Martin McIntosh Posted January 6, 2020 Share Posted January 6, 2020 When building the Tn Concorde I got sent a 64mm Power Fun EDF in error but decided to keep it with a view to doing a larger version of the Gnat. I decided on the Hunter instead since it has always been my favourite jet and my hand will fit round it better for launching. I got the plan blown up to 133% which makes the fan a perfect fit. I stayed with 1/4" for the wing but fitted some carbon spars for insurance. I substituted 1/4x3/16 for the stringers and 1/4 and 1/8 for the rest of the fus. to keep the wood volume in proportion. The 250 micron thrust tube, which I have used before, just had a mind of its own so I changed it to thin card. Much easier. This fan has mounting lugs so I used them. Unfortunately it twisted round a bit during fitting the blocks so is rather permanent. The wing slots need a little more cutting to get it through both sides. More later. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted January 6, 2020 Share Posted January 6, 2020 Although oversize i guess it still qualifies for the 2020 mas build Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 6, 2020 Author Share Posted January 6, 2020 Didn`t know the Hunter was the subject of a mass build considering that the free plan has only recently appeared. There must then be a thread on here somewhere about this. Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted January 7, 2020 Share Posted January 7, 2020 Announced in this thread Martin. Any of the Mini Jets is allowed. Announcement I also have a spare 64mm fan, but think I would prefer the TSR2. Kev Edited By Kevin Fairgrieve on 07/01/2020 08:32:24 Quote Link to comment Share on other sites More sharing options...
Toni Reynaud Posted January 7, 2020 Share Posted January 7, 2020 SIlly question maybe, but I notice there is no taper on your thrust tube. Shouldn't it close down a bit so the exit equals the area of the fan duct minus the area of the motor to maintain the airflow and thrust? Quote Link to comment Share on other sites More sharing options...
Nightflyer Posted January 7, 2020 Share Posted January 7, 2020 Glad its the TN Mini Jets. I am about to start the Gnat for myself, and my son has the Hunter. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 7, 2020 Author Share Posted January 7, 2020 Your eyes deceive you Toni, it is just the camera angle. Everything is exactly as per original plan plus 33%. Made a start on the 1/8th fus. sides, the first of which has the tapered piece glued down, then after coating with ammonia, rubber banded down and allowed to dry has been glued in position. I found it best to glue the stringers to the, in my case, 1/4" sides. Now wish that I had cut the stringers from a lighter grade of balsa since the weight is building up. I have had to make short extentions to the motor wiring otherwise it would be impossible to connect up at a later stage. Not happy with the TGY DeLux esc I intended to use since the start up refuses to budge from 20% throttle so have ordered a YEP 60A. Also, my current 2650, 2700 and 3000 packs do not deliver the oomph of a new 4500 so have ordered a couple of the rather expensive 4Max packs. Probably my fault for not putting them on a storage charge. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 9, 2020 Author Share Posted January 9, 2020 As the guy says, there is a lot of whittling to do on the fus., and I have hardly started. After adding the top and before planing down I shall need to add the parts for a canopy plug. Can anyone remember the mag. issue the article on making these using a mastic gun frame was in, or how to recall the tutorial on here because I have only had limited success with a vac former and have no intention of going down that route again. Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted January 9, 2020 Share Posted January 9, 2020 Check the December 2019 magazine. David Ashby mentioned it in his column. It is in the 2019 Special issue page 116. I used the very same method to make a canopy for my Mini Jazz. See here. HTH Kev Edited By Kevin Fairgrieve on 09/01/2020 21:12:00 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 10, 2020 Author Share Posted January 10, 2020 Thanks for that. It was the original Tim Hooper article I was after but I now have enough info. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 15, 2020 Author Share Posted January 15, 2020 Sort of got a canopy made now but a bit wobbly on one side. Main problem is that it well and truly stuck to the sanding sealer finished plug but have scraped off the offending bits and can restore to gloss internally with some clear lacquer. Should have given it a dusting of baby powder first I suppose. I tried drawing pins to hold the acetate to the wooden base but that did not work so I stapled it on. Fin, rudder, tail and most of the strake done and will probably cover as many pieces as I can before glueing on. Cheat hole, access hatch and nose cone next. I now have the ESC and batteries but cannot test until the hatch is cut out. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 16, 2020 Author Share Posted January 16, 2020 I now have the hatch and cheat hole cut out so have programmed the YEP 60A and tested. A healthy 45A/500W resulted from either a 4max 3300 or 2600, both of which seem to fit OK without cutting into the wing LE. With just the wing and battery in place the cg is correct but there is a lot else to add so may have a rethink on the servo positions before I continue, even though these are very light. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 26, 2020 Author Share Posted January 26, 2020 Now considerably advanced. There are a few pitfalls to get round on this model which were not apparent when I started, particularly covering round the nose and aligning the fin, strake and access hatch. I have made a second attempt at the canopy which is much better.The fin is not yet glued on until I have the other intakes fitted. These were covered inside and out before fitting to prevent warping (3/32balsa) and the LE`s fitted with 2mm wide carbon strips. I had to increase the width of the upper ones a bit from that shown on the plan. Basing this on XF527 gate guardian at the local RAF Halton. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted January 26, 2020 Share Posted January 26, 2020 Watching with interest, keep at it............ Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 5, 2020 Author Share Posted February 5, 2020 Some pics of the finished model ready to go. Quote Link to comment Share on other sites More sharing options...
Jon Laughton Posted February 5, 2020 Share Posted February 5, 2020 That's a stunning model build Martin - well done! Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted February 5, 2020 Share Posted February 5, 2020 Brilliant stuff Martin, looking forward to hearing how she flies. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 5, 2020 Author Share Posted February 5, 2020 Thanks guys. The basic weight is 1lb 14oz, 850gm. A 3300 is 9oz, 259gm but would require nose weight. A 4500 is 12 1/2oz, 355gm and can be moved to get the cg correct so I shall go with this. Should give a good flight time at 45A max, 500W. When left to my own devices I generally build quite light but am a bit surprised at just how much the 133% version weighs. It is certainly not lighter than air but there seems to be considerable thrust. On another thread I stated that I built a Dalotel at 10% larger than the 60 version for an OS 91FX. Rubbish on that but with a YS 110 it is brilliant. Hope that does not turn out to be the case with this model but 133% is the bare minimum to get a 64mm in. Due to the state of the patch and parking area at the moment I don`t know when I shall next be there to try it. Spent half the day sorting out my collection of balsa etc and did not realise just how much I had, so what next? Quote Link to comment Share on other sites More sharing options...
Dave Chatterton Posted March 4, 2020 Share Posted March 4, 2020 Thanks Martin , your guide did the trick. This is my attempt. Quote Link to comment Share on other sites More sharing options...
Dave Chatterton Posted March 4, 2020 Share Posted March 4, 2020 And the gnat Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted March 4, 2020 Author Share Posted March 4, 2020 Looks better than mine Dave, great job. Just added some trim to the canopy of my Gnat, but that is on a separate thread. Quote Link to comment Share on other sites More sharing options...
Dave Chatterton Posted March 5, 2020 Share Posted March 5, 2020 Thanks Martin. Love your crisp lines. Just had to do major surgery on it as found when putting the battery well up front to get the c of g that I had loads of trouble getting it out so cut a hatch underneath which was a pain but sorted battery probs out. Quote Link to comment Share on other sites More sharing options...
Dave Chatterton Posted March 5, 2020 Share Posted March 5, 2020 It’s also come out at 24oz inc battery which I am not pleased about. Quote Link to comment Share on other sites More sharing options...
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