Geoff S

I've missed the Nats for the past 2 years because holidays intervened but when we go we camp very close to the hanger on the airfield side of the peri track (originally because I was involved in the indoor flying in the evening). That's also very near to the control line circles so we get the noise but that's part of the power nationals. I'm not much of a noise freak but even I git a thrill when I heard the incredible noise of the pulse jets that was almost deafening from 400 metres So I very much agree with Chris (ceejay). However that's not the problem The real problem is finding somewhere to hold any sort of power nationals as Barkston has been closed for us. I suspect it's likely to be closed for good so a new venue with a sympathetic owner/manager/CO is vital. I don't care where it is but I'll be going if at all possible and dates don't clash. Geoff

Not a blow by blow build but here's a brief update. I've built one wing just about completely and I'll probably have the whole wing finished this week built more or less to Peter's drawing including his building method. One little problem I found was that after planing the chamfer for the aileron l/e there wasn't much of the top capping strip left, so I replaced it after glueing some 1.5mm x 1.5mm strip between the ribs to support it better. The problem is that the aileron is so thick and the leading edge material so slim at 6mm there isn't enough meat for a 90 degree angled chamfer so you just have to judge the optimum angle with the material available. That's a pity as my plane has a nifty attachment that allows you to plane at 45 deg accurately which makes perfect control surface chamfers with narrower material easy to achieve. It's not a serious problem at all but when I build the second aileron I'll set the top capping strip a further back and fit the support pieces right from the start. However, I needed to get the servos for the ailerons to complete the wings and I've opted for these from Airtek. They're metal gear, ball bearing and are specified to have 3.3kg cm torque (about the same as a standard Futaba 148). They weigh only 20 grams and are much smaller than 148s. They have brass(?) servo arm splines and secure the arm with a 2.5mm machine screw (though one of the 4 I bought had a 3mm screw which I've replaced from my stock). They take standard Futaba servo arms from what I can tell - they have 25 splines and the Futaba arms seem to slide on OK. They look quite good. I tested them using the servo test facility on my iCharger. They all centred very consistently and moved smoothly over =/- 45 degrees with 1mS to 2 mS pulse width (1.5mS centre) but could be pushed much further to +/- 60 degrees without a problem. They would go to +/- 90 degrees but they weren't too keen on the last 5 degrees so I didn't push it. This was all off-load testing so how they'll behave in real life is still unknown but they seem to be really good so far. What servos are others using? Geoff Edited By Geoff Sleath on 19/01/2016 15:01:21

I've had my 120 watt Henley Solon soldering iron since Big Ben was wrist watch and it works well for soldering 4mm bullet connectors because its mass is large enough for the temperature to remain constant. It was big enough to repair vintage motor cycle fuel tanks (specifically my 1932 Scott). I used to us my 60 watt (IIRC) Weller temperature controlled iron with a 700 deg F bit but it wasn't quite as good and it's now gone to the workshop in the sky. I may try my newish Precision Gold 60 watt temperature controlled iron on the XT60s because of the plastic casing which isn't a problem with 4mm bullets. And I wouldn't let lead-free solder anywhere near any electrical connections I solder. It's 60/40 lead/tin all the way for me. Geoff

If nothing else, John, it'll be good for business with all those replacement engines Geoff

Posted by Ernie on 18/01/2016 09:01:44: A big no no Sand and water don't mix with electronics and fiddly wee bits ernie Whilst you're right, flying off hard sand below the high water mark shouldn't be a problem if you do some basic maintenance after your flying session. What I never fancied was sailing a model racing yacht in salt water because the hull's underwater half the time if it's windy. It was bad enough washing down our dinghy after a week's racing on the sea. I'd second a Multiplex Fun Cub but they're not a buy and fly the same day ARTF foamie.  There's quite a lot of work (and expense) over and above the initial purchase. Geoff Edited By Geoff Sleath on 18/01/2016 12:38:18

Thanks to you both. I'd hate to spend a day soldering and then find my batteries were different from everyone else's. Rob: I've been involved with electrical connectors all my long life but the concept of what constitutes 'male' and 'female' seems to have changed. How can a connector be described as 'male' when it clearly has sockets? Not your fault btw because I've seen similar descriptions applied to servo plugs which to my mind are definitely 'female' and the connectors on receivers are 'male'. At least you do clarify that the male connector has sockets Thanks again. I'll get the big 120 watt soldering iron warmed up. Geoff

I'm seriously considering having a solderfest and changing over to XT60 flight pack connectors from the 4mm bullets I've been using for years. I don't want to end up with my own private convention so can anyone tell me what polarity and gender battery connectors are, please? I think the polarity is indicated and I'm guessing the female (ie sockets) are on the battery. Annoyingly all the battery pictures at HK have the connectors pointing the wrong way. Thanks Geoff

I quite like watching snooker. It's about 1000% more interesting than darts but that's damming with faint praise Actually I stop my Eurosport subscription in the winter because there's no cycling. Just waiting for the spring one day classics then the Giro. And of course the odd day up at the field. I used to go to work, you know. Geoff

