where do people buy there aluminum strips / U,L channel from? UK

been looking at many websites, but there are all pretty expensive, its going to cost me more for the frame then it is for the driver + led strips, any ideas on places to buy? thanks

Check your yellow pages for non-ferrous suppliers and get some channels from them.

You don't need heatsinks for the strips. You don't need lots of strength either so use thin aluminium, not 3 or 4mm stuff.

For my first light fixture that I built, I used those aluminium dividers that fit over carpets in door ways.
You can get them at Wilko's for a a couple of quid.
They worked fine, and the shape of them makes them act as a pretty good heat sink.
Looks a bit messy when finished though.
Alternatively, try Metal supermarket UK. They have a few locations around the UK and I went to my local one and asked for off cuts. They so them pretty cheap

I used some aluminium u-channels from *bay. £5.26 each including delivery (1"x1"x1/8"x24"). Maybe a bit over kill but it was my first strip build so I didn't really know what to expect heat wise.