Geoff S

If you're using a ply plate anyway then you don't necessarily need the cuniform motor mount. You could simply drill holes in the ply and mount the motor directly onto it and then choose appropriate places to fit the studding. In fact you may be able to get away with 3 rather than 4 mounting studs if it makes it easier to get in. Geoff

Posted by Justin K. on 05/12/2015 09:20:24: Here's an interesting one , a P51 Spitfire ! Was this an anglo American / British project ? Hybrid Whatever it is (neither P51 nor Spitfire) it looks quite tidy and not very unreasonably priced. Is it a cartoon scale of something or other or just someone's own design in US training guise? I'm no scale expert. Geoff

Posted by Steve Hargreaves - Moderator on 30/11/2015 21:11:33: Details here...... Interesting....it talks about the jigsaw having a DC motor so it must be a smallish size. I wish they would do a small circular sander too....that would be very useful... Actually most motors are DC (or, more strictly, ac/dc). Really cheap motors are shaded pole ac only - used to used in washing machines and cheap turntables, maybe still are. Then there's the definitely ac only brushless ones we use in our models. I was concerned it would need a DC supply, which I have, but I'd prefer it to be mains powered or, at least, with built-in rechargeable LiPos. I got one yesterday and it seems fine. The only problem was fitting it into the small rack pack on my bike. The box was bigger than I expected. I haven't tried it in anger yet but it seems it will be perfect for my needs. I did wonder where to get replacement blades and I'm relieved to find they're the same as Proxon and that Axminster stock them as well as available on eBay. I'm great fan of Axminsterr and have one of their smaller bandsaws I use a lot. Thanks for the info. Geoff

One problem those not familiar with electric motors have to face is that different manufacturers describe their motors differently. Specs need to read carefully. With glow, it's much easier even though (say) 40 size engines still vary in performance it's not so marked except for a few very high performance ones. For example, the motor I have in my Tiger Moth is an Emax Grand Turbo 3526/04 870 rpm/volt. I can only assume the 3526 refers to the rotor size because its outside dimensions are: diameter 44mm and length 52mm. It weighs in at 265 grams so its quite a substtanial size with a constant current rating of 55 amps (69 amps peak for 60 seconds). I'll be running it on 4S with probably a 13x4 prop. It's quite a big bigger than the apparently larger 3548 Pat mentions above. It would help if motor size and other specifications and descriptions were standardised. Geoff

Posted by Dane Crosby on 03/12/2015 11:29:46: Shouldn't jets/turbines have a separate vote? Gas turbines are internal combustion (ic) engines. It's just that the suck, squeeze, bang, blow cycles happen concurrently. Geoff

I just used location dowels at the front and magnets at the back to hold the hatch on the Fantasy. It hasn't fallen off yet but it is a close fit. Open cockpits allow more options than closed, of course. Geoff

And I always try to not split infinitives. But then, I find I prefer electric almost by default. I took my Maher's Thunderbird (Zenoah 26) up to the field just once this year and had a few flights with it. It's just too easy to take a load of charged LiPos and whichever electric model I fancy flying without the hassle of cans/bottles of petrol or glow fuel and the means of starting them. Plus electrons wash off so easily before loading up to come home. I built an electric conversion of a 60 size glow kit at the beginning of the year and I'm just about finished building a DB 58" wsTiggie, also electric. Next up is a 2 metre competition electric glider (just for sport flying) followed by a Dennis Bryant sixth scale SE5a which will also be battery powered. I just can't see myself building any more glow powered models though petrol is slightly more likely. Geoff

Posted by Dai Fledermaus on 02/12/2015 12:16:02: Posted by Steve Hargreaves - Moderator on 01/12/2015 11:06:26: Posted by Luke Lane on 01/12/2015 09:01:07: Thanks for the heads up. My lovely wife is going to get me the jigsaw on Thursday. Man can never have enough planes, engines, radio, workshop tools or gadgets. He who dies with the most toys.....wins!!! Steve I was thinking something along those lines just recently whilst looking around the garage at the tools I've collected over the years. Stuff the cost of which I couldn't begin to contemplate if I had to replace it, and just who would want them after my days. For example, I have a set of Stahiwlle AF double ended ring spanners which I bought when I was an apprentice 50 years ago and treasured ever since for that reason. My son, although a great guy has no interest in picking up a spanner let alone using one in anger. I have no desire to go to the great hanger in the sky just yet, but who knows. And on that cheerful thought............................. I have some very old tools that belonged to my father and his father before him. I think of him each time I use a tool that was once in his workshop. I also have a Britool BSF/Whitworth socket set that was a 21st birthday present 55 years ago. I haven't used it for years because everything's metric these days but I will never part with it. I can't imagine not having a workshop. Geoff

