Martyn K Posted March 27, 2015 Author Share Posted March 27, 2015 Ok - all finished and ready for its maiden. Rates and EPA set, CG is exactly as per plan with no ballast required and it standing on its own legs and A few detail shots Rudder horn fabricated from 24swg Aluminium sheet. The lower edge (on this photo) has been folded to add a little extra stiffness Radio bay layout - a bit dusty.. I'll sack the cleaner Receiver bay with throttle servo. You can see the row of magnets that hold the canopy in place Fuel feed bay. The T piece is on the pressure line. The idea is that I will be able to see when the tank is full before I fill the tuned pipe with fuel. It is vented to the LHS just below the fill point - both of which are sealed before flight (as if you need to know that). And the engine bay. I can just get my little finger over the venturi to prime it.. The sharp end. Although not up to Sam's standard, I am really quite pleased with that. A lot of work went into the manufacture and fitting of that cowl. Tuned pipe exhaust outlet and vent for cooling air. I may need to add additional vents, easily done if needed. Recessed servos for ailerons. These are Corona Digital MG, they seem quite fast and very smooth. Good centering as well. The undercarriage. This is a commercial carbon copy unit which was the right width but too long. Carefully cut then the two parts bolted together. Jury is still out on this but it looks better than a wire alternative. Of course, looking at the model the right way up it looks far neater. The wing is retained by 2 x M2.5 bolts located butted against the ply root ribs and screwed into the wing joining tubes. I wasn't happy using elastic bands to pull the wings together as suggested by Clive Of course its a Classic I have also run the engine. It was a bit too stiff for the starter motor so I flick started it. It started second flick (much to my amazement. Only had about 5 minutes of running but fuel economy seems OK and it idled OK - if a little fast. Currently running on a 13x6 prop. Ready for the maiden, but not this weekend - no car (and the weather forecast is awful) That's about it, I'll report back after it's been airborne. Martyn Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted March 27, 2015 Share Posted March 27, 2015 Nice bold colour scheme Martyn I like it, good luck with the maiden. John Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 27, 2015 Author Share Posted March 27, 2015 Thanks John I have to admit I quite like it. As you say quite bold but fairly simple Martyn Quote Link to comment Share on other sites More sharing options...
Peter Android Posted March 27, 2015 Share Posted March 27, 2015 What's the rpm on that prop Martyn . ????????? Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 27, 2015 Author Share Posted March 27, 2015 Didn't get chance to measure it mr A. It was the first run so was running a little rich. It sounded it was running at about 8k but I was more concerned about not overdoing it. I'll get a couple of tanks of fuel through it then try it with the tachometer and also with a 12x9 prop that I have. Quote Link to comment Share on other sites More sharing options...
Andy Green Posted March 28, 2015 Share Posted March 28, 2015 Very nice Martyn. I have a STOL sticker here for you, would you like one for this model. Andy Quote Link to comment Share on other sites More sharing options...
Sam Wragg Posted March 28, 2015 Share Posted March 28, 2015 I concur, very nice indeed and I bet the colour scheme will show up well in flight. The ARTF fraternity don't know what they are missing?.... You cant beat that feeling of satisfaction of creating something out of a set of plans and a pile of wood then seeing the product of your efforts take off into the wide blue yonder for the first time. Sam Edited By Sam Wragg on 28/03/2015 09:57:09 Quote Link to comment Share on other sites More sharing options...
Former Member Posted March 28, 2015 Share Posted March 28, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 28, 2015 Author Share Posted March 28, 2015 Thanks both It's not going to get maidened this weekend - I have no car - it died on Thursday and the weather here is absolutely dreadful anyway - I would be really fed up if it was glorious and I had no transport.. I had a PM from a friendly forumite recommending that I replace the direct wire trace linkage through the rudder horn with a plastic clevis to prevent metal to metal rubbing and the associated noise problems that could be generated. This is something I hadn't thought about so I have followed his advice. Andy - thanks for the offer but I'll decline if you don't mind. I am not sure where I would actually stick a sticker without disrupting the authentic 1980's colour scheme (no girly curves on this one - its a proper in your face colour scheme) . Anyway, I am thinking about what to build next.. I have got ( a brand new) one of these lying around and don't know what to put it in. Exhaust timing is 145 deg so would go on a pipe as well. It will turn an 18x12 at 10k (apparently) I am tempted to build a Steve Dunning Elation next although it may be a bit OTT for that.. Apparently, these make a good petrol conversion. But first I need to spend some time on the Chippie before Danny F gives up on me. Martyn Quote Link to comment Share on other sites More sharing options...
