Erfolg

Thanks Alistair I have an APC hub with 9*5 blades. I am going to try (flying, I have fitted) it, the main problem with these hubs is:- a) Large bore central bore, for most applications you have to sleeve the hub,shaft. Providing potential for eccentric run out. b) The blades have stubs moulded onto them, where as most hobs are made to accept retaining bolts. c) Most model shops do not seem to stock APC folders. I have tried the local model shops (Woodheys, Steve Webb) for 3mm system or collet, neither could help. No problem with 3.2, which I have 4. I will see how this works out. Regards Erfolg

I have a 120inch Dave Edmonds Algebra Glider, which I am now electrifying (Brushless and Lipo). Unfortunately I seem to have misplaced the tail planes. I thought that they were all flying but on examination of the fin realise that it must have had a conventional elevator. Which I guess is a simple rectangular plan form and not swept. Has any one out there have the following details a) Confirmation of plan form b) Span c) Chord d) Thickness Regards Erfolg

I have a 120inch Dave Edmonds Algebra Glider, which I am now electrifying (Brushless and Lipo). Unfortunately I seem to have misplaced the tail planes. I thought that they were all flying but on examination of the fin realise that it must have had a conventional elevator. Which I guess is a simple rectangular plan form and not swept. Has any one out there have the following details a) Confirmation of plan form b) Span c) Chord d) Thickness Regards Erfolg

I think this is the model reviewed in the rival cover Model World & Q&EFI. If so the model was flown with a 8 cell NiCad, then subsequently with a 2s 2000mAh Lipo. The report claimed that the model flew much better on Lipo. Seemed to imply that a brushless motor would be useful addition. There was no mention of the speed controller. So I guess you bought the item seperatly. If so, what you bought will determine what you can use. Naff write up, but each to their own. Regards Erfolg

Thr free plans? play an important part in keeping traditional model construction going. In the past the number of free plans were generally far fewer throughout the year. The models often quite small. Even then I have some plans on paper like todays. Generally speaking I like the present arrangements. I have only built one. But the plans have influenced greatly my own designs. Regards Erfolg

I have just converted an old free flight design from a 480 nicad powered flop, into a Brushless, lipo powered, as yet to be determined. My present problem is that I ahve a number of J Perkins folding propellers, which I have used with 480 motors, these are 3.2 mm collets. They will not clamp a 3mm shaft. I have tried to obtain a suitable collet or propeller assembly (folder) in the UK, to-date with no sucess (I have a 3mm adapter for conventional prop). Does any one know a source, preferably a 40mm spinner. Regards Erfolg

Another thought, conventional wisdom (at present), the harder you push the Lipo, the greater the need to balance the cells. If cell failure is to be avoided (this could involve fire). Regards Erfolg

My assessment is that you drew approx. 15,10 & 8C in order, in your experiment. In your 10 & 8C test I do not know how long you ran your batteries or what cooling was available. In my own experience my batteries, have to date not even become warm, in a non ventilated fuselage. I normally run at 50% of C rating. I would guess the batteries are nearer a 10C rating than a 15C. From reading lots of correspondence and articles, I would guess if I am right, you will merely shorten the life, and see a faster reduction in the capacity of the battery. You are probably away from the zone where puffing or fire is an issue. I do not know the electro chemistry of Lipo batteries, but exothermic heat in this type of cycle, is normally associated with wasted energy, at worst the required chemistry has not been achieved, where the reversible process chemistry has been compromised. Regards Erfolg

I understand the problem. The results from drawing to high a current should be considered. Because in this case it matters, a lot. It will not necessarily be a easy to determine the capability of any Lipo battery by looking at it (other than the missing label). The history of Lipos does not give much of a clue. The development is very much targeted at the mass consumer market and not modellers (as is usual). Being used from applications such as Mobile Phones, Mobile Computers and Power Tools etc. Each sector of the market having differing characteristics, high amps per cell, high discharge rates, small volume etc. Our suppliers are just tapping into this market, not driving it (I will be suprised to be told otherwise, other than by a Brand PR representative). From the modellers point of view, the lowest C rating I have seen stated for model battery pack is 5. I would suggest caution, a ruined pack is not the worst scenario, there could be fire. Regards Erfolg

I think it is worth noting that I have seen modellers draw a current that is greater than the maximum C rating. The result (always) seems to be a bulging pack, and sometimes a total failure (no current at all). The "make" does not seem to matter, the biggest designer labels to the most obscure names. Always the same. Sad. The C rating is important, and staying below the maximum discharge seems to be the first commandment for Lipos. They do not seem to tolerate abuse like a Nicad etc. They are more akin to a Formula 1 car than a 4WD car. Used within their environment, nothing can touch them, not much good if used otherwise. I personally have had no trouble to date, but I am a little cautious Regards Erfolg

You can buy a pack of Ultra Deans (plug & socket) for $3.25 (K C Products) or approx £1.6 from the USA. If you keep your purchase below £18 you avoid the duty. That is quite a saving from the £9 for 3 I have been quoted in the UK. I understand that Maxpoly cells come with Deans connectors pre-soldered. Regards Erfolg

