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Shaunie

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  1. Shaunie
    One big thing that seems to be overlooked with soldering irons that Plummet has just mentioned:- If the soldering iron you own has no thermostat then it needs one important modification... snip off the lead and throw the lead and plug in the bin. You now have a valuable tool that used in pairs can be pushed into the ground to make a handy model restraint, or if you are also a gardener can be used as a handy dibber! There will be those who say they have soldered fine for years without a thermostatically controlled iron, absolutely, I've been soldering for so long that I can make a decent joint with some solder and a screwdriver heated in a blowlamp flame if I have to, this is down to skill and practice. For those who do not solder regularly a thermostatic iron will improve your results beyond belief. Once overheating is impossible due to the thermostat then the iron power can be safely increased. I use Xytronic irons at the moment as they are much cheaper than Weller gear and are rated at 60W, I'll work on surface mount stuff with these! The trick is not in having a high temperature, it is in having a good heat flow at a reasonable temperature. To do this you need a sensible number of Watts, a thermostat and as thick a tip as you can reasonably use without being "clumsy". Weller do a miniature soldering pencil (and it is pencil sized) for SMD work, it is 90W rated, just can't afford one at the moment. From memory CPC are offering a temperature controlled soldering station in the 50-60W range for about 40 quid, bearing in mind what we spend on this hobby of ours that's not very much. Update: Just had a look in CPC's website, catalogue numbers SD01695 (£41.99), or for a little more money, SD01119, SD01117, SD01120. Shaunie
  2. Shaunie
    The problem with legislation is it only affects the law abiding citizen. To the criminal what does it mean to be breaking another law? If the burglar knows he's going inside if he gets caught breaking and entering, is he going to be the slightest bit concerned to know he's breaking some camera drone law? Of course not! What we have in the UK are laws covering everything because they are too specific. As already mentioned we have privacy laws that are already applicable in these cases, the method of privacy breach is surely unimportant. It is of course fine in the eyes of the powers that be that they watch us from every street corner, but hate the possibility that we could conceivably use the same technology against them! The worry is that these devices are becoming mainstream, available from toy shops and flown by kids (of all ages) who have no regard or concept of the possible dangers of incorrect use. Youtube is full of clips of trains/cars/boats etc. being chased by camera planes. Now people with no common sense, having watched the clips can go into a shopping mall toyshop, walk out with one in a box and try to emulate this for themselves. The trouble is that the negatives inevitably outweigh the positives in the eye of the public so those with an ulterior motive can use the spin to introduce any legislation they wish and the public are led to think it is a good idea. As well as being a modeller I am also a member of a search and sescue organisation and am exploring the possibilities of building something to help us search for vulnerable missing people, probably a multicopter of some sort with thermal imaging.( If anyone here wishes to help me in this please PM me, I know little about multicopters, I'm a fixed wing man mainly.) (Finishes ranting, picks up soapbox, exits stage left.) Shaunie
  3. Shaunie
    Not had a chance to fly it yet but I gave it a ground run peaked at just over 11,400 rpm when I leaned it off somewhere between 1/4 and 1/2 a turn. So I had it quite a bit rich then. As a result I was able to richen up the bottom end which has sorted the pick up from low rpm. Hoping for great things when I do fly it. Shaunie
  4. Shaunie
    Hi Flanker, Same language, different interpretations, always a problem . Tacho's here now which should help. Wanted to have a go this weekend but:- A. Blinking cold. and B. Just got a car for eldest Son to get some more experience in before his test, so been out with him. and C. I help maintain/modify vehicles for a Search and Rescue team which took half of Friday and most of Saturday. How do we get involved in this stuff, I wonder? Back to the engine, if it was rich it would pick up whilst four stroking. You know what it sounds like when you open the throttle to realise your tank is dry, you hear the induction roar and naff all else, that's what it did. My thinking is top end was a little rich last time out. If I lean off the top end and richen the idle a bit that will adjust the mixture curve where it should be. Will report back when I get a chance to give it a go. Shaunie   Edited By Shaunie on 02/12/2012 18:42:00
  5. Shaunie
    I'm some and some. I've got two trainers on 35Mhz but I have a micro Stryker and a Vortex 400 on Spektrum (DX7) and have just swapped my 20 year old Dare-U to Spektrum as well. I'm happy with 35MHz but now that I have keyfob cameras on one of the trainers (TT OBL40) I reckon I can see 5 or 6 glitches in a 10 minute flight, with it on electric only one or two could be heard from the ground, if it was I/C I may never have known at all. These are all easy to hear on the camera as short motor cuts. This doesn't particularly worry me, like many things what you don't now doesn't worry you, conversely. . . . At the same site I have also had at least one drop out on 2.4! I think it may be the site, some are just like that, also it is maybe 200 yards from an electrified railway line (third rail) how much RFI does an electric train make when it crosses a gap in the third rail? My two big reasons for going 2.4:- 1. A friend bought a load of gear intending to take up flying again, changed his mind and gave me a brand new DX7 with 2 receivers, quite a compelling one that. 2. I like the features (mixers etc.) compared to a vanilla dual rate 35MHz Tx which all mine are. The biggest of these for me is exponential, now I have got used to it given the choice I would never use linear again! This is the reason I've changed the Dare-U over, I never really liked it on linear, with the rates on low it flew fine but was never very exciting, high rates made it lively but then it was scary in a straight line. On expo I can fly it straight and still have +/- 45 degrees with the sticks in the corners, lovely. Shaunie.
