The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • MPCNC: Tool Length Probe, Reshaped for Plotter Pens

    It turns out old-school plotter pen nibs skid right off the rounded top of the switch lever:

    MPCNC Tool Length Probe - plotter pen
    MPCNC Tool Length Probe – plotter pen

    You can’t see the nib inside the cap, but you get the idea.

    Flattening the top and adding a snippet of masking tape produces a better outcome:

    MPCNC - Reshaped Tool Probe switch
    MPCNC – Reshaped Tool Probe switch

    I aligned the flat section so it’s parallel to the platform when the switch activates.

    Stipulated: plotter pens aren’t a good test for tool length probing, because they have a locating flange to ensure a consistent position in the pen holder and a rigidly controlled flange-to-tip length:

    HP 7475A Plotter Pen Body - in holder
    HP 7475A Plotter Pen Body – in holder

    What’s going on here involves configuring and testing bCNC’s overall tool change process: not using cutting tools preserves both sanity and hardware!