Paul Adams

Fingers and Thumbs. I was taught to fly that way many years ago and it has the advantage that when flying inverted, if you lift off your finger, you can not pull back on the elevator stick if you get a little close to the ground.

Posted by Martin Harris on 17/12/2012 13:19:38: I really don't see the fascination for fitting a LiPo in a transmitter. Bearing in mind that the vast majority of transmitters over the past decade or two were perfectly happy on 700 mAH NiCads and the availability of low self-discharge (relatively low current) MiMHs of 3 times the capacity, why go to all the trouble of fitting a hand grenade LiPo I agree, and if Spektrum had incorporated a proper NIMH charge circuit into the DX8, I would still be using the NIHM supplied with the DX8. As it was I fried my NIMH battery by leaving it on charge overnight (the way I have always charged my batteries ready for flying the next day (same process for last 20 years)) I wrote to Spektrum complaining about the situation, but all I got was not to charge the NIHM for more than 12 hours. To me a design flaw. However since changing to LiPo, I am very happy.

Only problem I have has with mine is with the battery charger system. Basically with the NIMH battery charger does not cut off when the battery is fully charged and the charge rate is so high heat is built up in the battery which resulted in the battery overheating (Mine melted the heat shrink sleaving and foam insert inside the back of the DX8. Doing a search on the internet found that this is a common problem and you need to keep an eye on the battery temperature when charging and never leave on charge for more than 12 hours. To overcome this you can replace the 2000mAh NIMH with a 4000mAh 2S Lipo which works brilliantly. The charger in the DX8 monitors the battery when charging and switches off the charger when the battery is full. Because it is a LiPo it does not loose charge, as such all it needs is a charge up once a month (or so) - and thats flying Sat and Sun most weekends. The specific Lipo you require contains circuitry which protects the Lipo from overcharge and cuts the voltage off if it falls to a very low voltage (the DX8 will warn you much earlier that you have a low battery, so no fear of it just switching off when you are flying). Have just had a look on Ebay and someone is selling a new one for £15 plus £2.70 postage. Well worth the investment. **LINK**

Father Xmas has been good to me this year and received at Hanger 9 Katana. But what should I power it with? The manual says a 52/53 size two stroke or a 82 size four stroke or electric 52 size motor. As I prefer the IC route the choice is really between the 52/3 size two stroke or the 82 size four stroke. Looking at output power, the two stroke has more HP (but at a much higher rpm), weight is about the same, so which makes the better 3D machine?

Another thing to consider is the size of the cabling used on the switch. A thin wired switch feeding your receiver with digital servo's can have a significant volt drop across it lowering the voltage to your receiver. (If you want to prove this plug in one of the volt testers into the receiver, switch on and waggle the transmitter sticks quickly and see the red LED start to light), For that reason I always make sure I use a heavy duty good quality switch and 5 cells (of good quality) when using digital servo's. With analogue servo's the current drain is less, as such it does not appear to be a problem using 4 cells.

Agreed, steady climb ok,(ie you should not need to re-trim elevator between high trottle and idle). It made sence to me when I wrote it but can see the confusion. Paul

Its fairly close to where it needs to be. However what I always do with all my model is to gain altitude and throttle down to tick over and trim the model for a nice glide (This is one manuver your model will always have to do at the end of each flight when you are bringing it in for landing). Once trimmed for a nice glide, without touching the elevator, throttle up to maximum and see what the model does. It it flies level and just accelerates - no need to adjust the down thrust, it it climbs add down thrust, if it noses down reduce the down thrust. To adjust side thrust, go into a vertical climb at full throttle and see if it drift right of left. Note: Unless your model is well over powered the model will slow during the climb and what you are looking for is a generally straight climb during the time it is climbing at a good rate. Note: If you change the CofG during the trimming phase, you may need to repeat the above. Paul

Looking through my fleet of aircraft I see a few common threads:- Four stoke Engine 91 to 120 size Wingspan 60 - 70 inch Low wing or biplane Capable of aerobatic flying ie slow rolls, knife edge flying but not 3D. Solidly built - to put up with some punishment. So what's my favourite models:- An old Acrowot, foam wings fitted with an OS 91 surpass. Previous to this my favourite model was a full size Panic biplane, fibreglass fuselage and foam wings, 91 ASP engine up front. Why do I like these sort of models :- They will fly in any weather conditions (Flat calm to blowing a gale), can operate of a rough grass strip and can take a knock or two, easy to repair. What more can you ask. Before you ask, I have had a few light models, but find their limited to flying in calm to moderate winds and one heavy landing and your into a major rebuild.

