Bonesmalone Posted June 5, 2009 Share Posted June 5, 2009 Hi Guys, I am currently building a Wot 4 to use as a general sport plane for our not so smooth grass strip, but i am wondering what size engine to fit, as you probably know the box gives a wide range of rec engine sizes, but which is best suited to general sport flying ??? i have a selection of engines looking for home but which to choose ? Os 46ax with genesis quiet pipe Jen .57 Supre Tigre G51 Saito 56 Four stroke any input greatly appreciated. Also........ I have aquired an Acro Wot air frame, could anybody tell me where the C of G position please ???? Thanks in Advance Tony Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted June 5, 2009 Share Posted June 5, 2009 Hi Anthony, My last Wot 4 was O.S. 46 LA powered and very well it went too. Not unlimited vertical but just right so your .46AX would do nicely being a bit more powerful, the Jen .57 better still. Sorry can't help on the Acro Wot although Chris Foss is usually at his factory and I'm sure would help 01273 452642. I'm sure someone who's got one will be along soon.... Edited By David Ashby - RCME moderator on 05/06/2009 15:29:16 Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted June 5, 2009 Share Posted June 5, 2009 hello anthony-i've recently finished building a new acro wot-the instruction's state three and a quarter inch's from the leading edge plus or minus a quarter of an inch(good old british measure's)--as for the wot 4 i've had a couple of these lad's--any of your engine's will do the job-i would go for the OS46ax - perfect/nice and light and powerfull...... ken anderson.............. Quote Link to comment Share on other sites More sharing options...
Chris Channon Posted June 5, 2009 Share Posted June 5, 2009 Hi Anthony, i would use the Saito, really good engines, very powerfull, and the one you have will be just right for general sport flying. Regards as always Chris. Quote Link to comment Share on other sites More sharing options...
winchweight Posted June 5, 2009 Share Posted June 5, 2009 Mine (Acrowot) has an SC52 and it's pretty ballistic. Edited By Shaun Chant on 05/06/2009 17:43:27 Quote Link to comment Share on other sites More sharing options...
Mick Coley Posted June 5, 2009 Share Posted June 5, 2009 Hi Anthony Put a Jen57 with throttle pipe in it and you wont be disappointed!! Build it as light as you can and do all the Mods. Snap rolls and axial rolls were in the blink of an eye!! awsome. I can see why they call it WOT4!! Mick Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted June 5, 2009 Share Posted June 5, 2009 hello anthony-here is my acrowot-with a OS914st in the front................. ken anderson............ ya cannit beat a biggin...................'s.. Edited By ken anderson. on 05/06/2009 18:53:57 Quote Link to comment Share on other sites More sharing options...
Bonesmalone Posted June 5, 2009 Author Share Posted June 5, 2009 Thanks for all the prompt repsones guys, i think i`m gonna put the 46ax and pipe in the wot 4, and the jen 57 in the acro wot, Ken you have any issues with lateral balance with that sidewinder installation ????? Mick you mention Mods, any links so i can get myself clued up ???? Cheers Tony Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted June 5, 2009 Share Posted June 5, 2009 hello anthony-a small amount of lead on the opposite wing--youll find your wot's aren't really fussy about precise setting's-they have a thick wing section that will fly pretty slow-over the year's i've seen all the variation's under the sun-i've also seen some wreck's that should have been retired long ago-but the wot's are now legend's in model aircraft circle's-what ever you choose you won't be dissapointed-and the wot's are a very reliable/dependable predictable design(think i was on commision)... have fun ken anderson.......... Quote Link to comment Share on other sites More sharing options...
Mick Coley Posted June 6, 2009 Share Posted June 6, 2009 Hi Anthony, Mods are mentioned at the end of the build instructions. They include, Wing weight reduction. Two servo wing. Larger area ailerons. Tail wheel installation. Im just uploading some pics of the wot. will post when sorted! Quote Link to comment Share on other sites More sharing options...
Mick Coley Posted June 6, 2009 Share Posted June 6, 2009 Hi Anthony, If you look in my photos there are some general pics of my wot. The pic of the fractured pipe was taken after the second flight. it happened half way through the flight. I thought it was the end of the world!! the good people at Just Engines, from whom i bought it, replaced it with no charge. top company!>> My wot meet its maker at a recent fly in at Charlton Park. >> It flew like a demon all day, the circumstances of the crash I’m not sure about; felt like loss of control, my radio gear is off for repair! >> Quote Link to comment Share on other sites More sharing options...
Djay Posted June 17, 2009 Share Posted June 17, 2009 I have an RCV58 fitted to mine, and it is great, also sounds very different. Darryl Quote Link to comment Share on other sites More sharing options...
