Nigel R Posted April 12, 2021 Share Posted April 12, 2021 On 09/04/2021 at 21:55, Jonathan M said: One thing that perplexes me is that the supplied nylon aileron horns are mounted in a way that sets them back a few mm from the actual hinge-line. Not unusual for barn door ailerons. With the horns under the wing, it means you get (slightly) more up than down. If you are using two channels for ailerons, this can all compensated by getting the servos to move a bit more in one direction than the other. Or you can offset the servo connection on the servo horn to compensate. Many ways to skin the cat. 1 Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted April 12, 2021 Author Share Posted April 12, 2021 Nigel, you're absolutely right about more up than down with the horn set slightly aft - exactly what I'd normally want as a starting point - clearly got my own mental wires crossed in my earlier post and thought it was the other way round! Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted October 7, 2021 Author Share Posted October 7, 2021 Back to building (after a load of other life, projects and flying stuff), now on the final furlong of a very long, slow course of building... First the fin and rudder, this and the tailplane being made of 1/4" sheet rather than the delicate open structure of the kit: Then the tailplane - took care to ensure that not only was the surface exactly parallel to the wing and square to the fin, but that the distance from wing-tip to tailplane-tip was equal on both sides: As I'm using snakes rather than the forked linkage of the kit, made up a wire joiner for the elevator halves: Here the inadequate laser-cut inserts were discarded and proper sheet infills were fitted and faired, plus extensions to give the film covering something to adhere to: Elevator and rudder leading edges given a chamfer each side of centre to ensure a snug fit but with bind-free movement, and a clearance channel dug for the elevator joining wire: 1 Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted October 7, 2021 Author Share Posted October 7, 2021 Decided there was nothing to lose in adding a thin bandage of lightweight glass-fibre (34g/m2 or 1oz/yd2) to both sides of the wing join: Also visible above are the borders of previously-applied fuel proofer around the nose area etc. I've since gone over these areas with Poly-C, plus applied it in 1/2" borders to every area of the entire airframe where the edges of the eventual covering will sit - I don't want any areas of oily exhaust residue ever getting through and soaking into balsa over time! Now - finally - planning the actual covering...! I'm not a 'pilot-man' for sport RC models, so here the template for the internal area of the glazed cockpit area was taped marked out for a simple black Oratrim finish: Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted October 7, 2021 Author Share Posted October 7, 2021 And screwed in the aileron horns, then added a triangular gusset beside them to give the covering film something to hang on to... Can't delay starting the covering any further now! 1 Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted October 7, 2021 Author Share Posted October 7, 2021 The other thing I've been working on is beefing up the ridiculously thin and flimsy cowling. So far I've got five laminations of 34g/m2 fabric on (using Poly-C because it dries very quickly and ain't half as 'orrible as finishing epoxy!) but its a lengthy process and the plastic still remains pretty floppy, so just taken delivery of heavier 78g/m2 fabric... and won't stop until I'm happy with the stiffness! Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 12, 2021 Author Share Posted November 12, 2021 Covering underway, the yellow bits first... Servo leads coiled and lightly zip-tied, so that in the unlikely event an aileron servo needs to be replaced the extension lead won't be effected. 3 Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 12, 2021 Author Share Posted November 12, 2021 Yellow bits almost finished! On account of wanting black Oracover for the middle third-ish of each wing bottom, I wound up applying a total of six panels per wing, twelve all told... no wonder the thing took so long! Ailerons will be all yellow, but later the top of each wing will have a white Oratrim stripe applied span-wise - exact size and shape yet to be decided, but the intention obviously is that I hopefully shouldn't have any major problem seeing which way is up! ? Fuselage to be a lovely 1970s brown... also with white go-fast stripes! Brown fin and rudder might get a large white "G" each side...? Quote Link to comment Share on other sites More sharing options...