Why purchase and lug about a generator, when you have probably driven there in a vehicle with an engine, 12V charger circuit and you can sit inside with the heater on during the winter (or air conditioning if the summer if the sun ever does come out). My suggestion would therefore be to use a 12V charger connected to the car battery, then after a couple of charges, run the engine for 30 mins to recharge the battery. All self contained, quite and low electrical noise. It would probably use less fuel than running a generator constantly and by the time you have got home the car battery would be fully charged. Edited By Paul Adams on 05/11/2012 23:55:52

The flying times doesn't change much, Saturday and Sunday only, but the models do. The light models tend to get put away and the heavier built models come out (saying that I have been flying the winter hack from last winter all summer and enjoying every bit of it). The only other change is that the thermals come out as does the transmitter glove.

I have three of the below. Basic charger but can be used for your purpose, lead acid battery charging, quick charge (peak detect) of receiver batteries etc. **LINK** If you want to charge from the mains I attach **LINK**

I have a Irvine 53 in mine, but needed to put 30 gram's of lead in the tail (and that's without the cowling fitted). Looking at the spec the 40 weighs 403 gram's, 46 weighs 390 gram's and the 53 385 gram's, so the 53 is the lightest. The West 36 weighs in at 277 gram's but is much higher reving and getting the noise down to below BMFA limits requires the engine to be over propped. How does it fly: Very well, plenty of power, will accelerate vertically without problems. I am not a 3D flyer, but have been told that the CofG needs to go further back for this, but the CofG is far enough back so that only a breath of down elevator needs to be used when inverted. Hope this helps. Paul

Battery I now use is:- **LINK** The standard charger will take up to 20 hrs to charged the Lipo, so have used the ballance connector on the battery to charge using a standard lipo charger 2S at 4Amp, which charges within the hour. I now charge when it starts getting low (every 3-4 weeks of flying sat and Sun mornings). Paul

Have recently upgraded to a DX8 from a DX7 and would recommend the DX8, it has several additional features such as additional mixing capability, throttle curve adjustment, a number of timer modes which are very useful when using electric motors). However the DX8 Mimh transmitter charging is badly designed. The charge rate is such that once the battery is fully charged (no indication when this happens) the charger continues to charge at such a rate that the battery then proceeds to overheat. The battery in mine lasted about two months before finally giving up. On opening the battery compartment the battery insulation showed signs of severe over heating. Looking through the web sites, this appears to be a common failing. To get over this problem I have upgraded to LiPo battery where the DX8 stops charging when it is fully charged, so I would advise to upgrade to Lipo as soon as possible. Paul

I have been given a PIK 20 Pat Treakle glider in need of repair / refurbishment. One wing was snapped about a foot from the tip and the paint finish had crazed over both wings, the fuselage tail was hanging off as the boom to tail junction had 75% broken off and the tail plane was badly damaged. So far I have stripped the wings back and found that the resin holding the fibreglass cloth had also crazed, so have stripped the wings right back to the veneer. Have joined the broken off portion back onto the broken wing and will shortly be in a position to recover. The fuselage is made of fibreglass, so have aligned and epoxied the tail back into position and plan to reinforce the area with fibreglass cloth from the inside. Due to the repair and general condition of the fuselage, it will need filling to get back to the sleek lines of the original model Tail plane. I plan to remake out of foam and veneer etc. And now comes the part where I need a bit of advise:- Fibre glassing the Wings: The instructions state to cover the wings in fibreglass cloth using 2 cotes of Tufcoat - Is this still the best method or would Z-Epoxy, Poly C, Ronseal .... be a better solution. Spraying / Covering : I need a finish that can be applied to the Fibreglass Fuselage, The wings which will be covered in ? (answer to above question), tail plane (veneer / balsa) and all the control surfaces (balsa sheet he majority of which I believe were painted in Humbrol Enamel). The instruction video (had to get the old video player out the attic to view it) says to paint the wings, tail plane and control surfaces in Humbrol Enamel. Is this still the best method, or are there any products on the market which would be better, and if so are they compatible with the Fibre glass / Wing covering method, Veneer / Balsa and Humbrol Enamel finishes? Regards Paul

Tell her its like having CD's. You don't want to listen to the same one all the time, so you need a selection depending on how you feel. A light aircraft for when its not windy, a Slope soarer when the wind is strong, A rugged hack for those not so good days down the field, A 3D model, an aerobatic model, Hot liner glider, electric thermal soarer, a panic biplane when you want to be a hooligan etc ....

