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

  • Zire 71 Battery Replacement

    I tote around an ancient Palm Zire 71, which suffices for my simple calendar & to-do lists. This is my second, as the first failed when the flexible cable connecting the guts to the charging / USB connector crapped out; turns out that the slide-to-open feature that reveals the crappy camera also stresses the flexy cable to the breaking point. Now I don’t do that any more.

    The battery (well, it’s actually a single Li-Ion cell, but let’s not be pedantic) finally stopped taking a charge, so I did a full backup, tore the thing apart, and popped in a new battery. This being my second Zire 71, things went smoothly…

    I got a stack of surplus Palm batteries some years ago, but they’re readily available from the usual suspects for prices ranging from $5 to $50. We’ll see how well mine survived their time in isolation.

    The connectors don’t match, which means you just chop off them in mid-wire, then solder the old connector onto the new battery. A few dabs of Liquid Electrical Tape and it’s all good.

    Some teardown instructions are there, with fairly small pix.

    General reminders:

    • Stick the teeny little screws on a strip of tape
    • Watch out for the tiny plastic switch fin on the side
    • Torx T06 screws on either side of the camera
    • The silver shield around the shutter button snaps under the sides with more force than you expect
    • There’s a metal strip over the connector that can be taped back in place after the plastic posts snap off
    • Gently pry the flexy cable up off the base, using the tabs on either side
    • The speaker seems to be held in with snot
    • The battery shield is not soldered in place!
    • The battery adhesive comes off with a sloooowww pull

    Although it may not be obvious, I replaced the crappy plastic window over the camera with a watch crystal. Much better picture quality, although much worse than my pocket camera.

    Backup and restore with various pilot-link utilities:

    pilot-xfer -p /dev/ttyUSB1  -b wherever
... hardware hackage ...
pilot-xfer -p /dev/ttyUSB1  -r wherever
pilot-dlpsh -p /dev/ttyUSB1 -c ntp
pilot-install-user -p /dev/ttyUSB1 -u "Ed Nisley"

    The thing seems perfectly happy with a userid of 0, which is good because I haven’t the foggiest idea what else it could have been.

  • Tea Ball Revival

    Defunct tea-ball rivet
    Defunct tea-ball rivet

    The latch closing my tea ball consists of a nice stainless steel dingus held on by a grotty rivet of unknown provenance that I’ve repeatedly staked over the years. It finally came undone this morning, so I had a few minutes of Quality Shop Time right after breakfast.

    My tiny-screw box (left over from the long-gone Leichtung Workshops) has some stainless 0-80 screws that I found somewhere, but only brass nuts. Ah, well, we used to use brass water fixtures and lead pipe, so an 0-80 nut in hot water isn’t going to kill me.

    The ball rim has a recess for the rivet head, but the screw head was slightly larger. I braced the rim of the ball across the vise jaws and give the recess a few shots with a fat punch to enlarge it.

    Stainless screw and brass nut
    Stainless screw and brass nut

    Then…

    • A dot of Loctite on the threads
    • Assemble everything
    • Take it apart to put the latch on the correct side of the rim
    • Reassemble
    • Attempt to close
    • Gently bend the rim to flatten it out
    • Close
    • Attempt to latch
    • Brace closed rim on vise opening with screw head up
    • A few shots with a drift punch to settle recess around screw head
    • Success!

    It seems I ain’t worth a damn in the morning without a hot cuppa. The rituals must be preserved.

    I tossed the ball in the dishwasher and opted for a tea bag today…

  • Replacement NP-FS11 Li-Ion Battery Pack: Plan B

    Slitting the case
    Slitting the case

    Just for curiosity’s sake, I applied a slitting saw to the oldest defunct generic NP-FS11 battery pack, cutting carefully along the bonded joint between the two parts.

    No coolant, 1000 rpm, 200 mm/min, the saw is 22 mm diameter. Much slower than you’d use if you were in production, but I’m not.

