jogpad¶

Jog your 3D printer or CNC machine with keys and knobs you can feel, not with a touchscreen.

Levelling the bed with a sheet of paper means looking at the nozzle. A touchscreen has nothing to feel, so every tap is a glance away or a blind guess, and a finger that slipped to the next button moves 10 mm instead of 0.1. A mouse is no better when the printer is not next to the monitor.

jogpad turns a numeric keypad or a small macro pad with knobs into a jog pendant. Every key sits where your finger left it; one press or one knob detent is one step; your eyes stay on the nozzle. The same applies to mills, lasers and other machines: see use cases.

Which pad¶

• A small USB numeric keypad. It costs a few euros and works as it comes: plug it in, enter it in jogpad.toml, done.
• An old keyboard from the drawer: its numeric block works the same way. Wireless keyboards work too, but take one with a cable if you can. A key release lost over radio keeps a held key's axis moving until you press another key, see Safety.
• A macro pad with 9 keys and 3 knobs (recommended). The knobs turn like handwheels, the big one for Z, and the pad lights up in the colour of the step size. It is sold under many names. jogpad is tested with one that shows up with USB ID 1189:8840 (lsusb shows it), and jogpad program-pad sets it up without the vendor's software. Pads with 1189:8890 speak another protocol and do not work yet.

Status¶

Early development. Working today on Linux with Klipper, tested on a QIDI Plus 4 with the keypad of a Logitech MX Keys S:

• jog, home and stop from a numeric keypad or any USB keyboard
• a held axis key keeps moving until released, at a speed set with the step key, at most 250 mm/s
• every move and homing shows up in the Mainsail or Fluidd console
• a web page that draws the pad with arrows and signs in the colour of each axis, shows key presses live and the step size from green to red, learns keys and checks axis directions; open in the network, changes only from computers Moonraker trusts
• a switch in Mainsail and Fluidd that turns jogpad off, STOP included
• the pad and its state as a camera panel in Mainsail and Fluidd, sized to the pad and with a link to the full page
• an installer that sets jogpad up as a service next to Klipper and downloads Python 3.12 first where the system's is older than 3.10; updates with one click from the update panel of Mainsail and Fluidd
• programming a CH57x macro pad with 9 keys and 3 knobs, without the vendor's software; it lights up in the colour of the step size

How it fits together¶

jogpad runs as a service on the computer next to the machine, usually the Raspberry Pi that already runs Klipper. It reads the pad, turns key presses into moves and talks to the firmware over its HTTP interface. The web page and the API (reference) are served by the same process.