Added 3D and images

README.md

examples/linear_axis/README.md

examples/linear_axis/img/axis.jpg

examples/linear_axis/img/capstan.jpg

examples/linear_axis/img/capstan_spacer.jpg

examples/linear_axis/img/carriage.jpg

examples/linear_axis/img/carriage_under.jpg

examples/linear_axis/img/motor.jpg

examples/linear_axis/img/pulley.jpg

parts/bare_attachments/55x55x35.f3d

parts/bare_attachments/55x55x35.step

parts/bare_attachments/55x55x35.stl

parts/bare_attachments/motor_with_capstan.f3d

parts/bare_attachments/motor_with_capstan.step

parts/bare_attachments/motor_with_capstan.stl

parts/bare_endcaps/endcap.f3d

parts/bare_endcaps/endcap.step

parts/bare_endcaps/endcap.stl

parts/bare_endcaps/endcap_2.f3d

parts/bare_endcaps/endcap_2.step