Materials
Here are a few links to where one can find certain materials for building that homebuilt rig. Most items like: Aluminum profiles, bearings, tube, steel, light alloids, alluminum bolts etc. can be found on some of these sites. So take a look and see if there's something that meets your approval. For more recent links please check the HBS forum.
Awbearings
Sells Bearings of all types
Spaenaur
Different size bolts
Macqc
Composite Materials
Midlands xpress metals
Stocks on aluminum brass, copper,
stainless steel and steel
Aircraft Spruce
This site sells aircraft supplies and they carry Alodine,
a pre-painting agent that allows paint to stick to aluminium.
It's not anodizing, but it's an inexpenssive alternative to it
and can give great results.
McMaster-Carr
A great site for all of your building needs.
They practically have everything you will need.
Highly Reccommended!!!
Fastenal
Anchors, bolts, hardware, nails, nuts, pins, clips, rivets, screws
etc...
Fixture Works
clamps, Adjustable levels, knobs,etc
Morton Machine
clamps, Adjustable levels, knobs,etc