There's a drawing error on the tip rib. It's too big by 5mm. I think the bottom one may be too small. I'm guessing another 'improvement' of Peter's original Geoff

I'd also recommend Modelfixings for a reliable source of decent quality bolts at a reasonable price in small quantities. Geoff

Posted by AVC on 17/01/2016 12:55:27: Hi John The photo below is one of my tip. The height of the tip rib and the triangular support are not the same, the rib is higher and it shouldn't be I've been pondering the wing tips, too. I noticed that the tip rib is bigger than the cross section at the main spar. I think it's another modification introduced after Peter released his drawing. The height on the cross section is 10mm and rib is 15mm. I intend to adjust the tip rib height to suit the tip brace by slicing 5mm off the bottom. Geoff

As I see it the reason for 2 bolts is because it isn't a single one-piece wing as you build it. It's a lot easier to have a bolt in each side than try to contrive a single bolt through the part where the 2 wing sides are joined. Of course, if you were really determined to have just the single bolt you could have it in one side only Suffice to say I'll stick to a single dowel and 2 bolts which will probably be 5mm/2BA nylon. I note that Peter suggest fitting some brass tube to hold the wing dowel so that it can be replaced at the field if there's an acrobatic rather than a ballet style landing which results in its being broken. In my vast experience of acrobatic landings I find that if they're so severe that the dowel breaks then there's always a lot more needs to be replaced/repaired than the wing dowel I'm thinking of making the fuselage sides in 2mm liteply (which I happen to have in stock) and not bothering with doublers. It's a 48" length which means I can easily extend the sides to a more forward firewall to accommodate the electric motor. I'll probably cut lightening holes in the rear fuselage if I do that. IIRC it was how Precedent constructed the Hi Boy trainer. Not sure about the relative weights but it's just an idea as I build the wings. Geoff Geoff

It will indeed, Mouse and no other flux necessary. Geoff

Posted by Phil Green on 02/01/2016 14:56:01: ...bearing in mind that a cheap wattmeter might only be accurate to within 10%, try two or more and you'll see what I mean! Cheers Phil Edited By Phil Green on 02/01/2016 14:56:49 I have an original Astroflight Wattmeter which cost £50 about 15 years ago and an inexpensive HK one which also has a LiPo checking facity like most do now. I find they correlate quite closely and also incidentally with my Frsky current telemetry read out. I was quite surprised. In any case I think 10% isn't too big an error because readings can vary that much quite quickly as a freshly charged battery voltage drops. Though IIRC my readings were no worse than 5%. I've commented before on the poor data supplied by motor manufacturers (even one as respected as OS - though I suspect they're riding on their glow engine reputation) as regards current draw with a given propeller. They are often wildly out and usually in the wrong direction which makes a method of measuring current, particularly, just about essential. It's amazing how many electric fliers don't bother. In our club that includes F3a pilots who are running some very expensive power trains without a clue as to the current draw. Geoff

Posted by Lorenz Mueller on 15/01/2016 14:17:20: The problem with the Ju-52 is that in any decent size the corrugations would be a must to look right. However I haven't yet seen a reasonably simple way of doing them. .... Lorenz I did the corrugated fuel tank on my 58" DB Tiger Moth with corrugated card I bought for pennies on eBay. I didn't even have to paint it because it came in red (amongst other colours) which matched the fuselage. I'm sure it would work on a similarly sized Ju-52. My choices? Hawker Hind Gloster Gladiator I also quite like Phil's idea of a better looking scale-like trainer though I don't see the point of rudder elevator only. Learning to fly with ailerons is no big deal. I learned at 55 that way and younger starters would have fewer problems than I. I would prefer electric power or at least the option available without needing to redesign the fuselage as I'm having to do with the Ballerina. Geoff

Posted by Steve Hargreaves - Moderator on 15/01/2016 12:47:30: Ah yes but the earth wire probably fell off shortly after your exam Geoff.....eaten away by the acid flux.... Yes but I why should I care as, according to the certificate I probably have hidden away somewhere, I'm a Certified Radio Service Engineer? Forget the 'Certified' for a bit and remember that 99% of the radios I repaired still had valves and you'll appreciate it doesn't stand for much Even the manufacturer (Murphy Radio) whose service department I worked in hasn't existed for decades. Come to that, none of the companies I've ever worked for, except Rolls Royce, are still in business including the then giant GEC. Even Royce's seem to be on shaky ground! Plus ca Change! Geoff

Posted by Simon B on 15/01/2016 12:53:49: I know you've already got one, but I used one of these, which are good because of the way they route the wires out of the back: Link Those out-runners in a can together with very neat rear connection are a good solution to the tight space in a glider nose but I think this one might be better suited to the Phoenix 2k being more than powerful enough and a bit lighter. Geoff

