Mac Duberia Posted November 7, 2009 Share Posted November 7, 2009 hi to everyone, im complementing building this plane soon and have bought the cnc pack, im intending to install air retracts somehow, does anybody know which engine is best suited to it? any thoughts........... Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted November 7, 2009 Share Posted November 7, 2009 Im no expert but if you can give more details,such as estimated weight someone will come and advise you.I assume its I/C do you want 2 stroke or 4 stroke, the 4 stroke will sound better but need to be bigger,good luck getting some advise Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted November 8, 2009 Author Share Posted November 8, 2009 i do not want to exceed the design weight but i am thinking of cutting in some lightening holes in the ribs and maybe in some formers. At the moment i have an OS 65 LA, and thinking do i really want a fourstroke which i know will sound brillant, but which size and make would you guy/gals suggest, i've been drooling over OS, SC, Saito but there are'nt any 60 size fourstroke about. Personally, if i do go for fourstroke i think a '70', but im not sure this is where you guys/gals come in. In Tony's article it is suggested that some nose weight will be needed so im also thinking of making a scale exhaust system and hopefully serve as both. Quote Link to comment Share on other sites More sharing options...
batcho99 Posted November 8, 2009 Share Posted November 8, 2009 I think a .70 four stroke will have plenty of power for this model. I think TN's Spitfire had a .70 four stroke in and that flew very well indeed, check out the video on here. ASP do a .61 four stroke, I know because I have one in my geebee sportster, it goes well. Choice of engine is a personel thing, I own OS, Saito and SC, all great engines, My choice would be another Saito tho. Iain. Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted November 8, 2009 Share Posted November 8, 2009 My Son has a Saito 62a in his World Models Mustang and that fly very well. I love Saito engines they are so well made. Quote Link to comment Share on other sites More sharing options...
Hugh Coleman Posted November 8, 2009 Share Posted November 8, 2009 If I remember correctly, they had an SC 52 4-Stroke in the TN Prototype. And they thought that it had heaps of grunt. My self, I would put as ASP .61 4-Stroke or an OS 56 Alpha (if I could afford it). I have an OS 52 Surpass that will end up in a 54" Spit one day. Cheers Hugh Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted November 8, 2009 Author Share Posted November 8, 2009 Im thinking of saito 72 for this project now, as all the threads so for have been positive on the saito, no one has mentioned OS as been preferrable, i know they sound great as one of our club member has got one in his ultimate but his engine is a 1.20. Quote Link to comment Share on other sites More sharing options...
Snaba Posted November 20, 2009 Share Posted November 20, 2009 Hi. I'm also busy with the plane, so far all went fine. I chose a 4-cycle RCV-60SP for an engine as this has in-built 2:1 gear which allows to turn scale props with high pitch. This engine fits inside the cowlings and only the exhaust will stick out, although this can also be built scale. No sun without a shadow: I do have a slight but irritating problem: the retracts from Unitracts suggested by TN do not fit inside the wing when closed but hang open. if you look carefully at the photos in RCM&E this is indeed the case. Ugly mishap for otherwise great plan. This is because at the point where the wheel goes in the wing has a TOTAL clearance of 44 mm. However, from this the rib takes some 5-6 mm, meaning that the oleo and wheel could have a max thickness of 38 mm, 35 mm or so if you count in the hatch and its fixings. This means that if one would like to have a completely closing setup the thicknes of the wheel could only be around 22-23 mm. Has anyone an idea where to get 31/4 wheels with less than 1" thickness or do I have to start 'slimming' my Dub-Ro wheels? Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted November 21, 2009 Author Share Posted November 21, 2009 Hello, I haven't started my project due to work and studying commitments but im going to use saito 72 and air retracts on mine. I cant comment on your experience but i will bear in mind when i do get to this stage,i have measured my retracts against the plan and it would appear mine should clear top and bottom skins, but i shall let you know how i get on. I've been struggling to get obechi strip around where i live so opted for spruce, i could mail order for them but i dont think it would be cost effective. However im also thinking of making lightening holes in some of the ribs. Quote Link to comment Share on other sites More sharing options...
Trex700e Posted November 22, 2009 Share Posted November 22, 2009 I am currently building the Nijhuis spitfire of electric power Its meant for a 0.61 IC but i have a 5065 turnigy to power it. I wouldn't do air retracts if i were you. the plan shows mechanical retracts which you can buy form unitracts international. they will fit perfectly. If you did go for an air system i dont know where you would put the air cylinder becasue the wings are only about 50mm tall and the fuse is quite compact. Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted November 24, 2009 Author Share Posted November 24, 2009 Guess wot! i got myself saito 72 the other day for the spit, i shall let you guys/gals know how i get on but im a slow builder, bear with with me. Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted November 29, 2009 Author Share Posted November 29, 2009 hello, can anybody tell me why the retracts bearers extend beyond W3? thanks Quote Link to comment Share on other sites More sharing options...
Snaba Posted November 29, 2009 Share Posted November 29, 2009 No reason why they couldn't be shortened, I guess. For my retracts problem above: I have ordered 3" Du-Bro Diamond wheels which are only 23 mm thick, by removing a bit off the rib in the wheels bay they should fit in nicely with the Unitracts oleos. We'll see if the plane will be a nosy one by missing only 1/4 " from suggested...otherwise, some other changes for the plan was made: I also built in flaps going from W2 until the aileron, the servo for this will be built in the cooler unit. For the cooling of RCV60SP I have decided to use the scoop under the engine to direct air inside the cowling, the outlet will be either built around the live exhausts and/or via an extra outlet tubing leading the hot air to the coolers in the wing...ambitious plans, uh? Quote Link to comment Share on other sites More sharing options...
