Tim Mackey Posted June 7, 2008 Author Share Posted June 7, 2008 Surprisingly...Puffin's are way cheaper, and that's not something you hear everyday - service is way better too IMO Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 7, 2008 Share Posted June 7, 2008 I may have to get a couple of cells from Puffin, just to test that Timbo CheersDanny Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 11, 2008 Author Share Posted June 11, 2008 Latest development with my leccy wot4 is that I was going to change the motor ( the HiModel 919Kv was faulty, pulling way more current than designed for probably due to shorted windings or too many parallel coils ) -but I have naffed it in the meantime whilst trying to remove a mounting screw. Dont ask Meanwhile, back at the ranch, I have concluded that these soft pack LiFes do not like high discharge, and the current used on the 4s config was just too much for comfort ( around 43A for a measly 512 watts ) so I have experimented with them hooked up in series ( 8s ) on a lower Kv motor( destined for my Hangar 9 Camel ) and results look promising. This rig with a 13 X 6 prop is producing around 800watts at WOT for just 32A and averaging 330Watts for just 13A...I also got around 7 minutes on various throttle settings, ( static - not yet fitted and flown ) so likely will increase slightly once airborne. Average current during whole test period was only 14 and it will probably be "flying" at around this...after all its only for the missus to keep up her learning on. This is of course due to the high volts / low Kv and current draw scenario so I am going to get a lower Kv motor of around 600 -700 Kv rated at approx 600 - 800 watts and run it on the 8s ( circa 24V ) pack.This will also enable me to use my "spare" 4s Lipo packs too ( with larger pitch prop to increase power though ) without overstressing the motor. I am slowly getting to grips with the eagle tree graphing, and below are a couple of images of bench test result, one shows Amps and Volts, and the other shows Watts / RPM / and cumulative MaH. Remember of course that in series my capacity is now just 2000m/ahr. At the moment, I will certainly not be buying any more of these softpack LiFes, but having alreadyt spent £80 on theese two packs, and the fact that they are re-chargeable in around 20 minutes means I will perservere with them - although will still be getting some proper hard shell A123s for more experimenting.I have uploaded the images via photobucket - so they are big enough to see clearly ( click the image for bigger )I will make a further posting after flight trials when I can get the motor I want ( at Weston I expect ) although may also try this one here for experimental purposes although at 1200 watt its a bit heavy and large for wotty Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 11, 2008 Author Share Posted June 11, 2008 Incidentally, heres the images of the results from an actual flight with the "old motor " 919Kv and using 4s LifePo4s.screen 1 Amps and Voltsscreen 2 RPM and Wattsscreen 3 Cum MaH and quite interestingly ( well I think so anyway ) servo current used during flight. This was a fairly spirited flight with all the usual wot 4 moves including flick rolls etc, so servos were worked quite hard. It was also quite windy so I reckon this was a fairly typical loading for the surfaces. She is fitted with full size servos ( 4 in all ) 2 digitals in the wing, and analogue 3003s for rudder and elevator. It confirms my beliefs and earlier bench testing results that properly fitted servos, with free moving hinging and pushrods etc take little current in flight - note the average draw was under .25 Amp, and even peak was under .5AI may post this particular data elsewhere too for more peeps to see.Interesting too that despite being freshly charged, when in parallel mode ( 2 x 2000 ) this battery pack only gave 3000m/a yet in the first graphs ( in series mode ) - they gave pretty well all their 2000m/a. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 11, 2008 Share Posted June 11, 2008 It will be interesting to see how the "real" A123 compare Timbo, are you borrowing some from Chris or Andy to test??And about Weston..... it looks like my pass out was indeed restricted to Sunday and is not transferrable to another day so you will have to save my cream cake until either one of our fun fly's (Greenacres) or your scale electric day later in the year Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 11, 2008 Author Share Posted June 11, 2008 Huh - the lengths some people will go to, to avoid me Yep...plan on "borrowing some" from Andy with a view to purchase following satisfactory road test Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 11, 2008 Share Posted June 11, 2008 Timbo - that 8S test looks very promisingIf thats a 400Kv motor on a 13x6 prop, isn't that about right for 8S?The motor we have been swearing by on 6S A123 seems to have been split into 2 types600kV Motor and 700kV Motor although when we bought ours they were all rated at 670kVallelectric motor looks suspiciously similar except its silver, and they are on special offer.As we use them on 6S with 13x6.5 and 14x7 props, won't you have to go to quite a small (too small) prop to use this kV on 8S?Also, your batteries do show a steady drop off of volts, metal can ones dont do this.... Quote Link to comment Share on other sites More sharing options...
Andy Sayle Posted June 11, 2008 Share Posted June 11, 2008 Hey Tim,I'll pop a handfull of cells in the car for tomorrow (thursday) night, I'm heading down to the field for some flying all being well Failing that, I'll be at Weston Park this weekend Cheersandy Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 11, 2008 Author Share Posted June 11, 2008 Hi Chris....you may well be right there Yes - its a 400 Kv Turnigy and the reults are about as expected - I am planning to use this motor in my Camel with a 16 x 10E prop on 4s LiPo....slow and scale - and it has a BIG cowl.Earlier test results this year showed promising figures of 5000 RPM and around 600 Watts WOT ( 60 p / lb ) which I calculate to be theoretical pitch speed of about 46 MPH WOT...just right for scale biplane.For the new wotty motor selection, I was hoping to be able to compromise a bit in order to be able to still use my 4s LiPos ( I just cant stop it can I ) as an alternative and any lower KV than around 600 may be a bit too low for 4s without going too big on props. Bearing in mind that these cruddy softpack Life's do drop voltage more than LiPo under even moderate loading, then perhaps around 500 Kv may be better. Its all part of the fun of experimenting really I have still got the TP 670 Kv motor on my shopping list...but suspect that I will end up with a few variations for trialling. Heck, I may even just get another Turnigy cheapo 400 kv from HC, at under 20 quid you cant lose really. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 11, 2008 Author Share Posted June 11, 2008 Andy Sayle wrote (see)Hey Tim,I'll pop a handfull of cells in the car for tomorrow (thursday) night, I'm heading down to the field for some flying all being well Failing that, I'll be at Weston Park this weekend Cheersandy Yo Andy....sounds good. I will only be at Weston on Saturday...see here but hope to be at the field tomorrow for a session in the evening. Quote Link to comment Share on other sites More sharing options...
