McG 6969 Posted November 21, 2018 Share Posted November 21, 2018 I was thinking about your u/c Plan B, Colin. In order to have even more 'flexibility' for your rearward leg, why not use some moulding silicone instead of some bike inner tyre bits? You could build your desired ply box, get the u/c wire in position where you want it and then pour some silicone in the open/remaining space. Silicone is a lot more shock absorbing than even a soft shore rubber. Too late or too daft again, I suppose? Cheers Chris Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 21, 2018 Author Share Posted November 21, 2018 Not too late or daft at all Chris. I have been thinking about alternatives, although I have experimented with the cycle inner tube idea and it really is very resilient. Time for further thought because the process of producing the shock absorber box will be fairly late in the build. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 23, 2018 Author Share Posted November 23, 2018 Last night’s build plans went out of the window when son James and fiancée turned up! I went to Motorcycle Live this morning, but got going again later on so a bit more done. Battery position sorted out, I think it works and finally started back on the fuselage structure. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 23, 2018 Author Share Posted November 23, 2018 I left this picture off! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 25, 2018 Author Share Posted November 25, 2018 I always use the slabs outside the shed for eyeball lining up, it looks straight enough. An early morning start always helps to move things on a bit. Following Martin Fane’s approach and getting the back end done before returning to the front. Edited By Colin Leighfield on 25/11/2018 09:07:19 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 26, 2018 Author Share Posted November 26, 2018 Before fitting the 1/8” sides at the tail I thought it best to fit the tailskid. 14swg piano wire, fixed with aluminium wire and epoxy. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 26, 2018 Author Share Posted November 26, 2018 I did some more plodding tonight and hopefully can do some more tomorrow evening. Still miles behind but making progress and actually enjoying it more than the Chipmunk. Has anyone else noticed the contradictions in Dick Van Mourik’s article? In Part 2, page 42, he says it weighed 9lbs, 4300 gms and required no ballast in the nose. In Part 3, page 50, he repeated that I it weighed 9lbs but then said he had to add 10ozs of ballast in the nose! If it needed that much up front with a Laser 120 (overkill)? it is a bit worrying. Hopefully my angled battery mount will help keep that weight forward as well as making removal and replacement easier, I quite like it. The 3mm Liteply mounting plate/former also adds a lot of strength in the right place. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 26, 2018 Share Posted November 26, 2018 Looking good Colin Don't forget the diagonal 3/16 sq braces Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 26, 2018 Share Posted November 26, 2018 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 26, 2018 Author Share Posted November 26, 2018 Thanks Danny, noted! Despite doing everything I could to keep everything square I notice that there is a slight twist in the fuselage apparent when I drop the tailplane on. Can’t do anything about it now and I will square the tailplane up at the assembly stage. You might notice that I forgot about the 1/32” ply doublers. Because they aren’t featured on the plan it never occurred to me to look and somehow I missed your reference to it. Not too concerned because I can retro-fit on the outside I think, I might even replace them with 1/64” which I normally use for doublers on sheet fuselages anyway. Shortly I will be having a good look at the front end because I want to sort out the internal reinforcement around the u/c and finalise the detail of my “shock absorber box” idea. Then I need to think about the design alterations for the plug-in wings. Just seen your photo! Cheers, much appreciated. Edited By Colin Leighfield on 26/11/2018 23:08:05 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 29, 2018 Author Share Posted November 29, 2018 After a long day I made the usual mistake of sitting down in front of the TV and went to sleep! I managed to stir myself eventually and managed an hour and a half in the shed. I decided to stick with the 1/32” ply doublers that I had forgotten and spent the time doing some surgery to retro-fit on one side, I’ll do the other tomorrow. I have been pondering on the undercarriage shock absorber box scheme and decided to follow’s Chris’s thoughts and instead of using strips of bicycle Inner tube, to cast polyurethane rubber directly into the box with the wire in situ. Not having messed with this stuff before I’ve done some research and decided that a good starting point will be a Shore 60 A material, so have ordered that on line. It is going to be very interesting. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 29, 2018 Share Posted November 29, 2018 Should be interesting to see how you get on Colin. I have meant to get some myself, for moulding tyres..... one day... Cheers Danny Quote Link to comment Share on other sites More sharing options...