Posted by Mowerman on 15/01/2016 11:40:41: The majority of Americans believe in 'the right to bear arms' They also believe that John Wayne was the all American hero. I don't understand why anyone (particularly women) would want very hairy arms ending in paws with long claws. If nothing else it would make holding and operating a transmitter very tricky. Geoff

Posted by Phil Green on 14/01/2016 21:26:26: Ersin Multicore is the longest established, most reliable, most common 60/40 and beloved by electronics people the world over. I agree, though my current batch of 60/40 isn't Ersin I must have used a few rolls of it in the past 60 odd years. I can't see my needing to buy any more now as I've just started a new reel. The one to avoid for electrical work is Arax Multicore which has an acid flux which works for steel soldering etc. I sneaked a few inches of Arax into my Radio Servicing Exam soldering test back in 1958 just in case I needed it. I actually used it to solder an earth wire onto the tiny steel chassis we were given. I still passed Geoff

I would say definitely a rearward CoG. In the Flite Test web page they did say the Mustang CoG was further forward than what would be considered normal. You were very brave to keep flying it. I think I would have tried to get it down after the first circuit. The long grass certainly saved your and the model's, bacon Geoff

Blimey, your fuselage jig looks a lot cleaner than mine which is dotted with lumps of old epoxy and the lines have run a bit for some reason (some sort of solvent, I guess) but it still works a treat and is a valuable building aid. I struggle in my small purpose built workshop with tools collected over a 100 years or more by my father and grandfather as well as me. I can't think how those building on the kitchen table manage. I take my hat off to them. Making progress. I'm letting all you clever clogs get on with fuselage whilst I build the wings more or less to the original drawing except for having 2 servos for ailerons. I'm waiting to see how you solve the motor installation problems. I always start with wings when enthusiasm is at its height because they have a tendency to be tedious. The fuselage is always the more interesting part for me so I save it for last. Geoff

Thanks, Robert. I think you should have plenty of power available for a 9lb model so few worries on that account. Geoff

I thought you must have a very big workshop when I saw the first picture with the 1/72 model on the table. Fantastic job and superbly finished. If it flies as well as it looks then it's a double winner. Best of luck with the maiden though with the weather as it is I suspect it'll be a few weeks yet. What motors, battery etc have you got in it? I think your weight estimate was pretty accurate. I find models always end up heavier than you hope but you weren't too far out. Geoff

Posted by Biggles' Elder Brother - Moderator on 12/01/2016 22:31:08: Good questions Geoff! And ones I'm still pondering TBH. I don't really like the idea of leaving the bottom open, but a hatch is quite a faff. Having said that even with access I might not be able to remove the motor - the best I could hope for would be to be able to repair a failed solder joint or the like. Needs more thought. I quite enjoy pondering over future bits like that while I'm building, or driving, or suppose to be working! The solution usually comes to mind - eventually! I like to do my pondering in bed in the morning whilst listening to the 'Today' programme on R4 and enjoying the luxury of retirement - though the drawback is getting older (that's relevant today as it's my birthday yet again! ) Leaving the bottom open isn't too bad. It isn't noticed on the ground once you've fitted the wings and not in the air, either. It has the advantage of keeping everything cool. I don't like building things in. Perhaps I'm a pessimist but I like access for maintenance. It look more open than it actually is because the battery hatch is off and you can see right through. Geoff

As I said at the start I don't intend this to be a blow by blow build thread. I'm too shy for that and not always proud of what I make The laminated leading edge of my built-up tail plane came out OK and I've made the whole thing now. Nothing very special and much like those others have made. Not done the elevators or fin and rudder yet. I've moved onto the wing and cut out most of the parts. I did a dummy dry run of the starboard wing and it looks like my method will be OK. My method? Well I don't build over the plan but over a piece of lining paper protected by some cling film. That means I can see the drawing without its being obscured by inconvenient pieces of wood. I glued the bottom main spar to the bottom 1.5mm sheeting and pinned it to the board then used the 3mm plywood patterns I used to make the ribs to position the trailing edge capping strip and the rear main spar and its capping strip at the aileron. As Peter suggests I packed up the rest of the rear spar with scrap 1.5mm sheet. Where I deviate slightly is that I space the ribs by making a full set of sheer webs and use them to position each rib in turn. This also has the advantage that they fit well and it's a lot quicker than making each one individually. These are 60mm wide and 38mm for the narrow bay at the root. That makes it easy to build the wing without using the drawing as a jig yet ending up with an accurate build. I use a square to ensure the ribs remain parallel but it's not a problem anyway. I've ended up with a wing half 5mm longer than the drawing so mine will be a long wing span Ballerina by 10mm At least the wing loading will be slightly less!  This is the first time I've put a wing together like Peter  recommends and I really like it.  I've also marked on the outermost ribs the line for the sheet tip to make aligning it easier. I think I may glue a then strip of 2mm balsa sheet to locate the tip. Hopefully it'll ensure the tips at each end are identical - almost. I'll try and post some pictures tomorrow. Geoff Edited By Geoff Sleath on 12/01/2016 22:46:54