Big Bandit Posted January 18, 2012 Share Posted January 18, 2012 Posted by Martyn K on 17/01/2012 22:54:25:Hi Chris Is this a Hoggitt? Regards Martyn Hi Martyn, This is the one Cheers, Chris. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 18, 2012 Author Share Posted January 18, 2012 Thanks ChrisAnother one has been listed today so I have placed a bid.RegardsMartyn Quote Link to comment Share on other sites More sharing options...
Big Bandit Posted January 19, 2012 Share Posted January 19, 2012 Hi Martyn, Any problems, PM me. Cheers, Chris. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 22, 2012 Author Share Posted January 22, 2012 Progress has been pretty good these past few days. I added the center doublers (1/8 ply, full depth front and rear of the main spar plus full depth at the LE - each 2 bays - 150mm - out from th centre). And the wings joned together. I settled on 5 degrees dihederal which gave about 75mm at the tip with the other panel flat. Here is a close up with the glue drying. Hopefully, it will be sufficient.. 3mm light ply webbing was extended for 2 further bays each side then slots cut at the front of the mainspar for the hardwood undercarriage bearers. The original had the undercarriage leg bound to a plywood rib. However, Mr F Dunn has never seen me land. I have 2 variants, hard and very hard.. as the bearers are well glued to the ply doublers, I am happy that they will take the vertical impact load, but I am a bit concerned about the rotational load. To help stiffen the entire area, 3/16" gussets have been inserted then the two bays have been overlaid with 1/32" ply which will sit under the 3/32 balsa 'D' box. Time will tell if it is sufficient. Webbing has been inserted (note webbing grain is vertical between the spars - the purpose is to stop the spars buckling under load and balsa is strongest in compression). The webbing goes out as far as the ailerons on the rear spars and 2 bays further on the main spar. Sand everything down and now ready to start sheeting. The upper sheeting has been added to the LH panel, the only really tricky bit was dealing with the compound curve at the very tip.. A gentle scoring above the last tip rib gave just enough 'give' to get it down. Another shot showing the tip. Finally, I managed to get the upper sheeting fitted for the RH panel tonight - qhite a surprise, I though that would have been tomorrows task.. Coming along. This shot shows the dihederal quite nicely. I have also ordered the servos this weekend - getting the aileron servos fitted,lower sheeting and cap strips fitted is the target for the next few days. I need to go and but wheels andU/C wire.I think 8G should be sufficient. Weight of the wing so far is 720g without sheeting. More to come... Best wishes Martyn Edited By Martyn K on 22/01/2012 2 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 27, 2012 Author Share Posted January 27, 2012 A bit more progress this week. I decided that I was going to get the undercarriage legs bent. Some good suggestions were described here - it all became clear when I realised that the 8 SWG wire legs I thought I was bending were actually 6SWG. There is a big difference in effort in that next size up.. The wire legs were trimmed to length with a grindstone wheel attached to a dremel, it makes life so much easier than using a hacksaw. What I almost forgot was the reinforcement for the wing mounting bolts. The original had banded on wings so there was nothing on the plan to remind me... I have inlaid 3mm ply on the lower surface and then infilled will 13mm sheet to the top surface with a final 3mm of hard balsa.to make it crush proof. It should be strong enough. and When this was done, I could start on the lower sheeting, and fitted one side without any problems, cutting carefully around the u/c blocks to get it to fit neatly. That got me as far as Tuesday night, but I have had this nagging doubt about the strength of the U/C mounting. I nipped down to Barnstormers this evening and bought some more beech bearers and have inserted a piece of beech linking the main spar to the leading edge and glued to the liteply rib. The main block will take the landing load, these blocks will take the torsional load. Of course,this meant that I had to remove a piece of lower sheeting on the wing to fit this, but I think that it is the right thing to do. The second lower sheet on the other wing has now been added . and a start on the cap strips. And that is where I am at 1800 tonight... More to come Best wishes Martyn Quote Link to comment Share on other sites More sharing options...
