Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
My old BOB Yak trailer mounts to the bike axle with stainless steel grenade pins, which works fine. After all these years, alas, the rubber straps securing the pins to the frame have rotted away. The original straps are nicely molded affairs:
BOB Yak – original pin strap
I snipped a large O-ring, deployed four small cable ties, and this ought to last for another decade:
BOB Yak – new pin strap
The strap in the first picture hadn’t quite broken, but the rubber was cracked and ready to snap. So I made a preemptive strike…
This one came out surprisingly well, apart from the total faceplant with that resistor. With any luck, it’ll measure MOSFET on-state drain resistance over temperature for an upcoming Circuit Cellar column; it’s a honkin’ big Arduino shield, of course.
I think I can epoxy the resistor kinda-sorta in the right spot without having to drill through the PCB into the traces. Maybe nobody will notice?
The traces came out fairly well, although I had to do both the top and bottom toner transfer step twice to get good adhesion. Sometimes it works, sometimes it doesn’t, and I can’t pin down any meaningful differences in the process.
And it really does have four distinct ground planes. The upper right carries 8 A PWM Peltier current, the lower right has 3 A drain current, the rectangle in the middle is the analog op-amp circuitry tied to the Analog common, and surrounding that is the usual Arduino bouncy digital ground stuff. The fact that Analog common merges with digital ground on the Arduino PCB is just the way it is…
Continues to work just fine, much better than the first attempt:
Basement Safe Humidity – 2012-02-06
The paper scrap gives the weight of tray+desiccant, so when the humidity finally starts going up I’ll have some idea of the average leak rate. Most likely, opening the door for the more-or-less monthly logger readout introduces most of the water vapor…
During a recent rainstorm I grabbed the fiberglass marker pole at the end of the drain pipe to clear a wad of leaves out of the driveway gutters. Unfortunately, that left me with a finger full of glass fibers; it seems the top of the pole has deteriorated. The first tweezer I plucked from the stash around the pencil-oid tool holder hadn’t had its jaws aligned, so after I plucked (most of) the glass using those tweezers, I did a bit of filing and sandpapering:
Tweezer tips
That’s a millimeter scale in the background: these really are needle-tip tweezers.
A closer view:
Aligned and shaped tweezer tip
It still has a bit of overbite, but it grabs hairs from the bench with no hassle. Given that you can’t get all the glass fibers on the first pass, it’ll come in handy…
Putting the tool length switch atop the tooling plate has the advantage that it’s higher than most of the workpieces, but it also soaks up a bit of precious real estate. Moving it off the plate to the table puts it nearly level with the top of the plate, but at least now I have room for clamp blocks and suchlike:
Relocated tool length switch
It turns out that Sherline T-nuts protrude just an itsy above the top of the table (which lets them locate the tooling plate to the slot, for example), so I shortened one by filing it down to size:
Original and shortened Sherline T-nuts
Now, I’d like to front as if all that happened in a rational and well-thought-out manner, but the fact of the matter is that I completely used up one 10-32 stainless socket-head cap screw while thinking it was somehow still bottoming out in the slot, before realizing that the T-nut was sticking up. Drat!
The shaft that tilts the mixer head has started walking sideways out of its hole, which is not to be tolerated. Looking up inside the base column shows a locking screw that’s worked loose:
KitchenAid mixer – pivot shaft and locking screw
I took the thing apart and filed a flat on the shaft:
KitchenAid mixer pivot shaft – added flat
And then a dab of Loctite on the screw will prevent that from happening again:
KitchenAid mixer pivot locking screw
It’s still piddling oil on the countertop. If you have one of these things, always store it with the head tilted upward. That makes the oil run down the column onto the counter, rather than through the planetary gears into the mixing bowl…
The third hand grabbers I have all put bare alligator clip ferrules in the adjustable sockets with a thumbscrew to secure them. Over time, that thumbscrew crunches the ferrule and makes the clip hard to adjust. This has become enough of an annoyance that I rummaged around in the brass tubing cutoffs to find some that fit into the ferrules:
Alligator clip with brass tube insert
Given the sorry state of the ferrules, they required quite a bit of squeezing and shaping until that tube fit inside, but after that they rounded up nicely.
I suppose I should solder the tubes in place, but …
The Smell of Molten Projects in the Morning 