rcaddict Posted July 2, 2016 Share Posted July 2, 2016 just spent the afternoon converting a weston cougar 2000 to leccy, I cant believe the amount of ballast I am going to need to get the COG to 115mm from leading edge (googled it) it is going to take about 350g, - does this sound normal motor was LDPower 3540 130g lipo 3s 2200 I know I should have checked COG before I started - but I didnt !!! Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 2, 2016 Author Share Posted July 2, 2016 think I can answer my own query - os 46 = 700g a motor + lipo = 350g diff = 350g !!!!!!!!!!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted July 2, 2016 Share Posted July 2, 2016 Check again Old, I built my cougar with a .36 IC, and it was recommended It weighs 350 g, the same as a leccy set up Look over everything again, as mine balanced out with just Rx pack movement buddy Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted July 2, 2016 Share Posted July 2, 2016 How many watts are you aiming for in the Cougar OG?.... You won't get much over 400watts out of a 3S 2200 battery & I doubt that will make the Cougar perform.....I think a larger 4S battery might be a better option (plus the right motor/esc/prop combination) & I suspect you will find the cofg is restored..... Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 2, 2016 Share Posted July 2, 2016 An OS 46 at full wack is claimed to deliver 1.63 hp that's 1200 W. Of course you would not achieve this in normal flight but 800 W would be fairly easy to achieve. As far as I can tell the LDPower 3540 is a 250W motor used for quad copters. As Steve has pointed out it sounds like your electrics are quite a bit under specified for a 'like for like' conversion. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted July 2, 2016 Share Posted July 2, 2016 The recommended set up for this small very light weight model was a .36 IC motor, that comes out at 700 watts. The model weighs less the 2lbs, Whether IC or 3cell leccy, it should fly, it was, and is a very considered design. Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 2, 2016 Author Share Posted July 2, 2016 ok - so remember Im thick when it comes to leccy motor is https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=88480 i cant test the watts yet as new meter is still in post what I can tell you is that is goes really fast across my lawn in ground test with a 3s just made up lead weights in case I get the a break in weather tomorrow [Edited for language] Edited By Biggles' Elder Brother - Moderator on 02/07/2016 21:57:07 Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted July 2, 2016 Share Posted July 2, 2016 Just another note, I have the C of G 100mm from the leading edge Old, but I don't do harriers, I like to fly as if a pilot remains conscious in the canopy. Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 2, 2016 Author Share Posted July 2, 2016 me too Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted July 2, 2016 Share Posted July 2, 2016 I did a conversion on one of these for a mate a couple of years ago. I don't remember needing any lead - it balanced fine a with a like-for-like power level switch out! You certanly shouldn't be sticking 350g of dead weight in a model that is only powered by a 3s! That would be suidcide for any prospect of performance! BEB Quote Link to comment Share on other sites More sharing options...
Shaunie Posted July 2, 2016 Share Posted July 2, 2016 I would suggest you replace the lead with more Lipo and maybe more motor. Rather than add lead why not spacer the motor further forward. Shaunie Quote Link to comment Share on other sites More sharing options...
John Roberts 9 Posted July 3, 2016 Share Posted July 3, 2016 I too did a glow to electric conversion on a Weston Cougar 2000 a couple of years back. Unfortunately I can't look at the model right now for the exact specs because it is packed away for a house move. However, I recall that the motor is almost certainly a 42mm Hobby King NTM, 60A esc and I use 3600 Ah 4S Turnigy batteries. Power is around 900W and feels much the same as the recommended West glow motor that I replaced. No lead ballast required either. Quote Link to comment Share on other sites More sharing options...
John Roberts 9 Posted July 3, 2016 Share Posted July 3, 2016 On second thoughts the motor may well have been a 35-48 NTM / 60A esc / 3600 4S....................I can't be certain until I unpack everything in 4 weeks time! Good luck Quote Link to comment Share on other sites More sharing options...
Old Geezer Posted July 4, 2016 Share Posted July 4, 2016 As an alternative to lead ballast, why not stand the motor off a few centimetres forward of the firewall. Have a look on the 4Max site, his cage mounts are designed for just such a job - they might not look very substantial, but once all the nuts are pulled up tight they're rock solid and more than adequate for the job. Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 4, 2016 Author Share Posted July 4, 2016 Gurth Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 9, 2016 Author Share Posted July 9, 2016 ok - got my watt meter now 450w with 3s 2200mah, 80a ESC & 11X8.5, it defo flies !!!! Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted July 9, 2016 Share Posted July 9, 2016 It should certainly fly on 450watts OG but I suspect you will need quite a bit of throttle on most of the time....you are pulling a lot of current out of that battery too.....40-45A for a guess.....thats around 20C which will give you 3 minutes max at full throttle be careful you don't kill the battery by over discharging it.... Quote Link to comment Share on other sites More sharing options...
rcaddict Posted July 9, 2016 Author Share Posted July 9, 2016 thanks Steve - your bang on - 42A & I get about 4 min on 3/4 throttle would I be better with a 4s 2200 or perhaps a 3s 3300mah (not a lot of space) Quote Link to comment Share on other sites More sharing options...
Gordon Brown Posted July 9, 2016 Share Posted July 9, 2016 I have one I converted a couple of years ago using HK G32 motor bolted directly to the firewall, 13x6 or 13x8 prop, 60A esc slung underneath the fuselage between the u/c legs, powered by a 2450mAh 4S battery. With the battery right forward it balances perfectly, no added ballast, flies nicely. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted July 9, 2016 Share Posted July 9, 2016 Fly it & see how it feels.....if you're happy with the performance then go for the larger battery & this will increase duration & replace the lead... Personally I would go for a 4S set up in a model like this ....remember you can't just swap tge 3S for the 4S without changing something else....at tge very least you'll need a smaller prop Quote Link to comment Share on other sites More sharing options...
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