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Ian Jones' IC powered and Slope Tucanos

The plan is to build two!

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Ian Jones20/12/2012 17:07:06
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3218 forum posts
1397 photos

I still have a lot to consider yet but as things stand I will be building an IC version and slope version.

The master build will be the IC version from the complete woodpack and in parallel from uncut balsa will be the slope version.

Ian Jones20/12/2012 17:14:38
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3218 forum posts
1397 photos

The main issues to decide upon are:

Engine - to invert or not, inverted would certainly look best

Steerable noseleg - no point in a trike without steering so far as I'm concerned

Relocation of F2 to form a firewall - put in additional F2a in the original F2 position?

Check fuel tank size and for any modifications that might be required to accomodate it

Removeable wings

Position of servo for steering - use to balance A/c

Position of flight battery - use to lalance A/c

Reinforcement to the underside of the slope version

Flaps - probably pointless, hmmm... on the slope version though?

Engine shouldn't be an issue if inverted:

enginepositionfront.jpg


enginepositionplan.jpg

Edited By Ian Jones on 20/12/2012 17:15:42

Edited By Ian Jones on 20/12/2012 17:44:30

Martyn K20/12/2012 17:30:58
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4836 forum posts
3517 photos

That 25 is a 32... It will be a monster. nerd

Martyn

GrahamC20/12/2012 17:46:31
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1228 forum posts
196 photos

In terms of the nosewheel.... I would have to say that even though my electric version has a fixed nose wheel, it is the easiest plane to manuvre on the ground I have ever had! Steers very easily with a judicious blip of throttle here and there.

Ian Jones20/12/2012 17:47:55
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3218 forum posts
1397 photos

'eck you spotted that quick Martyn. I thought I'd be able to keep quiet about it, should've doctored the photo.

Edited By Ian Jones on 20/12/2012 17:48:12

Concorde Speedbird20/12/2012 17:48:56
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2714 forum posts
628 photos

Oooo looks fantastic with an engine!

cs

Ian Jones20/12/2012 17:53:44
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3218 forum posts
1397 photos
Posted by GrahamC on 20/12/2012 17:46:31:

In terms of the nosewheel.... I would have to say that even though my electric version has a fixed nose wheel, it is the easiest plane to manuvre on the ground I have ever had! Steers very easily with a judicious blip of throttle here and there.

Hmm, maybe I'll devise a test. Though it could be steered with some up elevator applied at the same time, I suspect that the noseweight of mine will be better suited to steering. I'll bear that in mind though, thanks.

Ian Jones20/12/2012 21:07:56
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3218 forum posts
1397 photos
Posted by ConcordeSpeedbird on 20/12/2012 17:48:56:

Oooo looks fantastic with an engine!

cs

Yes I think it will be fine and I don't think it will be all that obtrusive either - the glow exhaust extension being roughly in the same position as the turbine exhaust will help a bit.

Although my intention at the moment is to use the SC32 I may drop down to a 25 if that makes a better fit. I'd prefer to stay with the 32.

I may also end up using the woodpack for the slope version and making the IC one a little wider in the middle fus section. This would give me more room to work and it would also be closer to scale. We'll see when I've had a drink, erm think, hic! beer

Ian

Edited By Ian Jones on 20/12/2012 21:08:35

Martyn K21/12/2012 15:18:39
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4836 forum posts
3517 photos

Ian

I think that the 25 and 32 share the same crankcase, the cylinder is obviously larger on the 32 but I dont know by how much.

I suppose you can always fly it on tick over. You remember how fast the AstroHog25 was with a SC25? That was a bigger aeroplane than this with a much thicker wing

I look forward to seeing how this develops.

Martyn

Ian Jones22/12/2012 13:20:45
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3218 forum posts
1397 photos

Yes Martyn it's just the cylinder that is bigger on the 32 - I've got both so I'll check how that would affect the shape of the cowl. The 32 at lower revs would certainly sound better than a screaming 25.

I am considering a slightly enlarged fin and extended wing tips to cope with the torque.

