Tim Mackey Posted September 9, 2008 Share Posted September 9, 2008 I have plenty of spare JST XH pigtails if you want one...just PM. It wiull entail you cutting off the old one and substituting this, but its a cheap ( free ) way of doing it. I do it on all my non jstxh packs. Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 9, 2008 Author Share Posted September 9, 2008 Is it really that simple? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 9, 2008 Share Posted September 9, 2008 It is as long as you ensure the correct connections and ignore the colours as they differ from type to type. Easy really with a multimeter, find the first negative, then positive, negative and so on depending how many cells. The JST XH start with the first negative on the extreme right, with each conxn moving to the left as it were, until you end up extreme left which is main positive. I will try and upload a piccy later - easy really, but do one conxn at a time and heatshrink it before cutting the next wire, or you could release the magic smoke. Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 9, 2008 Author Share Posted September 9, 2008 Gulp..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 10, 2008 Share Posted September 10, 2008 Right, heres the "tutorial" - dont say you are scared to do it now, after I have spent ages doing this! What you need to do is this - first ignore the wire colours of any existing plug fitted. Find the balance lead which is connected to the main negative lead marked X in my first drawing. This will be at one end of the balance plug, but which end, and which colour wire varies between types. The best way to find it is to set your multi-meter to an appropriate DC voltage range of the battery EG: if it’s a 3s pack then its around 12V when full, so select say 20V ( never go lower than the battery ). Connect the MM negative probe to the battery’s main negative terminal, and temporarily insulate it with a little tape. Then CAREFULLY probe one of the end terminals of the balance plug with the MM positive probe, you should get a reading of either 0 or 12V ( approx ). The pin which shows 0V is the lead you want ( X ). Then, carefully again, probe the next pin adjacent to that one, and you should read the voltage of the first cell in the pack around 3.7V or so. Each subsequent pin along the row will show an increase of 3.7V up until you reach the end pin when you will be reading the whole battery. This will firmly establish that the wiring sequence is correct, and will also be a quick indicator of the state of balance of the pack, as each cell should be within a few millivolts of each other. Make a sketch of what you have done, noting the colours of each wire as you go. Now, the JST XH type balance plug is connected as per the second picture, and basically when it is viewed from the top ( with the little barbs UP ) the main negative connection ( X) is on the extreme right hand end, with, obviously, each successive cell wired to each of the next pins along. Remember what I said about ignoring the colours? -Here’s why! In this 2nd picture the main negative pin ( X ) is, quite logically BLACK, and the last pin ( on the extreme left ) also logically, is RED. Now look at the 3rd picture, same plug style, different supplier, and totally different colours, with the main negative pin ( X again ) being RED, and the last main positive being GREEN! The pigtail lead I am sending you is this one ( cos that’s what I have a few of ) so you need to now connect your pack to this plug with that sequence. So referring back to your drawing, you should be able to easily identify which wire needs connecting to which pigtail of the new plug. It is VERY important to do only one connection at time, insulating with heat-shrink each one as complete it, to avoid any shorting. The final picture 4 shows one of my F/P packs and they use yet another different colour code, with X being black, and all others red. In this picture I have attached the same pigtail as the one I am sending you. Don’t be phased, it really is quite simple if you follow it logically.Pictures to follow below in a few moments Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 10, 2008 Share Posted September 10, 2008 Each picture will enlarge when clicked. picture 2 picture 3 picture 4 Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 10, 2008 Author Share Posted September 10, 2008 I await the lead with some trepidation... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 10, 2008 Share Posted September 10, 2008 posted today Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 10, 2008 Share Posted September 10, 2008 Hmm, not sure why, but the 1st illustration above does NOT open up when clicked, so here it is again and this one does Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 12, 2008 Author Share Posted September 12, 2008 Thanks Tim. The lead arrived today so I'll have a look tonight. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 12, 2008 Share Posted September 12, 2008 Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 12, 2008 Author Share Posted September 12, 2008 Initally thwarted by a broken lead in my MM, I repaired it and cracked on. And....... it was easy. All sorted, thatnks for your help Tim. The diagrams made it all simple to understand.The battery has been balanced and took 400mah. So if I get a rx tomorrow, then the maiden is sunday! Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 13, 2008 Author Share Posted September 13, 2008 200 watts and 18 amps! And what a noise! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 13, 2008 Share Posted September 13, 2008 wait til you get up to around a kilowatt and 70A - thats noisy! Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 13, 2008 Author Share Posted September 13, 2008 Hooligan! Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 14, 2008 Author Share Posted September 14, 2008 Not a great pic, but a pic nonetheless! She flies! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 14, 2008 Share Posted September 14, 2008 Yippee - well done mate. Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 14, 2008 Author Share Posted September 14, 2008 It is great fun. The 1100 mah pack is too light and a bit short on endurance. The first takeoff was spectacular(ly bad). The jet went vertically up, stalled, then tail slid down! I recovered it onto the grass unscathed and moved the battery to the very front. This time the launch was fine, but the model still needed quite a bit of nose down trim to fly level. The ailerons are ludicrously responsive, so I put 50% on the dual rates and tried again. Much better, but still twitchy, so I dialled up 50% expo and then..... perfect!Now it flies superbly, but it eats up a 110mah battery, so I'll order another one, but about 1300 or 1400 mah.As for the colour scheme, if it wasn't for that big red tail, I'd have been knackered a few times. The model is quite small and fast becomes a black blur in the sky. Great fun though. I added a Pete's Pilot to the cockpit, much better looking now. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted September 15, 2008 Share Posted September 15, 2008 Well done, looks good that. Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 15, 2008 Author Share Posted September 15, 2008 It is nice especially during low passes. Bit quick for the camera though. Decals are waterslide and rubbish. They rub off at the slightest thing. Jetsome recommended using waterbased polyurethane floor varnish to seal them in. Anyone got a spare Skyhawk set? Alfa fliers, what batteries do you use in your Alfa models? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 15, 2008 Share Posted September 15, 2008 1200 F/P 3s BUT.... AUW is only 15oz - the key to success IMO Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 15, 2008 Author Share Posted September 15, 2008 I'll weigh mine tonight. Can't be much heavier though, the battery is only 95g. I kept it as light as possible, removing all the unnecessary rubbish (cable clips) as I rebuilt it. Can't do much about the esc and motor weights, though I could shorten a couple of wires by an inch or so, but that's about it.I'll weight it and let you know. With the battery I assume? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 15, 2008 Share Posted September 15, 2008 yep AUW - my batteries weigh a huge 106g Quote Link to comment Share on other sites More sharing options...
winchweight Posted September 15, 2008 Author Share Posted September 15, 2008 15.75oz! Lardy... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 15, 2008 Share Posted September 15, 2008 OK so weight is not the issue. I suspect that your setup is more powerful than mine ( I think you quoted 18A and 200 watts ) so that is why the duaration is down. My setup pulls just 12A static giving me around 130 watts - which I find plenty enough for the size of the model - flys real scale like at that - not ballistic fast like some.... but as RR used to say " adequate sir ". You fits your motor and takes your choice - speed / power versus duration. Quote Link to comment Share on other sites More sharing options...
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