Tom Wright 2 Posted May 31, 2015 Share Posted May 31, 2015 Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted July 3, 2015 Share Posted July 3, 2015 Hi All I'm new here but have recently acquired G-MMIH from Alan. I'm well on with the restoration to a point where the fuselage, elevator and rudder are fully complete and the engine has been re-conditioned and run. I have two usable lower wings which I am renovating prior to covering and I have built a CNC hotwire machine and cut the 10 styrofoam sections required to build a new set of top wings. I have a question regarding flying and landing wire lengths and gauges and where the connection points are and the recommended connection method. The section of the build manual I have is missing this particular set of drawings. Any help, or even better a copy of the missing drawings for the flying and landing wires would be very much appreciated. Andy Quote Link to comment Share on other sites More sharing options...
David Hardaker Posted July 7, 2015 Share Posted July 7, 2015 Best of luck, Andy . Please don't put a glass panel in it !! David Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted July 8, 2015 Share Posted July 8, 2015 Thank you David. Lol. Not even a battery in this one! Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 3, 2015 Share Posted August 3, 2015 I'm really making progress now. The wings went on over the weekend. Still got quite a bit of rigging to do and the ailerons to finish and fit. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted August 3, 2015 Share Posted August 3, 2015 I do hope this thread continues here, its very interesting. M Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 3, 2015 Share Posted August 3, 2015 Posted by Andy Carter on 03/08/2015 09:27:22: I'm really making progress now. The wings went on over the weekend. Still got quite a bit of rigging to do and the ailerons to finish and fit. Andy Thanks for the photos that looks like a beautifully finished aircraft , just love the cockpit detail and the new wing cores produced from your cnc cutter. Our factory foam cutter designed by the late Russ Light was an analogue affair but did produce hundreds of cores back in the day. Tom. Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 4, 2015 Share Posted August 4, 2015 Hi Tom Thanks for your kind words. I departed a little from the build manual during construction of the new top wings. I used polyurethane adhesive (Gator Glue) to both stick the cores and ply ribs together and also to secure the spars. I did some extensive testing of foam to aluminium bonds using both PU and epoxy. The PU seemed better in all respects. Due to its ability to foam and fill gaps during curing I am confident that the spars are very securely fixed with no gaps between the tube and the foam. I need to think about getting the aircraft to the airfield so I'm on with designing a trailer at the moment. I'll post some more pictures once I've started flight testing. Andy Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 4, 2015 Share Posted August 4, 2015 Andy I have used PU throughout my current 17 ft blue foam based model build and would agree it seems to be a better adhesive for this type of application. I think it creates a material friendly bond layer between the aluminium and foam and may even be more resistant to torsional and bending load fractures. Although it could well be better than epoxy it represents a deviation from the original so if you are building under the LAA would Francis D need to give thumbs up? I am way out of touch so don't know what the current procedures are. I see you have the low wind screen and what looks to be Jims rudder mod,although the all moving control surfaces keep things simple and light I have always thought that a slightly off set fin may have helped with the typical tail dragger yaw to the left on lift off ,but the increased rudder area and a current tail dragger experience should see things going to plan. Tom. Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 4, 2015 Share Posted August 4, 2015 Hi Tom No issues with either LAA or BMAA as I have re-registered G-MMIH as an SSDR microlight. As this category now applies to all single seat microlights regardless of wing loading the de-regulation means I can basically do what I want. The rudder is definitely larger than the one shown in my copy of the build manual, it has an extra 100mm or so on the top. I have also incorporated the 3 degrees of right thrust on the engine so hopefully the tendency to swing left on take off should be minimised. The small screen should improve prop wash over the tail and that will help too. I got my tail dragger rating a couple of years ago in a Super Cub at Clacton. Hopefully lots of fast taxi trials and some bunny hops will remind my feet what to do. I will definitely be mindful though. Andy Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 5, 2015 Share Posted August 5, 2015 Thanks for the info Andy, having now had a quick look at the CAA Q&A SSDR page it re kindles thoughts of new designs to take advantage of modern power units or even,dare I say, electric power for local flights. Your airframe up dates all sound good to me . As a matter of interest is the covering as originally supplied with the kit ? I ask as this was specially produced with a thicker glue layer. Martin Thanks for your post and interest. Tom. Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 5, 2015 Share Posted August 5, 2015 I was thinking of an electric powered 'Piper Cubalike' based on your construction techniques as a possible project for the future. Not sure what the maximum size for a foam wing would be due to weight though? Maybe 25mm foam ribs with thin ply bonded to the two sides with PU. It would make securing to a tube spar easier due to the increased gluing area over conventional ribs. I love blue foam as a building material. The Floormate sheets look interesting as they are slightly higher density and much cheaper. I used standard Solartex to cover the entire airframe apart from the rudder and the white panels on the top wings, which are Glosstex (I had a roll spare!). All joints have a 25mm overlap and are covered with a pinked 40mm wide tape. Adhesion to the bare foam seems adequate but isn't particularly critical as it's impossible to rip the joints apart, the fabric fails first. I used standard modellers tools to apply the covering, a temperature controlled iron with a digital readout and a digital heat gun. I looked at Oracover but it's really, really expensive! I used 6 10M rolls of red Solartex and 1 10M roll of Glosstex. I paid £62.50 per roll for the Solartex. All in all a very cost effective and quick covering job and it's extremely light. Time will tell regarding longevity but it seems plenty strong enough. Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 5, 2015 Share Posted August 5, 2015 A bit off topic but hopefully excusable as we are discussing blue foam construction. Have you seen this? I bought a copy of the plans out of interest a couple of years ago. www.machnone.com Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 5, 2015 Share Posted August 5, 2015 Another deviation from standard I made during the build/restoral was to dispense with the foam panels in the fuselage (they were missing anyway). Instead I used a conventional aluminium tube and gusset method to beef up the back end with cross bracing in 1 inch CF tube and diagonal bracing with steel cables. The result is a very light and rigid structure. I'm really looking forward to flying her! Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 5, 2015 Share Posted August 5, 2015 Posted by Andy Carter on 05/08/2015 06:09:55: A bit off topic but hopefully excusable as we are discussing blue foam construction. Have you seen this? I bought a copy of the plans out of interest a couple of years ago. www.machnone.com Andy thanks for the link to the Pup project, very interesting, I was under the mistaken impression that Bert Rutan and me were the only constructors using blue foam in the early 80s having said that my first full size project the Microbiplane ( photo at the page top) used white foam of a lower density than blue resulting in an empty weight of around 150 lbs and yet the machine was surprisingly robust . I still have a video tape of the Microbiplane performing loops ( very naughty) this was very unusual for the era but the diminutive machine survived transportation to air shows and a nasty prang when a pilot lost power on finals and encountered a deep ditch at touch down resulting in a substantial impact followed by an inverted tail first slide to a stop the damage was minimal and the pilot walked away without a scratch, perhaps this is testimony to the shock absorbing properties of foam structures? Your moment arm mods emulate conventional structures but I guess the materials used result in better strength to weight and an overall improvement, nice work . My large foam based models all use lightweight caps to eliminate covering contact with the foam this prevents indentations in the foam caused by rough handling and hanger rash it would be interesting to develop a similar approach for a full size design to maintain the excellent covering finish that you have achieved . Tom. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 5, 2015 Share Posted August 5, 2015 Current state of play with my current blue foam based project . Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted August 5, 2015 Share Posted August 5, 2015 Wow Tom. That looks amazing. All you need now is a small grandchild to pilot her What sort of spar are you using? I can't see any ailerons is it a rudder/elevator design? The Skypup dispenses with ailerons but by all accounts the handling is excellent on R/E. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 5, 2015 Share Posted August 5, 2015 Don't want to bore you with old bloke ramblings Andy but this model is an off the cuff quick build experiment undertaken after finding three sheets of inch foam during a clear out, I don't like to waste useful materials so in a moment of madness I did a rough concept drawing and some simple sums and cut out the out line with a hand saw. The 17 ft span model weighs near to 20kg so I have put it on LMA and got it cleared for covering,it has a 50cc electric equivalent up front turning a 24 x 12 prop the power train with four 5A five cell lipos returns 4 KW . The wing has four 5ft struts so the main spar is quite modest comprising of 2 inch deep 1/4 hard balsa with inch tri section to get good bond area to the foam ,the bending loads are transmitted via the foam to carefully selected inch by 1/4 hard wood spars bonded to the foam leading edge and to the foam trailing edge before the trailing edge is added. Possibly a daft way of doing things but it just evolved that way and did not break when loaded to + 4 G. Roll is rudder only which keeps things simple for a floaty none aerobatic machine and is a follow on after building rudder /elevator a 10ft blue foam model four years ago which can be seen here . Quote Link to comment Share on other sites More sharing options...
