Drawer Slide Inserts for Double Strung Continuous Rigging Lifts

Drawer Slide Inserts for Double Strung Continuous Rigging Lifts

This part was designed to provide a double pulley (v-bearing) insert for FTC robot telescoping lifts using aluminum drawer slides. A two-pulley design provides the capability for double strung continuous rigging.

As an alternative to conventional rigging with a straight return string (and tensioning spring), double strung continuous rigging routes the return string around the pulleys for a cleaner look and reduced potential for catching the string on things.

The design is based on and intended to be compatible with the single pulley insert design provided by Long Robotics for use with their LRS 300 Aluminum Slide.

These inserts are intended to be compatible with popular 300 mm aluminum drawer slides used in FTC robots, including:
* Misumi SAR230
* Long Robotics LRS 300
* Sugastune AR2-300

In addition to the 3D printed parts, the drawer slides, and the string (typically UHMWPE Cord or fishing line), the following hardware is needed for each insert:
* 2x V-Bearings (3x12x4 mm)
* 1x M3 Screw (35 mm suggested)
* 1x Small Head M4 Screw (10 mm) (Can use 2x with LRS 300)

The M4 screws need to be low profile to fit inside the drawer slide channel without interference. Long Robotics sometimes has a suitable screw in stock, but I hadn't been able to find another source stateside*. My source of supply has been M4x10x5.5mm screws from AliExpress seller "SCREWHOME Store" (cheap, but slow). *I am now aware that Misumi also offers a suitable screw, part# TSARAS4-10.

20230423 Update: Perhaps you want to do some kind of wire management on the other side of the adapter? Added a variation with a pocket opposite the pulleys. You could thread wires through or zip tie something to it.

20231224 Update: Perhaps you don't want the pulleys at the very end of the slide, for example to provide additional clearance if the slides are mounted diagonally? Added a variation with the pulleys and pocket 12.5 mm from the end. To reduce clutter, I'm only including a "RH" version, which you can mirror in CAD or your slicer. Added a line above about M4 screws from Misumi. Due to some questions received, added an illustration of how to rig the return line. Recommend using larger diameter fishing line (e.g., 1.2mm) to reduce the odds of the line jumping off and getting caught next to the pulleys.

The SolidWorks (educational license) source files are included for your modifications.