David Davis Posted June 1, 2010 Share Posted June 1, 2010 Barn Door Telemaster Build. Introduction Years ago I went to an old boy’s house to buy a plan. Suspended above the rafters of his garage were the damaged wings of a Senior Telemaster, an eight-foot (2.4 metre) wingspan high wing monoplane, He also had the tailplane and forward part of the fuselage but the fuselage from the trailing edge of the wing to the tail plane was missing. I bought some deal strip from a local hardware store, built a fuselage on the back of what remained, repaired the wing and covered it in yellow vintage Solartex, fitted a second-hand Merco 61 and flew it for years until it “went in” with “radio failure.” I’d probably not charged the receiver battery enough. I had always been impressed by the Telemaster’s flying characteristics having gained my A Certificate on the 66 inch version (168cms), so in 2008 I set up Telemaster Sales UK, to import the Telemaster range into the UK. Profit? What profit? A Brief Bit of History The Telemaster was originally designed by a German, Karl-Heinz Denzin. It was initially marketed by Alexander Engel and first flew in 1961 or 1963 depending upon whose story you believe. At some stage, probably in the 1970s, the manufacturing rights were sold to the American company Hobby-Lobby which retained Joe Bridi to modify the design. The original wing featured two pairs of balsa spars tied together with 1/8th sheet webbing, thereby producing an I spar and inset, so-called “Barn Door” ailerons, similar to those found on real aeroplanes. The Bridi wing features a single pair of spruce spars and strip ailerons. It also featured a steerable tailwheel. My Barn Door Telemaster My old Telemaster featured the original German wing so I got a club-mate who is good with CAD to draw up a set of plans based upon the wreckage of my old wing. I have substituted spruce for the balsa wing spars and have built flaps onto the false trailing edge. I got SLEC to laser cut the wing ribs and plan to feature bolt-on wings and tail and a glider tow release. I also plan to fit an inverted Laser 90 which I bought second-hand and have never even run yet. I hope to have it ready by 26th June so that it could fly at the Fiftieth Anniversary Fly-in of RCM&E. It is now 1st June, the structure is substantially built but that’s about it. Looks like I have 26 days to get it ready minus time off for a full-time job, my sister’s 60th birthday and a family wedding. Wish me luck! Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted June 1, 2010 Share Posted June 1, 2010 Good Luck David. I am sure you can do it, it just depends how much sleep you need. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 1, 2010 Share Posted June 1, 2010 Go for it David An 8 foot wingspan "trainer" with a Laser 90 up front! You've got to admit it - the guy's got style! BEB Quote Link to comment Share on other sites More sharing options...
David Davis Posted June 3, 2010 Author Share Posted June 3, 2010 D-25 Got the Laser running in the back garden last night, and it went beautifully. Unfortunately at least one of the previous owners was lacking in mechanical sympathy and only one of the four grub screws which hold the inlet manifold and the exhaust in place still survives. Two of the other three have been replaced with cheese headed set screws of the correct thread; these look awful but perform their function. The other grub screw has sheered off in the head. As a consequence, the exhaust jiggles about while the engine is running. I have three options: 1. Bodge the exhaust into place using Liquid Metal. 2. Buy a replacement head for the Laser assuming they still stock one for an engine which has been out of production for so long. 3. Fit a different engine. The candidates are: Laser 70, OS 70 and Thunder Tiger 91. Today's target is to build the starboard flap and aileron, fit servos to the rear of the model and to fit the undercarriage. I also intend to take a few pictures. Quote Link to comment Share on other sites More sharing options...
Klippy Posted June 3, 2010 Share Posted June 3, 2010 Do you mean Cap screws David? A Grub screw has no head, so won't hold anything. What size is the screw? If it's a common metric size you should be able to, carefully, drill out the old one and fit a Heli coil. Quote Link to comment Share on other sites More sharing options...
David Davis Posted June 3, 2010 Author Share Posted June 3, 2010 No they are grub screws Tony. If you visit the Laser website, go to "history" and have a look at the picture of their Laser 61, you'll see them each side of the inlet manifold. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 3, 2010 Share Posted June 3, 2010 Hi David only 22 days 18 hours to go.. Quote Link to comment Share on other sites More sharing options...
David Davis Posted June 6, 2010 Author Share Posted June 6, 2010 D-20 This is the state of the build; the elevator servo is mounted on a ply plate backed by balsa and ply to allow the screws something to bite on; the rudder servo will be screwed to two spruce strips across the bottom of the rear fuselage. I have "engineered" a solution to the wobbly Laser 90 silencer which I feel should work and if the tail plane looks a little second hand, that's because it has been recycled from my first Senior Telemaster. Quote Link to comment Share on other sites More sharing options...
Clem Posted June 6, 2010 Share Posted June 6, 2010 David, I've never tried it, but.... Assuming that you can strip the Laser head of ALL other ferrous material, then you could try dissolving the remains of the broken screw out.Submerging the workpiece in a hot, saturated, solution of Alum (Aluminium Potassium Sulphate) in an Aluminium/Pyrex pan is frequently suggested as a method for removing broken taps in non-ferrous materials. Alum is certainly available on ebay, if not locally. I've no idea as to how hazardous Alum is, although I suspect that assuming "normal" precautions are taken, then it's a lot nicer to work with than the other oft suggested chemical for tap removal - Nitric Acid! If you google "aluminium sulphate broken tap" you should find plenty of information. Clem Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 18, 2010 Share Posted June 18, 2010 Hi David How's it going? Just over a week to go...... Quote Link to comment Share on other sites More sharing options...
