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Gary's Brian Taylor P-47 build

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Gary Clark 110/06/2020 14:36:04
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241 forum posts
131 photos

Hi Guys,

Regarding gear doors, my plan is to use a small servo on each door and a sequencer to open/close them before/after the gear. You can always use a normal voltage servo with a voltage reducer for lipo batteries instead of high voltage ones. I do this for all my receiver batteries so that you get the increased capacity and reliability of a lipo.

The jigs are on the right hand side of the wing plan below the aileron and flap rib drawings shown below

20200610_134310.jpg

There is a not also talking about the slight twist built into these parts.

Once pinned to the board (or glue them to a sheet of balsa an make a complete jig) you just build the surface onto them

20200610_133909_002.jpg

I like to shape the balsa block at the from roughly enough to get the top sheet on and then the twist should be locked in and they can be removed for final shaping and fitting of hinges and so on. Let me know if you are missing these and i can copy mine and send them to you Nick.

Gary

Nick Somerville10/06/2020 17:20:41
109 forum posts
68 photos

That’s great Garry, all clear re the jigs now. It is so helpful having someone with previous experience to follow as this is all so different from the large scale vintage gliders I used to build from plans.

I have cut some of the spars from some Western Red Cedar I had as my 1/4 sq balsa feels a bit fragile. I will double up on some of the webbing too. I can see that you have done the same with the webbing. My retract took some fettling to squeeze it into the correct place. I ended up with about 1mm clearance top and bottom of the retract rear body corners and the outer facing axle stub also is tight. I will probably add 1/16 capping strip to the bottom of the wing ribs to give myself more wriggle room when making the door fit flush.3c29b3e3-8bd7-4377-857c-b27f893bf79d.jpeg

Edited By Nick Somerville on 10/06/2020 17:22:10

Gary Clark 110/06/2020 21:07:18
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241 forum posts
131 photos

All looks good Nick and it's a big job done getting those retracts in and sorted. One thing I would say is I use screws to attach my retracts rather than captive nuts purely because captive nuts are too good. The danger is a bad landing and the captive nuts bring everything out with them instead of the screws just bursting the wood. I suppose the proper solution would be perfect landings every time.....

I have put webbing both side full length. It's a small weight gain for a good strength gain. My rear spar is extended a bit as well as per earlier in the thread.

Gary

Nick Somerville15/06/2020 11:06:06
109 forum posts
68 photos

Hi Garry, looking forward to your next update. I skinned my first wing top surface yesterday and am looking at the shroud areas. Can you explain what the curved section is that I have highlighted on this picture. I have made up a 20mm strip with a feathered edge to fit under the skin but do not see why it needs to be curved away towards the tip from the lower rear spar. Hoping you have done this bit already and have the answer.dc721eec-d724-44d0-8c04-212e4b1ee444.jpeg

Edited By Nick Somerville on 15/06/2020 11:07:27

Gary Clark 115/06/2020 15:11:28
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241 forum posts
131 photos

Hi Nick,

The top skin is straight (dashed line) and it's the shape of the aileron that is curved. Use the dashed line to cut the top sheeting to the correct overhang (shroud) and once the aileron goes in it will make sense hopefully.

I have shorted mine but not yet sorted the shroud to the correct depth yet so dont have a good photo for you.

If that doesn't help then let me know and I'll try get a photo of some kind to help.

Gary

Nick Somerville15/06/2020 16:09:33
109 forum posts
68 photos

Thanks Garry, confirms my thoughts and further study of the rib sections made me realise it was the block leading edge of the aileron that is curved. There is a lot of work in the inner shroud make up but rewarding nonetheless I am hoping. I have the flap on its jig and am shaping the LE currently. Look forward to seeing some pics of yours in due course.

Gary Clark 115/06/2020 19:54:08
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241 forum posts
131 photos

Glad that makes sense for you nick. These bits can get confusing, especially bits that are hidden under shrouds so cant use photos of the full size to help. I'm been messing around with the retracts on my left wing and trying to get them to match the right. Retracts are something I don't particularly enjoy due to me not having a clear way of doing it other that just trial and error so always looking for others technique to help with those.

