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

70 inch OD Curved Quilting Layout Template

Mary sketched a quilt layout on ordinary Letter-size paper using her quilting templates, but the final design will be a 30×30 inch layout requiring a suitably upscaled template. Running the numbers suggested a template with curved edges lying on a 70 inch diameter circle, which was easy enough:

Quilting Template – 70 inch dia – short

The normal-size acrylic template with a 20 inch diameter sits atop the upscaled cardboard version. We decided cardboard would work fine for a single-use tool; should she need one in the future, I have the technology.

It turns out that the inner curve also has a 70 inch diameter: its center point is displaced 200 mm along the center radius from the outer curve. The straight sides are parallel, not radii of either circle.

She decided a much longer template would simplify smooth edge-to-edge curves, so I laid out a skinnier version with a keyed joint in the middle:

Quilting Template – 70 inch dia – long

The grid represents the OMTech laser’s 700×500 mm platform, so I used LightBurn’s Cut Shapes function to chop the template into two overlapping parts:

Quilting Template – 70 inch dia – split

The cuts at the keyed ends extend slightly more than needed, but weren’t critical. Similarly, I didn’t worry about kerf compensation for two pieces of cardboard joined by packing tape.

The template looks a lot like a scimitar:

Quilting Template – 70 inch dia – long

The shorter version had its corrugations running along the short dimension. I put the longer version’s corrugations along the longer dimension, thinking they would prevent bending. That was true, but they also interfered with the pencil tracing the curves. Next time, I’ll know better!

2022-06-15
Memory Is the First Thing to Go

An email from Amazon arrived a few days ago:

Purchase Reminder – not found

I suppose we’re even, because I have no recollection of setting a Purchase Reminder on anything at any time.

By default, my email client does not display remote content in messages, which chops out the cute pictures, as well as killing all the cruft and tracking widgetry infesting commercial email these days.

2022-06-11
Pine Pollen Season

When the driveway runs yellow in the rain, it’s pine pollen season:

Pine Pollen Season – Driveway Flow

Our robot vacuum snuffles up quite a collection of dust:

Pine Pollen Season – vac filter B

Peeling a layer of the usual fuzz off the filter reveals the pollen:

Pine Pollen Season – vac filter A

This, too, shall pass and my eyes will rejoice.

2022-06-10
Sunbeam 3035 Clothes Iron: Rusted Spring

Some weeks ago the Sunbeam clothes iron Mary uses for her quilting projects stopped retracting its cord and a few days ago the entire compartment holding the cord spool simply fell off:

Sunbeam 3035 Iron – detached cord compartment

One plastic stud and two thin plastic tabs held the compartment onto the rest of the iron. How they lasted this long I do not know, but they are neither replaceable nor fixable.

When you see badly rusted screws in an electrical device, you know the story cannot end well:

Sunbeam 3035 Iron – cord connections

And, indeed, it hasn’t:

Sunbeam 3035 Iron – retraction spring rust

This being a steam iron, it has a water tank that gets filled through an awkward port with a sliding cover. Mary is as conscientious a person as you’ll ever meet, but the occasional spill has certainly happened and it is painfully obvious the iron’s designers anticipated no such events.

The coil spring had rusted into a solid mass:

Sunbeam 3035 Iron – spring rust – detail

I removed the spring, soaked it in Evapo-Rust for a few hours, then cleaned and oiled it:

Sunbeam 3035 Iron – relaxed spring

Rewinding and reinstalling the spring showed it has lost its mojo and cannot retract more than a few feet of cord.

She’s in the middle of a quilting project and will replace the iron with whatever cheapnified piece of crap might be available these days. Similar irons have reviews reporting they begin spitting rust after a few months, which suggests the plastic tank or stainless steel hardware in this one have been cost-reduced with no regard for fitness-for-use.

2022-06-03
Kenmore Gas Range Control: Solder Joint Failure

The entire control panel of our longsuffering Kenmore gas range became increasingly erratic, eventually reaching the condition where touching the upper right corner would blank the display, touching the lower right corner would restore it, and gently touching the temperature knob might elicit an F2 or F4 error code on the display. Given the symptoms, the old adage “It’s always the connectors” sprang unbidden to mind; I was pretty sure the oven temperature sensor had nothing to do with it.