  6. Shaunie
    Thanks for that Flanker, This is definitely lean on pick up from idle, gasping not four/eight stroking. Although about two years old the engine was unrun when I got (given) it. It has ground running of about 20 mins and about 8 7-10 min flights, all done by me, may not even be fully run in yet. I've always tuned top end by ear so will be a novelty to use a tacho on it. I always expect engines to lean out a bit when it unloads in the air and I may have allowed a little too much. Unfortunately I don't have the luxury of a cut strip, otherwise I'd do a circuit and land, tweak and do another circuit etc. until it's right. For me it will be a restart every time as the grass is too long. Just need some decent weather to have another go. Shaunie.
  7. Shaunie
    Couple of points to throw in the mix:- Many modern engines with high compression want to "bite back" when you flick them, so effectively you are forcing the crank over TDC against the pressure of combustion which cannot be good for it. An engine that does this will start really easily from a backwards bounce. I am not a believer in too bright a glow, I use the Enya No3 plug which is rated 1.3-1.5V and usually use a NiCad style clip so down at the lower end of the range. What many don't realise is the natural ignition advance inherent in glowplug engines. At idle the plug cools off which tends to give a slightly retarded ignition point, yet as the throttle is opened the plug gets brighter which tends to advance the ignition. Hence too bright a glow on the battery will increase the tendency for an engine to "bite back". I know this is a very subjective and emotive issue but I think a bright red/dull orange is plenty and bright yellow is far too much. Part of the problem is many flight box glow controllers are "constant current mode". I built my own controller many years ago which is "constant voltage". The advantage is that should the plug become wet the current rises and can be seen on the ammeter, so you know and more power is fed to the plug which dries it out more effectively. With constant current the voltage drops, less power is delivered to the plug and it stays wet. Shaunie
  8. Shaunie
    Thanks for all the replies Guys, The fuel is Southern Modelcraft 5%. The plug is an Enya No3, I tried loads of plugs in my early days, someone recommended I tried these and I've never had any reason to change since. I re-read my OP and promptly ordered a tacho . Would be useful to help work out what is going on. It seems the consensus is that the prop is fine I have to say I get on very well with all model engines particularly two strokes. The engine was a little rich up top and it may be that if I lean off the top end and can richen up a little at idle with the mid range blending between the two it may be right. Don't get me wrong the engine is not really bad, just that it's not absolutey spot on. My concern is that I could either have a rich midrange and good pickup or a sweet midrange and gasping lean on pickup from idle. I was wondering whether this was a characteristic of the carb on this engine. I have an OS 45FSR from about 1985 and although tired it carburates perfectly across the range, burbles a little at tickover but is absolutely smooth from that point to WOT with no fourstroking whatever. Which is what I was hoping for. The engine is also in sidewinder fashion and rubber mounted, maybe the engine wobble at low rpm is upsetting it but I always mount my engines like this to help keep the noise down. Shaunie
  9. Shaunie

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  10. Shaunie

    Shaunie posted a gallery image in Member Albums

  11. Shaunie

    Shaunie posted a gallery image in Member Albums

  12. Shaunie