Doing a similar exercise to Tim's on the DB Tiggie drawing results in a CoG at about the same point as he calculates ie 125mm (5" ) back from the top wing L/E and 25mm further back than that shown. I'd be delighted if that was a good position because I'm struggling to achieve the specified CoG without loading some lead into the front. There must be someone here who's built and flown a DB Tiggie who can enlighten us. After all the time I've spent tarting mine up I'm reluctant to test fly it with a potentially rearward CoG. Of course I could get the (in)famous Reg Shaw to do the test, he offered at the club AGM and perhaps I should take him up. He's less likely to stuff it in than I am. Geoff Edited By Geoff Sleath on 01/12/2015 22:55:32 Edited By Geoff Sleath on 01/12/2015 22:56:08

I would think 200 metres for me at the most. I have an altimeter on my Phoenix 2000 and I only allow it to climb to 200 metres in very good visibility because I can hardly see it in anything other than that. There'a wind turbine right on the edge of the airfield and it seems a long way away but the FPV quad pilots who have flown round it and back say it's only 1/2 mile according to their GPS readings. There's no way I'd fly anywhere like that far away. Geoff

Posted by PeterF on 01/12/2015 18:36:57: Here is a snippet from a 1/4 scale plan (89" wing span) which shows the CofG for that model at the rear cabane support at the back of the fuel tank. Not exactly what you want but more support for something in that general area. That seems a long way back, Peter. On the DB sixth scale (58" ws) Tiggie that would be 50mm further back than shown on the drawing. ie 150mm from the top wing L/E as opposed to 100mm. Geoff

I think that's the one Tim Hooper is building. It's the same as the one sold by Banggood and HobbyKing. There's some discussion here The 58" ws DB Tiger Moth CoG is given as 100mm back from the L/E of the top wing. Where have you mounted your battery? IIRC Tim has placed his in the fuel tank bay. Geoff

Myron: I knew Beecrofts well. It was on Pelham St which, as my step-mother used to say, was behind big Boots. It was more of a toy shop and I used to save up to buy marrionettes for my model theatre which was a passion of mine in the early 1950s.. However most of my money was spent at Redmayne and Todds for model railway stuff. Is it still there? I haven't wandered around Nottingham for a year or two. I used to buy 7d chuck gliders from the local toy shop. Not sure if they were balsa or cardboard or even a mixture of both. Geoff

Glyn: Both my Wattmeters have 4 wires. A positive and negative in (from the battery) and a positive and negative out (to the esc). I can't think why yours has 3 at each end. One of mine does have a connector for a balance lead so that it can check the voltage of each cell in a LiPo pack but the other ( an original Astroflight one that cost a small fortune when I bought it) just has the 2 in and 2 out. There is a wide variety of connectors for electric flight. I use 4mm bullet connectors but others use Deans or XT60 etc. Annoyingly my polarity of choice is opposite from the ones HK supply. I chose mine 20 years ago, almost at random and it's too much trouble to change now. Geoff

I built a Skyshark Fantasy from a kit last Spring. It's intended for up to a 60 size glow and I built it from the start as an electric model. I moved the firewall forward exactly as suggested for the Ballerina and made a similar hatch (incidentally it took ages ). I ended up having to push the battery right back over the wing in a battery box because it was so nose heavy. I keep meaning to move the elevator and rudder servos to the back but haven't done it yet. So all I'm saying is that having the battery so far forward may not be its best position, so make allowances for either a shorter nose or for a more rearward battery position. As you can see it has quite a long nose and battery is pushed back over the wing rather than just behind the motor where the hatch is. Geoff Edited By Geoff Sleath on 01/12/2015 00:01:59

I agree a so-called watt meter is an essential piece of kit for electric flight set ups but really all we're interested in is current. Knowing current it's easy to work out the power (watts). The meter just takes over that small chore. We have a few F3a competitors in our club and they all fly with expensive set ups ... and none of them have a clue as to how much current their motors draw! I'm sorry I won't be taking part in the mass build because the Ballerina looks a lovely model. I have a lot on my plate right now. I have a high performance 2 metre electric soarer to build - one designed by a fellow club member called Thermal Magic and a Dennis Bryant sixth scale SE5a which will also be electric - probably 4S but could be more. Even in retirement, time is still short Geoff