Pulling the thing apart reveals the PCB across the back of the control panel:

Kenmore oven control – PCB overview

Note that all of the external connections arrive on the white power supply PCB attached over the main PCB.

A closer look shows one of the two groups of wire interconnects between the two boards:

Kenmore gas range – rear PCB

There’s a similar group hidden behind the hulking transformer.

Removing the two obvious screws and easing the PCB out of the red plastic latches made the problem instantly obvious:

Kenmore gas range – failed solder joint

Yeah, that broken solder joint would definitely be touch-sensitive!

The solder joints in the other group also show signs of fatigue:

Kenmore gas range – broken solder joints

It’s of interest only the upper joints on the power supply PCB have fractured. Perhaps those ends of the wires were hand-soldered separately from the other ends in the main PCB?

Resoldering both ends of all the wires restored perfect operation:

Kenmore gas range – resoldered joints

For the record, the Kapton tape I laid over the entire control panel 2-½ years ago continues to protect the slightly cracked membrane over the pushbutton switches:

Kenmore oven control – Kapton tape cover

Gotta love yet another zero-dollar appliance repair …

2022-05-26
Laser-cut Pole Bean Ties

This is the season for erecting the structures upon which the pole beans will climb:

Garden Bean Poles – overview

They’re made from a dozen small trees and branches of larger trees harvested around the yard. They last for a few years, just long enough for the next crop to reach useful lengths.

We lash them together with fabric strips:

Garden Bean Poles – joint detail

My knot hand is weak, but seems sufficient to the task.

Mary formerly tore the strips from old jeans / pants / whatever, which required considerable effort, produced ragged edges, and filled the air with fabric dust. This year, I proposed an alternative:

Garden Bean Poles – laser cutting ties

The weird thing in the middle is a reflection of an overhead can light in the laser cabinet’s polycarb lid.

From starting the LightBurn layout to presenting the strips for final inspection required the better part of ten minutes. I scissors-cut along the main seams to get single fabric layers, with everything above the crotch seam wadded off the platform to the left.

As with my shop raglets, the layout depends on LightBurn’s overhead camera view to align the cuts with the fabric on the platform:

Bean Pole Ties – LightBurn layout

It’d be easier to see with lighter fabric, but that’s what came to hand in the scrap box and the beans won’t care. We do not anticipate complaints about the odor of charred fabric when they reach the top of the poles, either.

The strips must align with the fabric’s grain to put the warp threads along their length, which makes the main side seam parallel to the X-axis. Even I can handle that layout!

Yes, the strips have rounded corners and, no, it doesn’t matter.

2022-05-25
Laser-cut Shop Wipes

Wiping down a tool or wiping up a mess with a small rag and then throwing it out simplifies cleanup:

Shop wipes

Long ago, I applied scissors to old towels / t-shirts / whatever to get randomly sized squares, but when Mary began using rotary cutters for her sewing projects I immediately saw the light. A few times a year, I lower the scrap box level and restock the shop wipes boxes.

A laser cutter is even better:

Shop Rags – LB camera layout

Flatten the rag on the honeycomb, drag a few rectangles into place, and fire the laser:

Shop wipes – laser cut

Something like 50 mm/s at 60% power works for all the fabrics I’ve tried, from worn-out towels and dead sweatpants to napkins and t-shirts. Thinner fabrics can be stacked, but wrinkles and seams get in the way of clean cuts.

Rounded-corner rectangles are easy enough to draw and the scrap cloths have different shapes, so I don’t see much point in saving a file with any specific layout. Your scrap box may be more orderly.

A clean cut lets the outer cloth just lift away:

Shop wipes – on honeycomb

The wipes give off a distinct smell of charred cloth, but running them through the clothes washer in a big mesh bag with everything else solves that problem.

Obviously, one couldn’t possibly justify a laser cutter to make shop wipes, but if you happen to have one just standing around, well …

2022-05-20