Jeffrey Cottrell 2

Hi Guys Success, and thanks for your help. New tank, 8 x 4 APC prop,and new tubing. Had it on the test stand, hand start and absolutely screaming on that prop. Little jewel. Took a few minutes to find the comp setting, but after that, all good. Couple of thoughts. Think I might have overestimated the tank size. Old one that came out gave me 2 minutes flat out, which was enough to get to a good height, but no idea what size it was. Guess said 10cc, which is what I ordered, but test run seemed to go on far longer that 2 mins. Ho hum, test flight will decide. Also, I understand I can't use silicon tubing with diesel fuel, hence can't use a clunk tank, but could I use it just for the fill tubes? Got some Tygon for tank to engine, but it's incredibly stiff and a problem with the half buried fuel tank. Your thoughts? Jeff

Hi Guys, thanks ED Couldn't agree more about using a starter on small engines. In fact I don't even like using one on my larger engines. Much as I would like to make my own tank, I am up to my neck in other projects. So many models, so little time! Anyway came across a company who can supply ready made, so I have ordered a 10cc one from them. Should be here in a couple of days, we'll see. JD8 Apparently the external size is the same for 0.5, 1.0 and 1.5. it's only a guess that mine is 1.5, but it doesn't really matter anyway. Whichever it is has enough power to give a vintage like flight performance, so what I really need is to make it easier to live with. To that end I have the engine on a test stand, and a couple of APC props coming to test with. I noticed the old tank had a broken off upper feed tube. When I pulled that out it turned out to be a c/l stunt type wedge tank. That can't have been helping. Anyway, hope the new bits will make it perform better. Work in progress Jeff

Hi J D 8 Interesting. I have read that on the 1.5 you can see the bottom of the thread for the rear head bolt at the top of the backplate. I can see this on mine, which would suggest mine is a 1.5. I did mention that the upper pipe on mine had broken away, and since it looked more like a c/l tank than f/f certainly is not helping. Anyway, going to make some phone calls tomorrow, see what I can find. With such a small motor, I'm reluctant to use a starter on mine, but do you use one, and any after effects? Finally, what size prop do you use? thanks Jeff

Hi Alan, and thanks. Think you've broken the world record for replying to my questions. Almost before I'd finished typing. Nice one. Thanks for the tip on priming. I was squirting fuel down the carb, so maybe over-priming was an issue. Anyway, next step is to get it on a test stand so I can have a proper play. Did a quick google search on AE engines. seems there is no external difference with the 0.5 1.0 and 1.5. However one I read did suggest that with the 1.5, you could see the end of the thread for the rear head bolt above the backplate. I could see this sign on mine, which maybe suggests I have the 1.5 one. Anyway, suggested prop sizes for the 1.0 as 7 x 4, and the 1.5 as 8 x 4, so maybe a different prop is on the cards. Finally I have neither the facilities or the skill to make my own tanks, but Den's Model Supplies seems to have quite a range, so I'll give them a call, see what they say. Jeff

Hi Guys Little outside my comfort zone, so I could use some help. Bought a model at a swap meet recently. A Slicker, one of the prettiest designs from that era, imho. Came complete and ready to go, including a small diesel engine. So, first question. I am told it's an AM 1cc. No labels or markings on it, so could anyone confirm? Pics should be hearabouts. Runs well when I can get it started, but seems to start only when it wants to. Sometimes doesn't show any signs of life, even when I hit it with a starter, which I'm reluctant to do with such a small motor. So, looking round for possible causes. It is fitted with a wooden prop. 8" dia but pitch not known. The prop is feather light. Seem to remember they perform better with a heavier prop, something about 'flywheel' effect. Would I be better with heavier one? It uses neoprene tubing, which has gone stiff with age, so my fuel bottle doesn't fit very well. Can't say for sure whether the tank is full. Finally, what might be the biggest issue. Pulled the tank out, and it looks like a control line tank, with one pipe heading down and the other up. The upward pipe has broken loose (solder joint failed) so I need to replace it anyway. Anybody know where I can get a free flight tank for diesel fuel? Must admit I could pull the motor and go electric, but it has such charm as is I would like to keep it and make starting more reliable. Any thoughts? Jeff

