Andy Meade Posted November 24, 2015 Share Posted November 24, 2015 Good news on the wing section chap! I am fiddling with plastic parts on my Flanker at the moment - not a lot of fun at all. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted November 24, 2015 Share Posted November 24, 2015 Are you 3D Printing cheating again? Edited By Matt Jones on 24/11/2015 09:54:29 Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted November 24, 2015 Share Posted November 24, 2015 No, just using the parts Andy supplied with the plan (nose / cockpit / jet pipes). Actually not quite true - I found a nice 3D model of some reasonable pilots, so I will be 3D printing them soon Quote Link to comment Share on other sites More sharing options...
Daren Graham - Cambria Funfighters Posted November 24, 2015 Share Posted November 24, 2015 Posted by Steve McLaren on 23/11/2015 20:44:26: The official answer on the wing section from Phillip Knight at Cloud models is that it is Eppler 205. Which is very good news - it sounds like I'm still on track for a PSS model. The wings are now joined, the aileron hinges fitted (at least temporarily) and the tips sanded to their rough shape. The fuselage frame is also complete. So now it's on to the trickier tasks of making all those plastic bits fit properly. OOh, I see mr Knight has nicked my idea for aileron torque rods. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted November 24, 2015 Share Posted November 24, 2015 Absolutely Daren, no one ever came up with that idea before. Apart from all the other designers of models and full size who have been using torque tubes since mass production began. Nice try though. Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted November 24, 2015 Share Posted November 24, 2015 I think Steve mentioned the rods were cribbed from Andy Blackburns JP plan on page 1. Not sure how old that is, but it's been around a fair while... Quote Link to comment Share on other sites More sharing options...
Daren Graham - Cambria Funfighters Posted November 24, 2015 Share Posted November 24, 2015 No what I meant was slotting the wing for the torque rod, greasing it and forming a bearing tube with epoxy. Then putting a cap strip over the top. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted November 24, 2015 Share Posted November 24, 2015 Ah, my bad Daren, thought you meant the actual torque rod. I'll get back in my box now Quote Link to comment Share on other sites More sharing options...
Daren Graham - Cambria Funfighters Posted November 24, 2015 Share Posted November 24, 2015 It would be nice to claim credit for the torque rod but it would be a bit like pretending to have invented the wheel I think. Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted November 30, 2015 Author Share Posted November 30, 2015 Got the wing attached to the fuselage frame at the weekend. Then turned my attention to the nacelles, where I found a bit of a complication. The kit was designed around small electric motors (Speed 480s I think I read somewhere), so it's not surprising that the front of the nacelles narrow down to quite a small spinner. The front motor bulkhead as supplied is 35mm diameter. But I don't think this will look right. By my calculations, scaling from the wing span, I think a true scale spinner would be close to 65mm diameter. I found these nice rounded 70mm spinners in the local model shop, and I reckon I could trim away some of the back plate to bring them down to 65mm. But what to do about the nacelle mouldings? I'm still thinking about that - could I cut slices into the front half and flare the moulding out, and fill the gaps with balsa, or fibreglass? Or should I just chop the front off and build a conventional balsa front end? I have made a light ply former of the vertical shape I want to achieve on the front end of the nacelles, and a replacement front motor bulkhead. If I understand the kit instructions correctly, it seems to suggest making the nacelles removable from the wing, by locating them on a dowel at the leading edge of the wing, and using a small nylon bolt through the wing close to the trailing edge. But I am thinking that the lightest and strongest approach will be to permanently join the nacelles to the wing, and to use the joint between the two to provide strength to the nacelle. So I have glued the nacelle formers to the wing with PVA. I looks a pretty lightweight frame - I guess a lot of the strength required for belly landings will have to come from the plastic moulding and it's bond to the lower wing skin. But I added the diagonal braces you can see in this picture to try to improve the strength and stiffness of the frame too - not just for the landings, but also to stop me snapping the former off the leading edge whilst I'm building the rest of the nacelle. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 1, 2015 Share Posted December 1, 2015 Some tidy work there Steve. My view is that you ditch the vac formed nacelles entirely and plank / former to your own, more scale, design. It'll be easier than trying to modify plastic and probably stand up better in the long term to the rigours of slope flying. I'm looking forward to seeing this on the Orme, love the Mosi. Quote Link to comment Share on other sites More sharing options...