On the subject of built up wings/retracts I haven't decided which way to go yet, I think the sheet wing will win out because I'm unlikely to have room for a retracting noseleg (the fuel tank will have to be positioned as low as possible because of the inverted engine) and also I have loads of other projects so the quicker the build could be beneficial.

There's also the question of how much do you mess about with? A model that flies oddly after too many changes could have too many potential causes for it's behaviour!

Edited By Ian Jones on 22/12/2012 13:22:57

Martyn K22/12/2012 22:05:46
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4836 forum posts
3517 photos
Posted by Ian Jones on 22/12/2012 13:20:45:

There's also the question of how much do you mess about with? A model that flies oddly after too many changes could have too many potential causes for it's behaviour!

Edited By Ian Jones on 22/12/2012 13:22:57

The one thing I really like about aeromodelling is that you can experiment, predict the results, test your hypotheses and it wont cost an arm and a leg if you get it slighyly wrong... Go for it..nerd

Martyn

Ian Jones05/01/2013 01:05:05
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3218 forum posts
1397 photos

Well I spent some time at Barnstormers model shop today and eventually walked out with the engine of my choice - the bigger one.

Only thing nagging at me is will it sit still on tick over or will there be so much thrust to weight that it will be wandering off along the field before I've even opend the throttle? Hmm dont know.

Ian Jones03/04/2013 23:39:03
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3218 forum posts
1397 photos

Started at Last !

slecjig.jpg

smile

David Gilder04/04/2013 07:53:25
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1851 forum posts
656 photos
Posted by Ian Jones on 05/01/2013 01:05:05:

Only thing nagging at me is will it sit still on tick over or will there be so much thrust to weight that it will be wandering off along the field before I've even opend the throttle? Hmm dont know.

So its a nice set of retracts with independant braking next is it!! lol

RichFR04/04/2013 15:49:25
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139 forum posts

Stop playing Phoenix and get cracking cant wait to see the progress smiley

Ian Jones05/04/2013 00:11:37
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3218 forum posts
1397 photos
Posted by RichFR on 04/04/2013 15:49:25:

Stop playing Phoenix and get cracking cant wait to see the progress smiley

Okay, okay. Ooh but I was having fun.

Posted by David Gilder on 04/04/2013 07:53:25:
Posted by Ian Jones on 05/01/2013 01:05:05:

Only thing nagging at me is will it sit still on tick over or will there be so much thrust to weight that it will be wandering off along the field before I've even opend the throttle? Hmm dont know.

So its a nice set of retracts with independant braking next is it!! lol

You can laugh and I'm not so sure about the retracts but I have been thinking about wheel brakes. That's as far as I've got though smile.

Ian Jones05/04/2013 17:35:58
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3218 forum posts
1397 photos

Session 1

Work begins...

One model will be made from the CNC kit plus wood pack shown here. These parts will be used as templates for the second model:

cnc woodpack2.jpg

So starting with the wings I had to release the parts from their carriers. Fairly straight forward but some care was needed as the laser had not cut through the entire thickness of the wood in all places so some careful knife work was needed.

After that by judicious use of set squares, rulers and knives I cut the parts for the second wing, matching the wood weight and density as much as possible.

At the end of session one then I have two wings cut and ready for joining:

wingscut.jpg

CNC kit at the top, my own parts at the bottom.

Ian Jones14/04/2013 11:27:10
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3218 forum posts
1397 photos

On checking the middle panels of the 2nd wing I found one was not quite flat and the other had a small but noticeable twist in it.

As this is a problem that can & does turn with other bolds I started a new thread on the subject and of course received lots of helpful replies.

Result - two flat wing panels and work resumed.

Ian Jones17/04/2013 00:19:41
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3218 forum posts
1397 photos

So the watery solution to the twisted wing panels was to run quickly under the tap then sandwich them between some flat panels while they dry. If that hadn't worked I would have tried a drop of ammonia/bleach but as it turned out that wasn't necessary ' cos this did it:

untwisting.jpg

So that took me into...