David Davis Posted June 28, 2010 Author Share Posted June 28, 2010 Sorry gentlemen couldn't finish it in time but I took it to the Green Acres RCM&E 50th Anniversary event so that potential purchasers of Senior Telemasters could have a look at the construction. Currently the fuselage and tailplane are complete and covered and the mainplane is in the bones. The next tasks are to attach the tailplane to the fuselage, to work out a way of bolting on the mainplane, to fit servo mounting and strut mounting plates to the mainplane, fuelproof the structure and to work out why I've suddenly lost compression in the Laser. Good News: I'm off work this week so I should be able to get on with the model. Bad News: I should be on holiday in France but after eight years of absolute reliablity my car (2002 Rover 75 Cdt Tourer) refused to start. Serious electrical trouble. Good News: My best pal is a qualified motor mechanic he has identified the faults and has investigated websites where the components may be repaired or supplied much more cheaply than buying the stuff through an agent. Bad News: It will still cost hundreds to repair. Even Worse News: My entire team was given a month's notice on 18th June. We go on 16th July and the way things are looking at 62 I'll be lucky to get a job stacking shelves for £6 an hour. Superb event at Green Acres by the way, some lovely models and people, very well organised. Apologies for using the term "mainplane" instead of "wing," something made me think of my late friend Frank Wall, RAF Training Command. To him a wing was always a "mainplane!" Will post pictures later when I work out how to do it. Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 8, 2010 Author Share Posted October 8, 2010 Ok gentlemen, sorry for not keeping you up to date as the last three months have been spent trying to find a job and feeling sorry for myself. I'm pleased to report that I succeeded in getting a job yesterday, well a self-employed contract anyway, so I should be financially better off by Christmas. Not bad for an old man of 62. I suppose I should feel elated but the interview was extremely challenging and in a city over 100 miles from where I live, so this morning I just feel knackered On to matters aeromodelling. I have built and covered the Barn Door Wing Senior Telemaster and only need to install the throttle servo, to make up some struts and to connect the control surfaces to all of the other servos. I have covered the model in Vintage Solartex and intend to fuel-proof it with two or more coats of diluted Solarlac in order to make the model easier to clean. I have also had some vinyl decals made up saying "Senior Telemaster" which I intend to display on the upper surface of the wing and on the fuselage sides. My question to you all is, " Should I stick the vinyl to the model before I fuel-proof the Solartex or after I've fuel proofed the Solartex?" Pictures to follow. Edited By David Davis Telemaster Sales UK on 08/10/2010 06:21:34 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted October 8, 2010 Share Posted October 8, 2010 Vinyl does not stick to the fabric so well as it can only touch the top of the threads. I would suggest that it would be better after fuel proofing which will make the Solartex that much smoother. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 8, 2010 Share Posted October 8, 2010 Hi David, Peter is correct of course. But - assuming the vinyl is black? - what I would do is apply a coat of solarlac, then the vinyl, then a second coat of solarlac. My reasoning is: 1. the first coat will "flatten" the surface as Peter says and give the vinyl something to stick to. 2. The second coat will partially protect the vinyl itself - particularly the edges - and make them look less stuck "on" the surface - more "in" the surface if you know what I mean! The reason I ask if the vinyl is black is that I've found solarlac can leave discolouring on some light coloured vinlys BEB PS Many congrats on the job! Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 9, 2010 Author Share Posted October 9, 2010 Thank you gentlemen. Perhaps you can help me on another matter. I am about to make up the V struts, i.e, two spruce struts mounted at the wing combining together at a single mounting point at the fuselage. My query is as follows: Should I, (a) make up each strut of equal length thus producing an isosceles triangle in plan and attach the V strut to a point on the fuselage halfway between the wing mounting points? or (b) arrange the front strut so that is is parallel to the wing spars and bring the rear strut forward to meet it? This arrangement would produce a right angled triangle in plan and result in having the fuselage attachment point further forward than the isosceles configuration suggested above. Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 12, 2010 Author Share Posted December 12, 2010 Er... We're maidening it today Should be on You Tube. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 12, 2010 Share Posted December 12, 2010 Good luck David. It's cold out there again, but over here the air looks good. Look forward to the video. Chris Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 12, 2010 Author Share Posted December 12, 2010 The air is full of fog here. Maiden postponed till Thursday 16th December.Edited By David Davis Telemaster Sales UK on 12/12/2010 11:13:56 Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 12, 2010 Share Posted December 12, 2010 That's a shame David. I've been out flying myself (at Greenacres) today cold and muddy but had a good time. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted December 12, 2010 Share Posted December 12, 2010 We wait with baited breath David - I'll bet it will be brilliant - a model that size will have a lot of presence in the air I'm sure! BEB Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 2, 2011 Author Share Posted January 2, 2011 OK gentlemen. No snow. No rain. No strong winds. No freezing temperatures. No work or family committments. We maiden it today! I've booked Mr De Mill to video the event! Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted January 2, 2011 Share Posted January 2, 2011 Wheres the video,ive been waiting here all day Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 3, 2011 Share Posted January 3, 2011 Announcing a maiden before you do it is either very confident or....... asking for trouble! Quote Link to comment Share on other sites More sharing options...
Pete B Posted January 3, 2011 Share Posted January 3, 2011 That's an ominous silence.................. Pete Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 3, 2011 Author Share Posted January 3, 2011 If you've been in all day waiting for the video Stephen, you've missed some good flying weather! In the event it was a bit of a wash out. Firstly I had a few problems with the radio caused by lack of familiarity with my Dx6i, then the engine wouldn't run properly. We eventually diagnosed a blocked carburettor. I'm off work on Thursday and might not be working on Wednesday. I'll have another go after I've stripped and cleaned the carburettor. Quote Link to comment Share on other sites More sharing options...
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