Mark Stringer Posted July 13, 2015 Share Posted July 13, 2015 Many moons ago (1994 or 5?) when I was active with Ratby Aeroplanes I was sitting in the caravan on a Saturday evening of the Old Warden show dooling model things when I came up with a model that used a sharp but deep symmetrical wing section and had the engine thrust line, wing centre line and tail all on a straight axis. Once doodled I wanted it to be light and simple .. so sheet sides with ply doublers and just 5 rectangular formers for the body and then a big wing with a total of only 10 ribs .... Anyway, having build it and flown it I found it did everything from a walking pace to what, at the time, was pretty fast for me and very aerobatic and controllable .. this was pre-3D days remember! As it flew like a bat out of hell I did the RATby thing on it and named it the Rat Out Of Hell. So 20 years on the originals are still in nice condition but as I fly mainly electric these days I have intended to do a brushless electric and fancied delving into Depron .. so I thought it was time to have a go ... so here I go on my build. A couple of years ago I put it forward for the mass build and it did OK but didn't make the finals. At the time our very own Rich Harris drew the plans up for me in case they were needed - so that was handy as I have printed them out at 69% for this version (Thanks Rich ) Here is the original "Rat" - people during the mass build voting did say it was the ugliest model they had ever seen ... but I like it!! (Probably because I have flown it!!!!) Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted July 13, 2015 Author Share Posted July 13, 2015 So briefly to the build .. plan printed out at 69% twice ... one to use as templates .. the bits marked out on 6mm depron ... so not much time spent on it all yet .. (I was 2 ribs short at this point .. but not much in the way of parts really) Parts all cut out using a utility knife .. so marking and cutting took less than an hour. I added the first leading and training edges to the above parts. These will be sanded while sandwiched to make sure everything is identical where it needs to be and then a slot cut top and bottom in the ribs for the spars (again while sandwiched). Apart from these pieces there will be a handful of small 3mm lite ply formers, 6mm x 3mm spruce spars and the wing will be skinned top and bottom with 3mm depron .. add a simple undercarriage, 4 x 9g servos, motor (thinking a 2212 at the moment), ESC and receiver and that will be about it. Another of my "Lunchtime builds" so updates a little at a time as and when I get around to doing it. Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted July 13, 2015 Author Share Posted July 13, 2015 I should have added that based on the plan I am using it will come out at 1040mm (41") span and be 600mm (23.6") long from nose to back of rudder.I have added 2 more depron parts so just 5 bits of lite ply to add Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted July 14, 2015 Author Share Posted July 14, 2015 A bit more done today .. but just the slog bit still! Sanded all of the depron I cut yesterday and have also cut the lite ply formers which will be the main bulkhead for the motor mount, front and rear wing mounts and the undercarriage mount. The spars have also now been cut to size and marked with the rib positions - along with the all important "R" so I know which are the root ends. The wing joiner / spar doubler also cut to size And finally for today the ribs have been sanded (sandwich method) and while sandwiched the spar cut outs have been done. That is it for today - not very exciting but I am now at a point to actually start building which isn't too bad after a couple of hours work. Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted July 15, 2015 Author Share Posted July 15, 2015 Another busy hour today - a bit messy at times but getting there - and looking a bit like a plane today! Added the formers to the one side - just cyano for now but main formers will have epoxy added and maybe even doubles in places Second side added, tail joined and tail skid then cut to suit and fixed Then onto the wings - added the first spar / rib set - again cyano for now and once all straight with LE / TE added some epoxy / doublers may be added in places before skinning. And the second spar and wing joiners Second wing made - remembered to make them left and right handed! Then joined them together Ran out of time at this point - just time to put it together to see how it was looking I will continue on the wing for now as the fuselage depends on having it finished - leading and trailing edges to add, getting it all square and will then sheet one side in 3mm depron ... to be continued ..... Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted July 16, 2015 Author Share Posted July 16, 2015 Some fiddly bits today made harder by finding a twist on the one wing panel .. that is the trouble when I wasn't able to pin it down during the build - but I think they would complain at work if I started pinning things to the desks I decided to do the middle leading and trailing edges in balsa as these take the wing mounting dowels and wing bolts .. but the rest of the trailing edge and leading edge is in 6mm depron, the leading edge being a double layer. I got the twist pretty much out so they should be OK - just need to keep them straight when I come to sheet them - that will hold their shape although they feel very string already. I also sheeted the top of the fuselage in 3mm depron - so much easier than using balsa! Part of the top I plan to cut out to make a battery hatch one I have decided where the CofG comes out which will determine the battery position. So that is it for today - a couple of pictures of the progress Quote Link to comment Share on other sites More sharing options...
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