    First cut all the way around at 0.5 mm inside the case, then another pass at 1.0 mm. The second cut went ting as it passed the tabs at the base of the cells, so I knew the halves were released.

    Inside we find a pair of 14430 Li-Ion cells, wired in parallel, with a little protection circuit board just jam-packed with teeny parts. One may reasonably assume the circuit controls over-charge and over-discharge, as well as current limiting.

    Pack opened
    Pack opened

    So a reasonable (or, perhaps, amusing) thing to do would be to buy raw cells from a nominally reputable supplier, do a heart transplant, and see if that improves the situation.

    Protection Circuit - Outboard
    Protection Circuit – Outboard

    Photos of the protection PCB, showing the cell connections. Positive end of the cells is toward the PCB. I think there’s enough clearance in the camera’s battery compartment to allow a wrap of tape around the case in lieu of re-bonding the plastic together.

    Protection circuit - inboard
    Protection circuit – inboard

  • Fractured Tour Easy Seat Strut Screw

    Broken bolt
    Broken bolt

    Straight up: this is about a stainless steel socket head cap screw I installed eight years ago, not the original Easy Racers screw, so this is not their problem.

    I rode out for milk-and-eggs at the corner store, a flat one-mile ride, and stopped at the traffic signal. Light goes green, line of cars accelerates, so do I… and there’s a snap and the left side of the seat sags backwards. I am not a powerhouse rider and it’s March, so I’m not doing leg presses while getting up to cruising speed.

    I continued the mission by sitting slightly to the right on the seat and pedaling gingerly, then diagnosed the problem in the corner store’s parking lot. If I’d been further away, I’d have done the repair right there, but I figured it’d hold together until I got home. It did.

    The problem turned out to be a broken screw holding the left-side seat strut to the threaded eyelet on the rear dropout. The top picture shows the way I have it set up: seat strut clamp outboard, rack strut inboard, with a socket head cap screw extending all the way through, and secured with a pair of stainless nuts that went missing along with the broken screw end.

    Screw fracture closeup
    Screw fracture closeup

    Here’s the fracture across the end of the screw, which shows no evidence of foul play. As nearly as I can tell, the whole thing snapped off in one event, with none of the crud that would indicate a progressive crack. Compared with that wheel stud, this is in pristine condition.

    So it’s time to replace the right-side screw, as well, which means a trip to the Bike Repair Wing of the Basement Laboratory. While I had the bike up in the repair stand, I decided to reshape the head on the right-side screw for better chain clearance.

    As nearly as I can tell, the usual practice puts both the seat strut and the rack strut outboard of the threaded eyelet on the dropout, but that seems wrong to me. The seat strut puts a tremendous amount of stress on the screw, so you really want that lever arm as short as possible: put the clamp against the eyelet. While the rack isn’t as heavily loaded, cantilevering it outboard of the clamp just doesn’t look right.

    But putting the rack strut inboard of the eyelet means the screw head sticks out rather more than I’d like. Very rarely, the chain will snick against the head and even more rarely it jams between the head and the freewheel. Nothing much happens (it’s a freewheel, after all), but I think reducing the head thickness ought to help.

    Reshaped socket head cap screw
    Reshaped socket head cap screw

    So I chucked the screw in the lathe, shortened the socket by about half, and put a taper on the head. If I had a stock of round-head cap screws, one of those would be even better.

    The shortened socket makes it a bit tricky to get enough bite with the hex key, but this isn’t something that requires much attention after it’s installed… and I get to do all that in the shop.

    Dabs of Loctite in the eyelet and nuts, for sure!

    By a truly rare coincidence, a standard 1-1/2 inch cap screw is exactly the right length.

    Right-side mount
    Right-side mount

    Here’s a view of the installed right-side screw, looking rearward along the upper rear triangle tube. Seat strut to the outside, rack strut to the inside, and reshaped head above the cluster.

    Took the bike out for a 16 mile spin today and it’s all good.

