Where can I get like a retracting rod?

[Valiant]

I'm after something a bit like a giant car aerial or a boom pole if you're aquatinted with the media world, fully retracted it should be about 30cm tall and about a 4cm circumference max. Fully extended it should be about 150cm. Ideally made out of a lightweight material such as glass fibre or carbon fibre with twist lock compression type systems at each joint to stop it retracting into itself. The ones in the media world are 100cm > 800cm and about 5cm so a ratio of 8x for extension and they are extremely sturdy fully extended. So my poles of so 30cm > 150cm with a ratio of 5x with a 4cm circumference should work fine.

I've got an idea for a tent extension/gazebo for me tent. The top is a completely waterproof lightweight breathable material so the wind *shouldn't* try to take off with it, and a side panel can be made from a similar but non breathable material with a folded/pocketed design so that any side winds would be dispersed off without giving the person behind it a breeze?

The whole thing should fit into a box approx 30x10x5cm..

Whatcha think and where can I get the rods?

[tatanab]

Why not use tent poles?

   Buy online Tent Spares


Look under "discontinued and used" and you will see Solar Minor pole at £20.  They are a bit longer than 30cm folded, closer to 40 and are probably 4cm or less in folded diameter.

[tiermat]

How about telescopic flagpoles, a quick google threw up some on ebay etc but they are a lot longer than you want, when collapsed (115cm), but a further search may find what you want.

Blame having my view blocked at too many concerts for the inspiration...

[redshift]

Funnily enough, I was browsing some Carbon fibre suppliers this morning.  FibreTech do a variety of carbon fibre tube and poles.
Twist lock fittings similar to booms/fish poles can be found in walking/trekking poles too, or how about fishing net handles such as this one?  That's too long for your design, but you might be able to obtain/use spares. 

Tent poles with shockcord would probably be ideal.

[rae]

Camera monopod?

[andygates]

Walking pole.  Cheap and cheerful.  Alu, twist lock, might not get quite long enough.

[mike]

+1 forcarbon monopod - sounds like my Feisol 1401. 

[andrew_s]

A camera monopod would normally only be 3 or 4 sections, so may not make the 30cm -> 150cm target size range. You'll also get a better choice in aluminium rather than carbon.
It's worth looking for compact/travel  monopods...
eg
DealTime.co.uk - Find, Compare, and Buy Anything in Seconds    42-153cm ally
Manfrotto Mag Fiber 695 Monopod : Read reviews and compare prices at Ciao.co.uk 46-160cm carbon
Manfrotto 790B MODO MonoPod £20.99 - MyMemory 39-145 ally

Similarly walking poles are normally 3 section, so anything long enough would be more like 60cm compacted.

[Wobbly John]

My first thoughts were telescopic fishing rod. They used to sell them in Poundland, coz I considered getting on as a flagpole for the recumbent.

[Valiant]

I did think about fishing apparatus and tent poles, but neither seemed than sturdy nor folded down so small. I have several monopods and did thing of using them but they are too long when retracted. Mine went down to 60cm.