Gary Binnie Posted August 31, 2010 Share Posted August 31, 2010 Hi folks, I have acquired a Chris Foss Xtra Wot virtually ready to go but sans instructions. All I would like to confirm is the centre of gravity position and the control throws for both rates if anyone has some instructions lying about. I could ring Chris but I've bothered him too much lately!! Cheers Gary Quote Link to comment Share on other sites More sharing options...
IanP Posted November 11, 2010 Share Posted November 11, 2010 Im in the same boat.This information would be much apprciated. Thank, Ian Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted November 11, 2010 Author Share Posted November 11, 2010 Ah well, I think I found it on another forum. The writer said 105 mm aft of datum (wing root leading edge) so I put a couple of stick-on dots there. Seemed in a reasonable position and holding it upside down on two fingers (not the easiest thing to do with this beast!) showed that it balanced there without any extra weight needed nose or tail. This is with an ASP 120 two-stroke. I've seen lead used under the tailskid with Laser 150s. Only way to find out was to fly it. No problem at all, quite stable (but responsive), spins nicely and recovers quickly and is docile at low speed. I like it a lot, only problem is fuel consumption (can use a gallon in a session). Cheers Gary Edited By Gary Binnie on 11/11/2010 13:19:30 Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted November 11, 2010 Author Share Posted November 11, 2010 For control throws I just set up two reasonable looking ranges with lots of exponential on the lower one (just in case it was 'twitchy'). The elevator doesn't need much throw at all but I like to be able to hold full 'up' for taxiing (which would be better with a tailwheel, mine has the supplied skid) to stop 'nose-overs', the expo comes in handy for that. GB Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted November 11, 2010 Author Share Posted November 11, 2010 I've had problems with the new ASP (not unusual apparently), rough idle and cuts-out in flight for no apparent reason. Have spent ages fiddling with needle settings. When it's 'on song' though it goes well. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted November 11, 2010 Share Posted November 11, 2010 Might be worth looking at a petrol conversion for the ASP.......a gallon a session....Wow!!! Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted November 11, 2010 Author Share Posted November 11, 2010 Yep!! I thought it was because I was running it deliberately rich but as it's bedded in and I've leaned it off a bit it still drinks the stuff (and I close the throttle sometimes)!! Might see if it is happy on less nitro or even straight fuel as that is the expensive part. After a few years away from power flying (I mainly build and fly gliders now) the oily mess is a pain. I'm using an oldish Futaba FF6 just for the power models, no matter how well you wipe your hands it still plasters the tranny! This is not such a problem for petrol jobs apparently but the fuel must still have oil in it? I'd like to put the 'slimers' on 2.4 but don't want to mess up my DX-7. Have a plan to get a nine-channel 2.4 Tx and then use the DX-7 for the power jobs. I get strange rudder glitching with my Wots-Wot, usually when it is flying towards me (nose on) and if I point the aerial directly at it, it worries me a bit. There are a couple of guys flying petrol engines at my field, I've had a chat with them about changing the engine. The Xtra-Wot seems to be in a too small size bracket for petrol engines but I don't really know what's out there and have never used one. The intention was when I bought this model 'ready to go' was to see if I liked it and then buy a new kit and build it with all the fancy carbon bits and possibly a different engine. I do like it but have not got round to ordering a new kit yet (saving up!)!! Cheers Gary Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted November 11, 2010 Share Posted November 11, 2010 Not done a petrol conversion myself but there are a good few members of the forum who have done......might be worth a search around..... Just Engines (see here & here & here) & others offer CDI kits to convert your engine.....you need a magnet in the prop driver to trigger the sensor....mount the sensor on the crankcase, swap the glow plug for a spark plug....fit an extra 4 cell battery to power the ignition, .fill the tank with petroil (after changing the bung & fuel tube obviously) & away you go.......easy when you've never done it....!!!! Petrol motors use about 1/3rd the fuel that glow motors do & because they run on much lower oil contents.....30, 40 or even 50 to 1 you don't get the same residue running down the model.... Personally I think it would be a great feature in RCM&E.....give a typical aeromodeller an engine & a conversion kit & see how he gets on.....are you listening David???? Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted November 11, 2010 Author Share Posted November 11, 2010 I'm a 'typical modeller' I think, gimme one David and I'll see what I can do!! Good idea Steve. Seem to remember 'Brown' petrol engines floating about at Old Warden in big free-flighters, happy days. GB Quote Link to comment Share on other sites More sharing options...
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