Former Member Posted April 1, 2008 Share Posted April 1, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 1, 2008 Author Share Posted April 1, 2008 Yeh..I get the same message too - ever since they changed their name from U hobbies to Hobby city. I just ignore it, click continue and go shopping In the interest of fairness, dont forget our home grown peeps like BRC and flying wings.co etc.....also giantcod do some really keen prices on a small range of similar gear !! Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 1, 2008 Share Posted April 1, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 1, 2008 Author Share Posted April 1, 2008 Well, It might work. As mentioned, the 2 cells concerned would be giving more. The fact that the 2 cells in series would be supplying 3A does not mean they would be sharing the current though, only the volts - therefore the drain would be larger. The point about the 2 cells possibly dropping below a safe level and the ESC not necessarily seeing that, is what would bother me more. The "inflight balancers" ( such as the graupner DPM and Kokam version also ) monitor each cell individually, and upon seeing any abnormality in levels will shut down / stutter the motor. This I fear, would be happening all too soon and frequently with your scenario.I think on balance ( dreadful pun intended ) I would stick to using a seperate UBEC fed from the main pack. The better ones will be compatible with a 6s pack anyway...Its what I am doing on my Hawk. Good out the box thinking and ideas though....nice one Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 1, 2008 Author Share Posted April 1, 2008 I have had it a while now, but only just startedthe build following extensive tests on fans and rotors etc. I am going to be using a midi fan rotor as the fly-fly version was too hungry on the 6s pack I am using, and also the stator housing developed a stress fracture and broke off the mounting lug I found that on static thrust tests the midifan rotor gave higher thrust for much less current used. I will NOT be glassing, although I have used a little poly-C and 4g tissue just to toughen up the fragile tips of wings and fins etc. I want it to remain absolutely as light as possible. I am using a 60A ESC and the 7A regulator I linked to earlier...minus the coils and switches etc...again to save weight. I shall however be beefing up the air retract mounts using ply plates etc..... to cope with our grass strip .Thrust stand setup - e-logger with RPM logging is on back order - my optical tach wont measure this fan! Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 1, 2008 Share Posted April 1, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted April 1, 2008 Share Posted April 1, 2008 Timbo Have run up motor & reversed its direction ( you were right about Futaba) No beeps happened but maybe thats cos I didn't connect the Lipo with the throttle full up.Now plucking up courage to power up the fan unit installed in the EZEfan & hopefully will hear some noises /beeps & take down the wattmeter readings .or should I just try & set the ESC before taking any readings later?. I have fixed the EDF unit on its lugs with 4 self-tappers ( 3 mm dia) into cyano impregnated balsa fuselage .Do you think they will hold ? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 1, 2008 Author Share Posted April 1, 2008 Myron..please start a new thread for this, or add to the one already running on your Als Hobbies EDF jet.you MUST teach the throttle setting to the ESC in the way I told you, before proceeding.Will it hold.....there's one way to find out Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 2, 2008 Share Posted April 2, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 Hi Eric. Neither. It goes straight to the receiver "batt" socket, with its other two wires connecting straight to lipo battery. Just think of it as seperate receiver battery. Jetsome, I have JUST come in from the workshop after testing the new housing I received this morning ( the lugs broke on the flyfly housing ) I have done a run in the exact same conditions as before but this time fitted the intake lip, and have seen a BIG increase in thrust. I am just about to input the data to my spreadsheet and will post here when done with all results. I have also been busy today making and fitting a lipo alarm unit to my DX7 to give a LOUD screeching alarm when I hit 11.3Volts. Even with the DX7 built in low battery alarm adjusted to sound at 10V....its still too low to let the tr battery get to. Just tested it all....works a treat !! I will post all the latest DX7 mods in the thread I started some time ago...Watch out for new "latest posts" ...err...later. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 2, 2008 Share Posted April 2, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 No need for that Eric...perfectly legitimate question - I have had far dafter ones that that i can tell yer! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 the aperture is where the ESC lives...out in the airstream. The 2 horseshoe bits are wing fences - and one of mine has broken already ....dont think its ply See the new post I made over in electric flight section called fan testing. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 2, 2008 Share Posted April 2, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Erfolg Posted April 2, 2008 Share Posted April 2, 2008 TimboWhen you say that the UBEC is connected to the Lipo, does this suggest that a "Y" lead needs to be fabricated (the other part of the branch feeding the motor).I am glad that some one else was wondering where the UBEC went.I assume that the BEC from the ESC is no longer used?RegardsErfolg Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 I am sure jet knows what wing fences are for Eric - quit while your ahead matey Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 The bec from the ESC MUST be disconnected ( snip /remove the red wire ONLY ) if using a standalone BEC.I splice the BEC input wires into the ESC battey input wires, so it gets powered up as I connect the pack, but cannot be accidentally left connected and drain the battery. Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted April 2, 2008 Share Posted April 2, 2008 Jet may know what wing fences are but I for one was pleased to have it explained because I had no idea. Also the reason for the saw tooth leading edge on the hunter was of use.Thanks Eric. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 2, 2008 Author Share Posted April 2, 2008 Yeh I figured the same, and will probably mount mine up front nearer the battery. Only downside is additional weight of 3 long cables to motor instead of 2. My 60A ESC runs barely warm after a full 6 minute run of variable throttle. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 3, 2008 Share Posted April 3, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted May 26, 2008 Share Posted May 26, 2008 Can I just add my reccomendations please for 2.4ghz users?On applications using over 3s [11.1v], or over 3 servo's, either a UBEC set at 6v output, or at minimum, an ESC/Switchable type. Our experiments have shown that brown out's can only be avoided totally with these options. Quote Link to comment Share on other sites More sharing options...
Lew Weaver Posted May 26, 2008 Share Posted May 26, 2008 Sorry to disagree - been using UBECs on 4.8v and up to 8S for more than a year now with no "brownout" - using up to 5 normal servos or 4 digital.So why should I need 6v provided the UBEC is rated for the current drain? Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted May 26, 2008 Share Posted May 26, 2008 For the simple reason that not everybody can work out how to rate it for the current drain for a start, and secondly, like many others, I have come to the conclusion that using Spektrum on anything less than 6v [when possible] is risky. If it works for you as is, fine, but many electric models that have had brown out failures on 2.4ghz [and even Horizon acknowledge this] have gone in because the BEC is not up to the job. Quote Link to comment Share on other sites More sharing options...
Nick Rigg Posted May 29, 2008 Share Posted May 29, 2008 Hi there - does this apply to Futaba 2.4g? I intend to use a Turnigy 60a UBEC with 4 standard servos and 4S power.Haven't flown yet but static tests seemed fine Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted May 29, 2008 Author Share Posted May 29, 2008 Well as it was Scott who made the suggestion, I will let him answer that - personally I have found the Turnigy ESCs very good, and with 4 x servos - even on 4s I would say it would be OK, as these ESCs deploy a switching regulator rather than a simple linear one... I know Scotts concern is about the brown outs that some have experienced with the spekky, not sure what the position is with Fuby. Quote Link to comment Share on other sites More sharing options...
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