cymaz Posted October 11, 2016 Author Share Posted October 11, 2016 Update .... At 3/4 throttle and the standard rudder movement ( out of the manual ) about 2-3mm of opposite aileron was dialled in and some 3-4mm of up elevator. A switch on the Tx was used to turn it off just in case of mishaps. Well, it seems to have worked. The tuck under is now not happening at all. There is enough control still on the sticks should the plane want to rock in cross winds. A good result, chuffed Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted October 22, 2016 Share Posted October 22, 2016 Posted by Kim Taylor on 27/09/2016 17:33:08: Copied this over from my 'prop selection' thread in the electric flight section, just to tie up loose ends! I have just had time to run a couple of different sized props, with results as follows: Using a freshly charged 6s LiPo in each case, on the previously tested 16x8, 86A , 1840w. 21.5v Then fitted a 15x8 and recharged the battery and got 70A, 1550w, 22.1v. All of the above are measured between LiPo and esc. Unfortunately, still no means of checking revs. From here, I've decided to use the 15x8 initially, based on the assumption that it'll unload a little in the air. Also, I've noted that coming only two 'clicks' back from W.O.T. reduces the current draw to 45A. If I get the magic smoke so be it, at least I'll know not to push things so far in the future!! Test flight as soon as the weather breaks and the wind drops on a day when I'm not working and my instructor is available - should be about a week next Michaelmas. Kim So, today was the day - finally maidened the elctrified Wot4 XL. Due to my inexperience I got Alen, my long suffering instructor to do the honours. I used the 15x8 prop as I proposed above and my thoughts were correct as no overheating of any of the components was noted post flight. On the strip, Alen reported a strong pull to the left which he managed to correct, and off she went, climbing strongly. A couple of clicks on the ailerons were required to keep the wings level but Alen noticed that the trim in pitch was affected excessively by the throttle position, which he put down to the c of g being too far forward. He passed the tranny over to me and I did a few circuits, but found that I was struggling with the nose dropping excessively when banked over. Anyway, by this time the timer, which I'd set conservatively at 5 minutes, was sounding, so I passed it back over to Alen for it's first landing. I checked that nothing was getting too hot as I mentioned previously and checked the LiPo which believe it or not had 75% remaining. The c of g was re-checked and I reckon it was at 103 from the leading edge, rather than the 105 mm minimum recommended. Some stick on weights (all we had) were added to the tail end, which brought the c of g to 106 mm. I also set the flight timer to 8 minutes. The next flight Alen had a bit of fun straight after takeoff, pulling her vertical and climbing hard up to 300 ft or so, so I guess we can confirm that the motor is powerful enough!! This time she felt much better, the trim change in pitch being much less pronounced, and not dropping her nose so readily in turns. After 8 minutes, there was just under 50% remaining in the LiPo, so I think eventually 10 minutes will be achievable with my style of flying, with a useful reserve if it's needed Before the next outing I'm going to work on getting the c of g back, so that we can play around in the 110 to 115mm range. I'll mod the battery tray so that I can move it back a few mil and on the recommendation of Alen I'm going to separate out the electrical supply to the radio with a dedicated battery, which I can then use to fine tune the balance. And that's it - she flies! All I need to do is increase my skill level to do it justice. Kim Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted October 22, 2016 Share Posted October 22, 2016 Further to the post above, just looked and 105 was the rearward end of the recommended range, not the front. Still going to move it back further though, it definitely feels better where it is now than at 103, where it was positively trying to drop it;s nose and the landing was a bit fast. Kim Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 22, 2016 Author Share Posted October 22, 2016 Its such a forgiving wing that you can go back further than the book recommends without too much risk of danger. Quote Link to comment Share on other sites More sharing options...
Graham Penfold Posted August 1, 2017 Share Posted August 1, 2017 I know the WOT4 XL build is now done and dusted but I am building one and there is a piece of covered square ply with a slot in it that I have no idea what it is or where it goes. Can anyone please help. Many thanks Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted August 2, 2017 Share Posted August 2, 2017 Posted by Graham Penfold on 01/08/2017 23:39:23: I know the WOT4 XL build is now done and dusted but I am building one and there is a piece of covered square ply with a slot in it that I have no idea what it is or where it goes. Can anyone please help. Many thanks If you look carefully at the underside of the wing, you can see a cut out below the covering for a glider tow release. The square bit of ply is a fairing to cover up the release mechanism when it's fitted. What motor have you used? I built mine as an electric but now I'm looking at converting to i.c. and I'm looking at alternative motors. Atm the ASP .91 2 stroke is favourite!! Kim Quote Link to comment Share on other sites More sharing options...
