wing thus creating more lift on one side than the other..... So if it "skids" to the left, it will roll to the right until the whole thing is so out of line that the drag on the fin pulls it back. However in trying to get back to "balanced flight" it has to skid the other way and then it rolls to the left and so on........ in a fullsized aircraft this can build up to an oscillation of 30 degrees or more each way. It is very difficult for a mere human to stop it and hence they invented the yaw damper which is a gyro stabilized device which applies minute amounts of rudder whenever it detects the smallest amount of yaw. If this is what is causing your fishtailing then I think a forward underfin will only make it worse and I think all you can do is increase the size of the fin and/or increase the length of the fuselage by a couple of inches to get the fin further aft....... Perhaps an AFT underfin or big tailskid might do the trick........ Paul
  20. Paul Jefferies
    "If flutter is part of the problem my first fix should help."............ Yes, that may do the trick though it would be better if the T.E. of the rudder was square which would create a cleaner "break" for the airflow. Please let us know how it works....... As for the linkage, flutter can be an incredibly powerful force and very difficult to stop with just good servos and linkages. If it really wants to flutter (IF that is the problem), it will and the only way to stop it is to change the condition that is causing it. If the 6mm tube doesn't stop it then try sticking a small weight at the T.E. and if it still fishtails then perhaps flutter is not the problem........ Paul
  21. Paul Jefferies
    'Fraid I haven't read all the links so forgive me if this has already been suggested but the fishtailing could be caused by rudder flutter........ I once had the pleasure of flying a very large (1/3 scale) Mustang and to cut a long story short, that initially suffered from very bad fishtailing at speed which was cured by thickening the rudder to about 3/4" at the trailing edge. Before replacing the rudder with a thicker one, you could check to see if this is your problem by simply sticking some thin strips either side of the trailing edge of your rudder and/or by sticking a small weight on it which would change it's frequency of oscillation....... Good luck! Paul
  22. Paul Jefferies
    As an aside...... I once met an ex-RAF pilot who had done an exchange with the USAF and had a ride in an F16. He told me they had come burning down the runway before pulling up into a loop........... the top of which was 29,000ft ! (That's 5 1/2 miles!) As Cymaz said, it's all down to power to weight ratio. Paul Edited By Paul Jefferies on 21/08/2016 08:17:08
  23. Paul Jefferies
    'A bit extreme perhaps but at last he had found a way to deal with next door's cat! Edited By Paul Jefferies on 16/08/2016 08:05:59
  24. Paul Jefferies
    Re. the original posting, Old Warden is the PERFECT venue...... there is also a botanical garden on site. Last weekend I played with my toy aeroplanes and she went and looked at flowers (or whatever you do in botanical gardens ). We met up for a picnic at lunchtime and we both went home happy! Old Warden is not to be missed! Paul 'Bought a bargain engine too..... Edited By Paul Jefferies on 26/07/2016 07:49:32
  25. Paul Jefferies
    Yes, CG may well be a contibutory factor and another thing I have seen catch people out is flying just a little too slow when turning downwind. When you turn you are pulling "G" which effectively makes the model heavier and increases the stalling speed so if you were flying just a smidge too slow all these things add up and coupled with a slight loss of airspeed when you turn downwind....... I think that would do it. Paul
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