    I've got a Thunder Tiger 46Pro in an old Dare-U fun flyer. The engine now has probably 1 to 1 1/2 hours on it. It runs well and starts practically first flick (or bounce, because I don't flick as such). I've got it propped with an APC 12.25 x 3.75. At full throttle it seems happy but is quite insensitive to needle valve setting. At flight idle it is a bit inclined to gasp when opening up, on a couple of occasions I've had to rock the throttle a bit to get a pick up, last time it happened I was mentally plotting a line between two large Oak trees when the power came back. Fuel was about 1/3 tank. If I open up the idle mixture it four strokes all through the mid-range. What I don't have is a rev counter at the moment, if I knew how many revs it was pulling that might help. Am I expecting too much of the engine for it to pick up cleanly from idle without having it burble away at part throttle, or is the prop a little too much? I know folks put this prop on O.S .55s etc. so maybe I am hoping for too much. Unfortunately there seems to be little choice in these slow fly props. Shaunie
  13. Shaunie
    I've had 128's in many of my planes, never ever had one give a problem. Still got some in good condition in a bag. I would have no issue in using them in an "undemanding" application i.e small trainer. Shaunie
  14. Shaunie
    Gummed up carb or airleak probably, but one other thought occurs... Has the engine run successfully on this prop as overpropping can give similar symptoms. Shaunie.
  15. Shaunie
    If you take time to learn the technique hand starting a glow engine is easy and avoids bending conrods. I have a really tired OS 45FSR that like a touch of the starter because the compression is well down, but other than that everything I have starts by hand really easily. The engine needs to be "sloppy" wet, but not so far as to be nearly hydraulic. Get the fuel throughout the engine by flicking with the glow plug off, I usually fill the carb venturi twice with a primer bottle and suck it through by turning it over. When the engine is nice and "floppy" just flick the engine backwards against compression by the spinner (a bit like spinning a top) the engine should backfire, change direction and start. As you don't put your fingers in the prop no chicken finger needed. I started my Thunder Tiger 46Pro yesterday, started first bounce, warm up, tweak mixture as it was a bit rich, go fly. When I get round to it I'll pop a clip on Youtube to show what I mean. In my opinion just thrashing the engine over with a starter motor just shows a remarkable lack of mechanical sympathy. Just going to hide in the corner until the flak dies down a bit . Shaunie
  16. Shaunie
    It appears to be a common convention for engines to rotate anti-clockwise looking into the drive end. So with a conventional north-south car installation that would be anti-clock going into the gearbox and thus clockwise at the front end. Whereas aircraft engines would be anti-clock at the front where the prop is. But it is only a convention so there are exceptions as we see. God only knows why Rolls Royce chose to rotate the Griffon engine in the opposite direction to the Merlin. Shaun
  17. Shaunie
    In my first flying career (about '84 to '93) I flew a lot but broke very few planes because I was too scared to push the envelope, everything being kit built at the time. The memory of the effort put into building them was too strong. As a result I got a bit bored and fed up with my skills failing to improve. Starting up again a couple of years ago, first with a plane built in 1992 where the "newness had worn off" I was less wary about pushing my luck. Then at Christmas I treated myself to a Micro Stryker, because it's a shop bought "toy" I've really explored the envelope and strayed outside on many occasions. But as a result my flying has improved immensely. My opinion is this: To improve you have to push the boundaries, sometimes it goes wrong, sure it's disappointing, live with it. Expensive model, try to stay inside the envelope. Cheap model, go for it. Shaun
  18. Shaunie
    Nice build! I have one of these (unbuilt) in the loft ,complete with engine, spinner, retracts and wheels. It was a gift from a friend who bought it and decided not to continue with modelling. Seeing this build has given me the bug to start on it! I haven't done a kit build since about 1992 but I had a count up, I have built 8 planes so far. Just don't want to start until I can do it justice. The engine I have been given with it is an RCV91CD which hopefully should be a good match. Look forward to more posts.
