Erfolg

I agree with Timbo (you just have to), the controller needs to be at least the same rating as the motor max. As Timbo has said a (safety) margin is very desirable. I have seen the motors cut out (by the protection curcuit) where this general rule has not been followed, there has often been a lot of sratching of heads until the cause has been identified. Unlike Timbo, my controllers are budget, using Robot birds "Budget" 3 off various ampages, "Pro-25", E-Sky and Tornado (overlander). For powered gliders, sport and scale these are fine. For 3D there lack of throttle sensativity (for hovering) etc. would be noticable. Tornado has one draw back, it really needs the Lipo to be fully charged each time you connect the battery, as it works out what has been connected. Although you have not asked, I have now observed a large number of motors from budget to expensive. In my opinion they all seem to work well, as long as you do not push them to hard, expensive motors seem to be more tolerant (a more conservative rating perhaps). I have seen all types ruined by pushing realy hard, cooling realy becomes necessary under these circumstances. I use Tornado, HET, E-Max, Xtra, to date all work fine. Erfolg 

I am seeking advice on the amount of exponential that people would use on a :a) 120 inch powered gliderb) On the elevatorc) on the rudderI am asking this question as I have recently flown my old open class glider on electric power. The brief flight of approx. 100 foot altitude, 1-3 minute flight. Was notable due to the sensitivity to elevator in particular. The flight should not have happened as I broke the end point attachment from the fuselage. This allowed considerable movement of the end of the outer cable with la loss of repeatability etc. The flight had originally been intended to be a 100 -200 foot powered glide. I got things wrong ended up doing a circuit. I do know it should not have happened.However the elevator was extremely sensitive. I wonder what amount of exponential others typically use and why.I am using a Futaba 6EXAP. SShould be set to a negative value?RegardsErfolg  

I am curious, is there such a thing as "active/acid" cored solder. If there is, who is the target group?  It just seems an atractive proposition to me. From time to time an active solder would be useful, soldering steel, tin plate. I have used Frys flux, but you need to clean realy well, be quick with the flux ( to prevent oxidation) and if you put to much heat into the peices the flux burns, runs (less effective) etc. Yet liquid active flux is a bind to store, when you use it a little as I do. With interest Erfolg 

Steve Think about the warren girder and the shear web, and think parallel axis Regards Erfolg

The only additional comment, that may be of any significance, is with regard to batteries.I have noted (after being told by others), when the batteries loose capacity, flight times reduce. Until a fresh set of batteries are used (NiCads have to low a voltage to fully charge.I have a broken fin on my boom, it does not seem to effect trim. Either there are subtle variations between identical models, or I am to insensitive to notice.Regards  Erfolg

Apolaogies for numerical conversion error. Will go to the back of the class. I agree with the view "Does it matter" In the past when competion flying, there were at least to ways of viewing the issue. a) Bent joiners, "could" be a safeguard against a structural failure of the wing. b) Bending wires, could well be limiting the tension/velocity on the tow, reducing the maximum height it was possible to gain. For competion flyers failures are generally accepted (with a sigh), as the limits are generally sought. Most recreational flyers, see things differently. As is with most things in modelling, I used to use as much common sence as possible (try at least), use the enginnering information to reverse the calculation to establish probable loads/stresses. For big gliders, piano wire did not cut the mustard. Tried stacking them ala "Parallel axis theorem", still not as good as flat bar. Erfolg

When I was a lad, there was not much time torqeing, we had job to do, widgets to make, woodruffs to quay. Talk about servos, only had Linwood, Waltron, SLM and other equally impressive stuff. We flew Spitfires out of the sun at the beastly Hun, our puny servos never failed us. Never worried about stalled motors, blown back controls. Our models hewn from the fabled Orange Box, nails removed of course. Used to regularly strip our famously expensive servos, to re-solder motor and the pot (some indulged I have heard said, for me it were six pints out of my dirty pot)to reverse the beasts. I do not think anyone has actually measured the loads on the various types of models, particularly at the extremes of their flight envelopes. But I would guess that the servos most of used in the dark dim distant past, were less than 2.5Kg/cm, essentially there was no choice. With the present vast choice and lack of info, commonsense and an assessment of duty and wallet must be undertaken. But it does surprise me what was flown on light duty? equipment in the past. Erfolg

Malcolm I also us straight bar (in brass extruded/drawn rectangular tube). Since this debate and few others have run, I have started to wonder what is it made of and how (did not even think before). It seems very unlikely that it is made specifically for us. So what is it? How is it made? For whom? Some one out there will know, dont you, so please tell Erfolg

