Carbon Foil Build

[Hawaiis]

Eppler 837 or 836 are hydrofoil specific foils.
Nice choice.

[Bradn]

Thanks Vvs and Hawaiis,
are they not both for lift?
shouldn't the mast be 0 lift just low drag?

[ronnie]

[quote="Bradn]

Also looking for ideas on how to make the mast, preferably without use of a cnc (no moneyz)[/quote]

It might work to buy a length of aluminium extrusion and fill it with carbon fibre. The aluminium would really only be a surface for the mast.
You could build the baseplate onto the bottom of it at the same time and theoretically the fuselage too, if you put the base at the top.
It would probably require vacuum to draw the resin through the whole layup, but too much would distort the aluminium.

The Aluminium extrusions most suitable seem to be for external louvres on buildings.
If you zoom this photo full size, it should show the actual size of the parts.

[Bradn]

The extrusions are a good idea, not sure if ullrich would sell 1m lengths but could always try
hopefully when uni starts soon they will allow students to use the cnc though

e836 seems quite thick,
scaled this one to 10% thick instead of 12.6%, any thoughts?

e836_scale080.png (9.79 KiB) Viewed 1556 times

have a few tricks to get 1cm thick but still strong enough ;P
ideally 100 x 10mm

[vvs]

1cm thickness, this small quantity. Yes, the resistance force is not large, but very difficult to obtain a sufficient strength and rigidity.

[Hawaiis]

Ronnie:
Those Ullrich aluminum extrusions look workable, are they available in the USA?

[Hawaiis]

The extrusions are a good idea, not sure if ullrich would sell 1m lengths but could always try
hopefully when uni starts soon they will allow students to use the cnc though

e836 seems quite thick,
scaled this one to 10% thick instead of 12.6%, any thoughts?
Attachment:

e836_scale080.png [ 9.79 KIB | Viewed 194 times ]


have a few tricks to get 1cm thick but still strong enough ;P
ideally 100 x 10mm

If you can make 1cm x 10cm and still stiff, that would be in a world class territory.

[ronnie]

Ronnie:
Those Ullrich aluminum extrusions look workable, are they available in the USA?

I tried emailing Ullrich about supplying individual pieces but got no reply. I guess they just want to supply wholesalers in Australia and New Zealand.

This USA company seems to supply louvres, but the size may be too big?
http://stores.homestead.com/hstrial-DBr ... Detail.bok

This Belgian company has an interesting extrusion.
http://www.fractal.be/profiles.asp?id=67

I guess you would find it easier to find suitable extrusions in the USA as Google seems to steer my searches toward the world or UK.

[ronnie]

The other way to use extrusions could be as a mould for the mast. After moulding the mast inside it, grind away each end of the extrusion and peel off the aluminium skins. You would then have to mould on the nose and tail of the mast.

[Hawaiis]

The other way to use extrusions could be as a mould for the mast. After moulding the mast inside it, grind away each end of the extrusion and peel off the aluminium skins. You would then have to mould on the nose and tail of the mast.

They would be perfect and not need modification for bi-directional.