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36" Morris Dancer (Read 11503 times)
Ployd

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36" Morris Dancer
Jun 20th, 2006 at 7:25am
 
I have been quietly beavering away on my new DLG and have taken the wing outline and structure previously posted and given it form. It is a little more advanced that the photos below in that one half of the wing is now covered (Aerospan) and doped.

The use of carbon as outlined has provided a very stiff wing and in the insertion of diagonals would have been overkill. The wing structually complete weighed in at 50.5 grams and I have set a target of 60 grams complete. This may sound heavy to some by at 146 square inches area (slightly larger than a 4" x 36" balsa sheet) and a projected AUW of around 85 grams,reasonable Smiley

I am still undecided about the fuselage construction, the tapered tube is quick but flexy (inconsistent launches the result) and I still lean toward a stiffer composite balsa/carbon pod and boom layout with a tip-up DT wing; open to ideas here.

Will keep you posted.

Ployd
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Pijuvwy

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Re: 36" Morris Dancer
Reply #1 - Jun 20th, 2006 at 7:43am
 
Wow!  That looks beautiful.  With the balsa layer underneath, I can see why diagonals would have been overkill.

The photo gives body to the plans on the earlier thread.  Any chance of some close-ups?  Also, does it follow the plan as you posted it, or does this build update on your original ideas?
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JoshuaF
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Re: 36" Morris Dancer
Reply #2 - Jun 20th, 2006 at 7:47am
 
Looks great. Now that I've seen it, it seems doable, though I'll be going carbon-less.
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Sand it down to nothing, then cut it in half
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Ployd

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Re: 36" Morris Dancer
Reply #3 - Jun 20th, 2006 at 8:00am
 
Hi JoshuaF

The structure is quite doable in all balsa but the carbon spar is essential. For the trailling edge, carbon made quite a difference but for all balsa version I would use say 10lb x 3mm x 6mm wide balsa and sand it down to form a wedge shape, unsupported it will warp.

Pij, Structure is as drawn in the previous post.

Ployd
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Pijuvwy

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Re: 36" Morris Dancer
Reply #4 - Jun 20th, 2006 at 8:17am
 
I've just been re-visiting the previous thread.  It all becomes clear!

Anyone who isn't sure what they're seeing here - I'd highly recommend going back to the "Let's all build one" thread, and not only look at the diagrams, but re-read Ployd's explanations.

At the time, I wasn't sure about your way of using the carbon 4-thou, but I like it.  Essentially a balsa wing, but with the strength sandwiched between the layers.  Nice work.
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kevin m
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Re: 36" Morris Dancer
Reply #5 - Jun 20th, 2006 at 9:18am
 
Ployd  - thats not a wing - thats a work of art.  Excellent building skills there - truly excellent.  I look forward to seeing more close ups.
Kev
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geo

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Re: 36" Morris Dancer
Reply #6 - Jun 20th, 2006 at 10:35am
 
Ployd:
Remarkable.  I've just spent 10 min. staring at it in wonder.  The difference between yours and mine is like the difference between the Wright Bros. and the Marx Bros.  The overall wing shape is quite nice and looks like it would be a relatively easy build as an all balsa structure, but I am interested in your comment that carbon bracing is necessary for the trailing edge to avoid warping.  Is this do to the shape of the wing or the relatively thin trailing edge?  I notice that your advice to Joshua was to build the wing out of fairly heavy stock.
Cheers
George
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Ployd

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Re: 36" Morris Dancer
Reply #7 - Jun 21st, 2006 at 7:07am
 
Thank you gents for the kind compliments but a work of art it ain't (it's rough in places).

Pij asked as did Kevin for some close ups, so I have posted 2 but I don't know if this is what you want.
Fig.1 shows half the wing covered from the spar line back to the trailing edge, the rest will be left as finished balsa with a spruce leading edge. I am not keen on bamboo but you have to use what is available.

Fig.2 is a close up of the left inner panel, the rest is self explanatory.

George. My suggestion to Joshua re an all balsa wing assumed that the construction would be the same as what you see without any carbon fitted. The trailing edge without some form of reinforcement would be the week link hence the use of a heavy balsa strip at the T/E only. The rest of the wing should be made from light timber in the 5 - 6.5lb density region except the intermidiate ribs (2.5mm) which I would reduce to say 1.5mm thickness and from at least 10lb balsa.

