Keith England 1

Incredibly, I purchased a Laser 200V twin on 23rd March and shortly afterwards discovered I have a terminal brain tumour, which has also resulted in my driving licence being revoked. So, clearly, I am not going to be able to use this engine. In May I asked Laser if I could return this, unused, still in its box, motor and I didn’t even get a reply. It is only now that chemotherapy has allowed me to function well enough to chase this. I’m really disappointed as, apart from anything else my wife will only get half my pension so she will really need this money.

Posted by Tony Richardson on 01/05/2020 02:01:33: Ok further to my previous question, Ethanol is out but where does Methyl Hydrate fall in this equation, it is also readily available here?? How to go full circle🤡 Methyl Hydrate IS Methanol! Is is just a VERY archaic name for it that should have fallen into disuse a century ago.

Posted by Tony Richardson on 01/05/2020 02:01:33: Ok further to my previous question, Ethanol is out but where does Methyl Hydrate fall in this equation, it is also readily available here?? How to go full circle🤡 Methyl Hydrate IS Methanol! Is is just a VERY archaic name for it that should have fallen into disuse a century ago.

Posted by Jon - Laser Engines on 28/04/2020 11:51:34: I would need to test it to be double sure, but im pretty confident ethanol will not work with a glowplug. By all means try it though, you arent likely to break anything. Jon, and Tony, an interesting experiment we did years ago in school was to heat a platinum wire red hot and hold it over a beaker of methanol. The platinum wire continued to glow even hotter as it catalysed the methanol vapour. That is what keeps the glow plug glowing in a glow engine. I don’t recall that this same reaction occurs with ethanol, but it just might do so. Tony could test this by healing a glow plug in the vapour from a small quantity of ethanol and seeing if it remains hot when power is removed - obviously be careful of it igniting i know how Jon dislikes onboard glow systems but I would suggest you might need to use an onboard glow to replace that catalytic heating. I suspect it may well run fine then? Don’t confuse methylated spirits or denatured alcohol as methanol. It is ethanol with a few percent of methanol as a toxic byproduct. I doubt it would be enough to keep a glow plug hot if ethanol doesn’t work. Edited By Keith England 1 on 28/04/2020 12:45:21 Edited By Keith England 1 on 28/04/2020 12:46:13

I’ve been binge reading Jack Higgins “Sean Dillon” Books. What’s funny from a flying point of view is that he has it in his head that 500 ft is dangerously low and there are several incidents where he causes an opponent to crash by a sudden manoeuvre at that height and the baddy fails to miss the ground. Strange really that’s the height light aircraft often turn onto finals at and most seem to survive the manoeuvre quite well 🤡 oh, and even in 2016 most of the heroes drive Mini Coopers and always have a Colt 25 with hollow point ammo concealed on their person. They are still a good way to pass a boring evening though and I’ve run out of Biggles books for now 🤓

Posted by Andy Stephenson on 05/04/2020 10:26:19: Posted by PatMc on 04/04/2020 22:56:38: Posted by Andy Stephenson on 04/04/2020 16:47:02: CL models usually have zero dihedral to allow the control wires a straight run to the elevator bell-crank. If converting to one to R/C you might find significant adverse roll on application of rudder without adding a commensurate amount of dihedral to the wing. A. Care to explain why ? Pat, With right rudder applied it tends to roll the plane to the left. We all know that on a rudder steered plane you need a fair amount of dihedral to induce a turn because the rudder yaws the plane then the forward going wing presents more air resistance which rolls it into the turn. I’m sorry but that is really not true at all, i have only ever flown one aeroplane, full size or model, that did not roll right if right rudder was applied - and that was the Excitation I mentioned above. it depends upon a lot of things but mostly where the vertical C of G is with respect to the centre of drag and diihedral. I got to fly a Taylorcraft plus D army observation plane and the pilot used to grip the stick between his legs and fly it completely on rudder leaving his hands free to operate the radio. it actually banked much better using rudder than it did using ailerons. Using rudder causes the outboard wing to move faster than the inboard and generate more lift, Hence banking the plane. it takes a very low wing without dihedral to counter that - which would be the case with some CL types - but certainly not if it was shoulder wing or higher. But it is not so much rudder, as instability,  if a low wing CL plane is flown as an R/C without some dihedral it will be unstable in roll and only really comfortable to fly inverted. Edited By Keith England 1 on 05/04/2020 12:16:13

