Biggles' Elder Brother - Moderator Posted January 1, 2012 Share Posted January 1, 2012 Nice build Martyn. That tailplane is enormous isn't it - I've built wings smaller than that! Good work on enclosing it in the mid position - very neat! BEBEdited By Biggles' Elder Brother - Moderator on 01/01/2012 13:16:50 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 1, 2012 Author Share Posted January 1, 2012 Hi Richard Thanks for that - it is very neat and I like totally enclosed. It look like 100% differential - all up and no down. Is that correct? BEB - thanks for the kind words. Progress over the past couple of days has been almost non existent - I am still thinking on how to put the wing together. Regards Martyn Quote Link to comment Share on other sites More sharing options...
Sparks Posted January 1, 2012 Share Posted January 1, 2012 Hi Martyn, No, the ailerons go both up and down. They are top-hinged and the leading edge of the ailerons are raked back towards the underside to allow down movement - perhaps not so clear from my pictures. I have put in some mechanical differential by offsetting the servo horn to provide more up than down. About 10mm UP and 6mm DOWN on the Hoglet (like that name). For reference, the recommended throws for the original full-size A Hog are: Ailerons 5/8" UP and 3/8" DOWN ('Barn door' type) Elevator 3/4" UP and 3/4" DOWN Rudder 1" RIGHT and 1" LEFT Regards, Richard Edited By Sparks on 01/01/2012 18:58:42Edited By Sparks on 01/01/2012 19:02:36 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 1, 2012 Author Share Posted January 1, 2012 Hi Richard Thanks for the clarification - and especially the recommended throws which are not stated on the plan - that is a lot of elevator throw especially because of the size Regards Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 5, 2012 Author Share Posted January 5, 2012 Very little progress this week. Most of my building time has actually been spent repairing due to an unfortunate 'incident' in the lull before the storm this week. However, here is the promised details on the aileron hinge used on the original 'hog. One very nice aspect is that as the hinge is quite low so the horn can be almost totally hidden when connected from above the wing. Rather than using horns, I'll be using a dedicated servo in each wing half. More to come. Martyn Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted January 5, 2012 Share Posted January 5, 2012 So, Martyn, are you going for the full on roller bearing hinges? Looks like a job for some Robart hingepoints to me! Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 5, 2012 Author Share Posted January 5, 2012 Hi Bob I'll be using hinges as described, but will probably fabricate my own bearings. I originally considered wheel bearings from R/C cars, but will probably make somthing out of PTFE. Power transistor lipped insulating washers are a likely source - and are quite hard wearing and very smooth running. I think that the original used bearings out of curtain hooks - very hard to find these nowadays. I'll take a look at the Robart units though - I am not aware of them. Thanks for the tip Martyn Quote Link to comment Share on other sites More sharing options...
kc Posted January 5, 2012 Share Posted January 5, 2012 Peter Miller used a nylon horn as the pivot for shrouded ailerons on his 57 inch Turbulent design for RCMW. ( instead of the wood and bearing as your diagram ) Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 5, 2012 Author Share Posted January 5, 2012 Hi kc Thanks, but I am having trouble visualising that. Can you post a diagram please? Cheers MartynEdited By Martyn K on 05/01/2012 23:16:53 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 9, 2012 Author Share Posted January 9, 2012 Started working on the wing this week - which brings me onto my first real whinge about the plan - 3 large sheets, but only 1/2 a wing is printed... So taking great care not to build 2 right-hand wings... I finished sanding the ribs and decided to build from the TE forwards. The TE is a composite of 1/16" upper and lower with a section of 1x1/4" TE section sandwiched between them . Even better, the section is flat to the front spar so starting by ignoring the root rib (which needs to be tilted and have lots of wood cut away for the ply spar doublers/braces. Note the 5/16 wide rear spar - essentially 1/4 square with a 1/4 x 1/16 spruce doubler. After a short while lots more ribs appeared in almost the right places. And the top spar was added. A number of the ribs were cut short for the inset aileron as you can see... and the shroud for the ailerons was carved and sanded (actually hollowed out with a dremel cylindrical sander then finished with a sanding block formed from 100grit glued to a film canister which gave the correct internal diameter.A number of the ribs were cut short for the inset aileron as you can see, which focussed my mind on the hinges. I eventually settled on the following. 3/8 wide hardwood engine bearer (the remains of the servo rails), 8mm drilled and inserted with PTFE rod which were then very carefully drilled with a 3mm drill. The hinge blocks were clamped and drilled in pairs to try and make sure that everything stayed true(ish).. The saddles on the original were cut from 1/2" sheet hard balsa. Mine were formed using the same block for the back of the saddle with 1/8" liteply sides. ... and again all clamped up and left to dry for 24 hours. This of course made the hinge block too tight a fit, but 2 minutes sandling left them a perfect sliding fit. Holes were drilled in the correct places and clamped up using M3 (sorry - nearly 6BA) bolts with Nyloc nuts.. I *really* am quite pleased with these - smooth with absolutely NO slop. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 9, 2012 Author Share Posted January 9, 2012 While all this was in progress and waiting for the glue to dry. I fitted the newly acquired fuel tank (10oz) using a retaining bar, Velcro tie wraps (a benefit of working in IT - we get lots of these) and lots of foam padding under and front and back of the tank. The foam I use comes from a discarded sleeping mat. One mat will provide a lifetime of foam.. ( I home that is not strictly true as I have about 6 square inches left). and Finally, my task tonight while the wing is off the board was to get the tips made up. Each comprises of 4 pieces of 1/2" sheet replicated using the pin prick method with one tip built on top of the other. Medium hard sheet for the front pieces and medium soft for the rear pieces And that is it so far.... More to come. Best wishes Martyn Quote Link to comment Share on other sites More sharing options...
Big Bandit Posted January 16, 2012 Share Posted January 16, 2012 Posted by Sparks on 30/12/2011 21:32:16:Yes Chris 36" span - model of a model. I'm thinking of doing a 48" span for the mass build. Just watching how Martin's full-size Hog progresses so that I can pinch his build tips Richard Hi Sparks, Martyn, The postie left me a Hoggitt part kit and plan this morning, what a nice man, it's for a 10 to 15 glow, at 40" span, bit of a flat back, but will soon sort that. Also inset strip ailerons and will introduce insets from the pici you posted sparks. I've got some OS pets and 15's hanging around looking for a job, they'll do. I still prefer Hoglet though Cheers, Chris. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 16, 2012 Author Share Posted January 16, 2012 Been playing with my Ohm Maiden el*ctric glider for the past 3 weekends - it is so nice not having to muck about with glow fuel when the temp is barely above freezing.. starting to think about a lightweight electric hoglet now (perhaps a hoglec?) M Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 16, 2012 Author Share Posted January 16, 2012 About time I did an update, progress has been painful this week with lessons learned a bit too late.. Astro Hog builders tread with caution. Full of enthusiasm following the assemble of my hinges, I coun't wait to get them fitted, so I did.. They are basically inset into the shroud and glued onto the lower rear spar.All quite simple but clearly important that the hinge pins (bolts) line up correctly. So far so good.I then had the challenge of building the aileron which meant carving and sanding the ailerons male form to fit (it's an offset curve). This was sooooo difficult with the shroud and hinges glued in place.If you are following my footsteps, make sure get these two parts carved and sanded properly before you get the glue out. Also note that as the aileron hinges any errors in the sanding process will result in the aileron binding... Trust me, it is not easy and I really wish I had spotted this first. Hey ho... So here is my guessimated aileron LE for the RH panel, note the slot cut for the hinge to fit. You will also need to relieve some extra wood to allow for clearance for the bolt. I used 1/32 balsa packing between the 2 parts while glueing it up -I made a better job on the RH panel than the left.. Deviating from the original,I reinforded the hinge to aileron LE with 1/2x1/4after adding the 1/8 liteply ribs and TE Another shot from a slightly different angle Now with Cap stripts added and still 'fitting' it.. The LH panel as of tonite. Somehow, I have managed to build a warp in the wing. The batteries are there to try and correct it.. I have to admit this has been far more difficult than I expected, I have quite a good seal along the top surface (about 1/16" gap), but it is about 1/4" gap on the lower edge The good news is that they move very smoothly without binding and are very rigid. Now I know what I did wrong, I would definitely use this method again. As you can see, progress has been very slow - I would guess about 15 hours work to get the second panel glued up and the ailerons fitted. But it is fun. More to come - I guess that the wing halves will be joined together in the next week and then I can start sheeting it up. I have cut the 1/8 ply dihederal braces- I am going for 5deg dihederal (total). Best wishes Martyn Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 17, 2012 Share Posted January 17, 2012 Those hinges look really solid Martyn - I can't see them failing anytime soon! The Robarts that were mentioned earlier would have been easier to fit - especially if you used their little jigging tool to locate the holes - but not nearly as much fun BEB Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Hi BEB It has been fun (although at times when trying to unglue the Aileron I was simultaneously tearing my hair out), but the learning curve was important. Now I have sorted out the mechanics, I would be more than happy to use the method again. Alignment was actually quite simple, I just used a 12" steel rule and measured back from the spar (to the hingepin) and vertically from the board then kept easing the wood away until it was snug and all in the correct place. The other thing I did was kept the hinges paired all the way through the assembly process so any systematic errors were hopefully eliminated. The only other thing I should have done was to cover the inner edge of the shroud before fitting the aileron. Not a hope in hell's chance of doing it now.. Martyn Quote Link to comment Share on other sites More sharing options...
