Shaunie

Really frustrating as I was going to bunk off for a day from showing at another show (Paws in the Park at Detling) to go to this one. Doubly frustrating as it's local to me too! Can't work out why the flying show doesn't take precedence as I presume it was booked first (just conjecture you understand). Shaun

My first thought with both of these engines is are they over propped? Second thought is plug problems. Remember airleaks have a decreasing effect as throttle approaches W.O.T. They are more significant at lower throttle settings due to increased vacuum. You could picture it as at low throttle an air leak is a larger proportion of the total airflow than at full throttle. What this means is an airleak round the carb base will cause a poor idle but is unlikely to have much of an effect at full throttle. Hope this helps, Shaun

Got no figures to hand but the stronger the magnet the lower the temperature it can withstand, some of the strongest rare earth magnets can be affected by any temperatures over 50 deg C from memory. Shaun

Just picked up on this one, with a great deal of interest. I am a member of a search and rescue organisation (sorry no names until I am given permission) as well as a modeller and I have been looking at the idea of a multicopter with an infrared imaging system to help us locate missing people, this looks like it may handle a lot of our positioning requirements. Will investigate further when time (and sobriety) allows.

Hi Tony, buy 6 inches of silicon rubber tube large enough to fit on the exhaust and cable tie the loose end to the right main gear leg a bit above the wheel. Not particularly pretty but almost all the gunk will be below the tailplane as it goes by! Makes the engine quieter too. Even one of those little 45 degree rubber bends will make a significant difference. Is the engine two-stroking nicely or is it four-stroking rich as I suspect it might be?

iPhone for me please! I've had my 3GS for over 2 years now, it's always in my leg pocket (I'm in the motor trade, go out flying and do SAR work as well) and has survived fine. Due for upgrade at the moment but waiting for the iPhone 5 to come out before I do. Loads of my friends have had HTC's and moved on, my Mrs and daughter have Samsung Galaxy Aces, Wifeys keeps crashing. There does seem to be a higher quality feel to the iPhone. Just check the resale prices of various used phones, even iPhone 3's are still worth something. The only downside is the more modern look of the iPhone 4 with the edge of the screen exposed is more vulnerable to damage when dropped.

I was involved in the design and manufacture of CNC equipment many years ago (left the company in 1991). I always found it fascinating even from the inside, and still do. I once had to optimise the part program on a CNC internal grinding machine. The program took 3 minutes to run and I was asked (instructed) to get the time under a minute. I managed it, just. But not before I made a minor programming error, I missed a decimal point out and put a 50mm grinding wheel at 45,000 rpm out through the side of the workpiece, or rather the machine tried to, nothing of the wheel was ever found! Still they got the machine square and true inside half a day so no harm done then! Play hard with your toys and occasionally you break one, that's what I say.

The best thing is to buy a leisure battery for this purpose as they are better able to cope with deep discharge duty. It is widely accepted in the motor industry that as little as ten deep discharge cycles can bring a starting duty battery to "end of life". I am not sure of the reasons why but suspect paste loss from the plates collecting as silt in the bottom of the cell as the cause. It can be quite difficult explaining to customers that their brand new battery is toast because the garage they bought it from failed to test for, or find the charging fault or battery drain that the car is really suffering from that is the cause of their problem. The joys of being an Autoelectrician! When charging LiPos with higher numbers of series cells, more than 4, then the output voltage of the charger will be higher than the input voltage, in order not to break the laws of physics then it follows the input current will be higher than the ouput current charging the LiPo. The best answer is to work in terms of Watt/hours rather than amps. What this means is the current drawn from the charging battery is higher than it first appears. Many lead acid batteries are now rated at the C/20 rate not the C/10 or C/5 rate, just a way for the manufacturers to make their product look better! A friend of mine supplies and services stairlifts which commonly use a pair of the 12V/7Ah batteries, currently he is paying about £8 each (for MK batteries, which are as good as any) so £40 each is far wide of the mark even allowing for trade/quantity discounts. I've not bought any recently he gives me loads of good secondhand ones, got over two dozen in stock at the mo! The moral of this is that you may expect about half the number of LiPo charge cycles from a lead acid battery than the calculations just based on label derived Ampere/hours may suggest. Then again if lead acids had a really high energy density we would be flying them in our models and not LiPos wouldn't we? Just a few rambling thoughts. Shaun