The Cof G should be measurered with the battery installed. With an IC plane the worst case (furthest rearword) C of G is with the tank empty. When you add fuel you move the CofG further forward making the plane more stable. This is why when you trim a model, you wait until the end of the flight before you do your Cof G tests. With Electric powered models the C of G does not change, so you set them up with the battery in. Note: The C of G marked on the plan is only a starting point and the flight testing will probably result in the C of G being moved.

With regards to C of G balances, I use two pins laid on the wing surface at the required C of G location fixed with some low tack masking tape. I apply these early on in the build, so when I have located all the unmovable items I can check the C of G by just picking up the model, feeling where the pins are with my fingers and do a quick balance. I then lay on the servo's, receiver, batteries etc and move them about to try and obtain a balance without adding additional dead weight. Bob, I would recommend the calculator on this Website:- **LINK** I use it on every model I have and found it to be very good.

Looking at the video, I suspect that the engine has to much up thrust, but its hard to tell without actually flying the model. Reasoning:- When the engine revs are low / off the model appears to glide ok (can not see the transmitter sticks so hard to tell if you are holding down in, but suspect not). then when you power up the nose lifts. If this is the case try adding down thrust (add a couple of washers behind the top engine mounts). What you should be aiming for is a level flight path with engine at low to medium throttle and then when you power up the model it should just increase speed (not nose up). If it was a rear CofG you would have found that when you powered down the engine, and slowed it down it would come very unstable. With the glide you have that does not appear to be the case. Hope this helps. Mine flies brilliantly.

Cymaz - Your use of throttle could spell disaster for your model. The model does not know that it is flying in wind, all it knows is that it is flying in a block of air, so what you are effectively doing is increasing the models speed when flying into wind and slowing the model speed when going down wind. The down wind speed is where you could have problems. You slow the model down, so have to add a little up elevator to keep level flight. You then go to do your downwind turn, and the outside aileron goes down causing that wing to stall. I have seen several models falling out the sky, with the pilots saying I don't know what happened and blaming it on interference or other factors, when its actually pilot induced.

Pictures of installation:- Note:- Fuel tank positioned at C of G Ignition installed in normal fuel tank ared Ignition battery installed behind tank Ignition switch installed on front bulkhead (also have a kill switch in series controlled from the Tx/Rx) Receiver battery installed below servo tray (against rear bulkhead) Receiver switch installed on servo tray. With this set up the C of G came out spot on, (Note canister exhaust fitted under wing to help bring back the CofG). With a heavier engine you may have to look at mounting one or both servo's sticking out the side of the fuselage near the tail plane. Anyone spot the mini servo to save weight Regards Paul     Edited By Paul Adams on 30/04/2012 22:32:14

Yes - I have Phoenix installed on both my desktop computer and Laptop and both work fine.

To check if its a problem with the receiver, Try swapping the receiver with one of your existing known working receivers of the same type in the new model and bind to the transmitter. If both servos' work then its a receiver problem, if no change, its a transmitter setting problem. Paul

If you have a simulator try flying circuits with a helicopter, If you dont use rudder on a helicopter, they basically wont turn. Once you have practiced for a while you will find it will feel natual when you fly your fixed wing. Paul

Due to this more accurate centring around the position selected by the transmitter, resulting in the servo's working faster and harder if slightly out of position, this all requires additional power, ie more current to be drawn. This additional current consumption needs to be considered in selection of the battery (number of cells) and the switch assembly. On one of my models where a standard switch harness was used with a 4 cell battery pack, I could get the receiver to brown out by quick movements of the transmitter sticks (not a good idea when flying). I have never been able to do this with Analogue servos. To overcome this I always fit heavy duty switch harnesses and 5 cell battery packs in my models fitted with digital servo's.