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: Pen Wobble

    GCMC includes cycloids.gcmc, a test program producing a fixed set of hypotrochoids and epitrochoids, more commonly known as Spirograph patterns:

    GGMC Cycloids test patterns
    GGMC Cycloids test patterns

    I’m using them to get familiar with bCNC’s Workspace Coordinate System settings and to exercise the MPCNC hardware; ya gotta plot before you can cut.

    Most came out fine, but some showed distinct wobbles:

    MPCNC - Cycloid wobble - star
    MPCNC – Cycloid wobble – star

    Tight curves and higher speeds produce more wobbles:

    MPCNC - Cycloid wobble - loops
    MPCNC – Cycloid wobble – loops

    You’d probably never feed a wood router over 6000 mm/min = 240 inch/min, so this isn’t as much of a problem as it might appear. Also, I expect a few pounds of router will have fewer wobbulations than a weightless pen hung on a thin plastic mount:

    MPCNC - Pen Holder Detail
    MPCNC – Pen Holder Detail

    Just one more thing to keep in mind.