Collect parts for Continuous String assembly. This guide assumes you are building a four-stage lift with a Surgical Tubing (REV-41-1163) return. These parts are not included in the Linear Motion Kit v2 (REV-45-1507).
Drop the locknut (REV-41-1361) into the slot on the top of the endcap. Slide the bolt (REV-41-1360) through the pulley (REV-41-1368), pulley cover, and the endcap. Thread the bolt into the locknut and make sure you thread far enough into the endcap to have the end of the bolt supported by the endcap. This will act as a cantilever support and add strength in bending to the pulley axle when it is under load.
Add a pulley to the top of the first three extrusions and the bottom of the two center stages. All pulleys must be on the same side of the assembled linear motion system.
Add a screw post to the bottom of the last stage. The screw post must be on the same side of the assembled linear motion system as the pulley. Attach lift securely to robot frame using our plastic or metal brackets
Secure the string (REV-41-1162) onto the winding pulley. Run the string over the pulley at the top of the first stage and down to the pully on second stage. Then back up to the pulley on the top of second stage. The string then goes down to the pully on third stage. Then back up to the pulley on the top of third stage. The string then goes down to the screw post on the last stage.
The line may be hard to get onto the pulley with the pulley cover attached, but it is not impossible. An easier but more time-consuming alternative to get the line onto the pulley is to remove the pulley axle bolt and slip the pulley out from inside the pulley cover. Attach the line around the pulley and slide it back into the pulley cover and reinsert the bolt and tighten.
Note: The motor needs a winding pulley attached to it. Attachment of the pulley will vary depending on motor type. In this example, the REV Core Hex Motor (REV-41-1300) has a 5mm Hex Shaft with a spool held in place with a pair of Shaft Collars (REV-41-1327).
Push a screw into an end of the surgical tubing.
With string tightly wrap the surgical tubing onto the screw and tie it off. Then tie a loop of string such that the loop can be hooked over a screw post.
*alternatively, you can simply tie an end loop knot in the end of the surgical tubing.
To set up the surgical tubing return system, add bolts on the back side of the endcaps from where you just attached the drive lines. The bolts will mount just like the anchor bolts for the drive lines you mounted earlier. Mount one at the base of the first piece of extrusion, and two more in each of the first two end caps.
Add bolts to the second and third endcaps like the last step, and a third at the top of the last stage, similarly to the last step as well.
On the back side of the lift, opposite the drive line, attach 3 surgical tube lengths to the anchor bolts in the end caps in an arrangement seen left.
Adjust the tension in each piece to adjust the force that pulls the lift down.