Geoff S Posted November 13, 2018 Author Share Posted November 13, 2018 I managed to find these Softbore tools recently amongst the modelling 'detritus' left to the club by a deceased member. I don't think they're sold now but I remember them being mentioned in the magazines some years ago. They're designed to make clean holes in soft balsa which usually tears when normal drills are used - at least it does when I try to do it. They looked to be unused. Anyway I tried one last night to drill through the wing ribs so I can fit a paper tube to feed the aileron servo leads through. It worked really well as can be seen here showing both top and bottom sides of wing ribs. I was a bit ambitious and tried to drill through 6 at once; it worked OK but got a bit hot and scorched the balsa but no more than laser CNC cuts do. It even cut through the ribs with 1/16" ply doublers without problem. Geoff Quote Link to comment Share on other sites More sharing options...
Dwain Dibley. Posted November 13, 2018 Share Posted November 13, 2018 Geoff, go with the doublers, as thick as possible, well, up to an 1/8th at least, they do not have to be rib shaped, but large enough to prevent the bearer "crushing" the rib on a heavy landing, by spreading the load. Nice looking build so far Matey. D.D. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted November 17, 2018 Author Share Posted November 17, 2018 It always surprises me just how many separate parts there are to build a wing - the ribs are just a small part of the build. I had to modify some of the ribs to cut notches for the undercarriage mounts and add doublers to give it some strength. I didn't want one slightly heavy landing to result in lots of repairs. I also cut slots in the ribs for the dihedral braces which seem to be very substantial - 2 X 3.2 mm plywood and 10mm deep. The drawing says 1/16" but the wood supplied is 1/8". Both had to be cut out from a piece of sheet. The steep angle worried me at first until I realised 10 degrees meant 5 degrees/side - I can be a bit slow sometimes. I also made an extra rib for a half bay near the root just where the wing exits the fuselage. As the design stood, all the pressure of tightening the wing in place would have born directly on 1/16" sheet half way between ribs. I also needed the centre open for servo lead access and to build secure mounts for the wing support dowels at the L/E. The drawing shows just one in the centre but, as that's where the centre ribs meet on the wing and where the crutch is on the fuselage, I think I'm going to go for 2 dowels and leave the centre free. The drawing and the instructions seem to deviate and, as Robert warned me about wings warping when ailerons are applied because of the flimsy structure, I decided to build a conventional wing with a 'D' section l/e and capping strips on the ribs themselves. I saved some weight on the t/e by just using 30mm x 1.5mm sheet top and bottom rather than sold wood - they are more secure than sold butt-joined to the rib ends. (the dark square is a Sleath bodge after I inadvertently broke the sheet in handling! I'm pretty clumsy) I've also made the aileron which is also built up on a sheet of 1/8" balsa - the aerofoil is flat bottomed. As the drawing calls for one carved from solid that's more weight saving to offset the extra I've introduced with full l/e sheeting. The wing as it stands with the dihedral braces fitted weighs 118 gms so the complete wing (uncovered) with servo mounts should be under 250 gms. So not too heavy so far. Geoff Edited By Geoff Sleath on 17/11/2018 17:55:39 Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted November 18, 2018 Share Posted November 18, 2018 Hi Geoff. Coming along nicely Regards Robert Quote Link to comment Share on other sites More sharing options...
Geoff S Posted August 7, 2019 Author Share Posted August 7, 2019 Well, everything came to a grinding halt around Christmas. What was intended to be a brief break in the build has extended to now (7 months!). I started looking at what I've done so far and it would be a pity if I didn't finish it. So, problems. This is not an easy build despite the name of the manufacturers. 1: There is no indication how the wing seat should be and I've tried several ways of blending the wing to the fuselage. The actual defining seat is OK. It's 2 vertical 3mm ply formers that are fitted lengthways. I've checked the incidence and it's 1 degree positive relative to the tailplane seat (which I had to invent as it's not shown on the drawing/sketch), which I'm guessing is reasonable. The difficulty is blending the round bottom of the fuselage with the wing. I tried various methods with 1'5mm sheet but eventually had to cut them out. Then I tried the obvious way (duh!) and used some 0.5" softish balsa to fill the gap. It seems to work and weighs very little. 2. The cowl is made from vacuum formed clear plastic. Putting it together is very difficult and cutting off the surplus (and deciding where to cut) even more so. I ended up cutting a ply disc for the front to give the floppy plastic some rigidity. Still no idea how to fix it to the fuselage and I'm toying with the idea of extending the fuselage sheeting and making the cowl shorter. It only needs enough to be removable to access the motor anyway. 3 The undercarriage fits on the wing and is made up with pre-bent piano wire. I think that may be OK however the spats are, like the cowl, vacuum formed plastic. I think I may leave them off. 4 The general fragility of the fuselage formers. I think they'll be OK once the whole fuselage is sheeted but, in the area where they're very short grain, the slightest touch breaks them! It didn't help that I tripped and fell on the temporarily stored fuselage and listened to the sound of splitting wood as tried to minimise the damage! Thank goodness for Cyano! Overall this is a bodgers triumph that reveals starkly my lack of dextrous building ability. Never the less, I'll press on in the hope that a little filler and the covering will hide my transgressions to some extent. You never know, it might even fly. Here's a picture of the whole airframe. The tail parts, all control surfaces hinged and the wing fixing is done. Sorry for the very cluttered background. Geoff PS Just had a look at the Ohmen thread and the similarity with the Ryan is quite striking. I bet building Peter's design and its flying qualities would be easier in the former and better in the latter than my 'orrible Ryan Edited By Geoff Sleath on 07/08/2019 14:45:15 Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted August 7, 2019 Share Posted August 7, 2019 Hi Geoff, Yes, it's all coming back to me now with my Catalina the fragile formers, impossible cowls, not enough hands to hold everything in place and yes it is an "easy built " model. She's looking great It will be all worth while once she's in the air Regards Robert Quote Link to comment Share on other sites More sharing options...
BikerDon Posted December 12, 2019 Share Posted December 12, 2019 Hi Geoff, slightly off-topic but related in a way. Do you have any info or contact details about the supplier of your magnetic building board? I bought one with similar fittings a year or two back at Wings and Wheels and have lost the leaflet that came with it. The Guy doesn't appear to have a website, not that I can find anyway, and I would like some more fittings. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 12, 2019 Author Share Posted December 12, 2019 No, sorry I don't. I bought mine at Cosford last year (probably from the same bloke) but he wasn't there this year or I'd have bought a few more blocks, too. I have 20 which is usually enough but another 10 would be useful. Geoff Quote Link to comment Share on other sites More sharing options...
BikerDon Posted December 12, 2019 Share Posted December 12, 2019 Posted by Geoff Sleath on 12/12/2019 14:26:40: No, sorry I don't. I bought mine at Cosford last year (probably from the same bloke) but he wasn't there this year or I'd have bought a few more blocks, too. I have 20 which is usually enough but another 10 would be useful. Geoff Thanks for the speedy reply Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted December 12, 2019 Share Posted December 12, 2019 There is this guy selling the blocks on ebay Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 12, 2019 Author Share Posted December 12, 2019 Thanks, Bob. I've just ordered 10 more blocks ready for next build They look to be identical to the ones I have already. Geoff Quote Link to comment Share on other sites More sharing options...
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