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cheapracer

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So, paid a bit more attention to the sheeting today, I am extremely happy that the matched holes all lined up on the rib's tab holes without any hassles.

I was expecting to have to drill out some holes, and move them around on the computer 2D because the tabs are bent over each on a different angle to make the curve, this with the slightly varying radius as they are bent over by hand would not unexpectedly create some variances - but I got a little lucky there.

.. But first I had to bend the sheets over for the front radius, never my favorite task, I have had it go wrong before, but went ok ......
 

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cheapracer

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So didn't get much done over the weekend but still chipped away a bit and got the hinge and elevator basically mounted ..

Elly 21.jpg

 
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cheapracer

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What a great day.

I had a go at a new rib system today which is stupidly simple for anyone to do, more accurate, stronger and cheaper.

Easier for me to produce because it's modular for any rib size or shape which particularly makes a tapered wing easy to produce and to build as seen by the 2 sizes I tested today.

Over the last couple of months I have been testing different rib configurations and this is just awesome!
 

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cheapracer

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So, I thought I would whip up an experimental fold up "Insta-Rib!" (with new chicken curry flavor!) rib which would be assembled at home in a minute, I won't use it, but doing stuff like this gains valuable information about design and processes for other future work, can never have too many ideas!
 

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cheapracer

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And in the meantime, did some real ribs today, one wing's worth in fact, only took about 3 hours ..

I can not describe how fantastically easy and satisfying it is to make these ribs, I think I have a new motto: "Making You The Expert!".
 

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cheapracer

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.. and now 2 full sets of ribs and some conversation about them ..



"I'm very intrigued by that method of making ribs. How would the weight compare to an equivalent with non-riveted flanges?"


The same eventually when I optimise it later, plus the rivets. Weight is weight, sure, but the rivet weight is miniscule.

I don't spend a lot of time on optimisation currently in case I change the part designs so I expect this actual craft's result to be about 10%~15% heavier than what it could be.




"From an engineering viewpoint view would your solution be any weaker than a bent flange?"




It's stronger - but also irrelevant, ever heard of, or anyone ever mention a fear of rib failure?

Doesn't happen.





"One of the things I like about your concept is that the exact rib size can just be CNC'd out, which makes it very easy for tapered wings. To make my ribs I had to first make wooden forms with provision for relief valleys, clamp and bash the hell out of it to bend the flange over, then fiddle about with each one for ages afterward to take out any warps. And that was just for ribs the same size as the wing is constant chord. Can't imagine fabricating several different size moulds for tapered wing, much less the elliptical shape if I ever end up doing a Spitfire.

Your method on the other hand takes out the work and also doesn't warp".



Geez, You summed it up near perfect.

1 hour for the laser (including travel), then about 4 hours to clean then rivet both wing sets, including me hand drilling and de'bur all the holes.

Or if you like, a long day or weekend to have a full set of tapered wing ribs done (this is just the D box ribs, remember the other side of the spar needs doing as well).





"You mentioned in a previous reply that you'd done flanges at non-square angle to account for wing taper - how'd that work? Just a gentle curve in those flange strips?"

Yes, about 93+ degrees with springback, mileage might vary. There's more trickery to it though, need to be careful to understand that the inner radius of the flange is that, a radius, and that the squared edge of the rib doesn't like to match up, all cured by a simple little trick when assembling them that actually kills 3 birds with one stone.

I'm uncertain if to match hole them or not, as it's so simple to do and impresses the powers to be for the 51% rule of actual fabrication work undertaken and learnt skillz for your Repairman's Certificate.



full rib sets.jpg

full rib sets 2.jpg
 

cheapracer

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So working tonight into the freezing cold evening, I present to you the closing (literally) stages of the elevator by the glow of my electric heater!

I also made a mistake and I had to redo the 2 top sheets late this afternoon, and I did in the old hand style (measure, scribe, centerpunch and pilot hole)and you can see the resulting wrinkles and poor finish (relative to cnc lasering) on the edges in comparison.


Elly 22.jpg
 

cheapracer

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... and then time to pay attention to the wings things, stage 1, basic Spars..

Bits including Spa Caps and Spar Web that is tapered and folded on the sides for self jigging besides extra strength..

wings 30.jpg

Next the major Gusset Plates that also act as jigs for self jigging, the little rivet star cluster you see in the middle is also a tricky little self jigging moment to align the 2 Gusset Plates perfectly, darn it makes life easy..

wings 31.jpg

Introduce the Spar Caps to the gussets, clamp them together and drill through the lasered holes in the Gussets (already done here) ..

wings 32.jpg

Drop into the tapered Spar Web, slide sideways and it all jams together to self locate, easy peasy ...

wings 33.jpg

wings 35.jpg
 

cheapracer

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"It looks like you now have the task of bending all the flanges on each rib to attach them to the spar (unless those holes at the spar end of the ribs are to attach them to a spar mounted flange?). If you do not bend them all to exactly the same angle, there will be a discrepancy with their alignment at the leading edge. You probably already have an accurate solution to that potential issue."


Ok, I figured it out over the weekend, meant I had to scrap 2 wing spars, but was worth it, was too messy a system due to a poor foundation, and needed improving.

First I laser'ed a jig plate that clamps to the spar caps so I can very accurately drill the holes to accept the 'rib to spar' brackets (that I also figured, laser'ed and folded, I love lasers!) ..

... then added the rib brackets, distances between were perfect, and test ran a rib, worked great, very easy. Notice the rib sitting on it's little shoulders on the spar cap edges located to perfection, g'clamp, drill, clean and rivet!

ribz locating jig.jpg

ribz locating 1.jpg
 

cheapracer

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I have to get serious about skinning the wings soon, so today I lasered out a bit of tin and set up some ribs to do a trial run rather than take the risk with some aluminium.

Lucky I did because it did need some modification to the length of skin going over the tip of the nose. All sorted now.
 

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cheapracer

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.. and another milestone reached today, after a lot of thought, designs, time and attempts, the wing spars are now properly attached to the fuse.

Another case of just because something looks good and works on a computer, does not mean it works in real life, stupid computer.

Please note that the turtledeck and VS are just sitting on loosely in these pictures ..




wingfix 3.jpg
 

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cheapracer

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So today I was playing around with retaining the gullwing shape I like very much. While mucking around with it I was delighted to realise a simpler way to construct the wing as well, simpler and less work (same foundation though).

The 'Gull' is a bit softer than originally planned, but will still be there ....


Gull 3D.jpg

Gull 1.jpg

Gull 2.jpg

Gull 3.jpg
 

cheapracer

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So have successfully figured the mounting of the mid wing ribs, not all shown here. Oh the actual mounting is easy enough, it's just what you do now that you have to be wary of how it affects things 8 steps further along the design, as ever.

And also happy to find the rear spar fitted as drawn ..


mid ribs on 1.jpg

mid ribs on 2.jpg

rear spar 1.jpg
 

cheapracer

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Anyway, been busy with some other stuff but trying to get a few hours in here and there and should be back into it for a bit now.

Current step is designing and building the Ailerons and Flaps, as well as Wing Tips.

They are almost 100% matched hole assemblies and I put the final iteration of the basic Ailerons together this afternoon, took less than 2 hours. Still needs operating quadrants finalised.
 

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