Looking for some sort of rotary cutter, like an end mill, that is around 6 or 7 inches long, and has at least a 5 inch long cutting area, and here comes the good bit, it needs to be 6mm dia. We would make a supporting frame for this and the endmill would run in a point on its bottom end.
Another idea is a jigsaw blade that is 6mm thick, but has teeth along 5 inches of its length? if its possible. Google searches find extra long end mills, but not with the full depth cut I need.
The reason for all this, is an aluminium extrusion job which comprises of 2 outer plates with a 6mm gap between them. The gap is maintained by 4 longitudinal ribs. 3 of these ribs need removing each end of the lengths (that are 2.7m long) to a depth of 180mm. A circular saw is no good due to the arc. It would cut through the 4th rib to get the first 3 to depth.
End view of the extrusion is sort of like the effort below. Were not talking about a couple of lengths here, more like 2000
l-l l-l l-l l_l
If anyone knows of such tooling, please advise. Bob