Andy Blackburn Posted December 1, 2015 Share Posted December 1, 2015 I agree about ditching the vac formed nacelles. The other construction option you have is to tack some blue foam in place, sand to shape (not as difficult as it sounds if you attach the spinners) and then finish them with glass & epoxy/acrylic varnish. Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted December 1, 2015 Author Share Posted December 1, 2015 Hmmm. But that sounds like so much work! I was hoping to avoid all that sanding to shape! I might end up there, but I'm going to see what I can achieve with these mouldings first!! Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 1, 2015 Share Posted December 1, 2015 But planking is so satisfying! Quote Link to comment Share on other sites More sharing options...
Andy Blackburn Posted December 2, 2015 Share Posted December 2, 2015 I must stop saying 'I agree with Matt' ... Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted December 3, 2015 Share Posted December 3, 2015 Only just seen this so am joining in. When I was reading the flow of comments, I was thinking the same about wing sections and power models. As you know Steve I have the Skyways Models Hawk, which has is designed for a Merco 61. Everything is very large scale to cope with power and fuel. The wing section is quite thick and is semi symmetrical. It flies OK but does not cut through the air like the Jet Provost or the Alpha Jet which have much thinner sections. I really hope it works because it is a great looking model. I have given up flying it at Leek as it needs a steep cliff like the Orme. I was just reading the Tony Nijhuis Mosquito free plan and thinking - wonder if it would PSS when I found your blog - coincidence. Will be following with interest. The Hawk is similar - lots of plastic mouldings which are OK but need fettling with plastic tabs - have a look at my blog - **LINK** Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted December 3, 2015 Share Posted December 3, 2015 Only just seen this so am joining in. When I was reading the flow of comments, I was thinking the same about wing sections and power models. As you know Steve I have the Skyways Models Hawk, which has is designed for a Merco 61. Everything is very large scale to cope with power and fuel. The wing section is quite thick and is semi symmetrical. It flies OK but does not cut through the air like the Jet Provost or the Alpha Jet which have much thinner sections. I really hope it works because it is a great looking model. I have given up flying it at Leek as it needs a steep cliff like the Orme. I was just reading the Tony Nijhuis Mosquito free plan and thinking - wonder if it would PSS when I found your blog - coincidence. Will be following with interest. The Hawk is similar - lots of plastic mouldings which are OK but need fettling with plastic tabs - have a look at my blog - **LINK** Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted December 3, 2015 Share Posted December 3, 2015 Only just seen this so am joining in. When I was reading the flow of comments, I was thinking the same about wing sections and power models. As you know Steve I have the Skyways Models Hawk, which has is designed for a Merco 61. Everything is very large scale to cope with power and fuel. The wing section is quite thick and is semi symmetrical. It flies OK but does not cut through the air like the Jet Provost or the Alpha Jet which have much thinner sections. I really hope it works because it is a great looking model. I have given up flying it at Leek as it needs a steep cliff like the Orme. I was just reading the Tony Nijhuis Mosquito free plan and thinking - wonder if it would PSS when I found your blog - coincidence. Will be following with interest. The Hawk is similar - lots of plastic mouldings which are OK but need fettling with plastic tabs - have a look at my blog - **LINK** Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted January 3, 2016 Author Share Posted January 3, 2016 So, where was I before Christmas got in the way, and my workshop was commandeered as a food store? Ah yes, nacelles. I decided to cut slits from the front of the plastic mouldings, so that I could flare them out to meet the enlarged front former, like this: And then, after bonding in place with an epoxy + microfibres mix (I didn't have the recommended microballoons), and incorporating a few plastic overlap tabs as recommended by Peter above, it looks like this: These could be useful as extra cooling for the motors! But then I don't have motors! I didn't bond the front ends of these strips at this stage, just in case I didn't like the shape - I would then have the option to just them off. But I have decided to go ahead with this approach and have since bonded the ends in place. I plan to add some fibreglass cloth to the inside and rebuild the full nacelle shape with slivers of 1/32nd balsa and filler. If that doesn't work, I'll just have the cut the whole lot off! I found that the nacelle mouldings fitted very well, and