PatMc Posted January 21, 2018 Share Posted January 21, 2018 Not sure how you intend using these but it's not a good idea to extend the wires length between battery & ESC. What's the current rating off the switch & the gauge of the wires attached to it ? Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted January 21, 2018 Author Share Posted January 21, 2018 It is a wild shot tbh, nothing is specified but I 'presume' the device as a whole will carry the current the XT60 plugs will transmit. The extension was simply useful to have to cut to suit. The bulk head XT60 is near impossible to find in the UK, one place has them advertised, but out of stock. For such a useful connector, it is very rare, seems to be a drone racing item, but I would have expected a lot of availability. During some early spring cleaning of the dreaded 3rd bedroom with the wife, found a pic of the Stol when I bought it off the then owner John Dean (Birmingham based) Quote Link to comment Share on other sites More sharing options...
Colin Carpenter Posted January 21, 2018 Share Posted January 21, 2018 Hobbyking XT 60 Panel connector kit in stock in UK. £1-60 ish from memory. I use them a lot and have had zero problems. Colin Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 21, 2018 Share Posted January 21, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted January 21, 2018 Share Posted January 21, 2018 I would second Percy's comments, those switches are not up to the job of switching the main supply. A couple of years back I had one fitted to one of my 'planes and its contacts melted on take off! Fortunately no damage was done to the airframe and the power was actually cut on meltdown rather than the opposite! In the end I used the plastic body to house an XT60 plug and installed that as has been shown above in andy's post. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted January 21, 2018 Author Share Posted January 21, 2018 Well, I could swear in public. You all have search engines bigger than mine, and years of wisdom. When all this is done (will it ever end?) I'm going to do a Guide to not making Mistakes. On order, and thank you. Off to watch the snooker, I'm actually good at that! Away from electricity and fires, anyone noticed I've changed the orientation of the undercarriage? As built, and faithful to the plans above, the wheel c/l is true to the wing leading edge, but it looks wrong to me... Advice please. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted January 31, 2018 Author Share Posted January 31, 2018 Back to the Stol after a good few days with the classic car! The wiring on the switch proves it could not carry the current, so good advice not to use it! Spent some time trying to sort out fitting the batter 'isolator' from Hobby King (nice product, bought 2), and a hatch for the battery... After some time and some false starts, for better or for worse, it is all done, and I will be taking the wing off to change the battery! I will probably need a pause for my nerves to settle anyway between flights. The jump connection is a plug with a stout copper lead soldered across and the black grip cover expoxy'd into place. The ESC is in the direct draft through the large hole in the lower cowl, the wires all connect to the motor and the isolator inside the ply motor mount and the RX lead from the ESC reaches to the RX in the base of the plane. The ESC is velco'd onto 2 bearers that allow the wires to pass under it and to the inside of the box via a 15mm dia hole. The tie is for good measure and will be thinner when I can buy some. The battery is strapped in against the bulk head with a grippy rubber pad holding the back and sides tight. I have small hands, so access is OK! Charger has arrived so the final electrics can be checked, motor direction checked and the TX linked to the RX etc. Edited By 911hillclimber on 31/01/2018 13:33:49 Quote Link to comment Share on other sites More sharing options...
charles aldous Posted January 31, 2018 Share Posted January 31, 2018 **LINK** For a top safety system on electric prop models I use the above emcotec products. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted January 31, 2018 Author Share Posted January 31, 2018 Thank you for the link, but I'm all done now on this conversion! The Super Scorpion awaiting it's turn in the attic is in covered so will be much easier IF I go electric. Quite like the idea of an open valve 4 stroke and a LOT easier. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted February 13, 2018 Author Share Posted February 13, 2018 After a few family things are now done (a wedding) had a little time on the Stol. Radio all Binded after several failures, not sure why, but all controls work. Had to reverse 2 wires on the ESC to get the motor turning anti-clockwise and have to get the elevator trimming to work yet. These modern radios are so complicated with a million functions, 33 pages to set the thing up! Just finishing off the cowl attachment (rubber bands) and a touch of Humbrol colour to tidy the front up and we are ready to fly/crash/frighten at the air field. I have a good friend who's next door had flown large scale for many years, so hope to find where he goes and even if they have a training /instructor willing to help with the maiden flight. The prop dia seems a bit small to me at 9x6 but time will tell. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 13, 2018 Share Posted February 13, 2018 Just looked at this thread. Whichever way you decide to arm the model do not extend the battery to ESC wiring by even a small amount because it will almost certainly result in an ESC failure for rather complex reasons. Most people simply connect the battery at the flightline if possible. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted February 13, 2018 Author Share Posted February 13, 2018 Thanks for the reply Martin. I have extended the ESC power leads by a good 80mm! Now I don't know which way I should or should not turn. The ESC leads were really short, about 60mm, the battery leads about the same which made installation very hard, hence the layout in the plane. If you can't extend any lead beats me how to install anything! Maybe a 4 stroke is the better bet after all this messing about with wires and connectors.... Quote Link to comment Share on other sites More sharing options...
Andy48 Posted February 13, 2018 Share Posted February 13, 2018 Almost all my models have extended leads, one or two significantly so. My Puppetter probably has nearly 30cm extensions. Yet to have the slightest problem, and yet to damage an ESC. Many of my ESCs are over 5 years old. Love these doom mongers! Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted February 13, 2018 Share Posted February 13, 2018 Keep the faith hillclimber, all will be well. A 9 X 6 prop should be fine, and if you had bought a wattmeter you would know that to be true! Good luck on the maiden flight - fingers crossed or 'break a leg', as they say in the thespian world! Quote Link to comment Share on other sites More sharing options...
