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.
And kvetching, too
We spotted this crumpled front end at a local repair shop:
A closer look at the bumper tells the tale:
Pop Quiz: estimate the total cost of that collision, including the overhead of having to deal with the insurance company and arrange alternate transportation for a week or two.
Essay: explain why it’s possible for someone to insist that both deer and humans are better off under these conditions.
In this area, vehicles serve as the top predator for deer…
The Stop & Shop we normally use outsources their cash register function to us; we carry a scanner around, plink each item on its way into the basket, then do a credit-card swipe on the way out. On the last trip, this popped up after I scanned the “We’re done!” barcode at the Scan It! kiosk:
That means we were selected for a “random” audit, apparently triggered by the fact that we bought some non-typical items: ice cream! We proceeded to a nearby register, waited in line, I re-re-scanned my card, and … the whole fifteen minute process would have been a lot more amusing if said frozen items hadn’t been warming up while the harried clerk performed numerous ritual acts on the contents of our cart.
The main reason I use the scanner: there’s no other way to determine the price of any given item, what with all the unit pricing nonsense, mis-marked labels, pop-up sales, must-buy-N bundling, and so forth and so on. Secondarily, during a normal trip there’s no waiting in a lengthy queue (“Price check on Register 12!”) on the way out.
Mary hates the scanners, for well and good reason.
I have a deep and abiding cynicism about the wisdom of building Special Facilities for bicycles and pedestrians. We very much enjoy biking along the Dutchess County Rail Trail, but I fear the County’s initial enthusiasm and funding will quickly wear off, leaving us with another poorly maintained facility.
For example, the section of trail just south of Morgan Lake (a.k.a., Phase II) opened in July 2009, a mere four years ago. This view shows the North Grand Avenue at-grade crossing:
Shortly after the opening, the ADA-mandated vision-impaired tactile pavement strips at that crossing began to deteriorate and, by now, they’re just rubble-filled depressions across the trail on either side of the road.
The south strip:
The north strip:
Evidently, the Official Personnel traversing the DCRT lack the responsibility / authority / initiative to apply a broom and sweep the pebbles out of the path, much less schedule a repair crew. I suppose I should haul a shovel along on one of our trips and privatize the upkeep; it’s been two years, so further waiting will be pointless.
It’s not as though there’s no Official Traffic, as witnessed by this well-worn informal entrance at the south end of that trail segment:
There’s an Official Gate just to the left of the trail at that crossing, but, judging from the weeds, it’s evidently easier to stay in the car or truck than get out and unlock the barrier:
Perhaps pebbles now count as tactile paving.
As expected, that repair didn’t last very long at all; one hinge fractured along the same line as before. This time, however, we had a visit already in-plan, so I brought along my solvents and clamps.
Perhaps you wondered how I could have been so remiss as to not brace those thin white flanges. One picture of the unbroken hinge in the “lid down” position is worth a thousand words:
Need more? Here’s another thousand words from the other side:
As the lid opens, the gray tab pivots toward the edge of the lid until it’s nearly parallel, at which point all of the force tries to yank those two flanges apart and then crack the tiny solid part at the pivot pin.
Eventually, it succeeds. This is a view of the scanner base with the gray tab inserted in its slot, with the broken hinge in the “lid up” position:
Clever design, no?
I was unable to extract the broken fragment from the gray tab (actually, unwilling to apply more force, as I cracked part of the gray ring around the hinge pin), so this became an in situ repair. Once again, I applied solvent glue and squished the pieces together:
And clamped it while we ate lunch:
The brass rod applies the clamping force to the fractured part of the hinge through the pivot point. This isn’t the most stable clamp arrangement you’ve ever seen, but it worked well enough.
I pushed the scanner back half a foot, so the lid now clunks against the wall just before the hinges reach their limit. Maybe they’ll survive until the next visit…
This seems innocent enough:
Of course, that laptop:
I mentioned to my doctor that, if I were of malign intent, I would now have complete control of every PC on their network. That didn’t make much of an impression, as the same thing happened on my next visit.
Of course, moving to electronic records makes a lot of sense, but if you think they’ll be any more secure than any other online personal information, you’re wrong.
It didn’t take long to realize that Makergear doesn’t actually have any assembly instructions that convert an array of parts bags into a working M2 printer. The box contained a set of subassembly drawings, their internal BOM checklist, and an orange sheet with cautionary notes. So I figured I’d build enough subassemblies to reduce the clutter, then put them together into the chassis while working on Phil’s card table.
Unfortunately, the BOM on each drawing may not match the drawing, the drawings don’t quite match what’s currently shipped, neither of those match the instructions on the website, the assembly videos / animations aren’t particularly useful (at least to me; I don’t need animated trajectories for nuts and bolts after the first one), not all hardware has a corresponding drawing, and nowhere will you find enough information to actually put the thing together on the first try. Makergear is obviously running as fast as they can, making improvements as they go, and, while the task isn’t impossible, if you’re not pretty good at mechanical assembly, building an M2 from scratch won’t be a pleasant experience.
A thread on the Makergear Google Group suggests there’s an unofficial “Heathkit style” manual in the offing, which will be a major improvement over the status quo. The catch will be updating the instructions in pace with production improvements, while not losing previous owners along the way. The Google Group has pointers to some good build logs; I regret I can’t contribute anything of the same scale.
Some assembly notes that don’t fit anywhere else…
The chassis arrived with the Y axis slide, Z axis stage, and Z axis stepper motor preassembled and aligned in the chassis. Given that’s the part of the process requiring, by their own admission and video example, some finesse, I think they found it impossible for newbies lacking experience.
CAUTION! If you must assemble the Z axis or modify it, you must remove all four screws from the stepper motor’s case to get it in or out of the chassis. Do not let the motor endcaps fall off or become misaligned, because that will demagnetize the rotor and drastically reduce the available torque. Perhaps wrapping some tape around the sides of the motor to secure the endcaps will prevent disaster. As I’ll describe later, the Z axis motor has barely enough torque for its job and any loss will render it useless.
Use the shortest possible screws in the two huge rubber feet on the X+ side of the chassis, because the electronics case must fit flush to the chassis just above them. The recommended screws protrude too far through the chassis plate, which is perfectly fine on the X- side.
Secure the electronics case to the chassis side using M3 screws, instead of the M4 screws that fit the threaded holes, with three M3 washers between the case and the chassis. Put Nylock nuts on the outside of the chassis. You’ll understand why when you get there.
Tape the picture of the power supply plugs behind the electronics case where you won’t mislay it, because inadvertently swapping the power connectors will not go well.
Believe it or not, that giant lump of wire on the end of the harness actually fits inside the electronics case. Take it slow and it’ll be all good.
Cut a cardboard cover (I harvested a shoe box) to fit the build platform and clip it in place whenever you’re not actually building something. You will drop tools on that lovely glass platform…
Spotted this in a Lowe’s sale circular:
The thickness comes from the manufacturer and the area from the installer, so it all makes perfect sense…
Besides, 3 cm sounds much fancier than 1-3/16 inch, doesn’t it?
The Smell of Molten Projects in the Morning 