Heaven help me - I've just bought a delta kit :-)

[curious aardvark]

how easy is the carbon fibre rod to cut to length ?
looks fairly cheap to buy. http://www.ebay.co.uk/itm/1-x-3k-Car...QAAOSwwE5WVTJU

And whats the equation to work out length needed (obviously minus length of end pieces).

Right go look for wheels.
best buy looks like around £1 per wheel includign bearing. Bolts extra.
The swivel to tighten thing is neat. But I dropped them down from the top anyway. so that's not actually necessary. 3mm bolt and printed insert/washer will work just as well.

So we'd be looking at 3 x 1.5(ish) metre struts
and 6 x ?