cymaz Posted August 2, 2017 Author Share Posted August 2, 2017 Posted by Kim Taylor on 02/08/2017 14:48:42: Posted by Graham Penfold on 01/08/2017 23:39:23: I know the WOT4 XL build is now done and dusted but I am building one and there is a piece of covered square ply with a slot in it that I have no idea what it is or where it goes. Can anyone please help. Many thanks If you look carefully at the underside of the wing, you can see a cut out below the covering for a glider tow release. The square bit of ply is a fairing to cover up the release mechanism when it's fitted. What motor have you used? I built mine as an electric but now I'm looking at converting to i.c. and I'm looking at alternative motors. Atm the ASP .91 2 stroke is favourite!! Kim I use a 20cc petrol...love it Quote Link to comment Share on other sites More sharing options...
Graham Penfold Posted August 2, 2017 Share Posted August 2, 2017 I am fitting a YS140FZ with a Hatori silencer, which I have had for some time. A bit over the top maybe but will find out soon enough🙁. Many thanks for the info and solving my mystery. Quote Link to comment Share on other sites More sharing options...
cymaz Posted August 2, 2017 Author Share Posted August 2, 2017 Posted by Graham Penfold on 02/08/2017 17:20:15: I am fitting a YS140FZ with a Hatori silencer, which I have had for some time. A bit over the top maybe but will find out soon enough🙁. Many thanks for the info and solving my mystery. WOW....Wot formula1 ! Quote Link to comment Share on other sites More sharing options...
Graham Penfold Posted August 2, 2017 Share Posted August 2, 2017 😥 Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted August 2, 2017 Share Posted August 2, 2017 I've looked at petrol motors but the downside for me is the weight of a 20cc, which I think is the minimum viable size. The main reason for the change to i.c. is to reduce the weight of the electric setup, which is 10lbs with a 5800mAh lipo. I'm putting it on a diet where I can, such as getting a carbon fibre u/c which saves about 4 oz. and I may trade off a bit of duration and use a 4000 - 4500 lipo which will save 6 - 8 oz. Kim p.s. I know if I use a petrol I won't be carrying as much fuel, so weight saved there!! Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted August 3, 2017 Share Posted August 3, 2017 The one I am shortly going to assemble will have my OS AX 120 2s in it running a 16 x8 prop . It's loads of power and will be a tug plane. I have had this engine in a Wot 4 XL before and it's "fully powered " ! Take of is instant and vertical unlimited. If I had choice of any engine for this plane it would be a 120 four stroke. Quote Link to comment Share on other sites More sharing options...
cymaz Posted May 8, 2020 Author Share Posted May 8, 2020 In a mad moment I thought, “ How difficult would it be to put a spare 30cc motor in my Wot4 XL?” After checking the firewall and bolt spacing, it sits in nicely. The only biggish job was to drill two new top mounting holes for the standoffs. Behind the firewall I made and fitted an aluminum back plate ( similar in shape to an electric motor mount) to spread the loads over all the ply rather then in just 4 specific points. All I need to do after dinner is to tighten and loctite a few bolts down and do a run up. What could possibly go wrong Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 8, 2020 Share Posted May 8, 2020 I've fitted a 25cc V Twin to mine. I don'r know what could possibly go wrong but it'll certainly sound better than yours. Quote Link to comment Share on other sites More sharing options...
cymaz Posted May 8, 2020 Author Share Posted May 8, 2020 “What could possibly go wrong” It did....checked the tank on fueling..leaking stopper. Replumbed the tank, still leaks. I reckon I’ve lost my tank build mojo. Fed up as I couldn’t run it up in the garden and set up the idle and end points, so bought one of these as retail therapy. Feel better now Edited By cymaz on 08/05/2020 17:45:21 Quote Link to comment Share on other sites More sharing options...
cymaz Posted May 24, 2020 Author Share Posted May 24, 2020 Should be doing a test flight soon. I purchased one of these. We have a site noise limit of 84 dB @ 7m. Having done a test in the back garden, it should be right on the limit. It’s lost 800 rpm at WOT. I’m using an Aerostar 19x8. There seems more than enough pull. Quote Link to comment Share on other sites More sharing options...
cymaz Posted June 2, 2020 Author Share Posted June 2, 2020 Put a tank of fuel through the DLE 30 it took about 35-40 mins. Ran the engine for 5 mins at a time @ under 4000rpm, as per manual. the engine was given time to cool thoroughly and repeated. Compression has improved markedly only just after this short run. Quote Link to comment Share on other sites More sharing options...
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