Tim Ballinger Posted April 16, 2018 Author Share Posted April 16, 2018 Very irritating indeed. I have little explanation for my brain fade; it seems like I switched off and started flying as though it was my standard aero hack the Riot XL which has oodles of power. Really gutted. Tim Quote Link to comment Share on other sites More sharing options...
Geoff S Posted April 16, 2018 Share Posted April 16, 2018 I know how you feel, Tim, but it's part of the game. I lost my Ballerina on Saturday due to stupidity on my part. At least it's repairable once I get round to it. My ordinary Riot is my warm-up hack. I'll fly it in anything. Geoff Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted April 20, 2018 Author Share Posted April 20, 2018 GTC fuselage repaired and hanging on wall waiting ...... ... for the wing repairs. Today was too good to miss, flying wise, so took the Skywriter out. No mishaps today but I suspect I wa a little more cautious than last time ! Tim Quote Link to comment Share on other sites More sharing options...
Levanter Posted April 20, 2018 Share Posted April 20, 2018 Tim It looks like it might not be too long before you get back in the air. I would be very interested to see how you sort out the wing repair and a few photos and words would be great. Levanter Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted April 20, 2018 Author Share Posted April 20, 2018 Not sure anyone should be subjected to such gruesome detail but I’ll give it a go. I still have to cut out all of the splintered wood but from what I can see I will need to replace both front half’s of R1 and scarf in ( close as 20:1 as I can get) some new LE. Might laminate the new piece before insertion. Probably need a rebate to accept the replace top sheeting. That’s about as far as I have planned atm . Tim Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted April 28, 2018 Author Share Posted April 28, 2018 Perhaps it's because I don't look but i have not seen any how to repair blogs. Anyway this is more of a reprise than a re-build log. Despite a vertical arrival the soft ground prevented a complete bag of bits. In fact once I took a good look the damage was remarkably localised. First up for me after a smash and before starting repairs is a close examination of the covering all over the model. Major breaks are obvious but opening up all the wrinkles in the covering can yield otherwise unseen issues. If the film has wrinkled its a good bet something has happened to the structure underneath. Most of these inspections revealed only cracks in sheeting adjacent to glue lines; easily fixed with thin cyano. One crease in the trailing edge revealed a crack right through upper and lower TE capping which when paired back revealed a partial fracture in the TE itself. Fracture was treated with Cyano and TE capping cut back top and bottom either side creating a good 4 cm overlap before replacing and gluing with aliphatic. No other dramas under the covering so onto the 2 major damage sites. The nose fractured just behind F2 and had to be dug out of the ground. This was one of those fractures that left both sides pretty much intact and the break while ragged just slotted all the balsa fibres back together such that it actually held back in place by itself in the exact alignment of the original. This then was a case of trimming away the surrounding covering and treating with thin cyano to bond it back. While I was as neat as I could be I had to sacrifice the Marine corp logo on the port side which mercifully was the only decal to suffer.Once back together F2 was rebuilt & reinforced inside before replacing the battery tray which actually connects F!, F2 and the sides to midway between F2 and F3.:all these repairs with aliphatic resin. I was cracking on at this point and had forgotten to any pictures of the damage/repairs. The remaining wing repairs I did get some pictures and they are next .... Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted April 28, 2018 Author Share Posted April 28, 2018 The major damage mechanism was the inertia of the heavy wing disengaging from the fuselage. At the rear the 2 nylon bolts simply sheared and as the ing moved back it bashed the sloping former ( F5B I think) . A simple replacement as once cleaned away it slipped back inside the planking which had remained in tact. The front looked at bit more of a mess .. Cutting back the damaged wood revealed much less trauma than i expected.. The crushed LE was cut away on the longest scarf I could manage between R and the wing join at R1. In this case about 8:1. All this damage was basically caused by the wing dowel breaking out sideways as the wing travelled aft in the impact. I had thought I would need to rebuild all of the R1 ribs and section that housed the dowel. However the failure mode was to simply break out the lower quarter of the ribs enclosing the dowel and the dowel itself which had not broken had left a clean exit, seemingly the the glue only having found a bond at the front and very rear of the slot/hole. I always wandered just how much glue contact you achieved when pushing a dowel into hole. Now I know and the lack of all over bond worked in my favour. Upshot was that I could replace the dowel exactly as before giving me no realignment issues when piecing it back together . So with new R! quarter rib slotted around the dowel and the top and bottom sheeting replaced ( supporting lips glued in first to achieve a as flush a finish as possible) all was back together and ready for covering. And after recovering.. GTC is ready for flight once more. While she flew pretty well on the pier set up I had I have taken the opportunity to install slightly more powerful motors which should give me more scope in the future; nothing I know can mitigate for pilot