Hi again After all that forgot to attach the photo. Jeff

Hi Denis Sorry its taken so long to get back to you, other projects keep getting in the way. Anyway, to horse: As requested attached is a side view of my model. Apart from the colour scheme looks identical to yours. Measured on the wing, distance from le to front of wing tube is 90mm. That puts centre of the wing tube at 100mm. I see internet posts of flying at 100mm, and my c/g finding program says could be 109mm. Anyway, added some more nose weight to bring it to the 75mm from the manual. Clubmates pronounced it very nose heavy, and after a test fly, I would have to agree. For the test flight, as well as the nose weight, I re-calibrated the esc to produce more power, and cut down the control throws to avoid the overcontrolling from the first flight. Anyway, test was encouraging, if only a little. Took a while to get off the ground, as expected, and control responses were sluggish, also as expected, but it flew and landed in one piece, so that's progress. Main thing is I flipped it to inverted and it took full forward stick to fly level. Seems my clubmates were right, too forward c/g. So, I made the extra noseweight removable so can pull it off bit by bit, see how it goes. The weight fitted by the original builder is glued in, so will require surgery to remove it. Not sure whether to go that route. Depends if it could use the c/g going even further back once I remove my weight. So, work in progress, slowly. Any thoughts would be appreciated. Jeff P.S. Came across a guy in York, who was flying his with fpv gear at the rear pilot position. This plus even more noseweight pushed the overall weight to over 8 lb. He said it flew fine at that weight, but landing speeds were pretty high. There's hope for mine yet. J

Hi Guys, the plot thickens. Had the Extra out for its maiden this afternoon. First flight, and very nearly its last. Model was almost uncontrollable. So called level flight had the tail hanging down at 30 degrees or so, and over sensitive on the primary controls. All signs of a too rearward c/g. Nowhere near enough power either, but I think I have sorted that. Did a re-calibrate of the esc, Now showing 36.71a and 859w on a 14 x 7 prop. Got a 15 x 7 on order, hope to get above 900w. Main thing, though, is the c/g. Not sure what to do about that. It has a massive metal tailwheel set up, and that could be swapped for a simple skid. Lose a bit of weight at the extreme tail end. Also the esc could be moved to right behind the motor which would help a bit, but can't help feeling that won't be enough. Any ideas? Jeff

Hi Guys Erfolg Agreed I find it difficult to navigate the Aliexpress website at the best of times, and the CHNL shop isn't any better. Looking for some 5000 6s packs. Put 5000 in the search engine, got the message 'nothing matches your search', really? Did a search for 6s instead and got loads, but nothing at 5000. Seems you can put either 5000 or 6s in the search engine, but not both, ho hum. However, not all bad news. Not sure if you're aware, but CHNL do have a UK warehouse, not mentioned on Aliexpress. Looked on there a couple of days ago, no luck. Just got an e-mail saying they had re-stocked, and the packs I was looking for are now in stock. Nice touch, didn't even have to register my interest, like I would with HK. Out of interest, the 5000 6s packs come at £126 for two, that's £63 each. Equivalent at 4Max are £115 each or at Overlander are £105 for the cheapest. Quite a saving there. Only got a couple of CHNL packs at the moment. Pretty good so far, but can't comment on quality long term. We'll see. Forgot to mention, anything over $69 from UK warehouse is free shipping as well. Jeff

Hi Caveman Just done the same operation, and the results are interesting. By my calculation I could have the c/g at 109mm. However it does show the distance from le to ac (aerodynamic centre) as 75mm Could it be that Seagull just chose the wrong number to put in the manual? Anyway, I seem to be heading to the model being safe to fly at 100mm. Still not sure about all up weight, but only flight testing will tell me that Must remember spare underwear for the maiden. Be a little while yet. Decided to swap the wing servos as well, might need a bit of lateral thinking. Work in progress Jeff

