Linear bearing is made from aluminum channel (or part of rectangular/square tube), aluminum angle, bearings, shims, fasteners and Delrin rings. Like the sliding element, it consists of 1½" long mounting section(s) and 1" long bearing section(s).
The bearing section consists of pair of wheels (bearing+ring) mounted on the angular wheel mount attached to the channel by a screw. The mounting section has a pattern of holes on each side of the tube to mount 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
|1||rectangle tube 2x1.5x1/8, 3.5" long||http://onlinemetals.com|
|2||aluminum angle equal 3/4x1/8, 1 1/8" long||http://onlinemetals.com|
|4||linear-bearing delrin rings||custom part, buy or machine on lathe|
|4||precision shim 10||http://www.mcmaster.com/#91140A255|
|4||screw 10-24 3/8L pan||http://www.mcmaster.com/#90272A240|
|2||screw 10-24 3/4L bsc||http://www.mcmaster.com/#92949A245|
|2||hex nut 10-24||http://www.mcmaster.com/#90480A011|
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 (3/8" length) since their OD is also a bit less. For example, stainless steel screws may not fit in the R3 bearing.
- Thingiverse: todo
Make the channel piece from SVG templates, according to the instructions in Howto section.
Angular wheel mount
Make the angular wheel mount from SVG templates, according to the instructions in Howto section.
To mark the wheel mounting holes in the angle, use 3/8" dia transfer punch and press it against the inner wall of the angle when punching. This will ensure that the holes are accurate, resulting in good alignment of the wheels.
The DIY version does not have a center slot - instead, a hole is drilled through the center of the angle and tapped 10-24.
- Pre-fabricated rings will be available for purchase separately from a kit.
- Delrin rings can be made on a lathe