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

Zenni Optical Glasses: Metalbending

The new batch of glasses I just received makes me take back any nice things I previously implied about Zenni Optical’s nose pad alignment:

Zenni eyeglass pads – as received

Zenni does have a guide to reshaping the frames, but it does not include aligning the pads parallel to your nose, which definitely goes better with wire-bending pliers in hand.

They should look more like this when you’re done:

Zenni eyeglass pads – aligned

I suppose this is a consequence of being able to get two eyeglasses + two sunglasses in three different frame styles and two different prescriptions, each with progressive lenses and antireflective coating, for about $350 delivered halfway around the planet.

Makes owning a set of metal-forming pliers look downright economical.

A few years ago, Mary paid more than that for a single pair of badly fitted glasses from a local outlet. Those days are over.

2023-08-28
DMM Probe: QC Fail

Clearing off the Electronics Bench unearthed the probes for my fancy Siglent SDM-3045 bench meter, which had been producing erratic readings. I isolated the problem to the red probe, which had an irregularly variable resistance ranging upward from a few ohms.

The probe being a non-repairable thing, I used the lathe to cut it apart and eventually found the problem:

Failed Siglent DMM probe

The probe tip on the right originally had no solder on it at all (*), with the curved part of the soldered wire fragment resting around it. The plastic pieces originally molded around the tip and wire applied enough force to hold them together, but the wire fragment fell out as I dismantled the probe.

Apparently the assembler didn’t get enough heat on the wire-to-tip joint to melt the solder on the probe tip, but the plastic shell got it past whatever QC might have happened between assembly and the shipping department.

A few years back, I refurbished all my failing alligator clips (using the Siglent meter and its test probes!) and no longer believe increasing my spend for such things will increase their quality. I’d love to be proven wrong, but the evidence is definitely stacking up the other way.

(*) I tried soldering the pin just to see if it was solderable: yes, it was.

2023-08-16
Worm Bin Valve Transplant

For reasons not relevant here, I have a spare water heater drain valve with a thread matching the drain valve for the Can-o-Worms bin:

Can-o-worms drain valve vs. water heater valve

It lacks the flange required to seal the O-ring against the outside of the bin, but I can fix that:

Can-o-worms – sleeved valve

It’s a chunk of PVC pipe faced to the proper length, bored to fit the valve body, then gooped in place with acrylic caulk.

Snug the nut inside the bin and it’s all good:

Can-o-worms – new valve installed

The original valve depended on having a smooth plug turning inside the outer shell, but years of grit scarred the interface enough to produce a slow drip. It also had the annoying mis-feature of aiming the opening inward, between the bin legs, where a jug didn’t quite fit.

The water heater valve depends on compressing a smaller O-ring against a seat inside the body, which may tend to clog with crud. We added a mesh filter to hold back the worst of the gunk, so this is in the nature of an experiment using free hardware.

2023-08-15
Mini-Lathe Carriage Stop Rebuild

I finally managed to whack the mini-lathe’s carriage stop handle with the chuck, prompting a quick repair:

Carriage Stop – handle epoxy clamping

I probably should have epoxied a rod into the recess under the handle, seated in a drilled hole into the hub, but let’s see how long this quick-n-dirty version lasts.

While ~~I had the hood up~~ epoxy was curing, I lasered a block of edge-lit acrylic to replace the credit card shims:

Carriage Stop – spacer

Which turned out to be one itsy too thick. Rather than sand / machine it down, the step over on the left grew a little brass shim:

Carriage Stop – spacer and shim

Both pieces depend on snippets of adhesive sheet to hold them in place, which seems reasonable because they’re always in compression. That also eliminates the hole and pin I originally thought would be necessary; living in the future is just grand.

Thing looks like it grew there:

Carriage Stop – installed

The orange stripe on the handle is laser-safe PSA vinyl.

That was easy …

2023-08-14
SJCAM M50 Condensation: Redux

The SJCAM M50 camera gasket seems unable to cope with The New Normal weather conditions around here:

SJCAM M50 – screen condensation

I think this was probably another case of diurnal pumping, given the exceedingly hot days and cool nights in late July.

Plenty of water condensed on the bottom of the battery compartment cover:

SJCAM M50 – battery lid condensation

And inside the compartment around the AA cells:

SJCAM M50 – battery compartment condensation

Unlike the previous leak, the camera lens wasn’t involved, so I did not disassemble the case. I let the opened camera (without batteries) dry out in the hot hot sun for the rest of the day and it seemed fine by evening.

Keeping it out of full sunlight during the day definitely limits the locations I can use.

2023-08-10
Dandelion Weeder Repair

This dandelion weeder was no match for the rugged weeds among the decorative grasses Mary planted along the road out front:

Dandelion Weeder – bent

You might expect the tang to extend well into the handle, but that’s not what you get in a cheap tool:

Dandelion Weeder – ferrule detail

The Bucket o’ Rod-like Materials had a rake handle about the right diameter, so I sawed off a suitable length, set up the steady rest with a bushing, and turned the end to match the ferrule:

Dandelion Weeder – end turning

Pound the ferrule into place and drill the new handle to fit the tang:

Dandelion Weeder – drilling setup

The handle seemed a bit raw and, as it was already chucked in the lathe, got a synthetic string wrap with clear epoxy coating:

Dandelion Weeder – string epoxy

The pourable epoxy is reaching the end of its shelf life, but seemed entirely suitable for the purpose. I wrapped two layers of string around the dry handle, laid paper over the lathe bed, slathered epoxy over the whole affair, and let the lathe turn dead-slow for most of the day to even out the coat.

The next day: hammer the blade mostly straight again, smear JB QuikWeld on the tang and into the hole, gently hammer them together, chuck the blade, apply more epoxy to the ends, and let it turn:

Dandelion Weeder – end epoxy

A careful inspection reveals my casual disregard of the finer points of tool handle craftsmanship, but it came out surprisingly pretty:

Dandelion Weeder – repaired

The blade remains the finest butter-soft cheap steel and still doesn’t extend the length of the handle, but Quality Shop Time™ is not to be sniffed at.

And, hey, nary a trace of 3D printing or laser cutting!

2023-08-07
FitBit Charge 5 Reboot

Wearing my FitBIt Charge 5 tracker in the shower without activating its Water Lock feature occasionally produces odd results, but the most recent mishap ventured deep into the peculiar:

Jammed FitBit Charge 5

Its complete lack of buttons makes the thing completely waterproof, but also means it cannot continue when the touch / swipe interface gets horribly confused.

The recovery process requires snapping it onto its USB charging cable, then pressing the nearly invisible button embedded in the USB connector shell three times, with one second between each press: click hippopotamus click hippopotamus click.

Then it restarts / reboots and eventually all is well again.

Perhaps I can now recall the magic incantation without digging through the online help again, because I am certainly not going to suddenly remember to do the Water Lock dance before showering.

2023-08-03