Most of my time recently has been sorting out some models to go flying.ive always been a builder that does a little flying here and there rather than the other way around but decided to bite the bullet and join a new club. I went to Watton RC club here in Norfolk yesterday to introduce myself and what a fantastic welcome I got. Lovely and friendly bunch of guys and I ended up spending 3 hours chatting and watching flying. This got me excited to go flying for the first time in a long time so thanks to those guys over at Watton RC club for that.

I'll get some more progress on the jug this week hopefully.

Gary

Nick Somerville24/06/2020 13:51:09
109 forum posts
68 photos

Things are filling up in the wings. I have sorted the flap and aileron servo positions on both wings but really need to get those fiddly aileron hinges made up so I can test all the linkages before committing to finalising the servo hatches. Also the inner gear doors will need fabricating and hinging before I decide on a location for the micro servos that will operate them. It’s been an expensive week what with those huge wheels, seven servos (I already had two for the rudder and elevator) but now counting realise I still haven’t bought a servo for the tail retract. So that’s ten in all for the model! Doubling up the webbing on the main spar has meant I have no clearance for the wheel so may have to relieve a bit of the webbing.

Btw Garry, I was pleased to hear you have found a friendly club. Like you I am more of a builder than a flier, but am working at gaining confidence. I have a large Extra 330 with the Laser 180, destined for my P47, that I am trying to fly regularly and though I only play at mild aerobatics it is ideal for making repeat landings and takeoffs. Hopefully by the time I finish the P47 I won't have any worries about flying it.
36839d66-ca9e-4753-8807-fb46c8e2e758.jpeg

Gary Clark 124/06/2020 19:40:37
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241 forum posts
131 photos

That wing looks the buisness Nick. I went with foam wheels on mine that look pretty good and not too hard so bounce shouldn't be an issue. I love building planes but I hate spending lots of money on them (relatively of course) when I rarely fly them so mine cost £9 for 2 from Banggood! Same ones that are on my moth minor. They're nowhere near the quality of yours but look fine. I'm just on the way out to the garage to get back into it after a couple of busy weeks. Only downside of not building is that my bench gets filled with crap. First job tidy, second job finish the retracts!

Gary

Gary Clark 124/06/2020 21:09:51
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241 forum posts
131 photos

I got the retract in the left wing fitted and it seems to line up well with the other. The retracts are certainly not as sleek as yours nick and seem a lot more chunky but I can make it work and hopefully get them looking scale enough by the end. Just the servos to fit and then I'll join the wings and once that is done then it will be back to the fuselage so that I can get the wing mounted then get on with planking it.

Hopefully I'll get time over the next few nights and try and catch nick up!!

Gary

Nick Somerville27/06/2020 14:47:52
109 forum posts
68 photos

07d5f552-648b-4336-b93b-230f84df1c70.jpegHi Garry, I have been working on the aileron hingeing and have been looking at DaviQ’s build on RSMB and in particular this photo. I have made up all the hinges and have made a start at cutting the first aileron to take the hinges but can’t see how David accomplishes any movement with just a small cut out. Seems to me a full slot is needed, deeper under the aileron but also through a good deal of the leading edge upper surface.

Nick Somerville27/06/2020 14:57:48
109 forum posts
68 photos

This is the view of the underside cut out on the central hinge.84f12635-c8c4-4830-9859-f4ed16619bd4.jpeg

Trevor27/06/2020 16:18:08
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450 forum posts
57 photos

Nick, Looking at the geometry of that aileron bellcrank, I reckon it’s going to give you more down travel than up. You might want to consider using a 60degree bellcrank instead of the 90degree one.

Trevor

Nick Somerville27/06/2020 17:15:42
109 forum posts
68 photos

b4793ea4-d91d-47de-bb3c-ee999a617597.jpegI put the 90degree one in as that was as per the plan. I have used a servo checker to measure and I am getting equal up and down travel from the output of the bell crank so any differential if required will be set on the transmitter. The recommended throws are just under 10mm up and down so not much.

Took dogs for a walk to clear my head and returned to make a paper mock up as I should have done originally, to better understand the geometry. I can see now that once the hinges are all glued in I will be able to fill any slots made as per the picture of DavidQ’s build.1fb4f9eb-420d-4f23-9641-e133892cc4e3.jpeg

Gary Clark 127/06/2020 22:10:09
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241 forum posts
131 photos

Hi Nick,

The hinges aren't something I've spent too much time thinking about yet so great to see what you've done. The paper template is a great way of visualizing the final outcome.