Posted by PatMc on 04/04/2020 22:56:38: Posted by Andy Stephenson on 04/04/2020 16:47:02: CL models usually have zero dihedral to allow the control wires a straight run to the elevator bell-crank. If converting to one to R/C you might find significant adverse roll on application of rudder without adding a commensurate amount of dihedral to the wing. A. Care to explain why ? If the vertical C of G is above the wing, as it will be on a low winger, then right yaw will induce left roll which is (to say the least) not expected behaviour for the pilot. For example, using rudder to counter adverse yaw from the ailerons would actually more than counter the ailerons instead and result in an opposite roll. A small amount of dihedral will cancel that out. A good example, (which does look somewhat like a scaled up control line plane) is the Pete Tindals Excitation. Which had a massive wing cord and no dihedral. It flew very well and for years was very much my “go to” plane. But the lack of dihedral did make it very different to fly - it needed arm fulls of (say) left aileron when left knife edging or flat turning and vice versa when to the right.

Posted by Jon - Laser Engines on 03/04/2020 08:27:33: I also think one of the first things i would do is make a reduction drive. Get propeller rpm down for much reduced noise. I already have the design done. It would fit our 100, 120, 150,155,160v, 200v, 240v and 300v with only one component change needed per engine and would allow a 200v to swing something like 22x14 3 blade or 24x14 2 blade at a gentle 4400rpm on the prop. Loads of thrust, nice and quiet. i take it the component would be the front crankcase and, presumably this would (or at least could) move the prop shaft higher on the engine (or lower if inverted) which would have the added benefit of moving the carb and cylinder head nearer the centreline too. If so it sounds like a win on a number of fronts.

By far the best site for ALL your battery questions is Battery Universe, in this case:https://batteryuniversity.com/learn/article/how_to_store_batteries. To answer two things that have come up here. I moved house last year and was in the temporary accommodation whilst a new house was built. I ended up not flying for almost a year. Not one battery that I left at storage charge of 3.8V/cell had degraded at all and had not dropped more than 0.1V in that time, self discharge in Lithium Polymer is almost non-existent. One battery, only a month old when I stored it, I accidentally forgot to discharge and was fully charged, that was puffed and much higher internal resistance. in the early days of LiPo flying the perceived wisdom was that it was harmful to leave LiPo’s discharged so, I always charged them straight back up when I got home. This was great, I could go flying at a moment’s notice, AND NOT ONE SINGLE BATTERY LASTED MORE THAN TWO YEARS, and it was always winter that killed them. Fully charged and very cold or very hot is a very bad combination, very cold and storage charge is ideal. Bearing in mind a 6S 5000mAh was over £200 then it was pretty awful. These days, I’ve got a lot of batteries, so most only get around 50 cycles a year, I always bring them up or down to storage charge within a day of flying and I’m still using batteries purchased in 2012. note: Lithium Iron (LiFePO4) batteries do have a higher self discharge. Those should be checked every couple of months or so in storage. Edited By Keith England 1 on 26/03/2020 13:12:24 Edited By Keith England 1 on 26/03/2020 13:12:46 Edited By Keith England 1 on 26/03/2020 13:18:49

Posted by kevin b on 25/03/2020 17:30:37: Slightly off topic, but I think Jon should self isolate at the workshop, whilst all the other staff are off. He will be able to use the machinery to turn out lots of lovely new engines ! He looks like he is doing pretty well as it is 🤓

Posted by Nigel R on 25/03/2020 12:03:39: I fully expect the day the lockdown is eventually lifted will herald a few months of rain and wind. I’m not convinced that the sudden great weather is just a coincidence, removing tons of cloud seeding fossil fuel pollution from the atmosphere certainly wouldn’t do any harm. So it is equally possible once all the pollution starts again the weather will worsen again? Edited By Keith England 1 on 25/03/2020 16:54:43

Posted by Jon - Laser Engines on 24/03/2020 10:00:34: My availability page tells all. I do wonder why people dont read it **LINK** Oh we all read it Jon, but there is the 200V sitting there tantalisingly out of reach with “out of stock” against it and there is us stuck at home itching to get a plane ready to fly and refreshing the page regularly to see if the “out of stock” sign magically disappears, hell it’s now my home page 🤡. And we don’t know if it’s going to happen in days, weeks, months 😥😭

