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

  • Garden Step2 Seat: Axle Repair

    The cart in Mary’s Vassar Farm plot returned in need of repair:

    Garden Seat - fractured body
    Garden Seat – fractured body

    Those fractures near the end of the axle let the axle erode the side wall:

    Garden Seat - eroded body
    Garden Seat – eroded body

    This will obviously require some sort of reinforcement on the body holding the axle, but the first challenge involved getting the wheels off the axle:

    Garden Seat - axle cover
    Garden Seat – axle cover

    Some brute force revealed the hub covers snapped over an install-only locking fastener:

    Garden Seat - axle retaining clip
    Garden Seat – axle retaining clip

    More brute force cut those fasteners (a.k.a. star-lock washers) to get the wheels off the axles.

    While contemplating the situation, a box of 606 bearings (as used in the PolyDryer auto-rewind spindles) failed to scamper out of the way and produced a victim fitting perfectly on the 8 mm axle:

    Garden Seat - bearing idea
    Garden Seat – bearing idea

    I regard such happenstance as a message from the Universe showing I’m on the right track. The alert reader will note the axle should not rotate, but does sport scars showing it’s done some turning in the recent past, so the bearing may not be a completely Bad Idea™.

    Finding a Lexan snippet exactly as thick as the bearing suggested bolting a plate across the side of the body to support the bearing, like this:

    Garden Seat - reinforcing plate installed
    Garden Seat – reinforcing plate installed

    Some layout work in LightBurn produced a template to mark the body for hand-drilling the holes:

    Garden Seat - drill marking template
    Garden Seat – drill marking template

    In retrospect, that was a mistake. I should have:

    • Laser-cut an MDF sheet to make a drill jig
    • Drilled one hole and inserted a screw
    • Drilled the rest of the holes in exactly the right places

    Instead, three of the holes in that nice Lexan sheet ended up slightly egg-shaped to adjust for mis-drilled holes in the body.

    Lexan does not laser-cut well at all, so that sheet was drilled to suit after using the template to mark the holes:

    Garden Seat - plate drilling
    Garden Seat – plate drilling

    Then it got bandsawed / belt-sanded into shape.

    I squeezed 5 mm rivnuts into whatever fiber-reinforced plastic they used for the body, which worked better than I expected. They’re intended for sheet metal, so I set the tool for 5 mm compression and they seem secure. I hope using plenty of screws across a large plate will diffuse the stress on each screw.

    Then I threaded the axles and used acorn nuts:

    Garden Seat - repaired axle installed
    Garden Seat – repaired axle installed

    In this situation, I regard JB KwikWeld epoxy as “removable with some effort”, as opposed to the destruction required with those star-lock washers. High-strength Locktite might also be suitable, but I do not anticipate ever having to remove these again for any reason and do not want the nuts to fall off in the garden.

    The re-replaced seat conjured from a cafeteria tray continues to work fine, as do its 3D printed hinges.

    It’ll reside in the shed until Spring rolls around …