RE: DeHavilland Mosquito
Dears, I'll try to get you a video but I guess I'd need a youtube account...? Best, /Magnus
Posted on: 7/11/2012 11:15 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11151513

RE: DeHavilland Mosquito
<![if gte mso 9]> <![endif]><![if gte mso 9]> Normal 0 false false false EN-GB X-NONE <w:lidthemecomplexscript>X-NONE</w:lidthemecomplexscript> <![endif]><![if gte mso 9]> <![endif]><![if gte mso 10]><![endif]> Colleagues, The Mossy had its maiden and it went well. A bit of trim and she was rather easy to deal with. A bit sensitive on the elevator thus perhaps slightly tail heavy but not too much. One of the engines went out of tune in the air but nothing critical. Landing was uncritical but – one of the gears mechanics broke. What seemed sturdy enough turned out to be really weak. Indeed the E-flite 60-120 gears are meant to fold sideways and not front to back. I cannot recommend them for this application and you should beware of side wind landings if you use them in a plane folding sideways. I am back to the gear drawing board… and I will try to build gears similar to Peterf. This ARF is rather time consuming... Nevertheless, I am pleased with the plane. It looks great on the ground and fantastic in the air! Best, /Magnus ps. sorry, I can't get rid of that first line...
Posted on: 7/10/2012 8:46 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11149975

RE: DeHavilland Mosquito
Spitty, Thanks for worrying. Everything's OK, I just had no time to go flying. Kids have been finishing school and so on. They will go visit the grandparents and my wife's away on a residential course, thus - fly-time! Soon. Best, /Magnus
Posted on: 6/30/2012 1:05 PM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11137834

RE: DeHavilland Mosquito
Colleagues, I am nearly finished. I realized the the cowls do not lign up to the engines - the spinners are both about 3mm to the right and 6mm high. Caramba. Well, it was far enough off to make new mounting holes... Having done that I went for an engine test and a roll. Actually, as long as the engines are well synched she rolls rather straight... The tail comes up immediately, and then she's flying with the wheels on the ground. She even made a 10 meter jump but I decided that there were too many things to check before flying so I put her down again. - I suspect the CG is still a bit too far to the rear since she took off so easily. It could also be that the left elevator is slightly warped. TBI. - The gears both lost a lock nut and came loose. Vibrations... - Theres a leak in the needle valve on the right engine. One of the outer flaps is hanging a bit as well. I might have to do something about it for peace of mind. I do understand those who get addicted of twins. The noise of two engines in synch is truly addictive! Soon in the air. Best, /Magnus
Posted on: 6/15/2012 6:22 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11118926

RE: DeHavilland Mosquito
Colleagues, I finally got around to painting the pilots (note the strange look in the twin’s eyes; without any doubt due to tension in view of the maiden flight) and to make the "safety moulds" of the canopies. Maybe I'll have time to fix the canopies tonight. I have added a 600g disk of lead in the nose to get anywhere close to the correct CG... ... and I updated the build log: http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/JamaraMosquitoBuildImageDirectory.htm Cheers, /Magnus
Posted on: 6/4/2012 1:40 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11105482

RE: Why not a Webra engines thread?
You can use the method here: http://www.airfieldmodels.com/information_source/model_aircraft_engines/make_a_backplate_gasket.htm Used it without problems. The head gasket is different; it's rather a shim to control the compression. You'll need one with thickness to suit your favourite fuel and glow plug. I can't give you guidelines since I never played with it but I am sure others in the forum can. Cheers, /Magnus
Posted on: 5/24/2012 4:39 AM by Author "fast_mag" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11092777

RE: Why not a Webra engines thread?
Broken Wings, Your link suggest that the crank thread is a question of age: older engined most likely have 1/4 inch thread and newer would have 8mm. Indeed my engines are old. Cheers, /Magnus
Posted on: 5/24/2012 3:06 AM by Author "fast_mag" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11092724

RE: Why not a Webra engines thread?
ChiefK, Sorry, I don't know enough to give you a straight answer about the engine. What's written on the box, however, indicate that you should be happy with the combination as long as the engine correspond to the box. Cheers, /Magnus
Posted on: 5/24/2012 12:02 AM by Author "fast_mag" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11091958

