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

  • Bafang BBS02: Terry Symmetry Battery Mount Tee Nuts

    The two middle mounting blocks under the Bafang battery plate have 5 mm holes for the screws going into the water bottle studs brazed to the frame. The outer blocks clamp around the frame and it seemed like a good idea to secure the plate to them, as well:

    Terry Bafang battery mount - trial installation
    Terry Bafang battery mount – trial installation

    Those two blocks have a recess for an M5 tee nut:

    Terry - Bafang battery - station 2 - bottom view - solid model
    Terry – Bafang battery – station 2 – bottom view – solid model

    I snipped off the prongs with hardened diagonal cutters and filed the stubs to a uniform height:

    Modified M5 tee nuts
    Modified M5 tee nuts

    Applying a hot soldering gun to the plate melted the stubs into the block:

    Terry Bafang battery mount - tee nut in place
    Terry Bafang battery mount – tee nut in place

    An M5 screw with a wingnut atop a big washer kept the tee nut properly aligned while pulling it into the melty plastic; I was pleasantly surprised at the lack of drama.

    A ring of JB Plastic Bonder urethane adhesive glued the nut to the block:

    Terry Bafang battery mount - tee nut gluing
    Terry Bafang battery mount – tee nut gluing

    The adhesive starts out runny and flows under the nut, so there’s more surface in play than meets the eye.

    Clamping the partially cured goo to the frame atop a layer of waxed paper squashes any protruding adhesive lumps flat and prevents them from marring the tube’s paint:

    Terry Bafang battery mount - tee nut adhesive molding
    Terry Bafang battery mount – tee nut adhesive molding

    Anchoring the battery to the bike at four spots makes it utterly immovable, which seems like a good way to ensure longevity:

    Bafang BBS02 - Terry Symmetry full assembly
    Bafang BBS02 – Terry Symmetry full assembly

    That’s a test assembly predating the cable management cleanup …