Colin Leighfield Posted September 15, 2016 Share Posted September 15, 2016 IT looks great Simon, well thought-through. Edited By Colin Leighfield on 15/09/2016 07:10:57 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 15, 2016 Author Share Posted September 15, 2016 Slowish progress today as I had a bit of a disaster with the LH aileron. To cut a long story short it had to be completely re-done - just as I was about to build it in for good! Still, all now sorted just got to join the wings together. The tailplane is an all Depron structure but tapered in thickness with 2 mm skins. Done this way gives adequate stiffness and is of course very light. The elevators are done the same way with a glass fibre connecting torque tube that also acts as the inner hinge pin. The outers are home made acetate 'pin' hinges similar to those I used on the' VTO' A4b.. To keep to a single hatch I intend to mount the Rx in the cockpit so there is access to 'rebind' if required. That way there will only be a battery hatch that weakens the fuselage structure. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 16, 2016 Author Share Posted September 16, 2016 It actually starts to look like a Ballerina with all bits can be glued together but still quite a bit to do. To save weight it will have a very simple colour scheme,just the control surfaces blue with all the rest white. Weight? It is looks like it will end up just under 16 oz (450 g) complete. So 3/4 the size but only 1/4 the weight! Just as well I left the battery position undecided! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 16, 2016 Share Posted September 16, 2016 That's beautiful Simon. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 17, 2016 Share Posted September 17, 2016 Great progression, Simon. You're nearly there now... and I'm still 'fighting' with my tailplanes... Am I allowed a question, please? What kind of glue are you using for the acetate to the Depron? Hakuna matata Chris BRU - BE / CTR Progression Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 17, 2016 Share Posted September 17, 2016 Very nice indeed Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 17, 2016 Author Share Posted September 17, 2016 Thanks for the kind words Chris I use UHU POR but technically it is not acetate but the clear sheet, possibly Polyethylene Terephthalate Glycol (PETG) salvaged from vacuum formed packaging. Almost nothing really sticks to it so it requires its surface to be coarse sanded to get a good mechanical bond. To be safe I only use it structurally where the glue joint is only loaded in shear. The battery has had to go quite a bit further back than I had expected. It is now right up against the cockpit front bulkhead. No problem as I actually prefer a 'push in' battery as it needs no further restraining. The top decking and battery hatch can now be completed. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 17, 2016 Share Posted September 17, 2016 Thanks for your answer, Simon. If it was from 'vac forming' scrap, it probably was PET. So far, I only used acetate, PET or even 'bankcards' after it was duly 'coarsed' and then only when laminated between for example foam sheeting. But glad to have learned that I could use it 'outside' as well in the future. Hakuna matata Chris BRU - BE / CTR PET Control Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 With the top decking complete, a battery hatch and a bit more paint it is virtually complete. There are some finishing touches still to added like the windscreen, the fairing over the tail plane and the U/C 'triangle' to be filled as well as the 'still to be delivered' DSMX Rx to go in the cockpit, Taking all the above into account it should weigh 12.8 oz (362g) with the 1500mAh 3s.. With 120W available that exactly matches my target of 150 W/lb. Maiden soon. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 19, 2016 Share Posted September 19, 2016 A great & very fast build, Simon. With that power/weight ratio I guess you could even try a VTO(L)... Just a few bits of Depron to make a launch base' and up she goes... Did you cover the balsa spars with Depron or just had a coat of white paint on them? Congrats & hakuna matata for the maiden Chris BRU - BE / CTR VTO(L) Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 19, 2016 Share Posted September 19, 2016 Very Smart Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 19, 2016 Share Posted September 19, 2016 Don't forget the pilot. (A very light one). Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 Chris Just a coat of white paint - in fact the whole front of the wing including the spar is painted. as the actual 'leading edge' is 'sanded' Depron so pretty rough. A little trick I use is to smear neat PVA over sanded Depron as this fills the grain. When dry it can be sanded smooth and with repeat coats as required an almost gloss surface can be created. Relatively heavy so I normally only do it on the actual leading edge itself and try to leave the rest of the skin is natural Depron surface. The Petiterina has been painted with Acrylic which tends to be heavy. Where a large area needs doing i use household emulsion which is much thinner and only 'colours' rather than 'fills' the surface hence the need to maintain the Depron's natural finish where ever possible. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 So just how strong is that Depron wing? My "rule of thumb" test is to simply pick the fully loaded plane up by its wing tips. This produces a maximum bending load at the wing root equivalent to pulling close to 4 G. Of course this is only testing the bending strength not the wings ability to resist any twisting that might occur. The scale high aspect ratio wing, built the same way as the Petiterina, for my 2.1 m Depron Libelle could just pass this test although it took on a scale 'flex'whilst doing it! It was looped - gently! The smaller (1.01 m) and thick wing on the Petiterina should of course be much stronger (and stiffer!). This picture shows the wing easily supporting 3 times the planes normal weight. Which by my rule of thumb suggests it should be good for close to a 12 G manoeuvre although I doubt it would actually be able to fly fast enough (3.5 times the stall speed?) to achieve it! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 Calm(ish) this afternoon so it had its maiden. A bit blustery so it got blown about quite a bit but it flew no problem.. It has a Lemon 'gyro' Rx in it although for the initial flight it was turned off. When I did switch it on later in the flight it promptly tried to loop. Fortunately my finger was still on the switch! Of course when I landed the culprit was obvious - the elevator gyro action was revered!! Doh! Video to follow Edited By Simon Chaddock on 19/09/2016 17:27:35 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 19, 2016 Share Posted September 19, 2016 These things happen. Don't tell anyone but when I recenty test flew my V tailed glider I had the rudder action reversed. I will not live that down for a long time. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 The maiden video edited down from over 5 minutes. Hand launch but as the video shows it can ROG quite well despite the rather long rough grass. More important there was no damge! Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 19, 2016 Share Posted September 19, 2016 That was great. She just asks to be thrown around the sky. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 19, 2016 Share Posted September 19, 2016 Congratulations Simon. Another great flying machine! Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 19, 2016 Share Posted September 19, 2016 Great achievement, Simon. As Colin wrote "another great flying Ballerina"... Up to the Comet now, I guess? ... Hakuna matata Chris BRU - BE / CTR Comet Control Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted September 19, 2016 Share Posted September 19, 2016 Very good Simon Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 19, 2016 Author Share Posted September 19, 2016 Thank you gents. I saw others had commented that their first Ballerina flights had gone without a hitch and mine was no different. The only trim change was one click of down and I am not all sure it really needed even that! So a big thank you to Peter M for what is obviously an excellent design. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 19, 2016 Share Posted September 19, 2016 Very Nice Simon , And as always enjoyable watching you're build Blogs, Cheers Steve Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 22, 2016 Author Share Posted September 22, 2016 With the gyro now working as it should I made this video this morning. Calm(ish) conditions but it is very controllable and can be put into some quite alarming 'low slow' attitudes quite safely. As shown even from a slow pass it can maintain a continuous vertical climb - even if the camera can't see it! Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 22, 2016 Share Posted September 22, 2016 Just superb, Simon. I'm just envious of your Petiterina in fact. And I wish myself that one day I could fly like that... even if your servos will always be lighter than mine... Congratulations & hakuna matata Chris BRU - BE / CTR Envy Control Quote Link to comment Share on other sites More sharing options...
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