Alvin Espley Posted July 8, 2009 Share Posted July 8, 2009 Hi all... can anyone help, i have just finished building a depron eurofighter typhoon and need a little avice on fitting out the the electrics,The model will be a pusher prop rather than a ducted fan, and due to the fact that the motor is at the back but the receiver and battery is at the front the problem is how do i connect the esc to the receiver and motor ,the motor wires are only a few inches long as are the esc wires so some how i need to extend them , now is it better to extend the motor wires and have them running the length of the plane to the front or would it be better to just join the motor and esc at the back and extend the receiver and battery leads to the front? I will be flying on 35 meg so i am trying to avoid radio noise and the dredded glitches, it is also worth a mention that the rudder and elervon servos are also at the back so there wires will need to run the length of the fus. Any help will be greatly received..... PS, LMA cosford soon (cant wait) please can we have some more sun.Edited By Timbo - Moderator on 09/07/2009 00:15:48 Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 9, 2009 Share Posted July 9, 2009 Usual advice is to extend the motor wires NOT the battery cables. probaly best to fit the receiver away from the motor and ESC if possible, and a ferrite ring or two on the servo and ESC throttle leads just as they enter the receiver ports may help to prevent glitching. Edited By Timbo - Moderator on 09/07/2009 00:19:39 Quote Link to comment Share on other sites More sharing options...
Peter 'Ivanna Crashalot' Savage Posted July 9, 2009 Share Posted July 9, 2009 My dad had an f15 in depron and we just extended the battery wires, i think at that point we still used 35mhz and to my knowledge we didn't get any interference Could you use an Iron nail as a ferrite ring? I am gonna be going to the LMA cosford thing aswell! should be interesting, never been to an LMA show before! Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted July 9, 2009 Share Posted July 9, 2009 I would use an extension on the connection to the RX if you have room to mount the ESC close to the motor. Use 2 frettie rings one at the ESC end an one at the RX end. Quote Link to comment Share on other sites More sharing options...
Dave Towell Posted July 9, 2009 Share Posted July 9, 2009 All sound ideas. I love depron models at the moment (have 7 on the go). Here are a couple of other ideas:- Wrap your Rx in foil Put ferite rings or clips over the servo leads Have used all of these methods on the same elecy model while i was on 35meg and it work well, but since i swaped to 2.4 I've had had no probs. Quote Link to comment Share on other sites More sharing options...
Alvin Espley Posted July 9, 2009 Author Share Posted July 9, 2009 thanks guys, it sounds like extending the motor wires is probably the best and having the esc as far back as possible. Also i have herd someone say about wrapping the rx in foil before , does that really work ? Also please forgive my ignorance but what is a ferrite ring ? iv never come across that before, the problem is most of my flying is done out of my back garden with a mate and we are a bit in the dark about souch things, Peter the lma cosford show is one of the best model air show around with loads of trade stands and some of the best pilots in the uk ,you will have a great day ,just take loads of cash as there are some really good bargins to be had. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 9, 2009 Share Posted July 9, 2009 Wrapping the Rx in foil is only AFAIK effective against microwave frequencies,,, but it shouldnt hurt to do it. ferrite ring = HERE is one place Maplins etc should have em. Quote Link to comment Share on other sites More sharing options...
Alvin Espley Posted July 9, 2009 Author Share Posted July 9, 2009 thanks Timbo.. thats really helpful, i will get some this wk end, thanks for the pics aswell . What is the idea with ferrite rings , do they cut down radio noise within the model or do they help boost the servo signal? as i have never herd of them before. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 9, 2009 Share Posted July 9, 2009 Simplistically...they stop long leads like extended servo leads etc becoming aerials. They have no effect on the signal itself - they certainly do not boost it unfortunately! Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted July 9, 2009 Share Posted July 9, 2009 If I may add my two pennies worth. Timbo is correct, the enemy is common mode currents (flowing down cables in phase). Wanted currents are differential currents (down one cable and up the other). Ferrite chokes/rings are used to increase impedance and in doing so reduce the common mode currents. Use as many turns as you can. By stacking the rings you can reduce the number of turns, but ideally keep as many turns as possible, as you will need a large diameter ring to reach the optimum number of turns. Wrapping foil round your receiver is not effective. Far better where cables runs are close together is to separate out the 0 volt lines, wrap them all together in foil with a length of bare copper wire (strap wire) inside the foil and connected to true 0 volt. This can be used instead of the ferrite rings. This creates a low impedance path for the common mode currents. Use whatever method works. It is also possible to bypass or decouple to provide a low impedance path by using a ferrite bead/beads on the cable and a ceramic (1-10nf) capacitor to 0volts. Peter, a ferrite ring is manganese/zinc or nickel/zinc it is not iron. There are different ferrite mixes for different frequencies. A rusty nail could produce unexpected results. Quote Link to comment Share on other sites More sharing options...
Alvin Espley Posted July 9, 2009 Author Share Posted July 9, 2009 i think the ferrite ring sounds most strait forward , also it sounds like a good way of keeping all the wires nice and neat, i might try that on all my models as i do get the odd glitch now and again, Also i may make the jump to 2.4 soon, as i understand it is far more glitch resistant... Quote Link to comment Share on other sites More sharing options...
Grant Wright - Mr Foamyjets Posted July 11, 2009 Share Posted July 11, 2009 Guys, i would suggest extending the battery wires, i have for all my models and continue to do so. I believe there is a possibilty of getting a large spike when conencting your battery when battery wires are extended but this has never occured with me, where i have proven that extending the motor to esc wires does effect the timing of the motor quite dramtically. in the model i am presently building below, the esc to battery wires are 1m long for each fan, just my opinoin for whats its worth Grant Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted July 12, 2009 Share Posted July 12, 2009 Grant, Out of interest and I suspect of interest to others. What is the setup, are you operating near the limits of the ESC? What was the original length of the cables and have you increased the gauge of the cables to the same degree? Sparking on connecting is caused by the current rush/serge. Spikes are caused by the switching within the ESC and are smoothed by the input capacitors. Increasing cable length can often impose additional loading on these capacitors. Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted July 12, 2009 Share Posted July 12, 2009 Grant, Just found your Airbus A380 build thread. Quote Link to comment Share on other sites More sharing options...
Dave Towell Posted July 12, 2009 Share Posted July 12, 2009 could you put the link in please. am thinking of getting one. Quote Link to comment Share on other sites More sharing options...
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