RE: Why not a Webra engines thread?
ChiefK, What engine is this? The only .61s I have with 8x1.25mm thread are 1033 (long stroke rear exhaust with red or green head). Great running engine, but not exactly suitable for a dirty birdy. All other good old .40, .61, .70 and .80 with side or rear exhaust and front or rear induction in my possession are 1/4x28 thread and most of them are bought in Europe. Cheers, /Magnus
Posted on: 5/23/2012 6:18 AM by Author "fast_mag" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11091559

RE: Why not a Webra engines thread?
I would get another adapter. The 8mm thread is longer and more sturdy. Best, /Magnus
Posted on: 5/16/2012 2:11 PM by Author "fast_mag" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11083391

RE: DeHavilland Mosquito
Thanks Kahloq, I'll consider that. Cheers, /Magnus
Posted on: 5/16/2012 3:59 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11082682

RE: DeHavilland Mosquito
Andy, It would please many if you could lay your hands on the leftover stock from Webra :-). For engine mounting, I am only in to 2 cycle engines, but I have found few inconveniencies with the engine at about 140 degrees which is half inverted (except that the carb gets rather low compared to a normal tank position). It also allows the exhaust being less visible right under the fuse. Cheers, /Magnus
Posted on: 5/16/2012 12:36 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11082614

RE: DeHavilland Mosquito
Build log should be accessible now. Apologies. /Magnus
Posted on: 5/15/2012 2:07 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11081177

RE: DeHavilland Mosquito
Sorry about the log being inaccessible. I'll fix that tomorrow... Engineshop! It's a bit outside the scope of this forum, but what engines would you sell? Cheers, /Magnus
Posted on: 5/14/2012 12:31 PM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11080462

RE: DeHavilland Mosquito
Colleagues, After a few weeks of family visits I am back on the mossy again. I hesitated a lot but finally decided that my wooden rod for the elevator wouldn't cut it and I replaced with a Sig graphire rod. I changed the mounting of the fuse servos to have the elevator rod passing over the rudder servo. The result can be seen in the pics. I also mounted the engines (sorry, not pics yet, should work on the cowls and spinners first...), fixed the gears, changed the wheels, etc. thus the wing is technically almost ready to go for a roll. I received the pilots, unpainted... I feel that pilot painting may put a halt to the build to the point that the first flight may have to be without... Spitty, what paint did you use for yours? By the way, did anybody try to fly without the canopies? ... and I updated the build log: http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/JamaraMosquitoBuildImageDirectory.htm Cheers, /Magnus
Posted on: 5/14/2012 1:47 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11079916

RE: DeHavilland Mosquito
would have found it's way to the trash real fast without serious help, and these were trainers
Posted on: 4/27/2012 4:59 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11054776

RE: DeHavilland Mosquito
David, It seems like perhaps the kits in Europe are without the decals. This is the picture I find with the adverts and indeed exactly the content of my kit. Cheers, /Magnus
Posted on: 4/24/2012 6:13 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11054729

RE: DeHavilland Mosquito
Guys, Thanks for the positive words! I believe this kit has been on the shelf for a while... but I don't think I can know for kow long. It did come with the decal sheet. The interior is all (bad) ply at least . If it stops raining I'll finish adjusting the engines tonight (the pumps are really hard to get to once installed in the plane; better be correct before installation...) Cheers, /Magnus
Posted on: 4/23/2012 11:26 PM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11054515

RE: DeHavilland Mosquito
Dears, A test run of the hammerhead with straight FAI fuel over lunch confirms many things: 1) a pumped engine with dynamix carb can be a bitch to adjust 1b) two engines running at the same time does not make it easier at all 2) two two cycle engines with at full pitch with bisson pitts mufflers is LOUD. But also: 3) two engines on one tank far away appear very feasible 4) when running dry they quit within 5 seconds from eachother 5) 20oz is plenty for two .40 size engines 6) the two engines will certainly fly the plane; I get 12500 rpm +/- 50 at full blast with APC 11x5 props. The hammerhead almost took off. 7) the two engines are very similar; with equal carb opening they deliver very close RPM. I have to get the beast put together quickly! Cheers, /Magnus
Posted on: 4/23/2012 5:55 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11053232