I'm pretty sure the whole Model Designs range was adopted by Slec and, like kc, I also associate the name of Pete Nicholson with the range. You must appreciate that electrically powered models was very much a minority interest at the time and most of them were marginal in flight. One limit was that readily available chargers ran off 12 volt sources and were only able to charge 7 or 8 cell NiCad flight packs because switched mode power supplies as are common now were expensive to make. In other words I think range you mention was all there ever was. Geoff

I bought a tube of UHU from Poundland, too but, as I expected, found it wasn't very foam friendly when I experimented on some scrap. It's still a useful tool in my adhesive armoury. Fortunately Boyers general purpose shop in Ripley, stocks a wide range of useful stuff - razor saws, glue sticks and hot glue guns, a full range of Humbrol enamel plus the usual household goods etc - and also UHU Por, so I'm spoilt for choice. I just wish we still had a convenient model shop. There were several when I started modelling 20 years ago but despite my enthusiastic custom they've all closed and I'm left with Poundland and Boyers but, mostly, the internet. Geoff

I'm currently a digital subscriber only and it's working OK but I hanker after the feel of the paper I'm trying to keep my workshop clear of Is it possible to convert to a paper plus digital subscription? My current subscription is only a couple of months old. Geoff

The RM book recommends three possible solutions: 1: Use a snake angled to be normal to the rudder pivot. They actually say a tube/cable pushrod rather than a snake and didn't seem very keen on the idea. Perhaps snakes weren't available in 1975 when my secondhand copy was touchingly gifted to 'My dear Arthur' at Christmas. 2. A nylon horn scewed onto a through bolt which is free enough to turn as the control is applied. 3. A ball joint but it points out that the exit slot needs to allow for the rise and fall of the push rod which will be at rightangles to the hinge. I picked my copy up at a local secondhand bookshop in Cromford several years ago for £2. Despite its age there's still a lot of useful information and it's interesting to read about older radio systems and reflect how lucky we are now with modern computer sets. Geoff

Very nice, Tim. It's almost as nice as my DB G-ACDC Found some pictures of your prototype here It's in the company of DH Dragon Rapide on a beach somewhere with a long pier, not sure where. Geoff

I've been using cyano glue from Poundland on and off for about a year. At first I only used it for non-critical applications but my experience is that it simply works. I usally buy a small stock and keep it in the fridge until I open it. The last time I went in to get some cyano I also needed some 5 minute epoxy and so I've been trying that, too. It cures quite quickly (as it should) and also appears tobe perfectly OK. I only use 5 minute epoxy in non-critical areas anyway (I prefer longer cure where it really matters. It just seems to be sensible) so I'll be using it again. Our local Poundland is right by the bus stop so it's handy to have walk round if I have a 10 minute wait. I buy their sand paper and wet and dry as well as AA non-rechargeable batteries for bike lights etc.. Does anyone else use Poundland adhesives etc? Any problems? Is there any point paying more? Geoff

I think Balsacraft were selling their small electric models in the mid 90s, about the time I started getting interested in aeromodelling. I remember someone making a very neat job of a Hurricane at RRRMAC(Hucknall) but it barely flew on its brushed motor/NiCad power/energy source. I think SLEC/Precedent took over the marketing and production from the original designer whose name escapes me. Geoff

The charger I take to the field doesn't have a balance facility so I charge without it if necessary. It's not necessary to balance charge every time but if it's available I always use it. When I bought the old charger I take to the field most LiPos didn't have balance plugs anyway ... it's quite old. I have a couple of fancy (and expensive) chargers in my workshop so balancing's the norm. As Martin says, what do you call fast charging? I always charge at 1C ie an hour. It's supposed to contribute to long battery life and is probably more important than balancing every time. Geoff

My usual failsafe setting is stop the motor (or in an ic model down to tickover in case it's only a glitch and I'll still have power once it's ended) and neutral controls. It's so simple there really is no point beyond pressing the FS button on the receiver. If there are retracts (rare) then I select for them to be up. I always check afterwards, particularly the motor setting, which I consider to be the most important, Geoff