I have made a couple (some years ago now) quite successfully and used sheet steel from old (clean) engine oil cans. Thoroughly clean all edges as they are often coated as you suspect. Always take care with the edges as they can cut you easily. The method I used was to cut each end cap about 3mm oversize all round and fold a 90 degree return by cutting a hardwood block to the right size and tapping the edge over it with a small hammer. I fitted the caps over the sheet I had formed into the main rectangular section but it might be neater if a little more difficult to fit the cap inside. I soldered the end with the pipework first, checked it was ok and the fitted the plane end after. I used electrical solder but plumbers solder would probably be better, It's just that I'm an electrician not a plumber! Hope this is of some use.

It is possible to use a lamp dimmer on the primary (mains side) of a transformer for this application. Because of the way a transformer works when there is a resistive load at its output it behaves as a resistive load at its input but at a different impedance. As a result the dimmer doesn't mind this. Do not switch off the heater at the low voltage side, switch it off at the mains side. As always take care with mains voltages, if you don't know the proper way you are probably not competent, seek advice from someone who is! There are many low voltage supplies available at very reasonable prices intended for driving LiPo chargers which would do the job very effectively and avoid working with mains directly. The foam cutter I built many years ago used 0.8mm stainless steel MIG welding wire very effectively. Pop down to your local welders and ask nicely!

I was at Bodiam Castle yesterday (Saturday) heard big piston engines coming, C47 came over very low along the river, about 500 feet at a guess and travelling East to West. Got one one shot with the iPhone camera but then it was gone! Show season is coming! Shaun

Checking for big end play at TDC will always make it appear the engine has a problem, ABC engines with the "nip" at the top of the bore will make it appear even worse. At or near to TDC the rise and fall of the piston is very small relative to the angular movement of the crank.which greatly magnifies the apparent play in big and little end bearings. Check for play 90 degrees before or after TDC and the play will be practically imperceptable. I very much doubt if there is anything wrong with this engine, especially as it is running ok. Just fly it and enjoy it.

I'm a big subscriber to the "if it runs ok, don't mess with it" theory, sometimes I'll put the screw one click in or out but that's about it. Tune for maximum scream then a couple of clicks out and hold the nose up, if it dies open up another click or two. Just depends if you have a natural ear for engines or not. But I find I fly more and more electric now so I hope I don't lose my touch with the wet fuel stuff. BTW. modern car injection systems calculate the fuelling and ignition advance on a cycle by cycle basis not just several times a second, processor power is cheap now. Shaun

I wish I still had some of the bikes I rode through the woods when I was a Kid! Now got an Aprilia Pegaso III 650 after about 8 years off, a bit of fun without being too fast, I work for myself now and could not afford a long time off work. Already got that T-shirt, had a big stepping off about 20 years ago, hitting the Passat that failed to look left when pulling out was not the big problem, getting hit by my 400-four 1500 miles after a complete restoration that also flipped over the car was. 7 weeks off with a chipped hip and broken pelvis, somewhere I'm not anxious to go again. Shaun

I was just about to start a "how do you hold yours" thread when I found this poll . I am a fingers'n'thumbs man, still a woefully poor pilot of course but I think I do have very bad hand/eye coordination though. I was taught that the additional finger gives more tactile feedback. Certainly it feels I have less control until I have both fingers on the sticks (lone flier so hand launches mainly, no ROGs unless the farmer has just cut the field). But looking in the magazine I see lots of top pilots with their thumb on top hence my interest.

How big were the glitches? Just maidened a TT OBL40 trainer on electric power, to help teach a mate and the kids to fly, but also as a camera ship. It's on 35 MHz unfortunately but it is a "free plane" I was given the aircraft, the power set and the radio by different people. It flew it's first flight with two 808 cameras, reviewing the results I counted five motor glitches, I heard one big one from the ground but the others I had no idea about until I viewed the footage, bit like having a flight recorder really. My point is that perhaps we get more glitches than we are aware of. I've also had a glitch there with my Spektrum DX7 that caught me out so much I damaged my Vortex 400.