Rick Tee Posted June 16, 2008 Share Posted June 16, 2008 Excellent thread lots of great info. Timbo can you please tell me where I can buy a 40+Amp ESC for £12? that's a very good price. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 16, 2008 Share Posted June 16, 2008 Nooooo, don't let on lol they will have no stock left.......... We normally get stuff from United hobbies, but in an effort to support our own UK industry that is trying to compete how about this from allelectric, haven't tried one yet but looks a keen price http://www.allelectricrc.co.uk/suppo-su45a-opto-esc-4-7s-1281-p.asp Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 16, 2008 Author Share Posted June 16, 2008 Giant Cod also have some excellent cheap ESCs. Flying Wings .co.uk. also have 'em. I recently got a 50A unit for £9 - works a treat. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 16, 2008 Share Posted June 16, 2008 Danny - great minds think alike (and fools never... etc) I ordered one of these last night, http://www.allelectricrc.co.uk/suppo-su70a-opto-esc-4-8s-1282-p.aspLooks like my Fury is going to be dearer than yours! Just hope this is nothing like as big as the one they showed us at Weston.It has apparently been dispatched, so I'll let you know how it is soon. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 16, 2008 Author Share Posted June 16, 2008 Chris..that looks like the one I got from the flying wings guys - it is a bit on the large side, but works very well ( it was fittted to my wotty until I went 8s, and it is not happy on such a high input voltage) - changed to an 80A HXT. I have posted the actual flight figures from the one test flight done so far on the 8s LiFe and 400KV motor. It went pretty darn well actually, and duration was better than the 4s 4000m/a trial. Bought a couple more motors at the Weston show, one at 450 Kv and one at 670. I am going to experiment with the 450 jobby on both 8s LiFe (2000 mahr), and 6s Lipo ( 3200 mahr ) and with the 670kv motor on 6 X genuine A123s ( 2300 mahr of course ) and a 4s X 3700 m/ahr Lipo. I find all the trialling of different combos almost as much fun as building / flying - geeky I am afraid Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 17, 2008 Share Posted June 17, 2008 You are putting the "E" back into RCM&E, nowt wrong with that I must be getting, old I remember when there used to circuits in the mag not just plans....... Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 17, 2008 Share Posted June 17, 2008 Oh no - I ordered that ESC specifically for 8S, thinking that an 8S lipo spec would be more than OK with 8S A123's - Oh well, we'll see when it gets here... I have a couple of super simples coming from Hong Kong too. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 17, 2008 Author Share Posted June 17, 2008 Danny Fenton wrote (see)You are putting the "E" back into RCM&E, nowt wrong with that I must be getting, old I remember when there used to circuits in the mag not just plans.......Funny you say that....there was one this month Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 17, 2008 Author Share Posted June 17, 2008 Chris Bott wrote (see)Oh no - I ordered that ESC specifically for 8S, thinking that an 8S lipo spec would be more than OK with 8S A123's - Oh well, we'll see when it gets here... I have a couple of super simples coming from Hong Kong too.It is not exactly the same Chris...yours may well be OK, after all the specs do say up to 8s which will be referring to Lipo so on Lifes that is less volts anyway. My cheapo 80A HXT jobby fitted at the moment works great on it - and has PC connectivity for bench trials. Use for throttling, alter timings, direction settings etc, and display RPM - all using the mouse and no receiver required....brilliant bit of kit. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 17, 2008 Share Posted June 17, 2008 That sounds like a decent step forward in facilities - how much was cheapo? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 17, 2008 Author Share Posted June 17, 2008 Well as you know, I am not supposed to reveal the price I paid on forums, H/C do not like displaying this info too widely as it upsets their suppliers ! Suffice to say it was less than £23 but slightly more than £22.90 90A capable, 3A switched BEC. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 17, 2008 Share Posted June 17, 2008 Does that mean I need to delete the prices on my Sea Fury thread? I don't want UH to take away my "buys too much" status It will be interesting to fly the leccy 4's together Timbo I will try and get over to one of your bashes with it in case you can't make a GMAC event?? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 17, 2008 Author Share Posted June 17, 2008 Hi Danny...still hoping to make the July one - cant get a pass for this weekend...too close to Weston, and with a tank of petrol at £70 my "accountant" is moaning about costs. Just returned from the Orme - terrific lift today but the wife broke my Skizzo big style I am just off to the wotty now to try some different motor batt prop combos....Eagle Tree results later Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted June 17, 2008 Share Posted June 17, 2008 Yes the July one sponsored by YT looks like being a good one, a fair bit of trade have said to YT they will be coming. Lets hope the weather is good.Look forward to the Eagle tree's. Chris's eyes lit up when he heard you live by Orme, he is a closet sloper But has withrawal symptoms as he hasn't done any for years. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 17, 2008 Author Share Posted June 17, 2008 Then he / you should get up here for one of our sessions.....we always have a ball. Quote Link to comment Share on other sites More sharing options...
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