No right means point the motor to the right. Since you ideally want the propeller on the centreline of the model that would mean moving the back of the engine to the left of centre. Downthrust can be calculated (to an extent) the thrust line should run through the centre of gravity of the model so a very high mounted engine (as on many seaplanes) may actually need upthrust but drag will have an effect too so so a degree of experimentation is going to be needed. Sidethrust has more factors to consider. Basically there are a number of interactions but generally a conventional engine which turns clockwise viewed from the pilot’s seat will need right thrust to counteract a tendency for the plane to yaw left under power. It is always a compromise as reaction will vary with power, angle of attack and airspeed. Of course with modern radios you could always programme elevator and rudder mixing with throttle to correct for thrust issues.

It may have been asked before, but it’s a big thread so apologies in advance. How does one actually buy an engine from Laser engines, many show in stock on the website but there doesn’t appear (on an iPad at least) any button to actually “buy”? in fact, the engine I want is currently out of stock, but when it does become available I don’t want to lose the chance whilst trying to work out how to buy it 🤓. I’ve always coveted a laser V Twin, and I now have a Jiant Jabberwock that I think the laser V 200 would fit perfectly, especially as I really do not like the smell of petrol in my workshop.

Actually - if you want to talk state of the art and the future of our energy storage needs the area with the greatest - as yet sadly unfulfilled potential is methanol fuel cells. One or two of the mobile manufacturers are talking of having them ready "soon" with the methanol in little cartridges like the ink for fountain pens - so never have a flat battery on your mobile just slip another cartridge in when it gets low. These however are low power usage and are able to absorb enough oxygen from the air without difficulty.   Now extrapolate this to the huge portable power tool industry. The one big drawback currently for tradesmen is sites without electricity, so powering their tools with a refill of methanol would be a boon. However at the powers they need air would have to be forced through the fuel cell with a fan to get enough oxygen quickly enough.   Having a ready airflow for a fuel cell is not a problem to us so look at the possibilities. You turn up at the field with a gallon of methanol, fuel your 'plane up and go flying. When you want another flight, you fuel up again and fly again - sound familiar? The only difference is its with electric motors, no oil, and not too much noise. Thanks to Giant Cod I'm already flying 2KW set-ups for less than the cost of a Saito 125 – including 2 sets of batteries - I just need to not have to lug the car battery to the field and find that my 10 cell packs flatten it half way through the afternoon! Edited By Keith England 1 on 05/04/2010 19:23:32

Guys, Your focussing in the wrong place with this, the reason one taildragger will tend to ground loop and another won't (and also why nosewheel jobs don't do it at all) is mostly down to how far behind the wheels the C of G is. See my club newsletter article http://www.edmfc.org.uk/sept04/Sept2004newsletter.htm   The Wots Wot has a high U/c and its well forward of the C of G both will make it prone to ground looping easily. Getting the wheels back a bit will tame it most.  As several have suggested using elevator to hold the tailwheel down will help increase its authority and drag and so will getting the tail up as soon as possible so it is in the airflow and can control the plane - if it is difficult to control when the tail is up then you do need expo or reduced rates. Learning to get the tail up and keep it up until the plane is too slow for it to stay there is one of the lessons of good tailwheel control - watch a full size Spit -it doesn't run along the ground with its tail down on the take off run! once the tail is down full up will help the wheel steer.  I'd agree that a giro is overkill however, any Heli giro will work on a plane - I use one on a twin to give me a fighting chance if an engine fails and others are flying so I can't hear it. Generally a plane turns so much slower than a heli that you can use full gain but I'd start at about 50% and work up. A switchable Giro like the Futaba 401 can be used with the gain control on the gear channel - I use a 3 position switch so I have heading hold one way zero giro in the middle and rate mode the other way - the end points for the channel control the gain. Heading hold will be brilliant for take off and landing as the rudder will literally hold whatever heading you are on - but if you are not good at using a rudder it will get you into all sorts of trouble in flight. Rate mode - and you can get some cheap rate giros will just damp sudden swings and it wouldn't do any real harm in flight