Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Dunno how I missed that while I had the cover off, but there it is. For future reference it’s C165, 47 µF 50 V, with an 8709 date code.
This being a PCB made back in the old days, likely with self-adhesive tape strips, the component pads inside ground and power pours lack thermal isolation decorations.
The solder joints on the bottom side looks better than these, honest:
Tek AM503 – replaced capacitor
The new cap is 56 µF 50 F, which seems Close Enough.
The other caps have reasonable ESRs, but I must lay in a stock of high-voltage ‘lytics, as the “new” one is definitely old enough to know better, too.
Now that I check, the amp still produces a very low amplitude 2 MHz sine wave on its 1 mA/div and 2 mA/div settings, suggesting Something Is Not Right™ in the front end, but it works well enough to let me defer that fix until later.
The neutral conductor is down to its last three strands:
Damaged neutral – over Redondo near pole 62859
Perhaps the power drop got snagged twice, because there’s a splice only a few feet away:
Damaged neutral and splice – over Redondo near pole 62859
Spotted overhead on Redondo near Rt 376 during an evening walk. I reported it using Central Hudson’s dead streetlight page, because there seems no other way to get their attention. It may be the homeowner’s responsibility, in which case a second splice will surely appear after the next power outage.
One might expect the NYS Department of Transportation to maintain New York State Bike Route 9, a.k.a. NYS Rt 376 from Poughkeepsie to Red Oaks Mill, in a bicycle-aware manner.
One would be mistaken.
The most recent patch strip very carefully avoids the deteriorated shoulder, all the way around the curve:
The crew chief said they were there because “somebody wrote a letter” describing the conditions. I suppose that would be me, although after half a year it’s hard to establish causation, let alone correlation.
He also says no details of the letter reached him, which explains why they laid the patches in the travel lane, rather than repairing the conditions I described. He was adamant they were doing the best they could with the inadequate manpower, materials, and time available for the projects.
There are absolutely no requirements to consider bicyclist safety in their repairs, so laying asphalt over the shoulder never happens.
NYS DOT’s Bicycling FAQ says I should “take the lane” around that curve, due to the deteriorated shoulder, to ensure motorists pass only when it’s safe.
Whenever I offer to take a NYS DOT bureaucrat on an inspection ride along their roads, they never have the time. Of course, they don’t “work” on weekends, so they’re unwilling to join me on a pleasant ride around the area some Saturday or Sunday morning.
Just another day of bicycling along NYS DOT’s “complete streets” …
That’s a 0.035 inch = 35 mil hex wrench, of which Eks reminds me “Any time your design requires a tiny [obscene gerund] wrench, you’re doing it wrong”.
After a few days of downtime, an Official Makergear Thermistor arrived and is now installed amid a dab of heatsink compound:
M2 – Thermistor with heatsink compound
With the hot end set a bit higher than usual, position the platform at Z=0, lower the nozzle to be flat on the platform, tighten the lock screw, then run off a set of large calibration squares:
M2 – Nozzle Z Offset Recal – first test
The scrambled square in the front left says the Z=0 nozzle position came out just a bit too far above the platform and, indeed, the measurements (upper left numbers) say it’s off by 0.15-ish mm:
M2 Nozzle and Platform Re-Cal Measurements
Probably a little PETG stuck to the nozzle; I hate adjusting things when they’re burning hot.
The walls are also thin by a smidge, but the first order of business is to reset the Z offset with M206 Z=-2.15. With that in hand, the second set of squares came out at 3.00 to 3.08 mm (lower left numbers), which I defined to be Close Enough.
The 0.08 mm variation across the platform isn’t enough to worry about.
The first skirt threads were too thick and not solidly bonded together, but the second skirt came out normally, with a thickness from 0.21 through 0.30, which is also Good Enough.
The three-thread walls were still 1.15 mm, rather than 1.20 mm, so the EM should go from 0.95 to 0.95*1.20/1.15 = 1.05.
Next, a set of single-thread thinwall boxes to verify the Z offset and recheck the Extrusion Multiplier:
M2 – Nozzle Z Offset Recal – thinwall test
They’re dead on 3.00 mm tall, varying by not enough to worry about.
Their single-thread walls are 0.38 mm, not the intended 0.40, which suggests the EM should become 0.95*0.40/0.35 = 1.00.
It turns out the filament diameter at this part of the roll is scant of 1.75 mm, maybe 1.73 mm, so I decided to not fiddle with the EM.
The flange around the bottom of the arch support grid (in the middle) is intentional; it’s not an overstuffed first layer. The clamp sections rise from the platform just like they grew there.
So the M2 is back in operation and I have a spare thermistor on the shelf!
Not much to my surprise, my hack-job thermistor rebuild went bad:
M2 – thermistor – assembly 2
Having nothing to lose, I heated the brass tube over a butane flame to wreck the epoxy, which blew out with a satisfactory bang and filled the Basement Laboratory with The Big Stink.
Much to my surprise, the active ingredient still worked:
M2 DIY thermistor corpse
The multimeter reported absolutely no intermittent dropouts for as long as I was willing to watch the trace while doing other things:
DIY Thermistor Autopsy – Resistance Trend
So it must be my crappy soldering technique.
A brace of real M2 thermistors will arrive shortly …
