Andy Ennis Posted September 24, 2012 Share Posted September 24, 2012 I bought a YT International Miss Elaine as a birthday prezzie for my brother, and he has decided he wants to power it with an electric set-up. The model is a 73" span trainer/sports model, that YT say has a flying weight of 4.6lbs They recommend a 4250 (510kv) motor, a 60A esc and a 6S 2200mah lipo, driving a 14x7 prop We have a few leccy models, but they have all been BNF or PNP types with the power system already fitted, so we have no experience in picking the correct electric power system, but even so the YT recommended gear seems a bit OTT to me, plus I've not been able to find the recommended motor for sale in the uk. What do the experts out there think? Is the recommended set up right, or should we be looking for something a bit tamer. Andy Edited By Andy Ennis on 24/09/2012 19:50:51 Quote Link to comment Share on other sites More sharing options...
Simon B Posted September 24, 2012 Share Posted September 24, 2012 That's probably a bit of overkill! You'll be looking at about 1000w of power, if not more, or over 200w per lb. For a trainer about 100w per lb will be fine, so about 500w. I reckon a 4S set up would be fine, with a 600kv outrunner. It'd make it a lot cheaper too! Quote Link to comment Share on other sites More sharing options...
Alan Cantwell Posted September 24, 2012 Share Posted September 24, 2012 the specs come from the manufacturer, its a chunky beast, if there is doubt, i will do some finding out for you **LINK** here she is, what does the floor think? Quote Link to comment Share on other sites More sharing options...
Pete B Posted September 24, 2012 Share Posted September 24, 2012 I can be too helpful for my own good sometimes......... For the past few months I've been running my 3.5lb Phoenix Rainbow on an NTM 3548/900Kv, on a 3S pack and 12x8 prop, which gives about 320-340W and has performed very well. Seeing your question, and the Rainbow being within reach, I thought I'd just put a 4S pack on the same setup and see what sort of watts would be drawn as I reckon that motor would be about right for your proposed model. Just as I reached full throttle, there was a crunch and the motor and prop parted company with the model and set off across the room - fortunately with no damage to motor, prop or room! The motor, which peaked at 611W at 46A on a part-discharged 4S pack, had pulled itself off the ply motor mount and exited through the front of the cowl, neatly disconnecting the bullet connectors as it went. The ply mount now resembles matchsticks....... Hmm, seems the ply mount was fine for 300W but doubling it took it just a bit too far! An hour should see it all fixed again so no harm done......... Anyway, the point I was trying to make was that motor, a 60A ESC (I use either Hobbywing Pentium or a Giantshark cheapie with a separate UBEC), something like a 12 x 6 prop and a 4S 3000mAh pack will be plenty big enough for the Miss Elaine, with power to spare. I'd expect something like ten minutes or more duration at sensible throttle on that capacity. As S-R-B says, the suggested spec is certainly overkill, IMHO.......now where's the glue...... Pete Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted September 24, 2012 Share Posted September 24, 2012 If their weight estimate is accurate then yes - 200W/lb is a bit on the "spirtely" side! Having said that it depends what you wnat to do with it. If its like the Teledo Special - which it looks a bit like a chunkier/larger version of! - then it will be reasonably aerobatic - trainer or not! You don't say if your brother is a beginner or if he has experience. If a beginner then I'd suggest the specified power train is probably a bit too hairly and he'd be better off with the 4s solution giveing about 5-600W. But if he has some experience and wants to throw this around a bit - why not 900W! BEB Quote Link to comment Share on other sites More sharing options...