trimming them to shape was easy. But it was a different story with the lower fuselage moulding. I found that there was no way it could fit to all the formers at the same time. In the end I got it to fit to all the formers except the nose former and the tail end former. Any attempt to make it fit at the ends caused the sides of the moulding to kink outwards in a sort of fold, so that it wouldn't meet the fuselage side rail. So the only thing I could think off was to cut a few slits to allow the moulding to curve more at each end. I will patch up these slits with a bit of fibreglass and filler later. I also decided to take Andy Blackburn's advice and go with a Mk VI fighter nose, rather than the clear Mk IV bomber nose moulding supplied in the kit. I think this will be more durable for slope flying (particularly for my landings!), and it makes the whole business of fitting the balancing weight in the nose a lot easier. Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted January 4, 2016 Share Posted January 4, 2016 Well done for persevering with the plastic Steve. I know what a dreadful material it is to work with as it tears and rips. As I was reading I was thinking using blue foam was a good option. Planking is a bit old fashioned. The problem will be that if you use plastic, its benefit comes in the flexibility when impacted but with fibreglass cloth it will become stiffer again. Will be interested to see how it works. If you use just one layer however it will retain some flexibilitiy. Sounds like a good plan. Presuming you are using lightweight cloth of 25grams per metre. I would give it two or three coats of water based resin to stiffen it up. Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted January 23, 2016 Author Share Posted January 23, 2016 Yes the plastic is proving a bit of a complication. I discovered a problem with the rear fuselage where I thought I had cut enough slits in the plastic moulding to be able to form it to shape against the light-ply frame. But after bonding, when I put a straight edge along the light-ply fuselage sides, I find that, at the tail end, where the wood sections are all very slender, the light-ply frame has distorted significantly to meet the moulding. You can see the effect here. Without correction, this would mess up my tailplane incidence. So I have had to add some thin tapered balsa wedges onto the tailplane seat to restore the correct tailplane incidence. On the first nacelle I have added some fibreglass internally, and some filler externally. It's now looking like this. Still rough. It needs more filler and sanding, but I think it might work. With the tailplane and fin in place, it's now starting to look a bit like a mosquito. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted January 25, 2016 Share Posted January 25, 2016 Belated Happy New Year Steve. It's coming on, what size spinners are they? Quote Link to comment Share on other sites More sharing options...
Andy Blackburn Posted January 26, 2016 Share Posted January 26, 2016 Very impressed that you've stuck with it through the painful and perplexing plastic predicament... Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted January 31, 2016 Share Posted January 31, 2016 I also sympathise with the impossibility of plastic mouldings having been through it. On the plus side, they are very forgiving in the event of a hard landing as they do flex unlike any other material. So chin up! Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted February 14, 2016 Author Share Posted February 14, 2016 Thanks for the encouragement on working with plastic mouldings guys! I think I've just about reached the end of it this weekend. I used the back end of the nacelle top mouldings. but I will build the front ends in balsa, with a hatch, just in case I ever want to add electric motors. Then, this is the rear fuselage upper moulding going on:- after a bit of tidying up, it looks like this:- But again, I won't be using the plastic moulding for the front half of the fuselage. Instead, I will build a balsa deck which goes over the wing and takes the canopy. I'm hoping this will make the joint line at the front a bit less noticeable than in the original kit arrangement, but we shall see! This is how it looks so far, and I've run out of soft 1/2 inch balsa for now. Hopefully, I'll be able to find the right shape in there somewhere! Meanwhile, here's a picture of the elevator servo installation. One of the down sides of working with plastic mouldings, epoxy and microfibres, is that it all tends to look a bit messy! Or maybe that's just my bad technique? Overall, I don't think I'll go for plastic mouldings again. I can see that, done well, they could probably save some weight, but they're rather difficult and messy to work with, and I don't think they save any time in the build. But the experience has taught me to appreciate the joys of balsa sanding! Quote Link to comment Share on other sites More sharing options...
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