Overview
Linear bearing is made from half of rectangular or square aluminium tube, bearings and fasteners. Like with the sliding element, it consists of 1½" long mounting section(s) and 1" long bearing section(s).
The bearing section consists of pair of bearings attached to the tube by generic fasteners. The mounting section has a pattern of holes on each side of the tube to mount the perforated angle.
There are 3 sizes of the linear bearing:
3.5": bearing section / mounting section / bearing section
2.5": bearing section / mounting section
1": bearing section
Materials
- Aluminium rectangle tube, 2"x1.5", 1/8" thick (3.5" and 2.5" size)
- Aluminium square tube, 1.5", 1/8" thick (1" size)
- R3 bearings
- Screws, 10-24 3/4" 1/2"
- Nuts, 10-24
- Spring lock washers, #10
Many cheap R3 bearings seem to have inner diameter a bit less than 3/16" (by 0.005" or sometimes even more), so it's recommended to use regular zinc plated steel screws since their OD is also a bit less. For example, stainless steel screws may not fit in the R3 bearing.
Source Files
Making
Make the tube piece from SVG template, according to the instructions in Howto section.
Assembly
Insert the screw from outside of the half-tube and thread the nut on from the inside. To have good alignment, the bearing (and the screw) center axis should be at 5/16" distance from the base of the half-tube. This is achievable with help of 1/8" thick padding (UHMW works great for this), inserted between the half-tube base and the flat side of the nut. While the nut is held on the padding, carefully (to avoid pinching the padding), but firmly tighten the screw.
Place the bearing on the screw and secure it with another nut. Do not over tighten or the first nut might become loose.
See the picture on the right (the top picture shows old arrangement with spring washer).