Session 2

It sensible to wear a mask when creating all that dust, putting my overalls would have been quite sensible too smile:

maskwotboutoveralls.jpg

Now then, we are told that a few minutes with a razor plane will see to most of the wing profiling but hold on... planing along the grain is all very well but across the grain takes chunks out so instead I used a combination of a Perma-Grit block, razor plane and a sanding block:

wingtipprofiling.jpg

Oh I was supposed to crop that last photo so that it didn't look as if the Perma-Grit was radio controlled!, Oh well, that has completed the basic profile, I'll give it a final sanding nearer assembly/covering time:

2ndwingprofiled.jpg

I used the fuselage side in the kit as templates for the second fusalage and then just gave the edges a slight saning where necessary:

fussidesmatching.jpg

While I was at it I cut out the formers and used some of the remaining wood to make the duplicates for the 2nd model:

makeuseofsparewood.jpg

Ian Jones17/04/2013 01:10:19
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3218 forum posts
1397 photos

Session 3

It's time to be jigging up the fuselage sides but first it's necessary to transfer the profile of the wing to the fuselage sides. Several methods have been mentioned but I prefer to use a profiler as this can take the profile from the actual part of the wing chord that will meet the fuselage:

profiler.jpg

After cutting out the wing profile the fuselage sides can be jigged up. I've strayed away from what most people seem to be doing here.

Firstly I've used the formers as the contact points for the jig and allowed the fuselage sides in the cockpit area to bow a little. I think this will be more scale like and I think I will do the second fuselage the same, we'll see.

Secondly I have not reduced the height of the fuselage sides behind the cockpit, I don't think there's any need to. There's been much discussion about the plans being wrong and indeed they certainly do not match the instructions for the kit, so what's going on?

I tested the ability of the fuselage sides to bend to curves of F3 and found it was no problem so I thought that perhaps the triangle section strips were to go inside the fuselage sides. That would make sense as they would provide a good platform for the top sheet and would simply mean that on the plan the solid line for the bottom of the triangle stock should have been a dashed line instead. That's all very well but looking at the plan again it can be seen that a section across the fuselage shows that when the fuselage has been profiled the triangle stock has for the most part been reduced to little more than a continuation of the 3/16" sheet that was there in the first place! dont know

Oh, and in my wood pack there's 3/8" triangle stock for the front of the fuselage but no 1/2" triangle stock for the rear fuselage... does that mean something? I think it does.

I could of course be wrong but I suspect this is another case of miscommunication; a modification that's been made that has not been passed on. I think that somewhere down the line someone has realised that all this messing about with the 1/2" triangle stock just isn't necessary if the fuselage sides are made higher to replace it - that would also explain why there is no triangle stock in my wood pack idea. All I need to do to finish the rear fuselage is flatten out the top edges of the fuselage sides and put on the top sheet ready for profiling. The end result will be as near as matters to the long winded process with the triangle stock.

stillinjig.jpg

It has been identified that the fuselage at the back of the canopy is a week spot and since I am going have removable wings some strength and rigidity will be lost too. So I'm putting in 1/16" ply doublers. Doing so could affect flexibility when it comes to bending of the fuselage sides though and then there's the matter of cutting the doublers to shape too. I've got a coping saw but no blades and I want to get on with it. Well in the end I decided that if the doublers covered most of the depth of the fuselage sides then that would be enough, so they could be rectangular in shape; that also meant a few runs over both sides of the ply with a marking gauge would cut straight through it. Quick and easy:

markingguageonthinply.jpg

Butting the doublers up to F3 and the adding some triangular section in the corners will do the job just fine I'm sure:

doubler.jpg

I've added a couple of cross bearers to keep the fuselage sides in shape so that I can remove it from the jig. Being able to juggle the fuselage around will make fitting the snakes, servo tray etc so much easier. The kit model now has much of the fuselage and wings done and I'm using the motor mount for profiling the cowl. This will be the slope model as it requires less customisation and it will be good practice prior to building the IC fuselage.

kitwillbesloper.jpg

Edited By Ian Jones on 17/04/2013 01:12:44

Edited By Ian Jones on 17/04/2013 01:18:52

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