Here is a list of all the postings Paul Adams has made in our forums. Click on a thread name to jump to the thread.
|Thread: Aileron Differential?|
|Ultymate - That explains it.|
Am I correct in thinking that aileron differential is only used on non aerobatic models?
The reason I ask is consider a model undertaking a level roll (i.e. one where you add a bit of bottom elevator when inverted to keep the model flying level) when fitted with aileron differential.
I see it will go through three stages:-
Stage 1 - When you roll from level flight to knife edge the down going aileron ( i.e. the aileron nearest the ground) will go down less than the up going aileron.
Stage 2 - When going from Knife edge through inverted to knife edge the down going aileron (i.e. the aileron nearest the ground) will this time be greater than the up going aileron. Since bottom elevator is used to maintain level flight the wing during the inverted phase will still be producing lift (i.e. upward force on the model).
Stage 3 - Then from Knife edge back to level flight you are back to the correct way round.
I see how aileron differential will cancel out the Yaw effect during stage 1 and 3, but wont it make the yaw effect during stage 2 much greater?
|Thread: Acrowot - Landings|
Hi Biggles - Thanks for the advise, Its strange, all the other models I fly no problem (Pattern ships to 3d) its just this one model which refuses to land without bouncing.
Thanks Tom, Will go it a go tomorrow and see if it helps
What is the best way to land an Acrowot so it does not bounce. At first I thought it was just me, but after trying a number of methods ranging from flying it down to the ground, floating in, balancing throttle with elevator to do a three point landing all I get is a bounce. I do not know if its just my model but looking on youtube it appears to be a common feature of Acrowot landings.
I am open to ideas
Edited By Paul Adams on 03/12/2011 15:39:19
|Thread: Mini Panic - first build|
What servo's are people using? |
Edited By Paul Adams on 28/11/2011 23:07:38
|Thread: The dive test|
The dive test gives a good indication of the C of G setting, whether its a powered model or glider. In both cases you are taking any effect of the engine down thrust angle has out of the equation.
After I have adjusted the C of G using the above method, I then evaluated the engine down thrust, this I do by trimming the model to fly level at cruising speed, then decrease the throttle to tick over and see what happens. If the model dives towards the ground, then you need to increase the down thrust, if the model slows down and approaches a stall, then reduce the down thrust. What I want is a nice glide, as this manoeuvre is used every time you land, so its worth getting right.
I then go back and recheck the C of G by trimming the model at cruise for level flight, then rolling inverted and checking how much down elevator I need to apply to continue flying level. What I am looking for is just a bit of down elevator having to be applied. If a lot of down elevator has to be applied, the C of G is too far forward, if no or up elevator has to be applied then the C of G is too far back. Always do this test near the end of the flight when the fuel tank is nearly empty. (If done on a full fuel tank, near the end of the flight when the tank is empty the C of G will have moved further back).
I then recheck the thrust line as in step 2.
I then look at where the neutral elevator is set, If it is set so that up elevator is applied in the cruise, then this indicates that the incidence on the main wing is too low, if down elevator then the main wing incidence is set to high. This can be corrected by either adjusting the incidence (packing in the correct direction) or by adjusting both aileron either up or down (a bit of a bodge but it works).
Edited By Paul Adams on 10/11/2011 23:28:21
|Thread: Spektrum Servo Movement and Spoilers|
I don't have a DX6i but if its got programmable mixes then mix the spoiler control to a free servo position (Aux 2) on the receiver and set the mix to -100 on both positive and negative throws. Then just plug the second spoiler servo into the Aux 2 servo position. They should then operate in opposite directions.
|Thread: Are you or will you be building from a traditional kit or plan?|
|Does building a new wing out of foam to replace a built up wing for a ARTF model count as building from plan, design own or ARTF|
|Thread: Evolution 26GX dead stick problem|
The only way i have found to set the mixtures is by trial and error. A good starting point is to set the mixtures slightly lean on the ground as when the model gets airborne, the pressure measured by the carb diafram changes resulting in a change of the mixture (goes richer). In the first few flights I set the idle slightly high and adjust either the high or low settings by 1/8th of a turn at a time and do a test flight to see if things have improved or got worse. The good thing about petrol engines though is once they have been adjusted , you can forget about them. I have had an estimated 40 -50 flights (8-9 hours flying time) out of my Wot 4 XL without having to adjust the mixture.
I see from above that you will be fitting a cowling. When you do this you probably will have to adjust the mixture again as the atmospheric pressure will be different within the cowling. Many people solder a tube onto the diafram vent hole on the carb and extend the tube with a bit of silicon tube to either external to the model or to somewhere internal which will not be affected by changing pressure as the model flies.
|Thread: Building my new Fournier RF-4|
|Is there room to fit air brakes as our strip is fairly small?|
|Thread: Oily Messy Fuel|
|My latest model uses a petrol engine, although its 26cc with the power equivalent to a good 120 2 stroke, it uses about 5 oz of fuel for a ten minute flight, and since the petrol has an oil to petrol mixture of 1:40, most of which is burn't, the exhaust and therefore the model is basically clean. It also evaporates very quickly so your clothes do not smell of oil after flying. Normally after several flight its a quick wipe over, mainly where the wheels have sprayed mud / dust onto the wings after flying.|
|Thread: Wot 4 XL Mk 2 - Build|
I have tried a couple of props a 16 x 8 and a 18 x 6, both have advantages and disadvantages, so it will depend on your type of flying which suits you best.
16 x 8
Advantages - provides plenty of speed and vertical pulling power.
Disadvantages - Provides too much pulling power on tick combined with the ability of the model to fly at very slow speeds makes landings a challenge. To counteract this I have used flaperons allowing shorter landing.