Steve Dunning Posted March 28, 2015 Share Posted March 28, 2015 Just done a couple of talks on building from a plan. My initial statement is always that building (assembling) ARTF's means that people are missing out on an important part of the hobby. Whether it is a home design (scratch build) or an established design, nothing beats that moment when it takes to the skies for the first time. The availability of CNC cut parts takes some of the pressure off for those that feel they cannot manage accurate cutting but that does not detract from the exhilaration of building something that flies. Plus, our models don't cost £4000!!!!!! From enquiries I've had popularity is growing so all bears well for this season. Happy flying Steve Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 28, 2015 Author Share Posted March 28, 2015 I agree entirely Steve I make no secret that I am not a good builder but I am not ashamed of showing what I build. Hopefully, my building will get better (but after 45 years of trying I am not absolutely sure it will get good enough fast enough to make a difference). I have got one ARTF model- a second hand GP Groovy 50 I paid £40 for. It looks just as rough as my own models and it doesn't fly any better and I certainly don't get any more pleasure flying that than one of my own creations. I agree that they look nice and shiny out of the box but when they have been used for a while the flaws soon start to show through. Martyn Quote Link to comment Share on other sites More sharing options...
Sam Wragg Posted March 28, 2015 Share Posted March 28, 2015 As my late Dad used to say....... "As long as it looks all reyt in air, is all that matters" For me, flying is the product of building....... you have to build to be able to fly. I've/we've spent many an hour discussing how to improve a design and putting our thoughts into practice. To do this you have to build your own..... this is where the enjoyment is...... welcome to the wonderful world of Engineering This is what acedemics in schools have missed and now we have a serious skills gap Sam Quote Link to comment Share on other sites More sharing options...
Steve Dunning Posted March 28, 2015 Share Posted March 28, 2015 Hey, Martyn. I should hold off on the decision regarding the Elation build. Got the new Solace 110 coming out soon! Steve Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 28, 2015 Author Share Posted March 28, 2015 He he. Sounds interesting. I also have a pumped OS120fs waiting for a home Martyn Quote Link to comment Share on other sites More sharing options...
Steve Dunning Posted March 28, 2015 Share Posted March 28, 2015 Perfect! Quote Link to comment Share on other sites More sharing options...
Martyn K Posted April 15, 2015 Author Share Posted April 15, 2015 Well Got the maiden in last night. Eventually managed to get the engine to run OK, 2 tanks of fuel and reasonable pick up and idle so just before sunset I placed the model on the strip, taxied to the end, lined it up and wound open the throttle. First impressions was that it is very hairy on the ground, that rudder is huge and it was difficult to track straight. However, got it off the ground more or less in the direction I wanted and noted that the model was distinctly under-elevated. Needed full up trim and holding a little up to keep it level. Elevator was very sensitive so dropped it from medium to low expo/end point and that tamed it nicely. Aileron control was very smooth but the rudder was still very over sensitive. So Flying around for about 6 minutes just getting the feel for it, decided to land it as light was fading and on the downwind stretch the telemetry kindly gave me a warning letting me know the receiver battery was dying - 2 seconds later no control at all, 2 seconds later - this. . . . . . The model went in vertically from about 250 feet.... Not the best day's flying I have ever had, and so far definitely the worst years flying. I think I'll give up until 2016 So - what happened. Well - the battery was charged just before I went on holiday- about 2 weeks ago. I don't have the luxury of planning my flying, I just have to seize the moment so I tend to keep all models fully charged up. The battery in the other model that I had taken had died (left the receiver turned on - probably inadvertently knocked the power switch. So I borrowed the battery from the Concept and had a couple of flights - about 20-30 minutes switched on time. Then put the battery back in the Concept and turned it all on, ran a tank of fuel through the engine (still running it in), allowed it cool then decided to go for that fatal flight. - Say another 10 minutes.. But, while we were prepping the Telemetry informed me that the battery was low, I realised I hadn't calibrated the battery level. Measure the voltage on my battery checker - 5.5V (NiMh), set the telemetry up correctly - set the alarm to 4.7V - this cleared the warning, we started and went off. What I had forgotten - probably with nerves as all this was happening and the imminent Maiden, that I was using a 5 cell (6V) battery and it really was very low. No-one to blame but myself.. SO 6 months building, 6 minutes flying, not the best ratio in the world... Its being recycled tomorrow, hopefully it will come back as something useful Martyn Quote Link to comment Share on other sites More sharing options...