RE: DeHavilland Mosquito
David, Based on your information I decided to put the clear coat first and apply the decals after. We'll see afterwards in I need to paint over the decals. The state of the construction can be seen in the pics. I mounted the engines for testing on a Hammerhead engine test stand... Best, /Magnus
Posted on: 4/23/2012 1:35 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11053126

RE: DeHavilland Mosquito
All, Quick question: will the decals in the CMP/Jarama kit deform if I cover them with an automotive poly-urethan coat? Anybody tried? Many thanks! /Magnus
Posted on: 4/20/2012 6:31 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11049662

RE: DeHavilland Mosquito
Thanks David, I understand then that the dihedral may not be all that important... I'll drop another "bomb" then... I used PU expansive glue for the dowel and epoxy on the flat surface between the wing panel and the center section. I like the PU expansive glue because - it expands. It will creep and fill all the space between the dowel and the tube. It's really strong too. And light since it's mostly air. Future will tell if it has any drawbacks I didn't think of. Strength should not be an issue; the main spar and even the aluminium dowel are far weaker than the joint. I used PU glue also to line the space behind the firewall since when I cleaned out the compartment the surfaces were not completely flat. If I would have used epoxy I would have needed large amounts. With the PU glue I only needed apply a thin film that then expands and fills all cavities and it even complements where glue lacks from factory. If you never used PU glue: The PU glue is moist-activated. In order to "activate" the PU glue you may use a spray bottle with water as you use for flowers or when ironing. Spray a very light fog in the air and draw the part with glue through the fog. It will expand without this additional humidity but not as much. Cheers, /Magnus
Posted on: 4/19/2012 8:20 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11048488

RE: DeHavilland Mosquito
David, Thanks for the kind words! I glued the first wing panel yesterday and I noticed that center wing piece is not leveled when put on the table...? I had to put a 4mm balsa block under the front of the right (left looking from the front...) nacelle to make it level. Is that common? I glued the left wing first as it had a tight fit figuring I'll be able to adjust the right panel, which has a lot of play, to make it straight. I will get something like 15mm dihedral per side (I have something like 9mm difference in height of the LE between the panel root and close to the tip). Sounds normal? Cheers, /Magnus
Posted on: 4/19/2012 12:18 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11048149

RE: DeHavilland Mosquito
Hello, Thanks David! You confirm what I foresee: It will land like a brick... I have a TF Airacobra that weigh 4.7kg for 1m60 wing span and already that comes in scaringly steep, something like 40 degrees... I never needed to land it without engine so far but indeed the engine need to quit at the right place or really high up. I have updated the build log: http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/JamaraMosquitoBuildImageDirectory.htm I made the rudder linkage with a pull-pull and I modified the elevator linkage as seen in the pics below. Since i wanted to mount the rudder servo in the middle of the fuse it comes close to the elevator servo. No worries, there is no interference possible... I am still waiting for the mufflers thus I cannot finally mount the engines. A trial picture is attached. I am planning to experiment with outward thrust. The left engine will have 1 degree outward and the right engine 2 degrees. The sum will be ~1/2 degree right thrust. As I say this is an experiment inspired by Twinman and it's meant to make the control "easier" on a single engine... It means that the right engine mount is 2mm to the left and the right engine 1mm to the right of the center line in order for the spinners to line up. I will hopefully never be able to report single engine behaviour... Cheers, /Magnus
Posted on: 4/18/2012 4:51 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11046719

RE: DeHavilland Mosquito
Andy, Yeah... these wheels are really heavy... I will probably use another pair. Mind you, they would give a nice soft ride . I also have the tank behind the CG, thus the two effects will work together. One the other hand - perhaps less risk for stalling on the final . Cheers, / Magnus
Posted on: 4/18/2012 3:40 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11045601

RE: DeHavilland Mosquito
Andy, "the Engines NEVER should go dry " Yeah... I agree... What I mean is rather that you become less sensititive to e.g forgetting to re-fuel the second tank etc... but the system becomes more complicated and in some sence more sensitive indeed even though I have had no issues with pumped engines so far. I do not say it's the right thing to do but I will try and report success or screw-up eventually. I do have room for a fairly large tank behind each engine if need be and if I get a second chance... . I understand the CMP/Jamara mossi is no longer manufactured (not in the CMP catalogue anymore)? Cheers, /Magnus
Posted on: 4/17/2012 8:22 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11045631

