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.

Category: Home Ec

Things around the home & hearth

Solar-Flattening Fiskars Cutting Mats

Fiskars cutting mats must lie flat on the table to be of any use, but they’re remarkably sensitive to warping due to localized temperature variations; a hot cup of tea can wreak a remarkable amount of damage. Suggestions from the InterWebs generally involve a clothes iron, temperature tweaks, overnight cooling, and unpredictable results.

Given that the mats are large polypropylene sheets, I figured applying moderate heat to the entire mat while it’s compressed between two flat plates would work better:

Fiskars cutting mat – solar flattening

That’s one of Mary’s 36×24 mats atop an MDF sheet (with pictures of wood laminated to both sides), under a 7/32 inch = 5.6 mm sheet of non-tempered glass, with a maple shelf supporting the last two inches of the unwarped edge, all sitting on the driveway in full sun.

The first attempt started too late in the afternoon for good heating and, after a few hours, had only slightly reduced the warp. Laying it out the next morning got the mat up to about 110 °F = 43 °C around noon and the warp was completely gone by evening.

I don’t trust the IR thermometer’s temperature measurements on glass, but the surrounding MDF and driveway were plenty hot.

The next sunny day flattened the warp out of 24×18 inch mat on my desk, so success wasn’t a fluke.

We noticed that the larger mat is now uniformly smaller by about 3/16 inch along the 36 inch width and 1/4 inch over the 24 inch height. It was a tag sale find with unknown provenance and, due to the warp, Mary had been using her other large mat for layout, so we don’t know if this one arrived a little short or if my technique both flattened and shrank it.

The smaller mat seems unaffected by its similar treatment, so your mileage may vary.

In any event, a flat mat is much more useful than a warped mat, so we’ll call the operation a success.

2023-09-19
Coaster Cork Alignment Fixture

Having stuck many cork bottoms to many coasters and aligning nearly all of them pretty close, I finally made a fixture to get it right from now on:

Coaster cork fixture – test fit

A plywood disk anchors four arcs cut from a remnant of acrylic mirror left over from the card-suit coasters, using strips of adhesive sheet cut 1 mm smaller than the arcs:

Coaster cork fixture – adhesive sheets

Stick an arc in place, lay the cork inside the arc, and stick the rest of the arcs around the cork:

Coaster cork fixture – cork fit

Squish the arcs in place overnight with Too Many Clamps™:

Coaster cork fixture – clamping

In use, peel the paper off the cork, lay it in place, ease the coaster atop it, press firmly, remove the perfectly aligned coaster, then put a stack of them in the overnight clamp to solidify the PSA bond.

Should’a done this long ago …

2023-09-18
Craptastic Kitchen Scale: Shattered

So it turns out the surface of the craptastic kitchen scale really was tempered glass:

Kitchen scale – shattered glass

That’s after an inadvertent drop edgewise onto the concrete patio.

Stipulated: given what I’ve already done to / for the thing, the usual warranties do not apply.

The frame around the NP-BX1 lithium batteries held the glass fragments together surprisingly well:

Kitchen scale – shattered glass – detail

Of course, harvesting the good stuff resulted in a pile of fragments, but the carcass cleaned up nicely and, after grafting a temporary top made from scrap acrylic it still worked:

Kitchen scale – temporary surface

I expected to just cut a slab of 6 mm acrylic to match the original 5 mm glass, but for reasons probably related to dielectric constants, the touch controls do not work through that much acrylic. In fact, they don’t work through anything other than the 1.5 mm acrylic shown above, which seems a bit too flimsy for normal use.

The original glass had a design screened on the back surface and covered with paint, which I can certainly mimic, but right now I’m unsure how much effort to put into the thing.

2023-09-14
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
Magnetic Stirrer Resurfacing & Mug Decoration

Half a year of plunking my morning cocoa mug on the magnetic stirrer had pretty well scuffed up its platform, so this seemed like a good idea:

Magnetic stirrer – vinyl surface

Rather than add the blue disk to the small-scraps collection, I converted the Squidwrench logo into a LightBurn layout:

Squidwrench logo – laser cut layout

The roll of transfer tape I have on hand doesn’t stick well to the polyurethane sheet, so easing the vinyl onto the mug required careful tweezer work:

Squidwrench logo on mug

It’s on the other side of the mug from the original, somewhat battered, logo.

Now we can learn how long polyurethane sheets survive under the same conditions.

2023-08-25
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
Tree Work: Merlo Roto with Treecracker

[Edit: It’s a “Woodcracker”.]

The best bid on a recent tree removal project replaced most of the usual crew with a Merlo Roto telehandler:

Tree Work – Merlo setup

The orange gadget on the end of the boom is a Woodcracker manipulator with a terrifying switchblade chainsaw:

Tree Work – Merlo Woodcracker – rear

The saw has hydraulic motors, so you can hear the blade ripping through the wood.

The jaws above the saw hold the piece during the cut:

Tree Work – Merlo Woodcracker – side

Then lift it away:

Tree Work – Merlo Woodcracker – cut lift

The boom has a 115 foot vertical reach, so it can remove entire treetops:

Tree Work – Merlo Woodcracker – align

Then align the branch with the chipper’s gullet and ram it into the feed rollers, with no intervention from the ground crew:

Tree Work – Merlo – chipper feeding

The Woodcracker chainsaw isn’t quite long enough for the trunk, so the jaws stabilize the trunk during a manual cut:

Tree Work – Merlo Woodcracker – trunk support

Then haul the whole thing away:

Tree Work – Merlo Woodcracker – trunk lift

The Merlo can lift 11,000 pounds near the middle of its range, with a 1600 pound limit at the maximum horizontal reach and 5500 pounds at 115 feet vertically. As far as I can tell, nothing about this project came anywhere close to the machine’s limits.

The day arrived with a severe thunderstorm watch, but the main part of the storm passed far north of us. The local power company keeps this company on speed dial and called them for emergency work in the wake of the storm, so the Merlo left early and the remaining crew used a bucket truck to take down the last tree in old-school style.

The Merlo is staggeringly expensive, but lets one operator take down an entire tree without any climbers or riggers. I suspect the reduction in crew size (and insurance premiums) pays for the machine in short order; the crew was less than half the size involved in a neighbor’s project with another contractor.

Highly recommended!

Merlo’s promotional video has comparisons with similar machines and I’m sure you could waste an entire afternoon on such things. For sure, I didn’t get anything else done that day.

2023-08-09