Trex700e Posted December 1, 2009 Share Posted December 1, 2009 The retracts bearer extends beond W£ so that you dont have to fill it with somthing else. If you do not keep it extened then you will be able to see right inside the wing! Snaba, How did you do your flaps? I was thinking of doing the same idea but i guess you renefoced it with something becasue just the soft 2.4mm sheet wont be enough to with stand deployment at full speed! Quote Link to comment Share on other sites More sharing options...
Snaba Posted December 1, 2009 Share Posted December 1, 2009 Will, I just basically replaced the sheeting from the last bottom spar almost all the way to the t.e. with 2.5 mm plywood, but not all the way, there will be a 3x5 mm balsa strip attached to the t.e. so that the flap will cloes fully. I prepared three hinges that I glued inside the flaps and they are connected to the ribs with 3 mm nylon bolts. For the flaps I had to make little cuts at the position of the ribs so that the front part of the flap actually turns inside the wing when the flap is deployed. I could take a picture and post it here, maybe it would help explain the construct? Quote Link to comment Share on other sites More sharing options...
batcho99 Posted December 2, 2009 Share Posted December 2, 2009 Hi Snaba. I'm very interested how you have done your flaps. A picture or two would be great Iain. Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted December 23, 2009 Author Share Posted December 23, 2009 hi, I think i've got a problem with the wings and that is, after i sheeted the the top and took the wing off the board i found that the wing panel bowed slightly up and i wondered if it could be because only one side is sheeted, incidently both wing panels bowed about the same degree. Has anyone come across a similar predicament? Quote Link to comment Share on other sites More sharing options...
Snaba Posted December 23, 2009 Share Posted December 23, 2009 batcho, unfortunately, due to typical reasons (one of them carries 2 copies of x chromosome, the one is only 2 years old and the third helps to finance everything) I had no time to get to my plane recently but after x-mas I will dedicate a WHOLE week for it (all three excuses eliminated). So, I'll make some pics about the flap construction for all of us. Hopefully I can also start with the wing mounting, retracts I finally managed to get to go inside the wing using right size wheels. Macsood, I didn't have any twist in ym construction but I don't think a slight bend after paneling one side will be a problem, it can probably be compensated when paneling the other side. But just in case: I hope all your spars were straight? With one of my first planes I didn't check the main spars good enough for this and the end result was a one-sidedly twisted wing. As this was a ribbed wing without planking I could compensate this with the foil but with a fully planked wing this is not doable...or maybe it is but I just didn't learn the trick Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted December 25, 2009 Author Share Posted December 25, 2009 Hi Snaba, I did check my spars twice before commencing the build and they were straight, i am using spruce for my spars but that shouldn't have any effect on the build. Maybe or hopefully the panel will straighten out when i sheet the other side, like you mentioned but i'll see if it does. I await your pictures of your flap construction. Quote Link to comment Share on other sites More sharing options...
Snaba Posted December 25, 2009 Share Posted December 25, 2009 One more thing: did you make the sheeting wet when planking? If so, maybe this ocul result for the twist? Tomorrow my construction continues! Quote Link to comment Share on other sites More sharing options...
Mac Duberia Posted December 25, 2009 Author Share Posted December 25, 2009 Nope, it was completely dry. Quote Link to comment Share on other sites More sharing options...
Snaba Posted December 27, 2009 Share Posted December 27, 2009 I guess then the problem will either disappear when sheeting the other side, or, you'll have equally upwars bent wings on both sides Here some pics about my flaps construction, I hope they explain the basic idea. Now I'm installing the servos, the arm will be inside the flap. Curious to see how that'll work, test last night was encouraging, though...it's -4 and snowing outside, time to go back to the garage! Quote Link to comment Share on other sites More sharing options...
Snaba Posted December 27, 2009 Share Posted December 27, 2009 Another thing about the servos. In the last pic the servo is installed to the cover so that the arm would be towards the end of the wing. I turned it around to allow the installation of a bit longer arm inside the flap. Quote Link to comment Share on other sites More sharing options...
Paul Jarvis 1 Posted January 7, 2010 Share Posted January 7, 2010 Hi, This is my first build and its generally gone really well, except, since sheeting, the wings have warped. I joined them despite this mismatch and now I need to remedy it. In front view the L.E. tip of one wing is "raised" compared to the other, and the T.E. of the opposite wing is raised compared to the other. Seperately each wing looks fine, and blends in to the fuselage line, so my dilema is not knowing which wing is correct and which needs "bending" to match the other. I have checked the rib profiles, laid a ruler on them, checked against the plan, looked at photos of full size spits, but nothing really tells me which wing is correct. Has anyone any ideas how to confirm which has the correct angle of attack? Or does it not matter much ? Quote Link to comment Share on other sites More sharing options...
Hugh Coleman Posted January 7, 2010 Share Posted January 7, 2010 Hi, From the looks of it, from the photo supplied; the wing on the left looks ok, the one on the right looks to be twisted. You are going to have to try and get rid of this twist, but I do not like your chances. Your fuselage also looks twisted in this photo. This is the 46" Spit yeah? Cheers, HughEdited By Hugh Coleman on 07/01/2010 21:28:30 Quote Link to comment Share on other sites More sharing options...
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