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.

Tag: Repairs

If it used to work, it can work again

  • Laying On of Hands: Trackball Repair

    I have a pair of trackballs, one on each side of the keyboard, in the interest of dividing the strain on my wrists. The right-hand trackball, a Logitech Cordless Optical Trackman, suddenly stopped working one afternoon: the ball stops moving the pointer, the half-dozen buttons stop selecting things, the scroll wheel stops scrolling.

    I poke the resync buttons, replace the batteries, generally futz around, and discover that it’s actually working fine, but with an RF range measured in inches rather than feet. Not good; it’s on a pull-out shelf in the desk leg well and there’s no place for the receiver within a few inches. Besides, it’s supposed to work better than that.

    So I take the trackball apart, admire all the little bitty parts, reseat the ribbon cables, blow the fuzz out of the optical sensors, admit there’s not else much I can do, and reassemble it.

    Works like a champ again: I love zero-dollar fixes!

    I’m pretty sure this is Yet Another Ribbon Cable failure. Those cheap tin-on-tin connections get gassy after a few years, the resistance skyrockets, and (what with No User Serviceable Components Inside) the thing get tossed in the trash. Don’t get me started on RoHS.

    As part of all this, I discovered that desktop gadgets mostly use the 27 MHz band, with a few in the low VHF and Bluetooth at 2.4 GHz. I’d have laid money saying everything except BT was UHF, which just goes to show what I (don’t) know…

  • Blender repair

    Blender blade bearing repair
    Blender blade bearing repair

    So a while back I replaced the blade bearings in our cheap-after-rebate Farberware blender: a $20 pack of ten bearings (5 repairs!) from eBay for a $15 mixer.

    [Update: They’re 6 mm ID x 13 mm OD x 5 mm thick.]

    Of course, it turned into a shop project. I added spacers that held the shaft in the right position by eliminating some vertical play, dripped Loctite around the housing to fasten the outer races in place, silicone-lubed the seals, and generally did the last few dollars of engineering & manufacturing they couldn’t afford in a cheap blender.

    The blender now works better than it ever did before. It used to emit a horrible whining rattle and didn’t have much go-power. Now, while it’s not silent, it whirs solidly and engages the pancake batter with a vengeance.

    Blood no longer runs out of our ears…

    I think the original bearings were crap quality, badly sealed, poorly mounted, and failed so fast we never knew how the mixer should behave. Grumble, etc.

    Now that I know what to do, the next four repairs should go much quicker. If, indeed, the new bearings ever fail. The old ones were, IIRC, “dishwasher safe”, but I think that is a cruel hoax from the Planned Obsolescence & Early Failure Department. We’re rinsing the blade assembly by hand now.

    If I thought spending more on a blender would get better bearings, I’d probably still buy cheap-after-rebate ones just for the quality shop time…

    Memos to self: left-hand shaft thread, slightly shorter bottom extension, make stainless hardware.