David P Williams Posted October 27, 2014 Share Posted October 27, 2014 For info, the longitudinal reference datum on the Chipmunk is formed by the two nipple-like protrusions you can just make out in this pic: They are more or less in line with the sides of the cockpit. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted October 27, 2014 Share Posted October 27, 2014 I've never noticed that before, very practical. Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted October 27, 2014 Author Share Posted October 27, 2014 Thanks, David. I've never seen that either - very interesting. Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted October 28, 2014 Share Posted October 28, 2014 There is one thing I was going to mention to you David, and that is during the build ( may be too late now but could still be done ) is to move the U/C mounts about 10mm forward as the plane is prone to 'nose overs' on landings, especially on rough grass strips. The real one was also prone to this a wee bit. If you dont want any broken cowls ( I have replaced mine 3 times ) then moving the mounts solves the problem. I know it is not quite scale in doing so, but is hardly noticeable and more practical for the average strip. Oh and I have just posted a note on washout too on my thread if it is of any help. Regards ZK BAP MFNZ11300 Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 28, 2014 Share Posted October 28, 2014 Hello folks can one of you tell me if this shape is correct for flap/aileron please. John Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted October 28, 2014 Author Share Posted October 28, 2014 To ZK BAP... Ahhhgg, too late. I think. I suppose I could butcher the wing and reposition the u/c, but it would be a major job and, to be brutally honest, I really don't have it in me to go that far. I know I will regret saying that after I've nosed over umpteen dozen times. At least, I guess, forewarned is forearmed. To do the job properly I would have to cut out the hardwood bearers and cut out the ribs forward to accommodate the new position. Then re-sheet the holes. The Christmas/New Year hols are coming up when I will have plenty of time to do it. So if I ruminate on it between now and then I might just have the impetus to do it. You reckon 10 mm (1/2 and inch) will do it? Cheers David Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted October 29, 2014 Author Share Posted October 29, 2014 John, here are the cross sections of the flap and aileron as shown on the airsail plan. The plans are very accurate so would have no trouble accepting these as correct. It is what I have built for my chippie. Flap top and aileron bottom photos. David Edited By David Richardson 2 on 29/10/2014 00:09:59 Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted October 29, 2014 Share Posted October 29, 2014 Hi David, after the 2nd broken cowl I moved my U/C forward simply by placing another block forward of the original ones removing portions of the ribs along the way. Since then I have not had any nose overs. Like you say, may be best to wait but is a certainly a mod worth looking at. Another thing to add that is also a bonus is a steerable tail wheel. This can be done by using the rudder and having a piece of wire protruding straight through to the bottom and placing an arm on the existing one and simply linking them up by means of an adjustable coupling. I am currently helping a mate build his one and he is very lucky to have all the heads up so things are being modded as we build. We are putting a 91 four stroke in it so we have also beefed up where required as he wants the speed and vertical performance. What engine choice have you gone with by the way? Key factor is to keep the back end as light as possible. I would also recommend either a dual elevator push rod ( one for each side ) or more stiffer wire joiner as the slave side tends to get pushed back under high speed making loops not so straight. my one has a 61 four stroke in it and goes very well, but I have managed to get Brian Borland to get me another kit which I will start after we finish my mates, and I too will be using a 91 four stroke. Also make sure you have plenty of air going through the cowl as the heat tends to make the ABS cowl go brittle. Cheers for now Regards ZK BAP Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted October 29, 2014 Author Share Posted October 29, 2014 Hi ZK BAP, I'll go ahead and shift the u/c position if you think it's worth doing. Though I have to say that the present position seems pretty well forward as it is. Re. the engine size I have installed an ASP .52 four stroke, for two reasons... The recommended motor sizes are .32 - .46 2 stroke or .40 - .70 4 stroke. Your idea of a .91 will certainly provide more than enough grunt. But, anyway, I had a .52 4 stroke in a vintage "Red Zephyr" so it made sense to me to use it since it was within the recommended size range and it was going to save me having to purchase another motor. My style of flying doesn't include prop hanging so it should be OK. Getting back to the u/c is 10 mm further forward enough to make it worthwhile? Cheers David Edited By David Richardson 2 on 29/10/2014 03:04:44 Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted October 29, 2014 Share Posted October 29, 2014 Yes ten to fifthteen will be fine it just shifts the weight more onto the gear and will prevent the nose over issue Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted October 29, 2014 Share Posted October 29, 2014 I can't say that I've noticed my Chippie being particularly nose-over happy. I've had the odd one on longer grass but in general it doesn't seem to be a problem. I wonder if my C of G is further back than yours? I have had to tweak the legs forward on a few occasions when the tail has started becoming a bit bouncy but it's fine when the wheels are in the scale position. Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted October 30, 2014 Share Posted October 30, 2014 Hi Martin. bending the wheels forward is also achieving the same effect, but looks a bit funny. you are right about the tail bouncing. To keep the looks right shifting the U/C forward that wee bit will solve any nose overs. We mostly fly on grass, so it seemed the logical way to go. Of course if you are lucky enough to have an asphalt or concrete runway it will not be a problem. My C of G is as per plan, but the back end is incredibly light, so any resistance on the main wheels caused a nose over. Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted October 30, 2014 Author Share Posted October 30, 2014 To ZK BAP,,, Well, I've bitten the bullet and started the u/c surgery. I've taken the position 10 mm forward - hope it doesn't detract too much from scale. I don't intend to compete with it but I do want it to look the part, if you know what I mean. I should have this little job done in about a week so I'll post another ic when it's done. As an aside I was reading the other day about "cuffs" around the top of the u/c fairings. The Airsail plans don't show these and I cannot see what they are meant to be from prototype photos. Any ideas? David Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted October 30, 2014 Share Posted October 30, 2014 Hi David. The cuffs were made of ABS, but due to some reason or another were not included in the latest kit runs. You could use some scrap for the cowl/tip/belly mouldings. Mine fell off a long time ago on a hard landing and I never bothered putting them back on. When they are in place they hide the bend in the landing gear wire and must be placed in such a way that the leg can flex back and forth without hitting them. Needless to say mine were unsuccessful in doing so as the leg can move some distance. Even card could be used if you wish. To be honest I totally forgot about them and you have just reminded me to fabricate some up ZK BAP Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted November 1, 2014 Author Share Posted November 1, 2014 Well, that's it - done. Moving the u/c was not the giant exercise that I thought it would be. The final position is now 10 mm forward of the original. Hope it does the trick (of preventing nose-overs). Now it's back to the final colour coat. For the white I use Dulon AO20 High opacity white. As the name implies it covers easily in two thin coats. Then it's grey wings and lastly red lower fus and wing outer panels. Quote Link to comment Share on other sites More sharing options...