Hi Alan Been right through the manual I have, even found the pictures Denis posted. Everything I looked at convinces me this is the model I have. Servo layout, three bolt fitting for the u/c, glue in fiberglass control horns, the list in endless. Only thing different is the colour scheme, and we all know how often these are changed. I do really think the manual I have is the correct one. Anyway, took some pictures as requested. Caveman Apart from the colour scheme, that's the one I have. Front page of the manual is identical, and the dimensions match with my aircraft. Thanks also for posting a pic of the back page. Clearly says c/g 75mm back from le at wing root. I rest my case, m'lud.

Hi Guys, appreciate the help. Alan, you might well be right. I have the two seater, which makes it an L, despite having 300S on the tail. However more important is the 300S is a much bigger aircraft overall. Span is 63" compared to 55" for mine. Overall weight for the S is 6.6 to 7.5lb, S is max 6.6lb. Power requirement is .61 to .75 2str for the S, where the L is .46. In short, the L and the S are completely different aircraft, over and above number of seats. Caveman Thanks for the link, but that's not the model I have. First page describes gluing the wing halves together with a ply joiner. Mine are in two pieces, plugging to each side on an aluminium tube joiner. No doubt it is for a Seagull Extra 300S, but not the model I have. Either an earlier or a later version. Right at the end of the manual it describes fixing a 35mh aerial, so I would suggest earlier. Still have no idea why, despite having a bigger motor and heavier battery than recommended I still need some weight in the cowl just to get it to balance some 25mm further back that the manual recommends. Just one silly thought. Manual suggests marking the c/g on the top of the wing and balancing the model upside down. I did mine on a proper balancer right way up. Can't possibly make a difference, can it? Jeff

Hi Denis, thanks for the quick reply Not sure if it answers any questions, or brings up a whole set of new ones. First things first, you say yours balances at 75 mm, bang on the wing tube. My wing tube is 100mm from the LE, not 75. I did catch a post on RCUniverse from way back, where someone flew his at 100mm, so I might give that a try. However, a c/g too far back, and an overweight model is a recipe for a re-kit. Not sure what glow motor you have in yours, but I have a spare Irvine 53 over here, and that weighs in at 524g, On my electric set up I have a motor at 275g, two batteries at 362g each, or 724g and the weight in the cowl at 289g. That's a grand total of 1288g or getting on for 3lb in real money. Bear in mind this only gets it to balance at the 100mm point. Just to make it more interesting still, I downloaded the manual, and that recommends a 35 size motor at 830Kv on 4 cell. Whether that would have enough power to get out of the way of its own shadow, I'm not sure, but it would never balance anywhere near that way. Agree with you about attaching weight to the cowl. That wouldn't have been my choice either. The previous owner had epoxied a strip of lead, and 15 two pence pieces in there. The loose change alone would be 107g by itself. That of itself poses a problem. If I manage to find a way round this balance issue, won't be able to remove the weights without destroying the cowl. Might change thinking on aileron servos. Was going to use a pair of Emax ES09's, but I have a spare pair of midi size I might use instead, we'll see. Still can't help thinking I'm missing something obvious, any ideas? Jeff

Hi Guys Just bought a Seagull Extra 300L (1.4 mtr), and I need some advice. Pleased with the purchase so far, but a closer inspection reveals some oddities. First of all, I assume the model comes without servos, yes? Mine has a 3001 on rudder and a 311 on elevator. Seems to be working fine, so no issues there, but the aileron servos are ParkZone PKZ 1081. Can't find any specs on these, apart from discontinued and replaced by Spektrum SPMSA 382. Can't find any specs on these either, but they look pretty weedy so might replace with Emax ones. Now comes the real question, regards c/g and overall weight. Manual says c/g should be 75mm from LE. The model had a mark on the wing but this was 100mm back. Also the previous owner had epoxied a load of weight to the front of the cowl. Anyway, put it on my balancer, and even with the heaviest battery I could find, 2 x 3s 5000 in series, I could only get the model to balance on the rear 100mm mark. Also with the big battery, took the all up weight to a whopping 7lb 9 oz, or 3450g. Certainly won't have any issues with turbulence at that weight but it does seem awfully heavy to me. Am I missing something? Jeff

Shhh, don't tell everyone. That's probably getting an Irvine 53 up front !!!