Mark Jones 10 Posted November 12, 2021 Share Posted November 12, 2021 11 minutes ago, Jonathan M said: Yellow bits almost finished! On account of wanting black Oracover for the middle third-ish of each wing bottom, I wound up applying a total of six panels per wing, twelve all told... no wonder the thing took so long! Ailerons will be all yellow, but later the top of each wing will have a white Oratrim stripe applied span-wise - exact size and shape yet to be decided, but the intention obviously is that I hopefully shouldn't have any major problem seeing which way is up! ? Fuselage to be a lovely 1970s brown... also with white go-fast stripes! Brown fin and rudder might get a large white "G" each side...? Great looking. Love yellow and black. mine hasn’t progressed much recently. Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 12, 2021 Author Share Posted November 12, 2021 10 minutes ago, Mark Jones 10 said: Great looking. Love yellow and black. mine hasn’t progressed much recently. Cheers Mark. There's plenty of time left to get yours finished... after all I started this build thread four and a half years ago and am only just getting there! ? Quote Link to comment Share on other sites More sharing options...
Mark Jones 10 Posted November 12, 2021 Share Posted November 12, 2021 19 minutes ago, Jonathan M said: Cheers Mark. There's plenty of time left to get yours finished... after all I started this build thread four and a half years ago and am only just getting there! ? I will get mine ready to run the engine in soon I hope then see if she flys ? Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted November 16, 2021 Share Posted November 16, 2021 Jonathan, I can't help thinking you will need some tail weight to balance out the engine. I notice that Mark has, like me, fitted his tail servos at the back. Would it be worth building in this option before you cover the fuz. Quote Link to comment Share on other sites More sharing options...
RedBaron Posted November 16, 2021 Share Posted November 16, 2021 Hmm it is a pretty plane. I am getting close to ordering the 63 Lite. But can't find a clear statement on the MRM website that it includes plan and canopy. I would be grateful if someone could confirm this or otherwise. I will be aiming at electric power and two wheel tail dragger, maybe retract? Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 16, 2021 Author Share Posted November 16, 2021 Hi Andy You're probably right, but I've already added some extra weight to the rear fuselage by beefing things up and the tail parts are all solid; also fitted a slightly smaller fuel tank. The RX battery will be fitted as far back as possible at the former above the TE of the wing... then it'll be down to a few inevitable 10g stick-on-weights at the tail! I'm aiming for (guessing!) 5.5lbs to give a wing loading of 17.5oz/sqft, which shouldn't be too shabby even if it creeps up a tad. (For comparison my Wot4 is just over 21oz/sqft and the Boomerang up at 24.) What did your Gangster top out at? Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted November 16, 2021 Share Posted November 16, 2021 1 hour ago, Andy Stephenson said: Jonathan, I can't help thinking you will need some tail weight to balance out the engine. I notice that Mark has, like me, fitted his tail servos at the back. Would it be worth building in this option before you cover the fuz. I certainly needed to put weight on the back when mine was powered by a .61fs. Now that I've converted it to electric, I use the battery to balance it, pushing the battery back through the former and over the wing. Red Baron - No plan but yes to canopy. TBH it's not the nicest kit I've ever built - I felt it needed beefing up in various areas, I've now sheeted mine all over, which makes it noticeably stiffer. It must have added weight, but I've not weighed it, so can't be specific. Kim Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 16, 2021 Author Share Posted November 16, 2021 (edited) 12 minutes ago, RedBaron said: Hmm it is a pretty plane. I am getting close to ordering the 63 Lite. But can't find a clear statement on the MRM website that it includes plan and canopy. I would be grateful if someone could confirm this or otherwise. I will be aiming at electric power and two wheel tail dragger, maybe retract? There is no plan, just a very basic instruction sheet. If you do build one, then go back through this thread (and others) for all sorts of advice and modifications to the basic structure to produce a more robust model. A canopy is included, but the cowling is extremely flimsy. I've been trying to stiffen mine by building up layers of cloth soaked in Poly-C. The alternative is to devise a balsa cowling. PS - Just seen Kim's reply. He's right: "TBH it's not the nicest kit I've ever built". My experience is that it's only half-baked as a design/kit with loads of small but annoying errors in the parts. They're reputed to fly very well, which is why I didn't give up on building mine, but as I've said if you do buy one then be aware of the shortcomings and be ready to make your own mods. Edited November 16, 2021 by Jonathan M Quote Link to comment Share on other sites More sharing options...