Silver Wolf Posted January 17, 2012 Share Posted January 17, 2012 Hi Martyn, I built a Hog from the Sig kit some years ago and reduced the dihedral to about 4 degrees. This was in anticpation of building the Ryan STA Special that has a similar dihedral. Twenty years later still waiting to start the Ryan. The Hog flew extremly well in all conditions, I am tempted to build another or at least another fusalage as I still have the wings and tail plane. You will enjoy it and good luck with test flights DA Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Thanks DA I basically propped up a wing until it looked 'right' then measured the angle from that. Totally unscientific. Still quite a bit of work to go though... Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Posted by Big Bandit on 16/01/2012 17:57:57: The postie left me a Hoggitt part kit and plan this morning, what a nice man, it's for a 10 to 15 glow, at 40" span, bit of a flat back, but will soon sort that. Also inset strip ailerons and will introduce insets from the pici you posted sparks. I've got some OS pets and 15's hanging around looking for a job, they'll do. I still prefer Hoglet though Cheers, Chris. Hi Chris I have googled and it has failed. what is a Hoggitt? Where would I find one? Martyn Quote Link to comment Share on other sites More sharing options...
Olly P Posted January 17, 2012 Share Posted January 17, 2012 Can't believe I have missed this blog, some lovely building going on. Now subscribed. I'm in Sheffield quite often for work Martyn, will have to meet up for a fly sometime.... Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Hi Olly Thanks I actually live near Crewe in Cheshire, Sheffield is simply a much more pleasant commute than (say) Manchester or Brum. However, I do fancy some nice late afternoon, early evening slope soaring when the weather improves and we actually get some light. There are some nice sites around Sheffield - if you are up for that then so am I... Martyn Quote Link to comment Share on other sites More sharing options...
Big Bandit Posted January 17, 2012 Share Posted January 17, 2012 Posted by Olly P on 17/01/2012 14:25:28:Can't believe I have missed this blog, some lovely building going on. Now subscribed. I'm in Sheffield quite often for work Martyn, will have to meet up for a fly sometime.... Hi Martyn, It's from Nexus special interests 1995, the copy I was sent was a free plan in a comic (ooops magazine) but the plan doesn't say which one, on the other side is a mini and micro blitz. What with printed wood parts and an original plan (not a copy) not bad for £10. PM me for details if your interested. Olly, Martin, if your up for a session around Sheffield, give us a shout, some good sloping country up there. Cheers, Chris. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Cheers Chris I just need to get a slope soarer built Irritatingly, I threw a brand new one away a few months ago. A one piece home designed aerobatic soarer - I knew that I would regret that decision. OK on the hoggitt as well - yes - I am interested if you can share ordering information with me. Thanks Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 A bit of progress tonight but no piccies... I have located all the 1/8 ply braces in the LH wing and left it to dry. With that moment of exciting news over - back to the mundane. The wing is still warped. I think the glue must have softened in the damp environment of the shed. Tomorrow night it will get properly dampened and then pinned down for 48 hours in the house to let it dry out (and hopefully dewarp itself) properly. MartynEdited By Martyn K on 17/01/2012 22:22:04 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2012 Author Share Posted January 17, 2012 Hi Chris Is this a Hoggitt? Regards Martyn Quote Link to comment Share on other sites More sharing options...
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