Chaff blower fan
 

Am currently rebuilding our static bench and am after a large belt driven fan to deal with saw dust, chaff fan off a scrap drum would be fine, however I don't want to deprive a rebuildable drum of parts... ideally i'm after a seriously rotten one, happy to remove etc. but ideally as local as possible... not bothered about make etc., flat belt pulley driven one would be useful. or even a scrap drum to cannibalise... theres one on our ransomes that would do but I don't really want to pinch it...

We have considered the same idea Adam. However, American benches have a simple chain running under the bench with 'T' pieces attached to it which drags the sawdust away along a trough like a piece of gutter. This runs uphill to form a heap or into a bag away from the saw. The return chain runs over the top of the bench to loop underneath again. Simple but effective.