I have been seeing more and more folks use Misumi extrusions, saying that they are considerably cheaper than others. http://www.misumiusa.com/CategoryImages ... owser.html
I just looked and a single piece of slotted extrusion 160mmx300mm is $4.53 without any precision cuts or custom mount holes.
I think I will order a couple pieces and see how they are...
Which parts were that cheap for 160mm width? Widest pieces I found suitable for making a table was the 15100, at 100mm width. Best deal I could see on normal extrusions for the area was the 2080. I forget the prices.
I may go with a couple pieces of 15100 plus a 1540 to make up a table about the size of the stock 7x7 (table is roughly 9.5x8, or 240x200.) The extra slots (would be 9 full-length,) especially near the edge would be quite useful.
Only thing is Misumi doesn't seem to have any hardware for coupling pieces in parallel. For the span of the 7x7, probably just mounting the 3 individual pieces with the stock screw holes to the Y slide brackets would be sufficient. I'd probably ad a piece of sheet in between the sheets to keep the table as one piece.