iqon Posted July 12, 2014 Share Posted July 12, 2014 I am currently building a pattern type plane that will weigh around 5kg and will be powered by 8 cell lipo batteries. Should i be considering using a separate power supply for rx, thanks is there a limit where it should be separate or is it just personal preference ? Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted July 13, 2014 Share Posted July 13, 2014 Iqon - you should be using a separate Rx power source when using an 8 cell lipo setup. For a start, you will not lose your Rx and servos if for any reason the flight pack malfunctions and that is a major safety issue. Secondly, you can connect up your Rx and do all your pre-flight checks without having the aircraft live as it would be if using a BEC facility. The other thing is that many ESCs at this level will be opto-isolated and won't provide you with a BEC facility anyway. Most aerobatic aircraft are fitted with a 2 cell lipo (usually between 800 mah to 1,000 mah capacity) and a combines switch/voltage regulator to drive 5 digital servos. I get 5 flights before there is only 40% remaining in the lipo and I then change to my second lipo. I have used a twin power switch and 2 lipos but I've gone back to a single power source now. However, I have seen a single lipo misbehave resulting in the loss of a top rate aerobatic model so, if weight is not an issue then the 2 lipo solution provides even more security. Quote Link to comment Share on other sites More sharing options...
iqon Posted July 13, 2014 Author Share Posted July 13, 2014 Peter is there any that you would recommend or avoid, Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted July 13, 2014 Share Posted July 13, 2014 Iqon, Powerbox and Emcotec are the two that I know of and both have a good reputation and are widely used in the F3A (aerobatics) world. I just use Hobby King Turnigy 2S lipos and have never (so far) had a problem with either the 800 mah or 1,000 mah batteries. Quote Link to comment Share on other sites More sharing options...
iqon Posted July 13, 2014 Author Share Posted July 13, 2014 Thanks Peter, It was the ESC I was asking about.......sorry if i confused you...Having started to look at ESC`s it seams there is a lot to chose from but when you read they are mainly for 2 - 6 cell or 2 - 7 cell and not that many that will take 8..... Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted July 13, 2014 Share Posted July 13, 2014 Iqon There are a fair few that do this. If you look at this thread, you'll find some recommendations in the 110/120 size that cover three: Hacker, Jeti and Turnigy - scroll about half way down the page to get to that post. There is also Castle Creations that provide such ESCs. These ESCs will go up to 12S lipos. The thread I referred you to has a lot of information on trimming and flying aerobatic manoeuvres which, if you have not already found it, which you may find useful. The thing to remember about ESCs is that the ones that serve the specialist precision aerobatic pilots (F3A class) provide useful things like prop braking that can be adjusted. This is not a brake on or off situation but rather a means of providing prop braking, like an ic engine, when flying a vertical downline. The Jeti is very easy to set up and is used by over 90% of F3A pilots for this reason. Edited By Peter Jenkins on 13/07/2014 12:48:09 Quote Link to comment Share on other sites More sharing options...
iqon Posted July 13, 2014 Author Share Posted July 13, 2014 Thanks, i`ll have a read, Quote Link to comment Share on other sites More sharing options...
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