Martin Fane Posted November 30, 2018 Share Posted November 30, 2018 Hi Colin Where's the 1/32 doubler? I don't recall fitting it myself 🤔 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 30, 2018 Author Share Posted November 30, 2018 Hi Danny. It’s a far from new idea, Graham Smith was doing it 35 years ago! I remember him building a 96” span Miles Messenger that was so light it flew in a beautiful scale fashion with a Veco 61, his favourite engine. The plan was published in one of the magazines. He moulded the tyres for that and they were perfect, even down to the Goodyear logo. When I saw him with the Short Scion at Shawbury it didn’t sink in that it could be the same Graham because he looked so different, but I increasingly think it was him. He was a regular in the UK world r/c scale model championships in those days and his skills as a designer, builder and flyer were astonishing. He must be around 80 now, he is definitely worth talking to and if I see him again I will renew the acquaintance. If this works, the next time I do a fixed undercarriage like this I will try fitting both legs this way, that will give suspension and damping independently of the wire and get rid of fiddly springs. Hi Martin, it looks as if you have been caught out in the same way as me! It extends from the nose in front of F1 back to F2, full depth except 3 or 4 mm at the bottom on mine. If you look at the photo I posted last night you can just about see it. I toyed with the idea of leaving it out or replacing with 1/64” because I don’t think it would be a disaster, but in the end decided to do it after all. Edited By Colin Leighfield on 30/11/2018 07:51:31 Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 30, 2018 Share Posted November 30, 2018 Andy showed the 32nd doublers on his build as his is IC. I omitted them from mine deliberately as mine is electric and I didn't think the ply was recquired. Cheers Danny Quote Link to comment Share on other sites More sharing options...
Martin Fane Posted November 30, 2018 Share Posted November 30, 2018 Ah yes, now I recall. I'm electric so don't think I will do the surgery and install. Thanks for the replies gents. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 30, 2018 Author Share Posted November 30, 2018 Sorry Danny, I thought you had fitted them anyway, so my mistake. However everything I read on this tells me there is a serious risk of rearward c of g without some nose ballast, so a bit of extra weight up front might not be a bad idea ! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 1, 2018 Author Share Posted December 1, 2018 Got some more done this pm. Altered FS1 and 2 as per Danny’s advice. Also because I’m slightly concerned about ensuring that the engine cowl fits snugly on F1 I cut a 1/32” ply former using the cowl as the pattern, drawing around it with a pencil. Glued it onto the front of F1. Also starting to think about what issues there might be in fixing the cabane to suit plug-in wing panels. Should be able to get some more shed time in tomorrow! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 3, 2018 Author Share Posted December 3, 2018 Unfortunately I remain a long way behind but plod on, it is slowly taking shape. This certainly is a classical build, quite similar in many ways to a KeilKraft 3 shillings and 8 pence scalejob!scale job! I hope it flies better. Edited By Colin Leighfield on 03/12/2018 17:37:46 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 4, 2018 Author Share Posted December 4, 2018 More stringers tonight. I hope to get back onto the front end tomorrow some time. The polyurethane resin pack has arrived and I will make a small test piece before working on the undercarriage. Just wondering if I could use the idea to mount the complete undercarriage to provide shock absorption and damping in all three axes. Might not be that difficult to do. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 10, 2018 Author Share Posted December 10, 2018 Because of family commitments and other things I haven’t been able to touch this since last week, but managed to do a bit tonight and should be able to have another go tomorrow evening. I’ve finished all of the stringer detail including underneath. I’m looking around the wing seat and cockpit area sheeting next. One problem I have is that despite careful sorting I haven’t been able to find any 1/8” balsa that is what I would consider to be “soft”, the best I can find is more my idea of “medium”. It looks as if it will curve ok so will have to do. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 15, 2018 Author Share Posted December 15, 2018 This is where I am now. Wing seats done after a couple of mess-ups. The starboard sheeting done so far with a single piece of 4”x3/8”. The shape moving forward looks about right, although slightly out around F3 but sanding will sort that out, I think. Photos are the wrong way around, the last one shows the area behind the lower wing seat before I did the wing seats. Edited By Colin Leighfield on 15/12/2018 19:08:50 Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted December 15, 2018 Share Posted December 15, 2018 Well done Colin Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 15, 2018 Author Share Posted December 15, 2018 Thank you Danny! Sorting is out as I go along! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 17, 2018 Author Share Posted December 17, 2018 Left side sheeting in place, again a single piece of 4”x1/8”. Quote Link to comment Share on other sites More sharing options...
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