    A note for the weight weenies in the crowd: a rack on the back of the seat adds a redundant support structure. Without that, a failed seat strut can be a real showstopper. Even if you don’t use your bike as a pack mule, maybe you should add a rack.

    Memo to Self: add more nuts to the tool kit!

  • X10 Controller: End of Life

    X10 Controller Circuit Board
    X10 Controller Circuit Board

    After 30-some-odd years, the X10 controller we’ve been using to turn off all the lights at bedtime finally stopped working. For the last few months it had been occasionally jamming ON, even when nobody pushed any keys, and the only way to reset it was pulling the plug.

    The big silver can on the white cable is an ultrasonic mic, so perhaps the circuitry around that was getting cranky: the ultrasonic cleaner in the bathroom (which we use for eyeglasses) would reliably jam it. I think the controller was responding to the third harmonic of the 40-ish kHz cleaner power, delivered through the power line.

    As you’d expect, all the electrolytic caps were shot; ESR for the big one was “open”, the smaller ones around 5 Ω. The capacitance values were entirely within spec, of course. I replaced all three.

    X10 Controller keyboard
    X10 Controller keyboard

    While I had the hood up, I cleaned the switch contacts, even though that probably had nothing to do with the problem. Back in the day, they used actual metal deformable domes, stuck under an adhesive layer that did a fine job of keeping the crud and dust out.

    Put everything back together, fired it up, and it misbehaved the same way. I’d say we got our money’s worth out of it, though.

    A replacement is on the order of $15 from the usual eBay suppliers, so it’s not the end of the world.

    The new one probably doesn’t have the ultrasonic receiver, so it shouldn’t respond to the ultrasonic cleaner with the same enthusiasm.

  • “Clear Seal” Sealant Removal

    I attempted to assemble the Totally Featureless Clock’s case using Liquid Nails Clear Seal, figuring that it’d be easier to fixture than runny epoxy. I hoped that the joints would have enough surface area to allow curing, but was dead wrong.

    Hope is not a strategy and proper fixturing is your friend.

    Anyhow, I was left with eight surfaces on four dislocated panels covered with more-or-less cured sealant. I left ’em sit for a few days, then had to choose between:

    • Remove enough of the sealant to make the joints fit or
    • Machine new panels

    Turns out that xylene (from my can of Goof-Off) removes cured Liquid Nails Clear Seal just fine, without affecting the surface of the acrylic panel. Soak the corner of a rag, rub vigorously, and the gunk comes right off.

    Note, however, that Goof-Off comes in many different formulations. The one I have is mostly xylene, but the California “VOC Compliant” version is mostly acetone… which, I think, eats acrylic plastic for lunch.

    All of that stuff eats your liver for lunch, too.

    Don’t do like I did and use your bare finger in the rag. Alas, any solvent that actually works also eats any protective glove in my inventory for lunch.

  • Toolmaker’s Vise Repair

    Toolmaker's Vises
    Toolmaker

    Discovered that one of my toolmaker’s vises had a defunct screw securing the jaw to the body: one side of the head simply vanished over the years. Hadn’t mattered up until now, but I really wanted the jaw to not ride up when clamping the workpiece and the screw was rather loose.

    It’s difficult to tighten a screw with half a slot…

    Eventually I figured out that the screw has a 6-40 thread. My Brownells Gunsmith screw assortment (which they no longer offer) has, among others, 6-48 and 8-40 screws in flat, fillister, socket, and round head, but nothing in 6-40.

    After exhausting all other possibilities, I looked in the assortment box again and found four round-head crosspoint screws with captive lockwashers that I must have salvaged from some dead piece of gear.

    Of course, they turned out to be 6-40. Whew!

    Chopped off the lockwasher, added a dab of Loctite, and it fit perfectly. I flipped the sliding plate over, as it appeared somewhat worn, but I’m certain that didn’t make any difference.

    The screw must have a flat head (and you can’t flip the plate over) if you mount the vise on a machined V-way, but that’s not anything I’m likely to do. In that event, maybe I’ll just file the top off the screw and be done with it.