Big Bandit Posted January 27, 2012 Share Posted January 27, 2012 Martyn, that is stunning, certainly one to follow. Cheers, Chris. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 27, 2012 Author Share Posted January 27, 2012 Thanks Chris, but trust me, its not up to your standard... I could never throw a wing away.. Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 31, 2012 Author Share Posted January 31, 2012 Not done much this past couple of days. Somehow, I have managed to do my back in and any form of movement is agony. However, on Saturday morning, I started work on the servo mounting for the ailerons in the wing. Although I don't plan to remove them, I wanted them easily removable so have settled on this. Basically, 2 x 3mm liteply front and back with servo sandwiched between them with the mounting bar sitting in a slot in each piece. When the 6mm cross piece is added at the back (top in the photo), the servo clicks into place (held by the springiness of the foam pads) and is held quite securely. It can be removed and slid out by simply pushing the servo forward. The cover will be held in place by 4 small screws into a spruce piece running alongside the ribs. It actually looks neat and that is a bonus... More to come when I can get back in the shed... Martyn Edited By Martyn K on 31/01/2012 14:33:59 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 6, 2012 Author Share Posted February 6, 2012 It's been a slow week. I have done something 'orrible to my back and any movement has been very painful. The good news is that it's getting better so I have managed to spend an evening or so in the shed. On with the heating... A couple of evening sorting out the aileron linkages.. I have used a ball joint on the aileron with the brass screwed ball and rod simply glued into a 2mm hole carefully drilled. A couple of attempts bending a linkage to get it to fit and a keeper on the servo arm. When I was happy that all was properly connected and it wasn't going to fall apart, I simply sheeted in up to the servo box area. A 3/32" lite-ply cover will be screwed into the spruce braces alongside the ribs with a small block of foam to hold the servo in position. The linkage is very low profile - approx 6mm above the aileron itself. A 3/32" lite ply reinforcing strip has been added at the root with a couple of 8mm holes drilled to let the aileron cables through .. and the top sheeting added. Finally, the upper cap strips have been added.. .. and this is where I am up to tonight. Sanding it all down. A bit more sanding to do, match the wing to the fuselage, add the LE locating dowels and the wing mounting bolts. Getting very near to covering it now. More to come, Best wishes MartynEdited By Martyn K on 06/02/2012 22:10:32 Quote Link to comment Share on other sites More sharing options...
Andy Green Posted February 10, 2012 Share Posted February 10, 2012 Martyn Are you using standard servos in the wing? Andy Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 10, 2012 Author Share Posted February 10, 2012 Hi Andy In am using these (Tower Pro MG995) - yes - standard. They seem OK, very quiet and very smooth - absolutely no jitter (as you would expect from digital servos). I am going to use another for the elevator, but a cheapo for the rudder - I am bound to wreck it again. Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 10, 2012 Author Share Posted February 10, 2012 one thing I have changed since I published the photos earlier is to screw the ball joint into a piece of 3/8 x 1/8 spruce and inlaid that into the aileron. On inspection and reflection, I wasn't happy having it simply glued in - too susceptible for knocks. MartynEdited By Martyn K on 10/02/2012 13:40:34 Quote Link to comment Share on other sites More sharing options...
Andy Green Posted February 10, 2012 Share Posted February 10, 2012 I dont want to worry you , but have you seen this review. Andy Edited By Andy Green on 10/02/2012 13:45:55 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 10, 2012 Author Share Posted February 10, 2012 Hi Andy Worried - slightly.. That review is a couple of years old. I am certainly not getting any overshoot so manufacturing and materials may have improved. I'll go and weigh one and let you know. I'll also strip down one of the spares I have to have a look for myself. many thanks Martyn Quote Link to comment Share on other sites More sharing options...
Andy Green Posted February 10, 2012 Share Posted February 10, 2012 I bought 4 some time ago, from Servo Shop. 1 of them had a very high quiescent current draw. I didn't use them, gave them to a guy in the club, worked fine to my knowledge. Andy Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 10, 2012 Author Share Posted February 10, 2012 Hi Andy, I have just weighed one - 59.8g - this compares with 37g for a futaba cheapo servo. I have whipped the cover off. Mine is certainly manufactured to a higher standard than the RCmodelreview... You will notice that the input signal and power wires are a different colour - so this is obviously a different batch. More importantly, on the reviewed servo, the wires came in and soldered directly to the PCB. Mine has a reverse loop which - although is not as sound as a fully supported lead - will provide considerable vibration cushioning. The quality of soldering is excellent. The leads to the motor - again unsupported - are looped to provide vibration damping. The leads to the feedback pot are well soldered and of adequate length. My only concern with my visual examination is that the pot has 3 long leads out of the pot and the 3 red wires you can see above are simply soldered to these at the wire extremity (I would estimate that these are about 10mm long and are bare. I cannot imagine that they will fail, but I would have preferred to see an interim PCB here - if for no other reason to keep the wires apart. I can't comment on the electronic observations that were made, I do not have those facilities in my lab, however, I paid about £6.00 each for them and the quality is as good as I would expect for a budget servo. Note that this is a lot less than the $20 paid for them in the RC review. Like any other servo, if it starts playing up then I'll bin it.. But thanks for bringing this to my attention. I wouldn't have bothered looking if you hadn't told me. Best wishes MartynEdited By Martyn K on 10/02/2012 14:54:24 Quote Link to comment Share on other sites More sharing options...