When I'm not sure if things are going to work from a plan, I remember that it is a BT plan and chances are it's me that is wrong or cant see the outcome properly. 10mm isn't a big deflection at all but they are fairly substantial ailerons so that's why that works I'm guessing.

Great work nick. Sorry I've not been active the past couple of weeks, work is back on at full throttle. I'll do what I can and keep you updated but keep your progress on here, great to see.

Gary

Nick Somerville01/07/2020 10:51:24
109 forum posts
68 photos

23884655-e73a-4182-8110-7770848a6a73.jpegMade up the inner gear doors from litho and balsa, then fabricated the hinges using glass fibre sheet and 2m fixings. After gluing them in I drilled and used cocktail sticks from the outer edges to add strength. However, when looking at the linkage arm fixing I had to drill out the stick I had glued in place and replace it with the 2m bolt, so could have omitted the sticks on linkage sides as the bolt does the same job.

The two small Hitec servos have been installed between R1 and R2 and once the wings are joined I am thinking of cutting one hatch to allow access to both these servos as well as the retracts 1600ma battery and the Electron sequencer.3a33da91-3891-4abd-8899-7ee2a0308976.jpeg

Nick Somerville01/07/2020 11:33:03
109 forum posts
68 photos

Back in my workshop following the previous post I am wondering if I have made a classic error! Over focussed on working from the underside of the wings I have installed the gear door servos to be removed if necessary from the underside. However, the belly pan is intended to be fixed, though I know Trevor H made his separate, thus making this unworkable. In retrospect I think I should leave as is for now and then cut the hatch in the top surface after underside skins are in place and wings joined. I can always replace the servo plate screws with longer fixings from the other side.

Any thoughts welcome Gary.

Gary Clark 103/07/2020 19:11:31
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241 forum posts
131 photos

Excellent work as always nick. I think you can look at servo locations in 2 ways, either have it accessible via a hatch or just dont! Servos fail very rarely if looked after properly so either put a hatch in now or be forced to do it (but only maybe as it probably will never fail once set up properly) later. I would be tempted to leave a gap in the sheeting under the belly pan and once they are sorted just fit the belly pan. If they fail then cut a hatch in the top later. I call solutions like this "future Gary's problem". A hatch would great but no need for that effort now.

Are you making all the doors from Litho? I am undecided between litho, g10 or making my own from a glass cloth moulded on the skin.

Gary

Nick Somerville03/07/2020 19:35:37
109 forum posts
68 photos

Thanks Gary, I don’t have any g10, only a small quantity of the thicker Glass board that I have been fretting hinges and horns from. I do have some litho which for the inner door that combined with the balsa makes for a very light solution. As the leg doors are significantly more complex if following Brian’s technique I will have to ponder that when I get there.

Re the gear servos I will probably make an opening on the too skin and not bother with hatches. R1-2 is all hidden in the fus anyway and the dihedral brace will take most of the stresses along with the fuselage sides with the wings bolted in place. Thanks for your thoughts though and cover and forget has been a route that has also not been an issue for myself in the past. I just thought those little servos and the inner doors hanging in the grass could ....

Bought a new for me variety of laminating resin from Easy Composites (24hr delivery from order and very reasonable) and will be covering all the tail surfaces, flaps and ailerons this weekend so will report on how I get on.

Gary Clark 104/07/2020 19:03:44
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241 forum posts
131 photos

Good luck with the covering nick, I enjoy glassing but get frustrated with the constant fill, sand, fill, sand, fill, sand because I always miss bits. The results are worth the effort though.

The outer gear doors will be a bit of a challenge i reckon. It all depends on how scale you want to go but i want mine to overlap as per full size but it's hard to do since there is very little margin between the bottom of the oleo when retracted and the bottom skin depth (if that makes sense?) So the door must be thin and strong so either glass fibre or litho with balsa strengtheners and some sort of loop bracket that holds on to the oleo but allows it to slide up and down when the gear moves. BT uses brass for that but I think a 3d printed one could work and will be easy to modify. I'd say this is the next major part I haven't really cleared up in my head yet. As I said before "future Gary's problem" wink 2

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