Spikey Posted May 16, 2013 Author Share Posted May 16, 2013 I did, Ted, and they didn't really! Ref the ribs, I reckon it's another cockup. What do you guys think? **LINK** Bear in mind that those ribs are laser-cut. The cutouts for the 1/32 trailing edge sheeting is spot on, so capstrips are not an option. I seem to have two choices - either add strips of balsa between each rib, stuck to the leading edge of the spar and 1/32 below it so I have something to glue the sheeting down to, or finish the sheeting on top of the spar and pass the resultant step off as deliberate. I really do not fancy carefully fitting 20 extra bits of spar, so can anybody convince me that a 1/32 step down behind the balsa sheeting would cause problems? Edited By Spikey on 16/05/2013 13:41:00 Quote Link to comment Share on other sites More sharing options...
kc Posted May 16, 2013 Share Posted May 16, 2013 A good butt joint to spar should be OK if you cannot lap the spar with the sheet. However it looks to me as though the spar slots need to be deeper by 1/32. Just a touch with a file should do it assuming LE sheet is big enough to cover spar. Then it should all fit, but first double check the size of the actual spar material. No a step would not do much harm but it wont be there because the covering will stretch from LE sheet to TE sheet! The sheeted centre section is the place where a step will occur, but its under the rubber bands anyway. Edited By kc on 16/05/2013 15:12:56 Quote Link to comment Share on other sites More sharing options...
Spikey Posted May 16, 2013 Author Share Posted May 16, 2013 Posted by kc on 16/05/2013 15:08:24: No a step would not do much harm but it wont be there because the covering will stretch from LE sheet to TE sheet! Yes of course, you're right. It won't matter, so I'll just glue the sheeting to the top of the spar and have done with it. Onwards and upwards. Hopefully. Quote Link to comment Share on other sites More sharing options...
PatMc Posted May 16, 2013 Share Posted May 16, 2013 Posted by kc on 16/05/2013 11:39:40: I interpret the dotted lines on the tailplane as 1/8 strips underneath.......the top is 1/8 by 1.25 because it glues onto the fuselage but underneath it only needs strips. But the spanwise dotted line seems wrong it should just be along front of the TE. The strips are sanded to airfoil shape. All my opinion as I have not built the model. The chordwise dotted lines show the 1/8 sq spacers that are part of the centre frame of the tailplane. The 1.25 wide 1/8 sheet is glued to this top & bottom then sanded to give a symetrical section. The original plan had the tailplane held with elastic bands hence the sheet underneath. The spanwise dotted line at the TE is correct it denotes a reinforcing piece of 1/6 x 3/16 balsa but there should be no dotted lies across the spar or the LE. Quote Link to comment Share on other sites More sharing options...
PatMc Posted May 16, 2013 Share Posted May 16, 2013 IMO it would be best to deepen the spar slots by 1/32 or second choice - butt join the sheet to the spar LE. Quote Link to comment Share on other sites More sharing options...
david williams 9 ( whizzo) Posted May 16, 2013 Share Posted May 16, 2013 Hi spikey i.m sorry to you see you not having a good time so far building your MT. The problem by what you have described is the ribs are cut wrong. The plan shows the top of the rib forwood of the spar is 1.32.lower than the spar. I personally build straight from plan. Several evenings just looking at the plan and solving any problems. Then from templates i make a kit of bits. Try all parts against plan. When happy i dry assemble before commiting to glue.I found the MT a pleasure to build .Hope the rest of your build goes well spikey. As i said in earler reply its a great little aircraft that flys well. But the name on the plan after all is Mr David Boddington. Quote Link to comment Share on other sites More sharing options...
PatMc Posted May 16, 2013 Share Posted May 16, 2013 Posted by david williams 9 ( whizzo) on 16/05/2013 20:20:46: Hi spikey i.m sorry to you see you not having a good time so far building your MT. The problem by what you have described is the ribs are cut wrong. The plan shows the top of the rib forwood of the spar is 1.32.lower than the spar. I personally build straight from plan. Several evenings just looking at the plan and solving any problems. Then from templates i make a kit of bits. Try all parts against plan. When happy i dry assemble before commiting to glue.I found the MT a pleasure to build .Hope the rest of your build goes well spikey. As i said in earler reply its a great little aircraft that flys well. But the name on the plan after all is Mr David Boddington. DB's original plan had the 1/32 on top of the spar. **LINK** Quote Link to comment Share on other sites More sharing options...
david williams 9 ( whizzo) Posted May 16, 2013 Share Posted May 16, 2013 Thanks for a look at the original plan i have not seen one. But i note the differance is the rear of the rib is 1.32 higher not the front as on the RCME freebie. I think i was politly try to say check everything against plan before assembly. Not sure how i got same posting twice sorry. Quote Link to comment Share on other sites More sharing options...
Spikey Posted May 17, 2013 Author Share Posted May 17, 2013 Posted by david williams 9 ( whizzo) on 16/05/2013 21:19:14: But i note the differance is the rear of the rib is 1.32 higher not the front as on the RCME freebie. I think i was politly try to say check everything against plan before assembly Cheers David. Having now seen the original plan, I think it's a real shame that nobody seems to have checked the conversion of it to CAD. Ref checking everything against plan before assembly, that's what I did when I built my Lazy Bee from the plan. The mistake I made here was my naive assumption that £44-worth of kit put out by the publishers of RCME would have been checked before it was offered for sale. Funnily enough, the reason I bought the confounded kit in the first place is that I wasn't confident of my ability to cut 22 relatively small ribs accurately enough for the 1/32 sheeting! But hey ho, we live and we learn. Eventually Edited By Spikey on 17/05/2013 07:29:55 Quote Link to comment Share on other sites More sharing options...
GONZO Posted May 17, 2013 Share Posted May 17, 2013 The method for this type of leading edge design:- 1/ fix leading edge sheeting to leading edge spar, with sandable glue, right up to the front edge/corner(the pointy bit) 2/ when dry sand sheeting and leading edge to make a suitable shape by 'feathering' in the sheeting to the leading edge spar joint. Hope that all makes sense. As an aside, althought I hesitate to question the master DB, this type of leading edge construction is not a favourite of mine. Besides the sheeting/leading edge issue any frontal impact tends to cause the leading edge spare to act as a wedge and split the ribs length wise. Quote Link to comment Share on other sites More sharing options...
kc Posted May 17, 2013 Share Posted May 17, 2013 I think if you study the photo supplied by Spikey you will see that the laser cut rib is reduced by 1/32 at the front and that it's the spar slot that is too shallow. Someone doing the CAD drawing has positioned the slot relative to the rear of the rib not the front part. Why has nobody built from these parts to prove them accurate before they are produced in quantity & sold to the public? Reducing some of the ribs by an accurate 1/32 in some places is quite tricky and thats why it's so much easier to make them all the same and use capstrips! If anybody is cutting theirr own ribs consider doing this --it hardly adds any weight , can use up scrap 1/32 and makes a wing that is stronger ( in the handleable sense at least ) which is a bit easier to cover. Quote Link to comment Share on other sites More sharing options...
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