My original design was a bit lumpy and short of mounting points.This version works much better. Use a triangle bracket instead of a 3 hole strip to hold the obtuse brackets. This leaves a nice mounting hole. Use 12 brackets instead of 13 and put 2 thin washers in the gap. Also move the gap one hole to better position the rack strip under the pinion. So 3 obtuse brackets on one side and 9 on the other. Also, try several channel bearings to get the best fit. Some are too tight.