Bonesmalone Posted July 3, 2009 Author Share Posted July 3, 2009 Hi Guys, another question, the max 4st engine size for both the acro and the Wot 4 is a 90, would i be pushing the airframes to far if i squeezed my saito 100 into one of the airframes ???? Cheers Tony Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 3, 2009 Share Posted July 3, 2009 I reckon you would be OK - assuming the airframe is sound and strong. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 3, 2009 Share Posted July 3, 2009 hello anthony-not only pushing the airframe-but it's the weight of the engine really--if your going to put the saito 100 in front make sure it's well built-with the front bulkhead screwed on and backed up with some bandage and resin-do the same for the undercarriage plate and wing mounting plate...and use the best control surface link's etc........ ken anderson............ Edited By ken anderson. on 03/07/2009 18:22:10 Quote Link to comment Share on other sites More sharing options...
kc Posted July 3, 2009 Share Posted July 3, 2009 I think there something in the instructions about strengthening the tail plane and fin if you fit oversize engines. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 3, 2009 Share Posted July 3, 2009 go on -3 post's at the same time................ ken anderson..... Quote Link to comment Share on other sites More sharing options...
Bonesmalone Posted July 3, 2009 Author Share Posted July 3, 2009 I thought i may have been pushing it to be honest, Perhaps i`ll just put the Saito 72 in and save the 100 for a future project !!!! Thanks again Tony Quote Link to comment Share on other sites More sharing options...
Sheldon Holy Posted August 23, 2009 Share Posted August 23, 2009 Hi Anthony. Try and make the Acrowot lite and use the os 46. The Acrowot is a real dream to fly when kept light, with a .46, i have flown one! I flew a WOT 4 with a Irvine .53 and it climbed nearly unlimited and landed at walking pace. So put the Jen .57 in the WOT 4. I personally know Chris Foss, and in a conversation i brought the subject up and he whole-hartedly agreed. Good luck! Sheldon Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 12, 2013 Share Posted December 12, 2013 So the Acro Wot's balance point is 3.25 inches from the leading edge. Is that measured from the wing tip or at the juncture of the fuselage and wing? Bearing in mind that the leading edge of the wing is swept back, that could make quite a difference. The reason I ask is that I have just won an Acro Wot on eBay. The previous owner said he'd flown it on an Irvine 46. I fitted my red Irvine 46 and the balance point seemed to be too far to the rear. Fortunately I was able to fit an Irvine 61 to the same engine mount. I haven't yet checked the C of G with this engine fitted but I've flown an Acro Wot in the past with this engine and no additional nose weight was required. Quote Link to comment Share on other sites More sharing options...
Bob Stringfellow Posted December 12, 2013 Share Posted December 12, 2013 My AcroWot has a Jen57 with Jen Pitts Silencer, this setup fits very nicely in the cowl and sounds a bit different. Because the engine is light I have 10 ounces of Lead screwed and glued to the bottom of the Firewall. I believe the C of G should be measured at the Wing Root which I take to be the Leading Edge. This setup gives great vertical performance. Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 12, 2013 Share Posted December 12, 2013 Thank you Bob. I'll let you know how I get on. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted December 12, 2013 Share Posted December 12, 2013 Hi Tony My Wot4 has an Irvine 53 in it which gave it great performance. However, I then fitted a short throttle pipe on it and had to up the prop pitch to absorb the extra power which now gives it unlimited vertical performance - if you want it. By the way, as regards trimming the aircraft to achieve the best performance do take a peek at this thread which should answer all your trimming questions and some that you may not have considered. Click here Quote Link to comment Share on other sites More sharing options...
Braddock, VC Posted December 12, 2013 Share Posted December 12, 2013 David, the leading edge on my acrowot isn't swept back, you may have bought a clone though I can't comment on the artf version. Both Wot4s and acrowots can handle bigger power units than the box lid specifies, the limiting factor being prop size.Both fly well on a saito 82 with a 14x6 prop (2 blade), which is nearing the limit of diameter and trims grass from time to time. The wot4 with the classic wing does exhibit fairly abrupt torque roll tendencies if the throttle is slapped open though. The major benefit of fitting an engine toward the upper end of the range is that most normal flying is carried out at (much) less than full throttle whereas with a 40 or less the throttle will be open much more to achieve less performance. Benefit is less noise, of course. FWIW, my a/w or wot4 with 82 saito (which is probably just an ounce heavier than an irvine 46, I never used ballast per se, an alloy spinner and the throttle servo up under the bonnet was enough to get the balance point at the rear of the range, I also ducted the engine in the acrowot with budweiser beer bottles cut up to direct air over the cylinder and out through a cut out in the bottom of the cowl. I've gone off bud right now so will have to find something else in lovely soft alloy bottles! I used a cuphook screwed into the top of the fuselage or wing at the c of g rearward position, with a 3mm doubler beneath in the case of the a/w fuselage. hanging the plane from this makes it easy to check both the fore and aft cg and the lateral static balance. Edited By Braddock, VC on 12/12/2013 14:52:30 Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 13, 2013 Share Posted December 13, 2013 Thank you Braddock , Having put a straight edge up against the leading edge I find that there is no sweep back so the balance point is the same whether measured at the wing tip or root. With the heavier 61 engine installed the model balances correctly. What are the recommended control movements for the Acrowot? Quote Link to comment Share on other sites More sharing options...
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