RE: DeHavilland Mosquito
Hello, Thanks David for confirmation about the CG! I'll take a pic later. I am thinking that I might do your LE mod... I am back again after Easter and I have updated the build log: http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/JamaraMosquitoBuildImageDirectory.htm I mounted the gears. A video is available on http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/gear_test.AVI It can be safely played with windows media player. I am waiting for the mufflers thus I started looking at the tail. The rudder linkage appear really on the light side and looks like it would flex more than you really want for firm rudder handling... Are you guys using it or did you modify? I saw Davids mod which might be the way for me to go too... or I might put a pull - pull to save weight in the rear... Cheers, /Magnus
Posted on: 4/11/2012 3:20 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11035646

RE: DeHavilland Mosquito
BlkHwkCE I am planning to use a single tank. Without having the actual experience with two engines on one tank I believe you will have to install two pumps, one for each engine, and two clunks in the tank. This is the setup I am aiming at. The nice things with a single tank are - The two engines will run dry at roughly the same time regardless of individual consumption - The tank can be mounted centrally and in the Mossy below the carbs even in inverted position!!! I am using pumps generally when i put the tank over the CG. This is not easily achievable in the Mossy. Mine end up behind... The drawback is complication... Your choise! Magnus
Posted on: 4/10/2012 8:12 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11035974

RE: DeHavilland Mosquito
Colleagues, I have started my building and some pics with comments are available on http://hansenm.web.cern.ch/hansenm/planes/JamaraMosquito/JamaraMosquitoBuildImageDirectory.htm After working for a few minutes with the very brittle ply in the kit I decided to clean out the compartments behind the engines. I lined the sides with 1.5mm ply doubled the firewall with 6mm ply. The weight added is about 50g, all in front of the CG http://www.rcuniverse.com/forum/js/punymce/plugins/emoticons/img/trans.gif . I opened up the stomach to add the tank. It will end up behind the CG.Here some 25 grams were added, behind the CG this time http://www.rcuniverse.com/forum/js/punymce/plugins/emoticons/img/trans.gif . By the way: I went for the Bisson mufflers. I'll continue after Easter. /Magnus
Posted on: 4/8/2012 10:59 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11026198

RE: DeHavilland Mosquito
I have jumped into the mosquito swarm as well after very little hesitation. I am generally more of a builder but figure I should probably try an arf first as a teething excercise. Later I might go for a Brian Taylor scratch build if I manage to get this one flying properly. I have more or less decided for thefollowing setup: Two pumped Webra speed 40 (I run only Webras by pure principle since they went out of business) with a single large fuel tank in the central bomb compartment, dynamix carbs or perhaps Perry if I run into trouble. Probably side mounted. I will attempt 11x5 or 12x5 props. I am contemplating a Bisson or a Jtec pitts style muffler. If I go for inverted I’ll select the mufflers accordingly… Spinners from Traplet: http://shop.traplet.com/product.aspx?c=2619; they are for the Brian Taylor 71 inch Mosquito and they are a few mm too small. I will report compliance when they are in hand if somebody is interested. Gear mechanics from e-flite;the 60-120 gear appear sturdy enough. Homemade struts; Will report ifsomebody is interested. CG at 118 mm behind wing root by the fuse. Here I have read everything between 110 and 120. What’s the real deal? I suppose it matters if you take the upper or lower LE by the fuse asreference since it is not cut vertically? 118mm behind the upper LE correspondsto about 112 mm lower LE… Something like 2 degree outwards thrust as described somewhere in the thread in order to make handling“easier� on one engine… I figure that weight need to be saved in the tail, thus no extravaganza like tail wheel retract; every gram in the tail will require 6 in the nose to balance… I have questions about the servo performance requirements: I can understand if the aileron servos and maybe the flaps need to be high torque, but why the elevator and rudder servos? Unlike the aileron and flaps there is very little static force applied on the elevator and rudder…? Would somebody be willing to explain? Apparently the full scale aircraft used the wheel brakes to steer on the ground. Did anybody try ? Does anybody have experience with the bisson or Jtec .40 size pitts muffler concerning noise or power loss? I normally try to fit a tuned silent pipe in the fuselage but here it seems rather difficult… Cheers, Magnus
Posted on: 4/3/2012 9:38 AM by Author "fast_mag" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11020960