I personaly have no idea! There appears to be thousands of electric modellers, cars, boats and electrics from all over the world who seem to believe they are. How many have real experience I do not know, but I guess there is more than a bit of truth in their opinion. I only use gold connectors, because they have worked for me and are smallet than the Tamiya. Regards Erfolg

I am pleased to read that some modellers will give a chance to the smaller brands. I was recently reading about one of the Chinese retailers (seem to sell mainly to the USA) they were sourcing cells (from named) various respected manufactures and assembling the cells and packaging. There were some very good reports on the web about their life and apparent long term output and price. I think the UKs long term danger is from the over hyped products from the USA in particular. These organisations market well, have great PR and will ensure that the magazines get access to the products. Their goods are good but pricey (with the Reassuringly Expensive factor). I do fear for the small independent model shop who needs good margins to stay in business. But also needs to sell to get the profit. If they do not start selling the budget (but good products), purchasers may well shop even more via the Internet. All that will be left will be the big Mail Order model shops in the UK. Why do I think this may happen? Because it will be far harder to control battery, speed controller and motor market than it was for ic model motors etc. Regards Erfolg

What is happening to Lipo battery prices. When I look at UK adverts, they seem to have stopped going down. With the exception of one North of England Manufacturer. Yet when I look at sites from the Far East, prices appear to be still reducing. I understand that most of the Cells are manufactured in either China or Singapore (could be Korea). These are then shipped to other countries for assembly into the battery packs that we know. If this is so, then performance from the cells should be quite similar (within product range i.e. C rating). It has also been suggested to me that one well advertised supplier has stopped supplying the public direct, so as to be able to "add value" by distributing via the trade. Hype and reassuringly expensive prices, are thought enough to consolidate the packs as market leaders. If all or any of these things are true, is this "Rip of Britain" at its best. Will we be encouraged to buy abroad? Competitive prices are good for British model shops. Inflated price structures result in USA type situations, where many modellers buy from abroad (although importing into the USA is not as punitively taxed as the UK, so I am lead to believe). I am aware of a small number of Internet Retailers, who serve us modellers well (one in the North East the other in the London area, there could well be others). What do you think

The only bit not delt with is Freie Welle which I think is a a 10mm diameter spigot I was thrown by the shaft diameter, I expected a Durchmesser and a Schaft or Spindel. It only goes to show, that you need to learn yet another new language when things are of a techniacal nature. Some of the information is generally only useful if you have a software package which matches motor details to propeller sizes etc. I am sure that Alistair's help will have useful and hope that my own has not confused you. Best luck, modern electric packeges normall work very well and are not as difficult to master as the jargon suggests Regards

I bought the July issue because it had a Free Electric Plan. The model works for me. Seems that with a little reworking, it would make a passable RBF? Fanjet. That is with a higher aspect ratio wing, T tail. It could have Iron Crosses or a civilian livery. I also get very bored by the constant carping by the IC Ludites. I also agree with the point that with scale electric models, there is no cylinder head or exhaust hanging out in the breeze. I understand John Emms wish to defend the originality and quality of the ESCs he markets. I just think it is a pity that it is not acknowledged that quite a few of the Far Eastern products are also of good to high quality. Yes there are some poor quality products. I do believe that more than a few big names source from these areas. The likes of Robotbirds and BRC Models do us a favour by importing these Far Eastern products. I am very pleased at the performance and quality of these Far Eastern products (motors, ESC, servos). As for being inferior copies, as a Professional Engineer I spent my whole career copying and trying to improve other peoples ideas and concepts (Dyson did not invent the Cyclone, he only used it for domestic cleaning). I would suggest that the capable Czechs etc are standing on the shoulders of giants from Joule, Ohm, Newton. Who designed the IC the heart of most of devices, produced example circuit diagrams, the CAD auto router and circuit layout software. As you can guess it annoys me when manufactures and agents overstate the Intellectual Property issue. A very Annoyed Erfolg

Keith Alistair’s statement about making sure that the battery can deliver 20 amps may need extra information if you are new to electrics. Lipo batteries are generally specified in mill amps, that is amps to the power of 10-3 or 1/103 (however you like to write these things). Therefore if you see a battery classed as 2000mA, it can also be described as 2A. If the battery is classed as 10c, this is meant to tell you that you can discharge the battery up to *10 the stated ampage. Therefore our 10c, 2A, battery can be discharged up to 20A. If it were 20c, then the sum becomes 2*20=40A. Easy is it not. In the case of NiCads, people seem to abuse them with little problem. It is worth noting that the general common consensus at the moment, suggests that the harder you push your Lipos, the greater is the need to get the cells balanced during the charging process. I personally always use a balancer when charging, and they are cheap, approx £15. The problem with batteries, there are more myths and stories surrounding them, than the combined tales of Aesop and the Brothers Grimm. Some have a bit of truth, but suitably embellished to act as a warning and to sell more of the RIGHT Products. Regards Erfolg