With you on that Stuart. Recently bought a Smart Move kit that had been in storage for 22 years. Imagine what that's done to the wing veneer. Need a lot of work before it's even possible to start building. Long term project, methinks Jeff

Not so, Stuart If you go with the 4s 800 Kv combination you could play with prop sizes if the 12 x 6 doesn't float your boat. Electricalc says you could go up to at least 13 x 7 before the magic smoke starts coming out. Certainly a lot cheaper than switching motor and battery, plus you could get a selection of props and change at the field. Jeff

Hi Guys Bruce Agree with all you say. Although I only use 6s on my helicopters, it's a viable option for Stuart. Only snag I can see is finding the right Kv and prop size. Could you let me know what you use on yours? Stuart Sorry, black art time. Your idea of upgrading to 6s if necessary sounds good in theory, but won't work in practice. For a 4s pack and a useful prop size (12 x 6), a motor Kv around the 800 area would be needed. However if you then decide on 6s with the same motor you would need to drop the prop size drastically (10 x 5 max) to keep the current draw within limits. 10 x 5 would be far too small for your model. Other than that to go 6s you would need to fit a different motor with lower Kv (400 or so) which would mean a physically bigger motor, running very inefficiently. Decision on cell count needs to be made first. My thoughts anyway, would welcome Bruce's input. Jeff

Hi Stuart, still a bit of a black art, isn't it? I think the 40 in Joker 40 refers to the engine size rather than the model size. Looked at the Sebart Katana (couldn't find Sebring) but that looks more like a 3d model than an aerobatic. Big, fine pitch prop gives it away. Must admit I wouldn't use 5s anyway. Difficult to find a use for it on any other model. Oddly enough I did have a 5s set up for my Smart Move, but that needed a 16 x 8 prop, which was far too big for the model. Also looked at the Moonglow. Aerobatic model, but designed in 1968, for low powered 61 size engines, which were all that were available back then. Better bet to stick with the Bullet or Gangster. Here's the address for Electricalc: https://www.ecalc.ch/motorcalc.php You have to register to use it, but it's free after that. Don't forget I still have the set ups for my Smart Move. Project stalled, so I never got to use them in practice, but the one I would have chosen uses a 4s pack with an 800Kv motor and 12 x 6 prop. Pretty much in keeping with the style of model. hope this helps Jeff

Hi Stuart Couple of thoughts for you. On the 4Max website (www.4-max.co.uk) you will find suggested set-ups for various models. Go through the list and find a model as close as possible to yours. 2 on the list look close. Mick Reeves Gangster 63 Lite or PB models Bullet. On the page there will be a list of suggested components for each. Bear in mind these are only suggestions. Granted George at 4Max has a lot of experience in these, so probably better than guesswork. Otherwise, find out what prop a 55AX would use at what rpm, and use something like Electricalc to design a system that produces the same results. Bear in mind that an electric power system will generally use a bigger prop turning slower, so any results from Electricalc would be guidelines only. Some time ago I bought a DSM Smart Move, very similar to the Joker, which I was thinking of going electric. Did some experimental set ups on Electricalc, and found a few that would do. Project went no further than that, but I have the details still on file. Yours if they're any help to you. Jeff