JoanW Posted August 6, 2015 Share Posted August 6, 2015 Rudder/elevator-only control is quite Ok as long as there's sufficient yaw/roll coupling in the design. Quite a few US ultralights are designed that way because it can simplify wing design, I understand. One of the microlights I use for training is a derivative of the early 'Weedhopper' design, via France, by the name AX3. I tell everybody that the name is because it's predecessor design didn't have ailerons - looking inside, I reckon they originally designed the stick to control the rudder, with the pedals just dealing with the nosewheel. Anyway, this design, as you can see in the video, uses leading edge sweep-back to give strong yaw/roll coupling and it can be flown satisfactorily without bothering with the ailerons. in fact the ailerons are very simple design and produce masses of adverse yaw, so if you use aileron for roll you need even more rudder to drive it into the turn. In that respect it's an excellent training machine because the pilot has to use rudder or the aircraft will just wander all over the sky - the aileron is just there to help balance the turn... Tom, that is one BIG beast. I'm sure you'll enjoy flying it. Joan Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted August 6, 2015 Share Posted August 6, 2015 Posted by JoanW on 06/08/2015 12:41:53: Tom, that is one BIG beast. I'm sure you'll enjoy flying it. Joan Thanks Joan if the model turns out to be as STOL as your AX3 my experiment will have been worthwhile. We have a well manicured runway surrounded on three sides by large open fields but the runway is very short . Tom. Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted September 13, 2015 Share Posted September 13, 2015 Well. The day finally arrived when I could transport the Tiger Cub to the airfield. I built a custom trailer for the journey and with the help of some great friends she arrived safely Quote Link to comment Share on other sites More sharing options...
Andy Carter Posted October 3, 2015 Share Posted October 3, 2015 After a few months building, renovating and testing Tiger Cub G-MMIH made it's first flight in 30 years. It handles very well in the air and has very nice manners on the ground too. Visibilty is great and handling predictable. The Fuji Robin 440 engines delivers plenty of power and average climb rates were about 750' per minute. The most comfortable cruise engine setting, round 4800 RPM, gives a cruise speed of about 50 knots. Perfect. I have uploaded some videos to YouTube as well First Landing - **LINK** First Take Off - **LINK** Andy Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted October 3, 2015 Share Posted October 3, 2015 Many congratulations Andy well built and well flown,incidentally a Tiger Cub flew from Crosland Moor in 1983 nice to see history repeated. On the subject of blue foam based aircraft my own design 17 ft span model recently flew for the first time here is the link to the video **LINK** Best regards Tom. Quote Link to comment Share on other sites More sharing options...
Ian Webb 5 Posted October 15, 2015 Share Posted October 15, 2015 Hi Andy, I would just like to say that your tigercub looks great in the red German colour, I have a black germans colours tigercub which I hope to have ready For next summer, all my friends think it is a toy being made of foam but I think they are what a plane should be, simple and fun. I don't understand why more people aren't using foam to build cheep SSDR microlights, the micro bipe looks a bit scary too me to be doing loops in, Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted October 20, 2015 Share Posted October 20, 2015 Hi Ian Is this your Tiger Cub? **LINK** BTW The Micro Bipe was IMHO a deceptively tough little aircraft that endured all sorts of abuse . Quote Link to comment Share on other sites More sharing options...
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