Sam Wragg Posted April 15, 2015 Share Posted April 15, 2015 What can one say apart from its sad when this happens. Keep your chin up Martyn Sam Quote Link to comment Share on other sites More sharing options...
Jon Laughton Posted April 15, 2015 Share Posted April 15, 2015 Really sorry to hear about that Martyn and I admire your honesty. We all mistakes but it takes a big guy to admit it.. I really liked the look of your model and hope you will find the patience and doggedness to build another.....keep on flying! Jon Quote Link to comment Share on other sites More sharing options...
IanN Posted April 15, 2015 Share Posted April 15, 2015 Sympathies. This is one of those "there but for the grace of...etc" incidents. I think if we're honest that even the most careful of us will all have had a moment(s) when we've thought, post flight, "hang on, I didn't check that, got away with it there" But keep going. I've found these UKCAA builds very interesting and inspiring (I might even get around to my Pete Russell Striker plan one day) Quote Link to comment Share on other sites More sharing options...
Andy Green Posted April 15, 2015 Share Posted April 15, 2015 What a shame Martyn. If it helps (which it won't) my view is that they are all detsined for such an end as soon as the first wood is glued, its just a matter of when. Andy Quote Link to comment Share on other sites More sharing options...
chris Bond - Bondaero Posted April 15, 2015 Share Posted April 15, 2015 Commiserations, We have all been there Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted April 15, 2015 Share Posted April 15, 2015 Martyn, at least you had the pleasure gained in building it, and now you have a good excuse to start on the next project. NiMh performance is one reason I use LiFe almost exclusively now, losing a Katana onto an active golf course because of a dying battery made me very wary of nickel cells. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted April 15, 2015 Author Share Posted April 15, 2015 Thanks all. As usual, feeling rather foolish but that will pass. Wife is complaining that the bin is full.. Kato Aurora 60 next perhaps I'll use the same engine but keep it to fixed undercarriage rather than retracts as the plumbing around the nose leg is complex Anyone know what year this model is? I have googled and failed. Bob, I have got 3 LiFe batteries here, but 2 ballooned on the first charge. How do you charge yours? Best wishes Martyn Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted April 15, 2015 Share Posted April 15, 2015 I charge at 1C using a LiFe program (3.3v/cell), if they ballooned were you using a LiPo charger setting? I did that once and only realised when the Marabu started smelling a bit volatile - the pack had bulged and heated to the point that the heat shrink covering was breaking up My chargers have three lithium type settings under the 'User Setup' menu option, LiPo - 3.7v. LiIon - 3.6v and LiFe - 3.3v Edited By Bob Cotsford on 15/04/2015 13:33:18 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted April 15, 2015 Author Share Posted April 15, 2015 I used an old fashioned Futaba NiMh Trickle charger. I reckoned that a low voltage and low current would be safe. I was wrong.. I presume that you use a 5V regulator with these to get the voltage down to somewhere near the servos can cope? Martyn Quote Link to comment Share on other sites More sharing options...
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