Basically what you are looking at is a "bastardisation" of current F1 technology although a similar style has been used for the constuction of coupe (F1G) wings and stabs so I have not invented anything new, like the Borg...I have asimilated! Grin

Ployd
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« Last Edit: Jun 21st, 2006 at 7:13am by Ployd »  
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Ployd

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Re: 36" Morris Dancer
Reply #8 - Jun 22nd, 2006 at 6:33am
 
I have now completed the wing, weighing in at 55.75 grams! I reinforced the outer dihedral breaks and finger pin with 1oz glass cloth doped on initially then covered with balsa cement wll rubbed in (a technique I have used before on power models).

I'm quite happy with the way it turned out, now for the rest of model Smiley

Ployd
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« Last Edit: Jun 22nd, 2006 at 6:35am by Ployd »  
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kevin m
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Re: 36" Morris Dancer
Reply #9 - Jun 22nd, 2006 at 6:50am
 
Just out of interest, have you notched the spar to fit the carbon caps or have these fitted flush to the join? 
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Ployd

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Re: 36" Morris Dancer
Reply #10 - Jun 22nd, 2006 at 6:54am
 
Hi Kev

The carbon caps overlap the spar, gives a better joint.

Ployd
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PeeTee

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Re: 36" Morris Dancer
Reply #11 - Jun 22nd, 2006 at 12:08pm
 
PeterL

You are too modest by half, that's a mighty fine looking piece of workmanship.

On the fus front, I agree with your pod & boom/pop-up wing suggestion, but have concerns about the durability of Carbon/balsa/carbon for the boom. I realise that sideways arrivals are not anticipated, but my experience is that if a laminate boom is going to break, it'll be on a cartwheel arrival during trimming.......sod's law & all that; especially with a long moment arm. I'd have thought that your method of thinning standard carbon tubes would suffice, albeit not so tapered as with a small CLG or chuckie. I've got some thin wall 6mm tube which is quite light and very stiff. I intend to thin down the tailplane end, and it's the right diameter for a 6mm thick fus.

well that's my sixpennorth, good luck with whatever you do.

PeterT
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StevieB

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Re: 36" Morris Dancer
Reply #12 - Jun 22nd, 2006 at 10:54pm
 
Very nice work, I've always been a bit scared of carbon construction but your diagrams and these photos are very helpful.  You've also picked a great name for the model.

I agree with PeeTee with regards to the fus.  I would use some form of carbon tube/tapered boom, mainly due to their resistance to damage.  I've found that 4mm tapered carbon tube has proved strong enough for my 30" model and despite the narrow diameter it is also very resistant to twisting.  I wouldn't use such a thin tube on a 36" span model as I think this really would be pushing the limits of longitudinal and torsional stiffness but I have looked into alternatives.

One option I am considering for a 36" model is Mike Woodhouse's F1B/F1H carbon/glass boom.  I think this would be stiff enough but I'm not sure how it compares to other carbon options for weight.  He also does an F1G boom but I think this may be too flexible.  PeeTee's 6mm tapered tube option sounds good as I think 6mm is a good thickness for this type of fueslage.  I'm not sure but I think that Phil Ball used Mike's F1A boom over the full length of the fus on his 40" span model.
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geo

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Re: 36" Morris Dancer
Reply #13 - Jun 22nd, 2006 at 11:38pm
 
Peter, if not a work of art, then definitely the work of an artisan.  This may sound like a silly question, but, can your fingers reach the throwing peg comfortably with out the wingtip interfering?   Also, what did you cover the wing with?  53 grams for that size of the wing, considering the amount of carbon used, seems pretty good to me.
George
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« Last Edit: Jun 22nd, 2006 at 11:39pm by geo »  

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Pijuvwy

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Re: 36" Morris Dancer
Reply #14 - Jun 23rd, 2006 at 12:23am
 
Remember, George, that the black bits you see on this wing are only 4 thousandths of an inch thick.  Ployd's design uses very little actual amount of carbon, but cleverly placed to make it give the stiffness of a larger amount of carbon, by firmly anchoring the thin CF in layers.  The height between the layers becomes a sort of de-facto carbon spar, even though it's filled with balsa.

Have a close look at the pic from the original thread, ...
and also at the second pic in this thread.

Please correct me if I got that wrong, Ployd.
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« Last Edit: Jun 23rd, 2006 at 12:37am by Pijuvwy »  

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