Andy48 Posted February 13, 2018 Share Posted February 13, 2018 Now there's an interesting point. If you must never extend the ESC power leads to the battery, how do you use a wattmeter, because the wattmeter effectively extends the leads? Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 13, 2018 Share Posted February 13, 2018 Posted by Andy48 on 13/02/2018 20:16:00: Almost all my models have extended leads, one or two significantly so. My Puppetter probably has nearly 30cm extensions. Yet to have the slightest problem, and yet to damage an ESC. Many of my ESCs are over 5 years old. Love these doom mongers! Your right Andy, there is often not enough cable for a normal installation. The manufacturers just don't want failures of their products due to dodgy soldering, or the Back EMF from long cables. A long cable, and the motor, has a small amount of capacitance as well as resistance, and when the supply is interrupted, by switching off or disconnected The small amount of current in the cable, and the motor can runaway unregulated, simplified explanation of EMF And can be reverse polarised going into the ESC As you found, with good soldering and installation, and modern ESC components, these small amounts are rarely any problem Edited By Denis Watkins on 13/02/2018 21:03:34 Quote Link to comment Share on other sites More sharing options...
PatMc Posted February 13, 2018 Share Posted February 13, 2018 It's not the capacitance of the cable but the inductance that causes the voltage magnification problem, that's why it's often advised to use extra capacitors with long leads. There's no reversal of the polarity or back EMF to the ESC, simply high voltage spikes. Edited By PatMc on 13/02/2018 21:30:00 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 13, 2018 Share Posted February 13, 2018 No, I am not a doom monger, just passing on information learned the hard way. When I was building my Mosquito I was advised that all ESC manufacturers say not to do this, but you may get away with it if you add special high value low Z capacitors fitted directly to the ESC which I did since I needed to extend by 30cm or so with very heavy duty cable. Despite vigorous testing one failed at take off on only the second flight and the model was destroyed (12 months work gone). Draw your own conclusions. The offending item did not completely fail but only gave very much reduced power. I would say that given the OP`s stated very short wiring that short extentions should not be a problem, but the way round it is to lengthen the ESC to motor wires if that would help. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted February 13, 2018 Author Share Posted February 13, 2018 I have tried to minimise the extension and to keep both leads the same length. I used the extension lead that came with that isolation switch, and the ext lead gauge is the same as the ESC and motor leads. Is there a test I can do? I have run the motor without a prop fitted to see if the TX was working for several runs but with no load on the system. On a positive note, I banded on the flying surfaces and undercarriage and the CofG is spot-on. Obviously, I will join the local Club closer to reasonable weather, go along with the plane and cross my fingers! Thank you to all as ever taking time to help me on this quest. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 13, 2018 Share Posted February 13, 2018 Posted by Andy48 on 13/02/2018 20:38:39: Now there's an interesting point. If you must never extend the ESC power leads to the battery, how do you use a wattmeter, because the wattmeter effectively extends the leads? Just not for a very long time. My wattmeter tests are carried out for just a few seconds - enough time to note the current before shutting off. The problem is that many high value capacitors tend to have a lot of inductance associated with them because of the construction method. I used to use solid tantalum capacitors for things I designed at work which have an inductance the same as a block of metal the same size (ie not much). I retired over 20 years ago so presumably capacitor design has moved on that time The ones I used were mil spec because I needed them to work at high temperature. Geoff Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 14, 2018 Share Posted February 14, 2018 Extending the battery to ESC leads does not kill the ESC instantly (unless you make the leads very long indeed) but the resulting extra load on the capacitors shortens their life and when the capacitors fail the ESC dies. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted February 14, 2018 Share Posted February 14, 2018 Posted by Martin McIntosh on 13/02/2018 21:45:56: No, I am not a doom monger, just passing on information learned the hard way. When I was building my Mosquito I was advised that all ESC manufacturers say not to do this, but you may get away with it if you add special high value low Z capacitors fitted directly to the ESC which I did since I needed to extend by 30cm or so with very heavy duty cable. Despite vigorous testing one failed at take off on only the second flight and the model was destroyed (12 months work gone). Draw your own conclusions. The offending item did not completely fail but only gave very much reduced power. I would say that given the OP`s stated very short wiring that short extentions should not be a problem, but the way round it is to lengthen the ESC to motor wires if that would help. So sorry to hear about the demise of your magnificent Mosquito Martin. Can you be sure that it was the extended battery lead that caused the ESC to fail, despite you adding the special capacitors to smooth out the voltage spikes? As we all know, these ESCs are made in huge numbers and can inexplicably fail occasionally. An 'engine' failure with an electric twin would seem most unlikely compared with an IC model but never say never. Extend motor wires +1 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 14, 2018 Share Posted February 14, 2018 Hi Piers, I have actually pieced the wreckage back together and it is ready to go apart from a new bomber nose moulding. This time with YEP 100A ESC`s and the motor wires extended. I cannot say for certain of course that the battery lead extentions caused the failure. Pics on my Mossie thread. Quote Link to comment Share on other sites More sharing options...
911hillclimber Posted February 14, 2018 Author Share Posted February 14, 2018 Just read the Haynes Manual on the DH Mosquito, great book. I thought I would post the Stol as it now stands, ready for the first flight in the late Spring. Edited By 911hillclimber on 14/02/2018 13:07:39 Quote Link to comment Share on other sites More sharing options...
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