18 x 6
Advantages - reduced speed and allows maximum use of the Wot 4's slow speed capability and making landings easy without the use of flaps.
Disadvantage - Engine unloads when in a slight dive.
I am waiting for a 17 X 8 prop to arrive to try that. I expect it will perform very similar to the 16 x 8 but should reduce the engine revs and therefore the noise.
|Thread: DLE 30 noise reduction|
|Having tried to silence my CRRC 26cc engine, I have at last found a silencer which does the job. Its a canister silencer, see picture.|
Its a bit big, but works well. I was also considering adding some form of silicon tape to the outside to see if it reduces the noise even further.
I have tried a Pitts silencer in the past, but still over the noise limit, although blocking off one of the outlets did help.
Another thing I found affected the noise was the propeller. A prop with squarish ends increased the noise significantly, so try a prop which tapers to a point.
|Thread: Cutting out mid-flight|
I had a similar problem with an OS 55. After trying all sorts I changed the fuel to Castor based, and it's no longer a problem.
The other thing is how old is the fuel you are using / how is it stored. Fuel is hydroscopic so absorbs water, so if your fuel container is half empty, the fuel will absorb all the water from the air above it. If you empty your tank by reversing the direction of flow in your filling equipment (hand / 12v) it normally finish up bubbling air through the filling container, which results in more moisture being absorbed by the fuel.
So I would suggest scrounge a tank of fuel from someone else and see if that cures it.
|Thread: Wot 4 XL Mk 2 - Build|
So after about thirty flights under its belt, hows it hanging together. Very good, still enjoying flying it. Its slow speed handling is excellent making landings simple. I have flown the standard size Wot 4 and thought they were good, but this is better. A couple of our club experts had a fly and one is looking at getting one himself, so it must be good.
Only problems I have had with it is the spinner which after about ten flights fell off in flight. Its never been a good spinner and had defiantly been manufactured down to a price. So a nice new aluminium spinner was fitted.The only other observation I have is I should have replaced the fuel tank with a smaller one. At 15oz and with a petrol engine fitted it will last for well over half an hour.
|Thread: Phoenix Online Session|
Nice Flying, but bit of a pig of a site to land at, very pretty though.
|Thread: My WOT4 MK2 Build|
|What I do is measure back from the leading edge and lay a pin across the wing in that position temporary attached with a piece of masking tape. I then repeat the other side of the fuselage. All you do then is to feel where the pins lay with your finger tips and lift the model up. The model should balance slightly nose down with your fingers in that position. I have tried using a fancy balancing machine, but have found my method easier and quicker (and a lot cheaper).|
|Thread: When is it "too windy"?|
I learnt to fly on the slope, so never saw the wind as a problem, only lack of it. Now I fly powered, I still enjoy flying in windy conditions and often find I have the strip to myself. All I do is dial a couple of clicks of down trim to increase the model speed and enjoy. The only problem I find is the optical affect of landing my panic backwards.
|Thread: Storing i.c. models after flight|
|I have never had a problem with storing glow powered models in the workshop (spare room), but the wifes complaining at my latest model which has a petrol engine up front. No matter how I drain it down or clean it, it still has that smell of petrol for a couple of days after flying. Any ideas would be welcome|
|Thread: Wot 4 XL Mk 2 - Build|
On to the strip. Throttle opened up about a quarter at which time the model was accelerating down the strip, slowly increasing the power to about half way the tail plane lifted and the model left the ground and gained height. Had to add a couple of clicks of up trim and one of right aileron, but nothing drastic. Flew around for a couple of circuits to get the feel of the model, all felt very safe although the Aileron were a little twitchy near centre (a bit of expo required), but nothing uncontrollable. Throttled back to test the stall, the model slowed and stalled, but nothing nasty and immediately control surface authority was obtained. A couple more circuits and I closed the throttle down to tick over, the model slowed but required no change in trim. Applied full power and the model took off live a scolded cat, but still level flight. I pulled up into a vertical climb and the model just kept going straight up, so the engine thrust line is about right.
So a quick refuel (only used about 1/3rd of a tank (5 fluid ounces)), put a bit of expo (30%) into the aileron and elevator and back to the strip. This time line her up, apply the power, and after she left the ground, pull up until she is vertical and power up to the clouds, rolling as you go. Into an inverted spin to bring her back to nearer the ground and do a low flypast at head height inverted. Pull her up into a stall turn, and do a flypast the other direction inverted. Into a half loop and do a long slow roll. At ten minutes the timer went off, but as someone was about to take off, and I knew I had lots of fuel, I kept flying. I was having so much fun I flew for another ten minutes, at which time the engine went dead stick (must have been out of fuel) Straight into the back leg of a landing circuit and touchdown mid strip, what a flight. No vices beautiful flyer, great fun. The only problem is that my jaw hurts from all that grinning. Would I recommend it to anyone else? Defiantly yes.
The next flight I let someone I had helped learn to fly last year have a go, and had to prise his hands off the transmitter to let me have it back.
Had a good check over of the model when I got home to make sure all is well. A couple of loose bolts / nuts caused by the vibration of the large petrol engine, but nothing a bit of lock tight won’t solve. The only other problem I found was that one of the wheels on the main undercarriage was out of alignment, which surprised me as all the landings were good. Had a closer look and the stud axles are mild steel screws, which are defiantly not up to the job, so will be replacing with proper stud axles before I fly it again.
So overall, a couple of problems with the build, the fin needed extending, and the wheel axles, but nothing major. But the flying defiantly makes up for it. I can see it being my favorite model for some time. The 26cc petrol engine is on the large size and will take the model vertically out of sight, but at low throttle the model is an absolute pussycat and the slow speed handling excellent. Even in the very light wind it would nearly hover. Chris Foss has done it again.
Edited By Paul Adams on 07/03/2011 22:01:22
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