Plummet Posted March 16, 2014 Share Posted March 16, 2014 Ta all! But any hints on how to measure or transfer the angles and distances from inside the complicated holes into which our bits of balsa have to poke without leaving gaps. Plummet Quote Link to comment Share on other sites More sharing options...
John Manning Posted March 16, 2014 Share Posted March 16, 2014 Hi, The special razor blades are available from SLEC they are called safety razor blades and are sold in packs of 4 part number SL031B-S. Sorry to go on at you Plummet but I worked in Hospitals for 30 years and I like to keep people out of them! I find that marking a line down the piece I am cutting helps me guide the saw straight. Regards JohnM Quote Link to comment Share on other sites More sharing options...
Darran Posted March 16, 2014 Share Posted March 16, 2014 Posted by John Manning on 12/03/2014 10:20:16: Help. well sort of. I've started the fuselage and F4 seems to be too tall and not wide enough. I have glued it at the bottom of the slope ans indicated on the plan. The notch in the top is above the cut out for the wing bearer plate. Have I stuck it in the wrong place? Is it the wrong size? any comments would be most welcome, including a lnk to BEB's build blog! Many thanks JohnM John i had the cnc pack but chose to cut a new F4 from the plan to avoid the issues being mentioned with this former not being wide enough. I found that when positioned it was indeed to tall and would fowl the wing mounting. I corrected this after the wing seats were glued into position so I could see just how much I needed to remove. It wasn't much as it turned out so I sanded it flat. Hope this helps Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted March 16, 2014 Author Share Posted March 16, 2014 Posted by Plummet on 16/03/2014 18:36:03: Ta all! But any hints on how to measure or transfer the angles and distances from inside the complicated holes into which our bits of balsa have to poke without leaving gaps. Plummet You need a pair of these Plummet - inside calipers very handy for transferring dimensions, much more reliable than measuring - well for me anyway!,... Quote Link to comment Share on other sites More sharing options...
Plummet Posted March 16, 2014 Share Posted March 16, 2014 Ta BEB. I have and use them. Its when things do not meet at nice neat right angles that I struggle. With the DF fuselage. The bottom longeron is set flat to the board. The upper longerons are in the same orientation. There are true vertical pieces between the bottom longeron and the upper cross pieces. Their joints are easy - all right angles. The verticals side pieces are not vertical, because the fuselage is triangular, not rectangular. measuring the angles for their ends is tricky but possible. Then the diagonal side pieces have to contact as many faces as possible. They are oriented as in the face of the sloping side. I am hoping that someone has a clever trick for measuring the requires angles in places like that. Trial and error I am guessing. This is where I was using the razor blades. I was using them to try to sight the correct angles, to push the blade into the wood, to withdraw the wood, and to press on the blade to complete the cut. It worked "fairly" well Plummet Edited By Plummet on 16/03/2014 21:23:51 Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted March 16, 2014 Share Posted March 16, 2014 Plummet your way is probably the most accurate of the quickest ways and the same way I usually "guess" angles at work and whilst building. What we're working with here is called a compound angle i.e cutting 2 angles at once, and can be measured with a sliding bevel. The first angle would be marked onto the longerons and then copied with the sliding bevel & transferred onto the cut piece, the second angle is then marked, copied and transferred onto the perpendicular face of the cut. This is all well & good for something like a 6" x 6" newel post for stairs but almost useless for a 6mm x 6mm balsa strut! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted March 16, 2014 Author Share Posted March 16, 2014 TBH Plummet, I think the trail and error method is the best here and just accept that there are going to a few "rejects" that you just have to do again - I probably threw away at least 4-6 pieces I had sanded to the wrong angle or made to short to be corrected. BEB Quote Link to comment Share on other sites More sharing options...
Plummet Posted March 17, 2014 Share Posted March 17, 2014 Chris, BEB, Ta. Ho Hum. Plummet Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 17, 2014 Share Posted March 17, 2014 Now I am sure that somewhere I saw a mention of the undercarriage track needing to be 10". Yes? No? Contemplating the build, and have mocked up a rough idea. Ground clearance from a 12" prop is a little over 2". Will that be sufficient ? Told you it was a rough mock up. Kev Quote Link to comment Share on other sites More sharing options...
Plummet Posted March 20, 2014 Share Posted March 20, 2014 Odd. In Lindsay's magazine article he talks about sheeting the top of the fuselage using 3mm sheet. The wood supplied includes lots of 1.5mm sheet. I see that BEB used 1.5mm sheet. I have not found a thickness on the plans ( but that does not mean it isn't there. I know that BEB had to skin his with some thinner sheet for cosmetic reasons. Is it 1.5mm or 3mm (or perhaps two laminations of 1.5mm)? Plummet Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted March 20, 2014 Share Posted March 20, 2014 I used 1.5mm. It gives more than sufficient rigidity to the structure. John Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 27, 2014 Share Posted March 27, 2014 So I have made the undercarriage. Not my favourite part of the build. I got to thinking about the mounting, and like BEB I want to use brass. As I have never used this method before can someone please advise me on the thickness of metal I need. Thanks in advance. Kev Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted March 27, 2014 Share Posted March 27, 2014 BEBs build blog says he used 1mm (0.040 inch ?) brass which I would think is more than adequate. Incidently Great Planes make the same plates but in steel, may even be nickle coated brass as they seem quite soft! I used these on my DF and a Puppeteer I built last year as they seem much better than plastic ones. Quote Link to comment Share on other sites More sharing options...
Koen Smits Posted March 30, 2014 Share Posted March 30, 2014 Today, maiden from mine Dawn Flyer. Sorry no video, next time Powered bij Robbe Roxxy BL 3545 - 10 Propellor 11 x 5.5 APC-E Esc HK 60 Amps S-bec Battery 3S 2200 mAh 20 C Weight aproxx. 1700 grams. Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted March 30, 2014 Share Posted March 30, 2014 Koen, Looks very nice, how did the flight go ? Did your pilot bale out before the test flight. Regards John Quote Link to comment Share on other sites More sharing options...
Plummet Posted March 30, 2014 Share Posted March 30, 2014 Yes, not built according to plan. No scarf. Plummet Quote Link to comment Share on other sites More sharing options...
Vecchio Austriaco Posted March 31, 2014 Share Posted March 31, 2014 Always time to add one - only if you do not follow BEB's health and safety explanations.... As my plane doesn't fly reverse and even if so - the scarf is not long enough to get to the prop - I added one... By the way - used the 1.5mm material which was in the parts - works fine. VA Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 10, 2014 Share Posted April 10, 2014 What size servo's are you gentlemen using in your D.F's please ? Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted April 10, 2014 Share Posted April 10, 2014 John. I used these from HobbyKing. Kev Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 10, 2014 Share Posted April 10, 2014 Thanks Kev I shall give them a try Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted April 10, 2014 Share Posted April 10, 2014 Hi John, I've used these on my build. Regards John Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 10, 2014 Share Posted April 10, 2014 Cheers John I have had a look Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 10, 2014 Share Posted April 10, 2014 Last question folks then i'll leave you be Did you manage the 2lb 8 oz weight o.k. John Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 11, 2014 Author Share Posted April 11, 2014 Mine's a deal heavier than that John - with everything on board she tips the scales at a shade under 3Ibs! BEB Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 11, 2014 Share Posted April 11, 2014 O.K BEB Thank you Quote Link to comment Share on other sites More sharing options...
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