Back in the drought of 1976 the authorities vowed never to get caught with their pants down again, but memories are short. I have no idea how many new reservoirs have been built since then, I suspect very few, however there are now many more housing estates down here in the Southeast with of course the increased water consumption per property of dishwashers, car washing, washing machines etc. Personal hygeine has improved and along with it water consumption. As I see it water is free, it is only necessary to catch it and process it, that is where the costs are incurred. Also as more floodplains are built on, more water is caught by gutters, fed into drains and thence straight into the rivers and so less is available to replenish the water table. We are all dooomed, dooomed I tell you!

Just one small point...The temperatures required to achieve a good silver soldered or brazed joint can anneal music wire. You make a lovely job of the joint and when you make your first landing your wheels are pointing in different directions. Don't ask how I know!

Good job they do the way I fly! If it had been anything else that I fly the bits would have been over a 15 metre radius, all that happened with this is the nose came off.

Tried to put a #11 keyfob camera on mine yesterday, it was always a bit optimistic. Put it on CG above the left wing by the fuselage. 60g plane 18g camera, you can tell it was never going to work. Flew it without the camera afterwards and it took two clicks of right trim just to compensate for the Velcro on the wing! Binned it today, big spin from a couple of hundred feet (more a spiral dive, can't seem get a fully developed spin, how do I do that?) Centred rudder, centred ailerons, but put on the power before centring elevator, why did I do that? Just flicked straight into the ground as I was less than a mistake up. The glue is setting on the nose now!

Hi David, So do I, so I normally fly when its a bit warmer By the way, how do you launch? I was doing the overarm power off tactic but seemed to have terrible problems getting my hand on the stick quickly enough to "catch it". I've now started doing an underarm "chuck" holding the l.e with about 3/4 throttle on and 45 deg nose up which seems to flatten out nicely at about 20 feet and then you can just climb out from there. Shaun

I bought a second battery when I got mine and they are both doing ok at the moment, but I cannot disagree with you £17 (I think it was) for a battery that size is ludicrous. I only fly 5-6 mins at a time, how long do you guys set your timers for? How many flights can you reasonably expect before the batteries have had it? Shaun

Getting to grips with one of these now. It's not particularly tough unfortunately. I've knocked the nose off twice now, PVA works ok if you are not in a hurry. It is however terrific fun to fly, just about vertical which teaches energy conservation, very nimble and in any sort of wind can be landed with no forward speed. Bit twitchy in the windy weather but copes very well as it has a very good speed range. Getting to the point now where I'm not too frightened to "chuck it about" I am unfortunately a very conservative flier. Moving the battery right to the back of its tray crisps up the responses nicely, further forward than halfway and it is difficult to slow it up for a nice landing. Mines getting a bit battered, will I buy another when it's had enough.. you know I think I will! Shaunie

I wish I had followed my originally planned path to a degree in electronics. The reasons I changed direction and took the C&G route are too complex to bore everybody here with. But not the least of it was that the financial implications for my parents (my Father was an instrument maker, my Mother only doing part time work) made me feel I had to earn a living for myself as soon as possible. Suffice it to say I have been earning a living in electronics, mainly industrial control and production machinery applications, since 1978. My C&G in industrial control and servomechanisms has certainly been useful. Talking of servomechanisms the largest servo drive I designed into a system was rated at 75KW input with a 150% overload 30 minute rating, how big a rudder could you move with that? I have met many people in my career and find that having a degree does not automatically make the person gifted and that not having one does not automatically make them stupid. Who knows where I would have gone with a degree? Possibly I would still be where I am now, working for myself doing diagnostic/electronic work on cars. Now my children are getting older (17,15 and 13) I would love them to go to Uni but now the government is playing at social engineering I will never be able to afford the tuition fees. I think the governmental stupidity is stunning, those on benefits will get support, those who are well off will be able to pay, but those in working class families who are most likely in my opinion to put a degree to good use are those who will be excluded due to cost. I'm sure some will agree with my view and some will think it's just sour grapes but it is what I feel. Shaun

Read Terry Pratchett, he defines these explanations as "lies to children" i.e not entirely accurate but sufficiently close enough to give an idea of what's going on. Reminds me of a cartoon I saw years ago. Two kids watch a 747 fly over and one says " I wonder what makes it fly?" the other replies "Aerodynamics..... and two blokes with handlebar moustaches and 400 people praying". Shaun