Anyone cut custom wing ribs?

[Phillip Moffatt]

Hi all, sorry about my first post being a request for some cheap labour :D

Anyway, I'm making a two-element foil approx 1.5m in length, and I'm wondering if anyone on here offers laser cutting/routing of custom spars from plywood or similar to save me trying to hand cut them all, or if anyone can point me to someone who does small jobs like this?

Regards
-Phill

[Phillip Moffatt]

Actually, while I'm asking, would it be worth me knocking the trailing edges off the parts I send for cutting and adding them later, I'm just wondering if this kind of thin taper would give a big problem for laser cutting/etc.

 

Edited By Pete B - Moderator on 29/04/2014 20:06:38

[TigerOC]

You can try Stan Yeo at Phoenixmp;

**LINK**

he offered to to laser cut parts for last year.

Rob

[Codename-John]

Or you could try a forum member - LaserCraft services

[Tony Bennett]

try dylan at lasercraft.

he has done lots for me and is good.

[john stones 1 - Moderator]

Seen Dylans work on here, looks good to me.

[Phillip Moffatt]

Thanks guys, any thoughts on the trailing edges?
I'm planning on shaping them from some aluminium strip to give some strength on the wing but obviously it'd be easier to match if they were on the ribs too.

[Dylan Reynolds LaserCraft Services]

Thanks for the mention guys, appreciate it.

What software is that you are using Phillip?

[Phillip Moffatt]

I've just got a .pdf line drawing at the moment, and a point/co-ordinate plot of the respective profiles, but I can probably make it up in whatever is easiest for you, they're only slightly tweaked S1223 foils.

Edited By Phillip Moffatt on 29/04/2014 21:52:55

[Jon Laughton]

Falconaviation in Burnley - very good!

[David Davis]

Ian Hull at SLEC.

[Stefan Hafner]

Posted by Phillip Moffatt on 29/04/2014 20:50:50:

Thanks guys, any thoughts on the trailing edges?
I'm planning on shaping them from some aluminium strip to give some strength on the wing but obviously it'd be easier to match if they were on the ribs too.

We built a wing using the S1223 while at uni a few years back for the BMFA Heavy Lift. The railing edges were a bit of a puzzle to work out at first, but we ended up using balsa and glass to give them strength. We started by making a foam template that gave the correct underside profile, then added the ribs and the top skin, then weighted down the whole thing till it was dry. Then we simply sanded the trailing edge to shape and added a layer of glass cloth to the top and bottom to give more strength, applied with epoxy.

[Dylan Reynolds LaserCraft Services]

If you send me the pdfs I will take a look for you

[Phillip Moffatt]

Thanks dylan, I'll PM you later.

Stefan - I had originally thought about doing it in a foam core and then fibreglass skin it, but - as most of you have probably guessed - this is for the rear of a rally car (well, actually, a safari buggy), and I was worried about flying rocks and tree branches snapping the trailing edge off if they get caught, hence deciding to go with ribbed construction and then profile an ally strip for the vulnerable sections.

Edited By Phillip Moffatt on 30/04/2014 13:13:48

[Stefan Hafner]

I did suspect it was for a car from the pic above

Are you talking about making from a solid piece of wood or as a built up wing?

Personally i think you'd be better with a foam cored wing with a hardwood leading edge and an aluminium trailing edge.Then fibreglass the whole lot. Cobbled together a quick ProE model to give you some idea of what I mean.

I think this would be more ding resistant than a built up wing, as you could use blue foam or even pink foam for the core, these will give a core that will spring back to the original shape, where as a wooden wing will just crack. The aluminium sheet could easily be filed down to give the correct shape for the TE and will give a harder edge, or if you have the facilities you could lay it up on carbon before bonding it to the core.

If you want something really strong and you have access to vac bagging gear, the you can make a really strong one. If you take the same core with the carbon TE, then apply a layer or carbon cloth, then add a sheet of 1mm birch ply over that, then another layer of carbon cloth, and shove the whole lot in a vac bag till its cured, hey presto, super strong but light wing

Edited By Stefan Hafner on 30/04/2014 14:56:54

[Stefan Hafner]

Don't forget to add some hard points for attaching the wing though, as the foam itself is weak, couple of aluminium plated bonded into the foam top and bottom with a hardwood space would be ideal, the you can just bolt straight through

[Phillip Moffatt]

It was to be a built up wing, not solid, I had intended for the spars to be a 1" aluminium tube up front and 1/2" tube at the rear, which should be overkill really. I did think about a foam core and skinning it originally, but I have no tools for cutting the foam accurately, and I don't have vac-bag or anything available, anything with fibreglass, etc, would have to a wet layup.

Basically, an angle grinder and a file is about all the tools available, we're a pretty fast car/team, but we operate on an absolute shoe-string of a budget, most guys we compete with have more money in their engines or shock absorbers than we have for an entire car + spares :D

 Whilst it'd be cheaper to cut the wing ribs myself I thought a laser cut set might be cheap enough to be viable and take the most tedious part out.

Edited By Phillip Moffatt on 30/04/2014 15:19:33

Edited By Phillip Moffatt on 30/04/2014 15:20:02

[Stefan Hafner]

If you wanted go down the foam road (no pun intended), have a look at **LINK** for cutting wings, he did a set for me a few years back, that were spot on, and good price too. I finished them almost as described in my post above but with balsa and glass instead of ply and carbon. I did it by laminating on the first layer of glass and cloth and balsa then just putting the core back in the outer shells and applying lots of weight, then added the leading edge and glassed over the whole lot and sanded. Crashed the plane recently and broke the fuselage in 5 places but the wing just had some minor scratches, and I would guess that wing cost me about £60 in total.

[Phillip Moffatt]

Okay, thanks for that, looks like I've got some head scratching to do before I decide what to do :D

[Andy Green]

I think Barry at Foamwings does a lot of this sort of thing. Give him a call and chat though the options.

Andy