Andy Ennis Posted September 25, 2012 Author Share Posted September 25, 2012 Thanks for the answers and suggestions guys, it's much appreciated. Pete B, thanks for the motor suggestion, but we are staunch advocates of supporting our LMS, so will not order from HK unless there is absolutely no alternative. Although my brother is not a novice, he prefers the more sedate type of flying, with a bit of mild aerobatics (loops, stall turns etc) so a lower power set-up seems more suitable. A search on the net produced the Overlander Thumper 3548-05 890kv, 3s-5s lipo, 800w (I presume on 5s), turns a 13" prop (again I presume on 5s). To me this should be ideal with a 4s 3350mah or 3900mah lipo, a 60A esc and about a 14x6/7 prop. What does everyone think (sorry, can't post a link to the overlander site, as I'm posting from an Android tablet, and this site's "post a reply" box doesn't like Android devices). The good thing about the Overlander motor is a) It's cheap and b) I can order it through my LMS (they are agents for Overlander) Quote Link to comment Share on other sites More sharing options...
Simon B Posted September 25, 2012 Share Posted September 25, 2012 I think your suggested set up would be more than adequate. 100w l/b or a bit over (about 120W/lb based on your set up suggested) would be fine for basic aeros. Quote Link to comment Share on other sites More sharing options...
Andy Ennis Posted September 25, 2012 Author Share Posted September 25, 2012 Thanks S-R-B. It's all very confusing, much easier when choosing a IC engine. I recently bought a watt meter, so I'll be sure to test the power train before flight, to make sure we don't let the magic smoke out of any of the components Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted September 25, 2012 Share Posted September 25, 2012 Very wise! BEB Quote Link to comment Share on other sites More sharing options...
Pete B Posted September 25, 2012 Share Posted September 25, 2012 Posted by Andy Ennis on 25/09/2012 14:33:16: Pete B, thanks for the motor suggestion, but we are staunch advocates of supporting our LMS, so will not order from HK unless there is absolutely no alternative. Ah, if only, Andy - my LMS is about 50km from me and the last time I visited there were items still priced in francs.......besides, my philanthropy is exceeded only by my parsimony! Despite the apparent variation in published specs, both motors look remarkably similar in design, so may just be a badged variant. I won't comment about the price difference...... You might find that a 14x6 prop will draw too many amps - as I mentioned above, a 12x6 or 12x8 should give you between 500 and 600W, whilst keeping the max amps in the 40's....... Pete Quote Link to comment Share on other sites More sharing options...
Andy Ennis Posted September 25, 2012 Author Share Posted September 25, 2012 Thanks Pete. As I said earlier we are very much novices with electric power, and I was only going off what is on overlander's site, i.e. "Prop size from 13" (larger prop with fewer cells)" I think the best course of action will be to have a selection of prop sizes, and check the current draw for each. Andy Quote Link to comment Share on other sites More sharing options...
Pete B Posted September 25, 2012 Share Posted September 25, 2012 That table shows <13" x 5" which I take to be suitable for props of less than that size. It's always worth testing a variety but the variations in current draw can be surprisingly large for a small change in prop! I've found that different marques of prop, all with apparently the same pitch, can vary significantly too. Good luck with the model - let us know how it goes! Pete Quote Link to comment Share on other sites More sharing options...
Alan Cantwell Posted September 25, 2012 Share Posted September 25, 2012 Talked to boss, he says 650 watt is enough, do you need anything else? Quote Link to comment Share on other sites More sharing options...
Andy Ennis Posted September 25, 2012 Author Share Posted September 25, 2012 No thanks Alan, thanks for your help Quote Link to comment Share on other sites More sharing options...
Alan Cantwell Posted September 25, 2012 Share Posted September 25, 2012 any problems, let me know, pretty thing isnt it? fully sports type aerobatic vintage style model, years ago, i fancied building a juinor 60, making the wing flat, fitting ailerons, beefing up the structure, and entering the club aerobatic comp, a piped webra 61 was going to be used, i think the term hung drawn and quartered came to mind Quote Link to comment Share on other sites More sharing options...
Andy Ennis Posted September 25, 2012 Author Share Posted September 25, 2012 Yes, it is pretty. It'd be lovely on a hot still afternoon, putt-putting about with a nice four stroke up front, but sadly it looks like my brother has been seduced by the dark side. Any more of this and I may have to disown him! Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted September 25, 2012 Share Posted September 25, 2012 Lovely model good luck with it. Quote Link to comment Share on other sites More sharing options...
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