Hi Guys Now I'm confused. Fedex delivered my parcel this morning, actually a day earlier than scheduled, full marks to them. Main thing is, no Vat or handling charge was asked for, or paid. Total cost was only what I paid to HK. So, question. Despite everything that's been said, HK have actually paid the UK vat. (unlikely) or Was my shipment one that slipped through the net, and I was just lucky. (more likely) So, the packs I bought (Turnigy 2650 4s) were on sale anyway, so in total cost me £23.95/unit. However, I did find out the handling charge Fedex would have made, and the vat is easy to work out, so even if I had paid full price, and vat and handling on top, this would have added up to £40.18/unit, which is comparable to UK bought items. For those who use and like Turnigy Lipo's things not as bad as they may seem. Jeff

Hi Erfolg Now you have me completely confused. I have a shipment coming from Hong Kong via Fedex. In it's travels it arrived at the Fedex Hub at Roissy Charles de Gaulle, in France. Since this is a hub I can only assume the item did not leave the warehouse, or go through French Customs before being loaded for onward shipment to UK. I fully expect to have to pay UK vat, and probably a handling charge, when it arrives in UK, but from what you say, seems I might have to pay some form of EU tax as well. Have I read this right? Jeff

Hi All For years now I have fancied a Wedge biplane, Phil Ramsey design. Anybody know where I can get hold of plans? Thanks Jeff

Hi Guys EarlyBird Guess we'll have to agree to differ on our interpretation of the rules. It's all interpretation anyway, isn't it? Maybe more on that later. Graham Hinges on what you would call significant savings. I guess you should shop around for the best price on whatever size of LiPo you need at the time. More later. John. Thanks for the tip on Overlander. Their price for 2200 3s is certainly competitive. However, the price on 2650 4s maybe not so much. Anyway, I have placed an order with HK for some LiPos, so that should prove something either way. Used to run my Riot on 2650 4s Turnigy packs. Only ones I found that fit in the battery compartment without mods. However I have a couple of other models using the same battery, and I haven't got enough to go round. Reverted back to 3s for the Riot, but it's a lot less fun. So ordered three Turnigy 2650 4s packs. Total price inc shipping came out at £71.85, or £23.95/pack. Equivalent at Overlander would have been £44.99 or at 4Max £39.50 but with a blanket £9.99 postage. That's what I mean about significant price difference. Anyway, ordering from HK might prove whether our interpretation of the tax rules is correct. Watch this space Jeff

Hi Graham You make a good point, and I would agree with you except for a couple of things. First of all, we modellers are a parochial lot. When we find something that works for us and represents good value for money, we tend to stick with it. I know I do. HK covering film and Turnigy lipos have long been favourites of mine. To give a concrete example, I fly my Riot on 4s. I have found that the Turnigy 2650 4s fits the battery compartment without modification, where to accommodate other packs would require major surgery. Secondly, I think the cost issue is not so great as we would think. BTW, can't blame HK for LiPo shipping costs. They are now classed as dangerous goods, and few couriers will transport them at all, so choice is not wide. When (if) EU warehouse ever starts shipping to UK again, expect shipping costs to reduce, since they do not need to airfreight them. Anyway, been doing some research on prices, and here's what I found. Taking as a baseline everyone's favourite 2200 3s 40c. Current (ahem) HK price is £10.43 If you only buy one, shipping is £25.83 totalling £36.26 (ouch). However, if you buy two, cost is £20.86 but shipping is still the same at £25.83 so £23.34/pack. Buy 3 it's even better. 3 packs @ 10.43 is £31.29, but shipping only goes up to £33.06 so totals out at £21.45/pack. That's competitive. RapidRC do Turnigy packs but they want £15.99 for a 25c pack, and shipping pushes that up to £21.29, much the same as HK. I did to try to compare prices for three packs, but Rapid only had one in stock. 4Max have Purple Power packs (pretty good imho) at £23.50 but shipping is a whopping £9.99 so £33.49 for one pack. Buying three gets better. Shipping stays at £9.99. so cost/ pack comes down to £26.83. Better, but still some £5 more than HK. So HK global not as uncompetitive as you would assume. Food for thought Jeff