Alistair I may be briefly tempted, by the outstanding performance (speed), but not for long. My abilities do not run to it. What has impressed me, for a recently returned modeller, is convenience and practicality. I originally flew glow powered models, but there were restrictions to when you could fly (at the local club). In addition there was a truck load of equipment to take to the flight line. When you finally got there, you had to queue to fly. When the club started with the BMFA certificates to be allowed to fly, I had enough (and this was before New Labour). I started gliding instead, BARCS league etc. No need for all the junk, fly when you wanted (when I could find a couple of hours). The downside was that most flights were about 4 minutes, with some flights of 20 minutes or more. My attempts at electric flights were diabolical. Now 15 years later, 20 minutes is achievable (with electrics) with no effort (perhaps not quite as challenging). I do not even need a bungee. I have just built a FW152H with 42 inch span, to try a different aspect of flying. Modern electrics’ are so convenient, quite and low cost. I have a 32 inch Gee Bee R2 under construction, planning to build either a Heinkel 219 (twins are so practical as electrics) or a Heinkel 162 as a ducted fan. I have become an evangelist (for electric), and become even more boring. Everything is now possible, as long as the control freaks do not find out, unregulated fun. Regards Erfolg

Alistair I have used an APC set up,with no problem. The only issue seems to be that their replacement blades, do not seem to be widely stocked as Graupner etc. Strangly I have not broken a blade on landing etc (must be due for some then). My main reason for changing blades is to get a better match to motor or improve climb etc. I have a number of NiCads, but find them heavy for their storage and discharge capacities. The price of LiPo's has fallen considerably and discharge C rating gone the other way. I have found that LiPo's & Brushless (standard or outrunners) transform aircraft, like a magic wand. From staggering about to going like the wind. Regards Erfolg

A watt meter is indispensable. Without one you have no idea, if you are under or over propped to your motor, or what is happening to the battery. I have found quite a large variation from one propeller to another of similar size. With regard to the speed controller (I use primarily Robotbird budget models or Tornado (Overlander)), the timing option seems to have no effect on either the out runners or standard motors. With the speed controllers I use if you set the speed controller incorrectly, the motor does nothing, other than beep to tell you. My other main thought is make sure your propeller is strong enough, Graupner, Aeronaut and Overlander seem OK. I have used some budget set-ups from a UK Distributor and these have shed blades on two separate occasions. The damage to the planes was appreciable. Therefore keep well clear of the propeller with Brushless motors, +200 watts is quite a lot of power. Regards Erfolg

I am down to my last peice of extruded polystyrene foam (brown in colour). Where do modellers buy their mythical blue foam from? Regards Erfolg

I am unable to put downthrust in the motors easily (Major surgery). I have re-flown the models, one now has 5% down and the other 10%. These changes have made a tremendous difference. I will stick with them for the moment. I am thankful that I resisted the advice that full down may be necessary. I would certainly have been rebuilding. Thanks for the contributions, they have all been helpful. Regards Erfolg

I have tried the lower powered Sagitta with 15% down mixed with throttle. The model did not climb at all, needed up feed in to gain altitude. I will try 7 or *8%, I am hoping that these values will give a better climb out. I am now starting to think that very little down is really required probably 3 to 4% to obtain a authorities climb, at about 45% to the horizon. What is the most efficient angle? I have attached some pictures, so you have some idea about what I am talking about Regards Erfolg

I fly electric gliders, 2 off “Sagittas” (2m or 600) and 1 “Toll Heidi” (48 inch). They all have their motors aligned with the tailplane, essentially along the axis of the fuselage. In the case of the two Sagittas this is probably in the region of + 3 degrees to the underside of the wing, or +5 degrees from leading edge to trailing edge (Eppler 205), the Heidi is approx +2 degrees to under side of wing ( MH 32). All suffer from severe pitch up on powering up at launch and whilst flying . The Sagittas have a max power of approx +160 watts (3 lbs) and the Heidi of 130 watts (weight 1.5 lbs). I normally attempt to control this by use of down elevator, in the case of the Heidi it just goes up vertically under full power and is therefore not to much a problem. They all seem to have a narrow margin between climbing very steeply to going into a power dive with very sensitive controls. I am starting to experiment by mixing the throttle with down elevator. At present I have used 20% down. It is not clear to me if this is linear mixing i.e. 0 throttle 0 elevator. 50% throttle, 10% down, 100% throttle 20% down. Or is it a step change relationship i.e. 1% throttle 20% down. For me it is not as obvious as I would like, by visually observing the results., The transmitter is a Futaba 6 EXA. Any comments from personnel experience will be appreciated Regards Erfolg

Martin Last night I ran the motor on a 9*6 folder, Tornado hub/spinner with Graupner CAM blades (as those were blades I had), after receiving my 1500 3s1p Tornado Li-po (eventually). The combination indicated 16 amps at full throttle. Well done a very close estimate. Many Thanks Erfolg Th