Andy Green Posted February 10, 2012 Share Posted February 10, 2012 Your servo does look a lot better than the one in the review, sorry to have worried you. Andy Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 10, 2012 Author Share Posted February 10, 2012 Hi Andy Don't worry, this is all very useful stuff. I'll still be keeping a very careful eye on them. Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 12, 2012 Author Share Posted February 12, 2012 The last few days have been in the order of finishing off the detail - and checking that everything actually fits. When I actually tried the last bit, I ran into a bit of a problem. No matter how hard I tried, I couldn't get the wing to fit into the cut-out in the fuselage, no matter how hard I tried. It wasn't a case of being a couple of mm too tight, the gap was 25mm too short. I have not got a clue how that has happened. I have subsequently measured and measured again..- all the critical measurements are spot on. Not a huge problem, I simply removed 25mm off the trailing edge and inserted a 3mm ply brace plus 1/32 ply end caps on the TE where they had been cut.. Amazingly,the curve in the fuselage now fitted the upper surface of the wing perfectly and the incidence from the datum (top of fuselage sheeting) is also spot on.. Never mind. The wings are bolted into a 6mm ply plate held in two 6mm ply 'brackets' glued to the fuselage side. I have also inserted a 8mm (balsa and ply) front end to carry the LE locating dowel. I can now assemble it and take some photos, so here they are.. The dark patched in the fuselage are filler there are a few 'dings' in the side that I wanted to remove before I was ready to cover it. The main U/C down legs have had 14 swg piano wire plugs soldered to them so they are located.Only a single saddle clamp will be required to hold the u/c in place. and some outdoor shots. The engine bay has been painted matt black and fuel proofed. A cockpit floor is fitted and a light balsa former inserted to tidy up the office.A coat of maroon car paint and fuel proofed. A bit more sanding down of the wing and I have covered it with profilm underneath and orcafilm on top with solartrim colour bars. I'll leave it upto you to decide if you like it. My only disappointment is that the check pattern is showing through the yellow solartrim so I will probably have to double it up.. Not much more to come Best wishes, Martyn Edited By Martyn K on 12/02/2012 22:16:17 Quote Link to comment Share on other sites More sharing options...
Andy Green Posted February 12, 2012 Share Posted February 12, 2012 Fantastic Martyn, you have been busy. How much dihedral do you have. Andy Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 12, 2012 Author Share Posted February 12, 2012 Hi Andy A total of 75ish mm - about 5degrees with one panel flat.. Martyn Quote Link to comment Share on other sites More sharing options...
Big Bandit Posted February 13, 2012 Share Posted February 13, 2012 Looking good Martyn, uncovered airframes like that look just brilliant its a shame to hide all of that work. The covering looks good though, should show up Ok. Cheers, Chris.Edited By Big Bandit on 13/02/2012 01:36:56 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 13, 2012 Author Share Posted February 13, 2012 Thanks ChrisIts not bad but it certainly isn't brilliant. I don't have that real craftsmans touch like you and Andy have. My biggest worry is that wing feels very heavy thet usually feel light again when covered, this one doesn't.Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 13, 2012 Author Share Posted February 13, 2012 Thanks ChrisIts not bad but it certainly isn't brilliant. I don't have that real craftsmans touch like you and Andy have. My biggest worry is that wing feels very heavy they usually feel light again when covered, this one doesn't.Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 13, 2012 Author Share Posted February 13, 2012 Thanks ChrisIts not bad but it certainly isn't brilliant. I don't have that real craftsmans touch like you and Andy have. My biggest worry is that wing feels very heavy they usually feel light again when covered, this one doesn't.Martyn Quote Link to comment Share on other sites More sharing options...
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