  19. Shaunie
    I regard any 12v lead acid below 12.6V as only partially charged. Many SLA and Gel type batteries have a charged open circuit voltage up to and occasionally exceeding 13V (I have a couple in the workshop that have not been charged for some weeks and give a terminal voltage of 13.1V). I would think it unlikely that a battery supplying a LiPo charger could ever be too big, the charger will only ever draw the current it requires. Batteries on permanent float charge are eventually damaged by it, but this does take several years to happen (typically they are end of life after 4-8 years depending on float voltage and battery quality). I think if the battery has only been in service for a year it will be fine, if its a Hawker, Optima or similar it will probably last you nearly forever If you have a power analyser discharge th.e battery through it (into a headlamp bulb for instance) down to 10.5V and measure what its capacity is that way.
  20. Shaunie
    Another little thing... Deciding it was getting a little reluctant to slow up I checked the C of G. I have just added 5g of lead just ahead of the motor (took the motor plate off and drilled a small hole in the foam). I also removed some of the foam from the back of the battery bay so the battery can go farther back. What a difference! Now it slows up so much it just floats onto the ground if I want. Full back stick and it just drifts down, full forward and it flips upside down in the same attitude, Harriers everywhere. The reason; I've knocked the nose off so many times I think the weight of the glue has pulled the C of G forward. I would think just a couple of grammes at the nose would equal 5 at the back. A lot more sensitive on the elevator now, just having to relearn/readjust to it. I thought it was me not able to do these things! Worth rechecking C of G after even small repairs on these foamies, I know that now. Shaun
  21. Shaunie
    Gaz, Looking at doing this to mine. Did you use the gear channel or did you move the elevon channel in the reversed aileron socket to the normal aileron channel and play with the mixes? I'm also using a DX7 (not the 'S' which means I will have to set up the mixes manually what are you using? Any advice would be great. Shaun
  22. Shaunie
    General Garage Solvent (AKA Brake Cleaner) is an excellent solvent for the flux in cored solder. Pretty safe on most plastics but can't vouch for foams though, make your own tests. I presume Halfrauds sell it, you can buy it in 500ml spray cans from motor factors and probably an awful lot cheaper than whatever special cleaner Maplins or whatever charge. I buy it in 5 litre cans for about 8 quid IIRC (I hardly ever do any brake work as I'm an Autoelectrician, but I clean an awful lot of PCBs with it after repair work and I've never had a problem yet). Shaun
  23. Shaunie
    I've got to say something about engine balance (as relating to single cylinder engines) It is not possible to fully balance a reciprocating mass (the piston and conrod) with a rotating mass (the bobweight on the crank) as a result the best compromise is a 50% balance. The result of this is that at tdc and bdc there is a vertical force (visualising the engine upright) then at 90 degrees before and after tdc the mass of the bobweight is unopposed and there is an equal force acting sideways. Effectively there is a cyclic imbalance and the centre line of the engine tries to orbit the centreline of the crank in a small circle. So as far as I can see the plane of the piston effectively makes no difference to the vibration you will experience. The only ways to improve this are counter rotating balance shafts (where the bob weights cancel at the 90 degree point but reinforce each other at tdc and bdc) or a reciprocating weight at 90 degrees to the plane of the piston. None of which I've seen on a model engine. Other engine layouts are much better, a 90 degree v-twin can have 100% balance of one piston by the bobweight, 90 degrees later the force of the bobweight is is opposed by the other piston, i.e. the pistons balance each other via the medium of the bobweight. With flat twins that have two throws on the crank the pistons naturally balance each other. This is why they are both so smooth. I'm generalising here and ignoring rocking couples (which IMHO the WOO got completley wrong in this months mag) and the swing of the conrod stopping the piston travel being perfectly sinusoidal. I hope my explanations are understandable, if they're not I'm sure someone will be along shortly to correct me . Shaun
  24. Shaunie
    Not airline ones but... PCMCIA (memory cards etc.) People Can't Memorise Computer Industry Acronyms. NTSC (American TV standard) Never Twice the Same Color (so true, ever seen an old American colour tv clip?). Shaun
  25. Shaunie
    Not got the special yet but I think your visualisation of dynamic balance is spot on. We could get dynamic balance issues with a perfect statically balanced prop if the blades aren't tracking correctly i.e. the arc of one blade is in front of the other. As for drilling the prop hub, no way! I think the best way to balance the prop would be to move the centre of the hole but have no idea how it could be achieved in practise. I read something recently that APC props take a spacer in the recess to centre the prop, strange that you can get the props everywhere but I have yet to see the spacers on sale.
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