Skip to content

Your own tool

Mounting

Clamp onto the 8 mm shaft of joint 6 with a shaft coupler from the BOM, or print a holder with a coupler connector: the SSG-48 repository has a template, STEPS/coupler_connector_generic_STEP.STEP (and Gripper STL parts/connector_coupler_generic.STL), and the STL/WRIST/wrist.STL in the robot's files shows the mating geometry. Keep the tool within the payload and short: every millimetre past the flange is leverage against joints 4 and 5.

The joint 5 homing feature

Joint 5 finds its reference by driving the forearm's limit switch against a feature of the tool holder. Your holder needs a surface in the same place as the pneumatic gripper holder's; compare with Pneumatic_gripper_holder.STL. Then measure the homing offset: home, jog joint 5 until the pin fits the witness marks, and set j5_homing_offset in main.cpp to the steps that gives (Mastering).

Connections

Up to 24 V and CAN at the M8 connector, two air lines, and the control board's two inputs and two outputs at the base. A tool that needs more, a camera's USB for instance, runs its cable outside the arm, with enough slack for joints 4, 5 and 6 and fixed so the arm cannot catch it.

The tool frame

The software positions the tool centre point. In the Python API, register the tool once with its transform from the flange, or set an offset at run time:

rbt.select_tool("NONE")
rbt.set_tcp_offset(0, 0, -120)                 # the tip, 120 mm out from the flange: along the tool's -Z
index = rbt.set_tcp_transform(0, 0, -120, 0, 15, 0)  # with a rotation, intrinsic XYZ degrees
rbt.wait_command(index)

The Python API's tool frame has Y and Z the other way

In the Python API (version 0.9.1) the flange frame's Z points back into the wrist, the other way from the commander's and these pages' (The flange frame), so a tip in front of the flange has a negative z there (known issue KI-11).

A permanent tool goes into the API's tool registry as a ToolConfig with its collision mesh, so that the collision checker knows its shape (Tools and the TCP). The commander software has no tool setting: its poses are for the standard pneumatic gripper, and a different tool means editing its robot model.

Check before you run

Jog joint 5 and joint 6 through their ranges slowly with the tool mounted and watch for contact with the forearm: the software's joint limits do not know the tool's shape.

Comments

Found a mistake on this page? Edit it on GitHub · Report it · Get help · This page as Markdown · llms.txt · The whole manual as PDF