Take a look at peterstubs.com/silver.htm it gives all the information that most modellers let alone engineers may require, regarding the performance and characteristics of silver steel. I was thinking about the suggestion about the suitability of silver steel for wing dowels. The first thing of note is the material is normally supplied annealed (stubs has a note to why). I then thought of the value for Youngs Modulus (E) pretty standard for steel 205 GN/mm^2 about 200GN/mm^2 for Piano wire (I feel some one will challenge this) The yield is probably the problem Piano Wire is Circa 2000MPa Wire strands 1650MPa Steel high tensile 690MPa Steel Structural 250MPa The value that is quoted by stubs is 35-50tons/inch^2 which converts to 323 Mpa. Their quoted UTS before heat treatment is up to 60tons/inch^2. The problem is that both Piano wire and Wire strands have very directional properties (anistropic)and the testing will have been a tensile test. I still suspect that the silver steel will take a permanent set well before the Piano wire. How much sooner I cannot tell. Perhaps someone else can? As for heat treatment, with home equipment, best not tried for truly controlled results. Whilst looking at various materials, it was quite apparent that for most materials available to modellers that there is no better substitute for depth in a wing joiner. What shape it should be, is open to a little debate. Erfolg

I no, it is unbelievable, but it might be true. Its not a Russian either! I was talking to a Swedish friend, emigrated to escape Socialism (early 80s I think). He told me that there was an exhibit at the Oslo Museum (Norway)of the turbine built by Jens Ellig at about 1900. Apparently getting a patent and proposing the unit for aircraft (difficult I know, when the first flyer has not yet left the ground). I have also been told that a clergy man called John Barber, obtained a patent in Britain for a Gas Turbine in the 18th century. I know from working in a company that at that time made jet engines that the Brayton cycle was devised by an American at the turn of the 19th century. At least some of this is true. I am left wondering what he actually did first. Or is he the inventor of the jet in the same way that Dyson invented the cyclone? Controversially Erfolg

Congratulations, I like to hear about success. Will be glad to be able to access more adverts. Could you have an engine that could assemble similar products for the user. An example would be my recent search for an Allen key, by typing in Allen key, your advertisers selling Allen keys could be assembled on a page. I know its only an idea, if its any good, some one will have done it, or the software product will soon be on the market. Wishing you continued success Erfolg

Hi Thanks for the information, I tried the Perkins site, retrieved the info, then did a search on the local Model shops ( within 10 miles) web sites, not one was showing the Perkins Allen key set, a local model shop had a set 1-6 mm I think at £14. Seemed a lot for what I want. Have a good selection of the rest it appears. The Modelfixing web site gave me an idea. What about Engineers Tools Suppliers. I found one at 1.1 miles from my house, yes they stock a selection. I bought a long reach ball ended 2mmm for 70p, a standard 2mm for 30p, for a grand total of £1, I had found my personal heaven. Must not put in safe place. Regards Erfolg

Returning To adverts I buy magazines not only for the journalistic content, but for the the adverts. It is a way of finding a) Whats is for sale b) Who is selling what c) at what price I have no problem with adverts on the site, except 1) Flashing adverts can be distracting (I realise that this is the equivalent of the full page centre spread). 2) Would like to see more general advertising rather than concentrating on specific product promotion, as seems to be the case at present. I do think that advertisment placement on the web site should be seen as symbiotic (if that is how it is spelt). But some greater thought needs to go into effective delivery of the advertisers message/messages. Perhaps the site owners can arrange to receive a payment form every sale via the site links (I know they are not there at present). Perhaps the site could be seen as a magazine in its own right, where articles are similar to the paper product, with greater interaction of the viewers ie Forum and more effective for the advertisers/sales. Regards Erfolg

Ask my wife to pick up my usual magazine. What does she return with? A rest is as good as a change she said. Wouldn’t go to Skegness above 10 times for your hols would you, she advised. The look said it all. If you dare complain, there will be no next time. Forbidden fruit should taste sweet, but I am not sure that lemons are my thing. Regards Erfolg PS, No free plan either, can’t complain about the paper then, is that a plus?

Ripped of I agree, thats the answer By whom, is realy the question? Erfolg

We both agree that the material has a pearlitic structure. The full text provides details of the effects of temperatiure on the lamella and cementite. But the following is the most pertinent to experience of high tensile hyperutectoid wire as used in armouring, where annealing due to jointing had effected the cable performance The mechanical properties of the steel wires increased with increase of annealing temperature, and the increase was more significant with higher drawing strain. Also, as annealing temperature increased, the hardness and tensile strength gradually increased up to 200C and then dramatically decreased at above temperature. However, bending fatigue limit, including fatigue life, showed the some different phenomena with increase of annealing temperature. These different behaviors depending on annealing temperature were discussed in terms of microstructural parameter changes such as pearlite morphology, rearrangement and coalescence of the dislocations. The annealing temperatures were from 200-450C We both seem to have had different experience with similar products. Mine hyperutectoid cold drawn with silicon. Yours I guess is based on Piano wire and silver steel. Regards Erfolg

I have put the allen key that I use for my Aeronauht folding propeller in a safe place to prevent loss. I cannot find it know! I am asking for advice to where very small Allen keys can be purchased. They are not normally included in most sets of keys purchased from Halfords. My local model shop when open (now ceased trading) did not stock them. Any ideas Regards Erfolg

Having become a traitor and bought a rival magazine (I promise not to sin again, it is not that good anyway). I was thinking what do the rivals have to offer, not a lot it would seem. Low and behold there was a picture of our Alex, complete with camera, trussed up like some type of deviant in plastic bags and PVC (heading said it was raining, really). Does RCM&E not have a copyright on his image, I trust that a protest to the Press Complaints Council will made for the gross harassment. A Concerned Erfolg

