RottenRow

John, do you have any X series receivers (X6R, X8R)? If you do, try your setup on one of those first as they don’t have stabilisation so remove any confusion that might be causing. Once you’re happy with that, you can add the extra programming for channels 9 and 10 for the S6R. Brian.

I went to one of their fly-ins at Stow Maries. It’s a pity that RCMF faded away. As regards Giant Shark, wasn’t there a connection between the owners and the (then) publisher of RCM&E, based in Peterborough? It was Giant Shark, and Giant Cod before it, that got me into using FrSky modules and receivers with my old 35MHz radio. Which I still use today. Brian.

Absolutely no problem with mounting the SC91 FS on its side, or any other model four stroke that I’m aware of for that matter. If you mount it with the cylinder at the 9 o’clock position (viewed from the front) the exhaust will be conveniently located to exit from the bottom of the cowl. On all of this range of four strokes you can turn the carburettor around by 180 degrees if necessary, in order to put the throttle arm and needle valve in the most convenient locations for your particular model. Brian.

Yes that’s exactly how my LE is done. The other often-used method, where a square LE is fitted at 45 degrees into triangular cutouts in the front of each rib, is less useful as there is less to glue the sheeting to. Also there is more chance of a rib splitting if the LE is impacted at some point. Funny though… I always refer to the rear one (blue in KC’s diagram) as the false LE…. Brian.

Mid ‘80s I’d say. I remember watching them at the excellent Cranfield Expos, and Dave Bishop commentating on them from the top of his van. Brian.

You don’t need to do that. Make a template from thin plywood or similar, then cut the ribs out around that. Or draw around it and cut out to the lines. My template is the bottom one in the photo. Brian.

I went for a 2” rib spacing, or thereabouts. The first rib out from the centre needs positioning so that it is on top of the fuselage side, if that makes sense. Then just work out how many ribs you need for around 2” spacing over the rest of the wing. My wings are held on with rubber bands (which is the reason for the 1/16” ply on the T/E to avoid crushing the balsa. Yours are probably bolt on, in which case you’ll need to make the areas around the bolt holes solid and well fixed to the adjacent ribs etc. My wing tips are just balsa block, carved and sanded to shape. The Boomerang may have different style of tips, perhaps cut from sheet, but you can do them however you see fit. Brian.

Here you go, a few pictures of one half of the wing during construction. Also a complete airframe prior to covering. Brian.

KC the dihedral brace is birch ply, sorry I should have made that clear, though it is labelled on the plan. Yes they are film covered (standard Solarfilm) and I would think would be plenty strong enough for an ARTF model of a similar size. I never totted up the cost as the wood generally comes largely from what I have in stock. ADSJ the rear spar is at the bottom only, and all 3 are hard balsa, not spruce. Spruce would be ok but heavier. I’ll find some pictures and include them on here shortly. Incidentally I still use a single centrally-mounted aileron servo with torque rods, which is quite adequate for this kind of model. Brian.

I would use 1/16” for the webs, with the grain vertical. Also probably 1/4” square hard balsa for the spars would be enough. The inner 3 or 4 ribs could be made from 1/8” just for a bit more strength where the wing mounts onto the fuselage. 1/8” dihedral brace / wing joiner. Fit 1/16” cap strips from the LE sheeting back. False trailing edge 1/4” thick and the ailerons from pre-shaped section of the appropriate height. I sometimes build a 56” trainer called a Galaxy Escort GT. These originally had veneered foam wings but I make built-up wings. These turn out appreciably lighter. This is my plan… hopefully you can see it clearly enough. It should give you some idea how to build your wing. Brian.

That 'recommended items' list is of items only from the manufacturer's own product range, or rather that of their distributors in the USA (where TopFlite kits were based). A typical sales strategy of model distributors. Although that particular OS engine is no longer available, not new anyway, others are that are of the same or slightly larger capacity. The OS Max 65 is their current offering if you really wanted to use an OS glow two-stroke of that size. You could also look at four strokes, probably 120 size, such as the SC120 FS. Personally I would recommend that you go and listen to a few single cylinder two-stroke petrol powered models in flight before assuming that they sound anything like a real aircraft! If minimal cost is the most important factor, then electric power is your best option as you say that you have most of the items available. It looks like they might be suggesting running that motor / ESC / prop. combination on 5S as the list states 11.1V (3S) and 7.4V (2S) batteries being required. Brian.

Did you find one? Just seen this for sale this evening at Old Warden Club’s bring and buy… Brian.

Ideally you need a bit more than 10 hours at 0.1C to reach full charge, but that of course doesn’t take into account any remaining charge that the battery will have. I charge for 14 hours, unless I know that the battery is already well charged. There isn’t a problem with continuing to charge at 0.1C for a reasonable period after the full charge point has been reached. When cycling, I am happy if my batteries show up around 75% of their original stated capacity. Brian.

