Those curved swords again

Just a comparison for those that care (Derek you asked for some numbers)

6061 T6:
—UTS (Ultimate tensile stress) of 290MPa
—Yeild stress of 241MPa

General purpose aluminiums:
—UTS of ~117MPa
—Yeild stress of ~110MPa

So yeah…6061 T6 isn’t the aluminium you know and love.

But once again that relies on you getting the T8 result with home tempering without over inbrittlement. Most couldn’t but Derek with his armouring buddies and access to gear may be able to get that.

I was thinking of using commercial heat treatment :smiley:

Current plan is to get:
1 x 5m of 6.5mm rod
1 x 5m of 9.5mm rod

Chop it into 10 x 1m sword lengths

Curve them all and get them heat treated

Test the following to destruction:
1 x 6.5mm 6061 rod
1 x 9.5mm 6061 rod
1 x 10mm fiberglass rod

Oh your getting it commercialy done…

Just a suggestion you may want to also do a straight rounded tipped core and a “scrolled” end core (Ie rolled back on its self) and do a “poke through” comparison with that an a fiber glass core, I think with a rolled tip (like shown in the attached pic) it shouldn’t poke through.

I don’t think Aluminium will be any more likely to poke through than fiberglass.

What I normally do, on fiberglass weapons, is slip a bit of garden hose over the end of the core, so the last 50mm of hose has no core in it.

I think the scrolled end would work, to reduce punch through, but I don’t statistically see a need for it.

Would eleviate the neigh sayers :slight_smile:

Actually having a scrolled end would increase the density at that point and could create a nasty whip effect. Also the extra width of the scroll means its going to be closer to the edge of the foam, increasing the chances of a punch through.
I’ve used fibreglass, metal, plastic and even wooden cores and never have any issues.

A good trick is to tightly wrap the core in cotton first (bound with Ados).
This will vastly increase the adhesion of the core to the foam which helps prevent any punch through.

I think Dereks on the right track using an Aluminium core for a curved weapon.

Yes, I considered this. And several variants on it. Contact adhesive. Epoxy Resin. Shrink wrap. All sorts of things.

[quote=“Derek”]Test the following to destruction:
1 x 6.5mm 6061 rod
1 x 9.5mm 6061 rod
1 x 10mm fiberglass rod[/quote]

10mm is very heavy fibreglass rod for a 1m length. I’d use 7mm or 8mm for a sword that length - probably 7mm these days to get a weight similar to the latex weapons.

Okay, 7mm it is then In fact, if 7mm is what would be used in 1m swords, I may just drop the test back to 6.5mm aluminum.

These guys use 10mm

ateliers-nemesis.com/english/stock.htm

Every manufacturer uses different rod. Also, not all fibreglass and carbon fibre rod is the same - they can vary in construction and density, so you can have thicker rods that are not much heavier.

They say their rod is 3/8 inch, which is actually closer to 9.5mm than 10mm. I haven’t handled their weapons, but it’s possible they are on the heavier side.

The Ex-Caliber weapons are quite light, you’d probably get a similar effect with 7mm fibreglass kite rod. My new stock is a little heavier, feels more like 8mm.

9mm and 10mm fibreglass rod from the Auckland kite shop is really very heavy. I would only use rod that heavy in a staff, to stop it wobbling.