follies like that which caused the original accident, but it should help. In any case I now have 3541 1270 motors which should up the power to 740W giving me @ 100W per lb. As soon as it stops rain I will check the actual current draw and then wait for decent weather before the test flight. Tim Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted April 28, 2018 Share Posted April 28, 2018 Well Done Tim Repairs are always a bit of a pain but it looks as if you got away quite lightly really Nice job now. All you have to do is wait for the rain and wind to stop Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted April 28, 2018 Author Share Posted April 28, 2018 Yes weather forecast does not make happy reading. Still plenty of time to continue with my Cessna 172 rennovation project. Bit of nostalgia really as I built it in 1973 but then went off to university and never flew it. Still that’s for another blog if I can find a suitable place on the forum... Tim Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted May 5, 2018 Author Share Posted May 5, 2018 Checked the current draw for the new motors. A disappointing 54A on anything from 10x6 to 9x5..... then the penny dropped the current sensor in my TM was only rated 50A . Put it in just one side and bingo 30 A at 10.8V on the 3 blade 10x6 props giving me 648W. Could go up to 33A for each motor but better to keep that in the tank for now. So took her out to fly again today.... 3 wonderful flights which with no pilot induced stupidity also produced 3 landings. OK one was a bit fast and rather too firm , other 2 very pleasing. GTC now has lots of power if needed but spent most of the time at 1/4 to 1/2 throttle meaning if I extrapolate the 6 mins per flight I kept to today and only used half the 3700Ah battery that I should get something like 8 min flights. Will go for 7 min next time out. I had the cg at 25% root chord for the first flights and this is feeling a bit nose heavy so I have moved the eneloop Rx battery back to mid chord giving me a value of 29% root chord. Weather looks good for Monday still so will let you know how the next session goes. Still looks absolutely fabulous in the air ! A happy Tim once more. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 5, 2018 Share Posted May 5, 2018 Glad to hear that she is back on the flight line Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted May 7, 2018 Author Share Posted May 7, 2018 2 more flights today. All good but cg now too far aft. Will split the difference next time out. ie 27% root chord. Also bent my first retract pin today. It won't be the last I am sure. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted May 13, 2018 Author Share Posted May 13, 2018 2 more flights withe the GTC today. Trim/C.G bang on for me now. Now got that same fantastic feeling back I had after the first maiden. Beautiful ,graceful flyer and now with more power she pulls lovely large loops from level flight with ease. Not experimented too much with the flaps as yet but what I think atm is that they are not really needed with this model. Perhaps it’s the inherent drag of the large round tigercat nacelles but the glide slope was adequately steep with the power off and nil wind as was the case tonight. I will play further as I gain more confidence. Tim Quote Link to comment Share on other sites More sharing options...
Levanter Posted May 13, 2018 Share Posted May 13, 2018 Tim So pleased you are back in the air and better than ever it seems. A great job! Levanter Quote Link to comment Share on other sites More sharing options...
Steven S Posted May 13, 2018 Share Posted May 13, 2018 Tim - I've been following your thread from the beginning as I am building a GTC similar to yours, 110%, 100mm longer nose and retractable landing gear in the nacels. I am finishing mine as a De Havilland Hornet [but with a very long nose]. I am interested in your CogG, did you end up with it at 27%? I'm adding flaps also and they may be needed as the Hornet has twin Merlin V12's in very sleek nacels. So - did you end up with the CofG at 27 or 29%? Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted May 14, 2018 Author Share Posted May 14, 2018 Hi Steven, Hope you found the thread of some use, bear in mind I am no expert ! I have settled on 27% of root chord for the cg. She flies ok on the forward setting of 25% but was a bit heavy on the elevators and I always felt I had to be careful to keep the nose up in turns. 29% was just a bit too wafty ( a good aero term) and I suspect for me was an accident waiting to happen. I also reduced my expo down from 40 % to 20 % as I felt that suited me better for this model ie I liked the increased feel from smaller control inputs. I can see you have a few pictures posted but how about a few more of your build ? Tim Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 14, 2018 Share Posted May 14, 2018 Glad to see that you arehaving somuch fun and doing some fine trimming. Quote Link to comment Share on other sites More sharing options...
Steven S Posted May 14, 2018 Share Posted May 14, 2018 Hi Tim - I've gotten so much help and information from your build as well as Rob's and Levanter's. Thanks for confirming your C of G for me, and I have posted more build pictures in my album. I started my build with the fuselage and it looks like I won't be working on the wing and nacels until next winter. I hope to finish the fuselage during the many windy summer days. There's been a lot of them the past three years. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted May 15, 2018 Author Share Posted May 15, 2018 Great to see the pics Steven. Another neat builder like Levanter . You are going to have to give us some words when you get to your DH bits. Tim Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.