AVC Posted December 11, 2015 Share Posted December 11, 2015 Kc, I agree with your analysis, and I know that with this little tail and short tail moment, the effect of the difference in weight (if any) will be minimal. I'll do it that way just because I like open structures. Having said that, let's do the test: I'll weight the tail group once built, and we will compare with your solid one, ok? Quote Link to comment Share on other sites More sharing options...
kc Posted December 11, 2015 Share Posted December 11, 2015 Peter advised ( as I expected ) that1/16 ply is the stuff for templates. But of course many people won't have 1/16 in stock as it's not used in Ballerina. Simply laminating two layers of 1/32 will produce 1/16 though. ( obvious but you dont't always think of the simple solution ) Using thicker ply is possible but you get the chance of something similar to parallax when you run the knife around. Thinning the edges works better if you have to use 3mm or 1/8 ply. Nicer to work with thinner ply though. Quote Link to comment Share on other sites More sharing options...
Levanter Posted December 11, 2015 Share Posted December 11, 2015 It's not just weight with built up surfaces. Correctly arranged and especially if curves are laminated, they will be stronger and more resilient than sheet surfaces because the grain of the wood can be aligned better with the stresses. Besides they often be made from offcuts and can be much fun to do. Quote Link to comment Share on other sites More sharing options...
AVC Posted December 11, 2015 Share Posted December 11, 2015 Posted by Levanter3 on 11/12/2015 12:15:40: Besides they often be made from offcuts and can be much fun to do. That's my main driver! Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 11, 2015 Share Posted December 11, 2015 Posted by Peter Miller on 11/12/2015 08:22:06: I use 1/16" ply. It won't change shape because you are cutting round it and you have to be pretty cack handed to carve lumps of ply off over 20 odd ribs. I'm cack-handed in the extreme My ally Limbo rib template is stored in a lever arch file along with the Limbo kit instructions (my plan-built one was built after I destroyed a kit-built one ) My bandsaw cuts an ally template as easily as a wooden one. Your comments about the built-up tail are very welcome and very wise. I'm sure it won't make much difference in weight but it will look nicer and that's also part of the exercise. We must be bothered about appearance, I guess, or we would fit neither pilot nor windscreen or have a fancy covering scheme either. Never the less it will be interesting to see just what the difference is. I have been known to insert a hardwood strip in a soft balsa tail plane because I lacked confidence it would be stiff and strong enough without it. Again, probably unnecessary. Geoff Quote Link to comment Share on other sites More sharing options...
kc Posted December 11, 2015 Share Posted December 11, 2015 Having fun is what we do it for! But we are getting carried away here.....all this modification is for the experienced builders. Novices should stick to solid tail surfaces. There is a saying that "imitation is the sincerest form of flattery" so I think Peter should consider " customisation is the sincerest form of aeromodelling flattery" as the principle here. However with so many building the same model the comparison between various weights will provide useful data. I expect the best solid tail will be pretty near the weight of the builtup version while the worst solid one will be twice as heavy. But they will all fly well. Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Found my last hour for a bit of work today before the Christmas rush comes so utilised it as best I could. Made a start of doing some ribs. Wanted to do all of them but the bolts I had were not long enough. Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 I learned not to leave so mush excess wood around ribs today. Took me ages to sand and plane the waste off. I'll do a tiny bit more sanding on them when I get a bit more time. Them on to the rest of the ribs. Edited By Craig thomas 1 on 11/12/2015 17:09:38 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 11, 2015 Share Posted December 11, 2015 There are not many construction pictures in the magazine article. May I suggest going and looking at my orignal build blog. http://www.modelflying.co.uk/forums/postings.asp?th=108004 You will find a lot more which may help clarify anything you are not sure about Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 I've studied your build thread over the past week. Still confused on some things such as the wing trailing edge and aileron trailing edge construction. Put it down to lack of experience. So will be relying on other build threads with plenty of pictures. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 11, 2015 Share Posted December 11, 2015 The trailing edge is made up from two strips of 1/16" sheet, one above the ribs one below. These joun right on the end of the ribs. You then shape the strip of 1/8" X 3/8" balsa to a trailing edge section and join it on to the wing where the two aofore mentioned sheet ends. As an alternaive ypou can make the trailing edge 1/16" sheet 3/8" wider and shape a chamfer and join them lined up with the rear of the winv. Much harder to do a neat job. |I think I explained this somehwere else but here it is again. Actually if you look at the section on the plan where it says "Section at bellcfrank" it shows it very clearly. That particular bit of the plan is right at the left of the wing I hope that that will make itclear Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 The bit I can't figure out in my head is the how the trailing edge hard stock fits in? The ribs taper to to a point, and them I'm supposed to glue a another tapers strip of wood to that. I know it will make sense when I see a picture but at the moment I can't see it? Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Unless, not I think when the 2 1/16 sheets meet, you sand them to a straight edge, and then glue the trailing edge stock to that? Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 11, 2015 Share Posted December 11, 2015 There will be a cut out in the "buillt up" trailing edge of the wing for the aileron. That's where the trailing edge sits in to make the moving aileron. When fitted and hinged the overall trailing edge should line up along the wing. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted December 11, 2015 Share Posted December 11, 2015 Posted by Craig thomas 1 on 11/12/2015 20:36:28: Unless, not I think when the 2 1/16 sheets meet, you sand them to a straight edge, and then glue the trailing edge stock to that? Yep, it's a bit of hard straight stuff to give a nice crisp t/e...cut/sand to get a nice blend in John Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Ha. I think I have an understanding of it now in my head Peter. The 2 1/16 strips meet up, to create a flat surface. Then glue onto that. Boom. Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 The more I understand it the more excited I am to build it. I'm just hoping my wood working skills are up to the job. Knowing my luck when the planes finished 1 wing will be pointing up and the other one pointing down. Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 11, 2015 Share Posted December 11, 2015 Knife edge! Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted December 11, 2015 Share Posted December 11, 2015 Best advice Craig is to go over and over the plan till you know it well, any areas you are unsure of, try sketching the structure on paper to see if your view of it works Quote Link to comment Share on other sites More sharing options...
Rosco Posted December 11, 2015 Share Posted December 11, 2015 To be honest, I've been following this thread for a little while now and I thought making the ribs was 'building' but I also don't want to be the fun police either.The other thing I have thought was that this MB is also starting to get a bit too serious. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted December 11, 2015 Share Posted December 11, 2015 Posted by Craig thomas 1 on 11/12/2015 20:49:37: Ha. I think I have an understanding of it now in my head Peter. The 2 1/16 strips meet up, to create a flat surface. Then glue onto that. Boom. That is what I said and that is what the section at the bellcrank shows. Just look at that drawing Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted December 11, 2015 Author Share Posted December 11, 2015 Posted by Rosco on 11/12/2015 21:06:12: The other thing I have thought was that this MB is also starting to get a bit too serious. I'm with you on that one! But don't worry too much - everyone is sitting there with itchy scalpel fingers! Once the build proper starts and we start cutting bits of wood and gluing them together things will lighten up! BEB Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted December 11, 2015 Share Posted December 11, 2015 Guess I've been told off. 🙄 Well rest assured no more progress in cutting parts will be made. Today was my last bit of free time, the rest of the month will be taken up with a heavy work load and young kids. Roll on January when we can all get stuck in. 🙃🙃🙃😇😇😇😋😋😋 Edited By Craig thomas 1 on 11/12/2015 21:49:32 Quote Link to comment Share on other sites More sharing options...
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