Phil 9 Posted April 28, 2018 Share Posted April 28, 2018 the 50v level is guidance (a line in the sand) for electrical installations in buildings. 12s can be just as dangerous as 14s as it is current that harms the body and not voltage. you do not need to be a qualified electrician to put together a 14s model. Quote Link to comment Share on other sites More sharing options...
Trevor Posted April 28, 2018 Share Posted April 28, 2018 If building from scratch, then specifying an electric setup to power-match the specified i.c. engine may not always be the best way to start. A 100cc engine is a pretty brutal beast and the airframe has to be built to withstand the stresses and vibrations that go with that. An electric model of the same size can generally be built much lighter. You then have the choice as to whether you go for a lighter AUW and use a lighter, lower power electric setup or simply trade the structural weight saving for more battery capacity and duration and aim for the same AUW as the i.c. original. That said, I do agree that the cost of the electric approach does seem to increase very steeply once you get to these power levels - at least it does for single engined aircraft. It’s no coincidence that most of the really big electric jobs are multis! Trevor Edit: sorry, I obviously took too long typing this so most of my points have already been made! Edited By Trevor on 28/04/2018 20:10:06 Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted April 28, 2018 Share Posted April 28, 2018 Posted by Tom Sharp 2 on 28/04/2018 19:29:46: My washing machine motor will run on 110v to 240v and is no bigger than some of the motors used in the big models. So that could be a cheap source of a motor. That will be a synchronous motor designed to run on AC, it wouldn't run on a standard brushless motor ESC so you'd have to build your own variable frequency drive for it, doable but then it wouldn't look so cheap. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted April 28, 2018 Share Posted April 28, 2018 Posted by Phil 9 on 28/04/2018 19:58:47: the 50v level is guidance (a line in the sand) for electrical installations in buildings. 12s can be just as dangerous as 14s as it is current that harms the body and not voltage. you do not need to be a qualified electrician to put together a 14s model. Indeed, as the old saying goes "It's the volts that jolts but it's the mils that kills." In my teens (1950s) I used to suffer 7kv shocks almost daily at one time when I was testing TV line output transformers without harm other than the scratches I suffered from the aluminium TV chassis as pulled my hand away. The H&S Executive would have kittens if they saw the common practices even in the manufacturers service dept. where I worked back then. Geoff Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted April 29, 2018 Share Posted April 29, 2018 A car battery is capable of delivering 400+ Amps but but you can't feel a thing touching the positive terminal. A static charge can run to 10.000+ Volts. It may jolt but does not kill. Touch a 10.000 V power line when standing on the ground and you will fry, literally. The difference is? Quote Link to comment Share on other sites More sharing options...
Rich too Posted April 29, 2018 Share Posted April 29, 2018 Adrian, have you checked the FG forum? Edit - I just noticed you posted the ques5ion there too! Edited By Rich too on 29/04/2018 05:46:18 Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted April 29, 2018 Author Share Posted April 29, 2018 Hi Rich. Yes thank I pick up the posts there too. I just phrased the question slightly differently for the FG audience. I know in the US they have some really big stuff and I am just curious what comes back. How is your 100cc Sbach coming along? I know you said it was going to be slow going. I recently converted a GoldWing Sbach 60cc to electric this spring. I thought about doing the build on this forum, but I wasn't convinced of the interest given I had covered a similar technique with my Corvus 60cc a while ago. Anyway it would be good to hear your progress. Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted April 29, 2018 Author Share Posted April 29, 2018 Tell me Simon, as I am not too clever! Quote Link to comment Share on other sites More sharing options...
Rich too Posted April 29, 2018 Share Posted April 29, 2018 Hi Adrian, you should post your work if you want to, it is always interesting to read what others are doing - and sometimes I read the threads without commenting. I also find posting builds on here gives me more motivation to get the job done! I am plodding along on the Sbach and will update my thread soon. Other commitments have slowed things down, and I am being held up waiting for more stock of these http://www.xtremepowersystems.net/products.php?cat=8 - they are expected in stock by the end of the month. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted April 29, 2018 Share Posted April 29, 2018 Posted by Simon Chaddock on 29/04/2018 00:13:26: A car battery is capable of delivering 400+ Amps but but you can't feel a thing touching the positive terminal. If you have open cuts on your hands and then happen to earth yourself out from the +ve terminal, you'll get one hell of a packet from a car battery (reduced skin resistance)...............been there & got the tee shirt Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted April 29, 2018 Author Share Posted April 29, 2018 Rich. I have the photos of the build and electrics so I may well get on with loading it all up here soon. Nice bit of kit you are waiting for. Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted April 29, 2018 Share Posted April 29, 2018 Adrian if your 60cc conversion is successful and you are not planning on competition will a 100cc conversion offer you anything more in terms of enjoyment or performance that will justify the price tag and difficulties? Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted April 29, 2018 Author Share Posted April 29, 2018 Phil. There is more than grain of common sense there. You know how it is with the weather confining us the work shop, then thoughts turn to the "next big thing". I suspect if it had been flying weather I would have been out and about alot and these thoughts would be confined the background. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 29, 2018 Share Posted April 29, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted April 29, 2018 Share Posted April 29, 2018 Just as an aside; It's not the power available from a large electric set-up that's the problem, as far as I can see. It's the field-charging (that calls for massive leisure batteries or a generator), or the option of carrying a large stock of costly li-pos with you to the field. I do have a couple of 10-cell models, but rarely fly them because of the charging issues. I'm happy at the 5S watershed, it seems..... Tim Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 30, 2018 Share Posted April 30, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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