RedBaron Posted November 16, 2021 Share Posted November 16, 2021 Thank you to responders. Pity about the shortcomings. I think I will be able to work my way through it. As for the flimsy cowling, my usual approach is to 3D print my own and also a mounting ring for it. Having a plan makes that sort of thing just a bit easier. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted November 16, 2021 Share Posted November 16, 2021 (edited) The cowl is really only for electric power as it's too small to contain a reasonable size glow engine. I used a conventional balsa cheek construction around my Irvine 53. Weight with servos mounted at the rear mine was 5lb 5Oz and this was with beefing up the tail etc. Here's an extreme example of can happen when not looking ahead for where the Cg comes out, not mine I have to add... Edited November 16, 2021 by Andy Stephenson Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted November 16, 2021 Share Posted November 16, 2021 3 hours ago, Jonathan M said: A canopy is included, but the cowling is extremely flimsy. I've been trying to stiffen mine by building up layers of cloth soaked in Poly-C. The alternative is to devise a balsa cowling. PS - Just seen Kim's reply. He's right: "TBH it's not the nicest kit I've ever built". My experience is that it's only half-baked as a design/kit with loads of small but annoying errors in the parts. They're reputed to fly very well, which is why I didn't give up on building mine, but as I've said if you do buy one then be aware of the shortcomings and be ready to make your own mods. Jonathon is on the money - the supplied cowl is next to useless as once you cut it to clear the i/c motor it's floppier than a floppy thing. I threw it away and did a built up one using some chunky balsa sheet I had left over from something. Once you get it sorted, it's a REALLY nice flyer. I was complimented only last weekend on the flying performance of mine (now electric). I can assure you that my flying skills are no better than average!! Kim Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 16, 2021 Author Share Posted November 16, 2021 (edited) Kim - That's why I'm determined to get mine finished and finally airborne...! Andy - You got me worried enough to dash into my workroom, bolt the engine on, and pop the battery roughly on top of its intended position to check the balance, which is currently about 4"... phew! Once the fuselage is covered, the prop and cowling on, and the U/C in place etc, I don't think I'll be far off the 90mm (3.55") I'm aiming for. Edited November 16, 2021 by Jonathan M Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted November 16, 2021 Share Posted November 16, 2021 Jonathan, That should work OK but if you find you need a noticeable amount of up-trim, a small ballast weight at the tail my help with inverted flight. 1 Quote Link to comment Share on other sites More sharing options...
Jerry Newton Posted November 16, 2021 Share Posted November 16, 2021 My experience is that this is one of the best kits I have ever built, strength is more than adequate for all aerobatics and any landing short of a crash. Everything fits perfectly, the only mods I made were a balsa cowl and 2 extra UC clamps. Flight performance on an Irving 40 is excellent. I have a second kit waiting to be built, takes about 2 weeks of spare time using aliphatic. Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 16, 2021 Author Share Posted November 16, 2021 47 minutes ago, Jerry Newton said: My experience is that this is one of the best kits I have ever built, strength is more than adequate for all aerobatics and any landing short of a crash. Everything fits perfectly, the only mods I made were a balsa cowl and 2 extra UC clamps. Flight performance on an Irving 40 is excellent. I have a second kit waiting to be built, takes about 2 weeks of spare time using aliphatic. Glad to hear that Jerry. Do you have any photos? Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 16, 2021 Author Share Posted November 16, 2021 Made a start this evening getting the brown stuff onto the fuselage. I don't know what the 'approved' method is, but I'm finding things much easier by sizing and ironing on small panels - working from the underside up, and from the tail forwards. Quote Link to comment Share on other sites More sharing options...
Jerry Newton Posted November 16, 2021 Share Posted November 16, 2021 1 Quote Link to comment Share on other sites More sharing options...
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