ZK BAP Posted November 2, 2014 Share Posted November 2, 2014 That looks nice and neat David well done. The shift should be hardly noticeable from a scale point of view, but I think you will appreciate the slight change when landing on the the grass. My mate is going to fabricate some glass cowls up too so we always have a spare at hand. My third has now started to crack with heat and can only be patched so much before a replacement will be needed. Happy building. Cheers ZK BAP Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted December 17, 2014 Author Share Posted December 17, 2014 At last the weather has improved to the point that I feel easy about pressing on with the paint job. So have just done the white - two thin coats did the trick. Next will be the grey wing inners and wing root fairing, also mustn't forget the u/c fairings. Only four more days to the longest day so the weather HAS to improve before long! The P47 has nothing to do with the Chippie project - just thought I'd get it out for an airing! This was scratch built from Brian Taylor plans and got me first place at our National Chamionships a few years ago. Quote Link to comment Share on other sites More sharing options...
Braddock, VC Posted December 17, 2014 Share Posted December 17, 2014 Watching with interest. Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted December 18, 2014 Author Share Posted December 18, 2014 HELP!! Can anybody help me with good pictures of the RAF colour scheme underside? In particular I need to know how the wing grey joins in the centre section and how the red nose underside fairs into the grey. Colin, if you still have access to WP 848 would you be able to get a snapshot of this portion of the a/c for me?. Many thanks to all those enthusiasts who will come racing to the rescue! As an aside, has the Airsail shipment from NZ arrived in the UK yet? I will be watching with interest to see how the many builds go - all 50 of them!! Only another three days to go before the longest day of the year and then, hopefully, some decent summer weather. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted December 18, 2014 Share Posted December 18, 2014 Do these help David? There are loads and loads of pics over inthe Chip Shop section. Cheers Danny Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 18, 2014 Share Posted December 18, 2014 Hi David. Hopefully Danny's response gives you what you need? I'm not expecting to go to Norfolk and renew my acquaintance with WP848 until the spring, although I will take plenty of photos then. I'm in the office today and won't get a chance to look at this until I get home tonight, but I think the photos with Danny's post do answer your question. Your P47 looks outstanding by the way and by the looks of your Chipmunk so far, it's going to be of a similar standard. I hope mine will look half as good, will be well pleased if it is! Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted December 19, 2014 Author Share Posted December 19, 2014 Just for you, Colin, my P47 was built a few years ago when I had my heart and soul in a build. I have to confess that I tend to take a lot more shortcuts these days! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted December 19, 2014 Share Posted December 19, 2014 That's a stunning model David, I bet Danny will seriously approve of that one. To me the detail is museum standard. Are you happy now with the underside paint detail? I don't think there is any doubt about it from the information that Danny has passed on already. I've had a good look at the picture references that I've got and although there's nothing good enough to copy here, it looks right to me. The relationship with the under-wing fairings also looks right, so it's the way that I would go if I was using that scheme. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted December 19, 2014 Share Posted December 19, 2014 I definitely approve David a lovely model indeed! I am sure the Chippy will be as good Cheers Danny Quote Link to comment Share on other sites More sharing options...
David Richardson 2 Posted December 19, 2014 Author Share Posted December 19, 2014 Thanks, Colin and Danny. Yes, I am more than happy with the underside pics of the Chippie. Looks as though the red/grey boundary lies along the Airsail wing fillet line, top and bottom. The next trick (for me) is to mix the red and grey to the right shade. I use acrylic lacquer thinned 200 per cent. It is all high opacity these days so thin coats cover well. The white only took two coats. I only purchase the lacquer in the three colours yellow, cyan and magenta, plus B&W. I figure that if a common bubble jet printer can identify and mix 4.6 million colours I can do the same for only two on the Chippie! Cheers David Quote Link to comment Share on other sites More sharing options...
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