No clubs have noise issues… until somebody from outside complains. Then it’s often too late and the issue becomes terminal for the club or at least that flying site. Or they have to impose restrictions that are much worse than they would otherwise have been. Petrol engines can be made quieter, at a cost as Ron points out, but while people prefer to spend their money on another noisy engine for another model, rather than the same amount to silence an existing engine, we will always have noisy petrol two stroke engines. Until somebody complains… Back to the original topic, just because the guy at Weston UK doesn’t make a silencer for an ST2000 doesn’t mean they are bad engines. They too are a bit noisy (as I pointed out on the other thread where the OP was asking about these). The silencers to get are the BCM ones from Canada. These were previously sold in the UK by the now defunct Just Engines, hopefully there will be a different UK supplier soon, though they can be bought direct. Not cheap, but available is various configurations. Brian.

That’s a shame Phil. In case you don’t know, the bottom of the poster (shown on the website) gives landline and mobile numbers to call with enquiries. Perhaps worth trying if you don’t receive an e-mail reply. Brian.

I do exactly the same, though usually at a current as close as possible to 1/10 of the C rating of the pack. I use an adjustable constant-current charger (SM Services, so ancient but bomb proof). My batteries are usually buried inside my models, so are charged, and occasionally cycled, in-situ. This showed up something interesting; the on-board switch, in its ‘off’ position, is in series with the battery when it is being charged or cycled. Any slight resistance variation in the switch contacts would cause the cycler to turn off at a different stage in the cycle, indicating an incorrect level of the battery’s state of charge. Some receiver switches are of abysmal quality (already discussed in another thread) and I now only use good quality switches from RS Components. The same poor switches could cause variable volt-drop in the ‘on’ position when servos were operated, sometimes quite significant. The varying switch resistance would not normally effect the battery charging at constant current at near 1C, but could possibly trigger a delta peak charger to switch off early as the voltage could vary during the charge. I use Eneloop or the Vapex equivalent in several transmitters, but not in models for airborne packs. Brian.

That already looks like a better way of installing the sensor John, more of the tag in contact with the cylinder head. The silicon glue will help further. At work we used a similar method, with a ceramic cement, to attach small thermocouples to various points in high current electrical equipment for temperature testing. As to why the front cylinder runs hotter, perhaps it is set just slightly leaner than the rear one, but not by enough to show up as an obvious difference in the fuel consumption or exhaust smoke between the two. Or perhaps there is a little more friction in the front cylinder for some reason. Brian.

Thanks John, If you can't bear your finger on the cylinder for more than a second it's got to be somewhere over 60 degrees C. It sounds as though your tagged sensors aren't getting a good transfer of heat from the head, perhaps partly due to the anodising. Is it possible to turn the sensors around so that the whole of the tag is on the flat under surface of the head, not just the ring part? Perhaps with a spot of heat conductive paste between the tag and the head. I also see that PowerBox make a temperature sensor without the tag (part number 6619). The end of this might be slim enough to be able to be inserted between two cylinder fins, secured with a bit of epoxy. Brian.

34 degrees C is lukewarm… surprisingly low during or just after a run. Are you sure that the sensors aren’t getting cooled by the breeze or something? Or perhaps are just not in good thermal contact with the head? Does the engine feel only warm to the touch immediately after running? Ie can you hold a finger on it indefinitely? Brian.

They were having a laugh… or didn’t want to do the print. Find another printer! The place I use charges £3.00 plus VAT for a mono (black on white) A0 print from a pdf. If the plan is longer the cost is pro-rata. They will also enlarge or reduce if you require. They will post plans if required but that obviously puts the cost up. https://shop.fidelityprint.co.uk/product/a0-plan-printing I would think that most larger towns and cities will have such a place, do a bit of searching online. Brian.

That won’t work Piers. It’s too simple. The CAA doesn’t do simple. Brian.

Could you remove the anodising from around the plug hole, rather than the actual thread? Perhaps careful use of an engineering slot drill (turned by hand) would be enough to cut through the anodising, which will be very thin. Then when the plug with its copper washer are tightened down the circuit will be made. That is assuming that both of the heads have a point of electrical contact through the cylinder barrels to the crankcase, which is also anodised. Paul's suggestion that he just made might achieve the same end. Brian.

Ha ha. Perhaps you should ask all new posters to verify their inside leg measurement before their post is put online.... that should confuse most AI. I'm waiting (hoping) for a point to be reached where one AI platform gets so engrossed with another one that they all just tie themselves up in knots going around in circles until they all explode. Or implode. Brian.

I've not tried recently, but the last time I did, a couple of months ago, I couldn't get an answer on their 'phone, but did receive a reply to my e-mail after a couple of days. They then sorted out my query very quickly. Note that they have some slightly unusual opening hours. Brian.

Got it. That's definitely down to variations in the printer output. It is actually probably within the acceptable tolerance for the printers used by the print shop, as it's unusual for multiple prints to be joined together like this when any degree of accuracy is required. If it were on an individual printed page it wouldn't be noticeable. The more individual sheets that you join together, the greater the potential for error. As I said in my original reply, and since repeated by Piers above, your best option would be to get these printed out as complete sheets, using a mail-order printers if necessary if one isn't close to you. Even then they are probably not guaranteed to be accurate to within a millimetre or two over a long length. Also, as a friend found out recently, a full-size printed plan from Outerzone (etc.) might not be exactly the same size as an original from, say, Sarik. Otherwise, check for straightness with a long rule and use the plans as they are. Brian.