hi
went to local recycling yard today with some rubbish
and found this alu Click image for larger version.  Name: Picture 002.jpg  Views: 524  Size: 47.3 KB  ID: 1200 its 180mm x 90mm
this section is about 1200mm long , the other lenght is 5 meters
long,
(i see a big alu framed router) the bonus is the 6 meters of rack
that was screwed to it, how do i determine the pitch of the rack