I was sitting at the dining room table, thinking about mass concrete and concrete pumps. When it suddenly dawned on me, it was agreed that no building work at weekends, so my wife had said and it is Sunday. I then drifted into my world of soaring gliders, and the trouble I had at the flying field when my canopy had come of. Fortunately this time it was not followed by the Lipo (velcro'd in). If only I had one of those 2.4Ghz radios I thought, the model would land itself, totally immune from any electron pulse from any weapon that the Russians or maybe the USA may drop. I then drifted even further back in time. Did we not have a 2.4GHz set in the 70s and if so what happened to it. Does any one else remember with greater clarity than me? Regards Erfolg

From my expeierence that is what they do. Every one I have seen needs immediate trimming on start up after a charge, a slight adjustments during flight. All seem to benefit from nose weight, so that you go somewhere. I used the sticky nose weight supplied, others Blue Tack. Grand daughter (2yrs) was awe struck. Just managed to save it from a King Kong moment. Regards Erfolg

I think this is possibly a time to assemble what we generally can say we know. Wave bath solder as used today in lead free soldering has a melting point of between 220-227C dependant on Silver content, less silver, higher the temperature, (extract ANSI/J-STD-006,). Traditional Lead tin alloys have a Eutectic temperature of 183C, this is a minimum (Phase Diagram, Engineers Hand book, rev 13) . Solders used for electrical work traditionally have more tin and a little silver to reduce both leeching from electrical components, reduce the melting point and give better wetting characteristics to about 180C. This is the 62% tin,36 lead and 2% silver (EABS, on line library). Although many cored solders were actually, 60%, tin 40% lead with a melting point of 191C. Tempering is normally defined as a process which starts at 230C to 500C. The beginning of the range considered to be light straw 230C. The effects are, time temperature and mass dependant ( as well as Prior Heat treatment etc.) ( "Foundations of Materials Science and Engineering", 4th ed., McGraw-Hill & Ward French). Adiabatic (fancy word for complete combustion) temperature of gas air torch is quoted as 1995C, the true max is possibly 1500C (GAZ). Soldering irons particularly the temperature controlled usually start at about 250C the max is 400C. Lead-based solder uses 250°C to 280°C or 300°C while lead-free soldering needs a higher temperature, about 350°C to 400°C. (catalogue Antex) As can be seen it is entirely possible to affect the structure of the steel by use of a propane torch, or a high Wattage iron (30-100w) as the difference between the melting point of solder and beginning to heat treat can be as low as 230-227 = 3C or 230-183 = 47C (temp of a typical CH radiator). In the real world, we are potentially in the same ball park. The important issue for me if deciding if I want to solder is: a)Does it matter, if the properties of the wire change?. Where stress or forces could be high, possibly yes. Washers holding on wheels probably not. b)Do I have to solder or is there a viable alternative? In my youth I have seen crimped joints that seemed to work. Maybe an increase wire size to avoid re-enforcing braces etc. Maybe increase the wire size to compensate for any reductions in strength. c)If I have to solder, can I control the temperatures: 1)Use a low melting point solder 2)Minimise heat input, using a big tipped, high wattage soldering iron (to minimise soaking effects). 3)Avoid the use of a propane torch ( to difficult to control heat at the joint). I have purposely avoided talking about austenite phase, pearlite, or the detailed composition of Piano wire, silver steel etc. As I do not think it would add anything. I am now quite bored with it all, so I am going back to building. Whats that I hear? a cry of good. Regards Erfolg

A truly interesting blog. Learnt something about ammonia, and bending. Obviously an accurate buider, spirt levels etc. Keep it up Erfolg

Yes, we all have a wish list. Why do we not do something about it? I have bought kits of the a) Gee Bee Model D, by Coverite, just had to have it b) PT 19, by Stirling, so good looking c) MonoCoupe, by SN, Ahh shear delight d) Thunderbolt, by Guillows, perfect for an electric conversion. In addition to a number of kits bought on a whim (wife always says where are you going to store that one). The irony is I do build, but not these prized kits. It is mostly own designs. As to extravagant planes, always wanted 1) Douglas X3 2) Bell X1 3) Miles M52 4) Leduc 5) Heston Racer 6) Bf 209R and the list goes on and on and on an............... What does get in the way? Now back to Solar filming Regards Erfolg

I seem to remember that there is a limit on the value of gifts which you can receive before duty is paid. My family used to get parcels sent to the UK from other family members on the continent. These were opened on a regular basis, and with held until duty was paid (mother seldom bothered, value was to low). HM Customs are pushing to get duty levied at UK market values, not the country of origin, according to a money web site I recently visited. Seems the EU feels this flies in the face of removing protectionism and free trade. If true thank God for the EU. Regards Erfolg

Given that the Website needs adverts to pay for itself. Perhaps the site may consider (selling links to the advertiser, on a hit basis) via an advert button. I do not know how other users purchase goods, personally I use the inter-net a lot (since my local model shop closed). Just taking my anti-epilepsy tablets now (oooooh the flashing light) Regards Erfolg