Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
I managed to open a terminal emulator, whereupon all of the non-built-in shell commands couldn’t be found.
Proceed as before: binary-copy the entire MicroSD card to another one, pop it in the RPi, and it’s all good again.
For the record, the new card is an unused Samsung Evo Plus. I do not understand the difference between the “Evo Plus” and “Evo+” branding, other than to suspect one of being a very good fake.
In round numbers, MicroSD cards seem to last a year under what seems like not-too-demanding service; I’m not running the MPCNC all day, every day.
Another alignment camera contestant from the Big Box o’ Junk Cameras:
Logitech Pro 5000 Ball Camera – overview
It’s a Logitech QuickCam Pro 5000 with a native 640×480 resolution. For no obvious reason, it seems to work better on a Raspberry Pi than the Logitech QuickCam for Notebooks Deluxe I ripped apart a few weeks ago, where “better” is defined as “shows a stable image”. I have no explanation for anything.
Remove the weird bendy foot-like object by pulling straight out, then remove the single screw from the deep hole visible just behind the dent in the top picture:
Logitech Pro 5000 Ball Camera – disassembled
The stylin’ curved plate on the top holds the microphone and a button, neither of which will be of use in its future life. Unplug and discard, leaving the USB cable as the only remaining connection:
Logitech Pro 5000 Ball Camera – USB connector
Inexplicably, the cable shield is soldered to the PCB, so the connector doesn’t do much good. Hack the molded ball off of the cable with a diagonal cutter & razor knife, taking more care than I did to not gouge the cable insulation.
A glue dot locks the focusing threads:
Logitech Pro 5000 Ball Camera – focus glue
Gentle suasion with a needle nose pliers pops the dot, leaving the lens free to focus on objects much closer than infinity:
The CNC 3018-Pro doesn’t absolutely need home switches, but (in principle) they let you install a workholding fixture at a known position, home the axes, pick a preset coordinate system for the fixture, and not have to touch off the axes before making parts.
The X and Z axis switches simply press against the appropriate moving parts:
3018 CNC – X and Z Endstops
The little tab stuck on the tool clamp provides a bit of clearance around the upper part of the X axis assembly.
The Y axis switch needed a slightly tapered tab to extend the bearing holder:
3018 CNC – Y axis endstop
It’s made from a random scrap of clear plastic, hand-filed to suit, and stuck on the bearing to trigger the switch in exactly the right spot.
You can find elaborate switch mounts on Thingiverse, but I’ve become a big fan of genuine 3M outdoor-rated foam tape for this sort of thing: aggressive stickiness, no deterioration, possible-but-not-easy removal.
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The white jumper plugs into the single +5 V pin in the row and is soldered to a straight wire running along the entire row of header pins. I pushed the black plastic strip to the bottom, soldered the wire along the pins atop it, then clipped off the pins so they’re about the right height when flush against the PCB.
Use a two-row socket to hold the new row in alignment with the existing header:
3018 CNC CAMTool – Endstop power mod – alignment
Slobber on some epoxy and let it cure:
3018 CNC CAMTool – Endstop power mod – epoxy curing
And then It Just Works™:
3018 CNC CAMTool – Endstop power mod – installed
Well, after you install the switches and tell GRBL to use them …
Reminder: If you intend to put limit switches on both ends of the axis travel, you mustclip the NC lead from both MBI switches. One switch per axis will work the way you expect and that’s how I’m using them here.
If you regard your new CNC 3018-Pro Router kit as a box of parts which could, with some adjustments and additional parts, become a small CNC router, you’re on the right track.
In my case, the aluminum extrusions arrived somewhat squashed inside their well-padded foam shipping carton, which leads me to believe the factory responsible for tapping the bolt holes in the ends must be a fairly nasty place. In any event, the hammerhead T-nuts for the gantry struts simply didn’t fit into some sections of the slots, although they worked fine elsewhere.
So, file a smidge off the rounded sides of a few nuts:
3018CNC – 2020 T-nuts – filed
Which let them slide into place and rotate properly despite the bent channel:
3018CNC – 2020 T-nuts – trial fit
The assembly instructions used a word I’d never encountered before:
3018CNC – Gantry plate position
Turns out ubiety is exactly correct, but … raise your hand if you’ve ever heard it in polite conversation. Thought so.
I’ve not noticed any harm from rounding off the position to 46 mm; just position both struts the same distance from the rear crossbar and it’s all good.
The struts behind the CAMTool CNC-V3.3 electronics board were also squashed, prompting a bit more filing:
3018CNC – CAMTool v3.3 board – trial fit
The CAMTool board is basically an Arduino-class microcontroller preloaded with GRBL 1.1f and surrounded with spindle / stepper driver circuits.
As with the MPCNC, I’ll dribble G-Code into it from a Raspberry Pi. Alas, the struts behind the CAMTool board are on 75 mm centers, but the Pi cases on hand have feet on 72-ish mm centers. Pay no attention to the surroundings, just drill the holes in the right spots:
3018CNC – RPi case – drilling
Add more T-nuts and short button head screws, with rubber pads between the case and the struts:
I got an email asking how the Kenmore Model 158 sewing machine’s foot pedal pivots worked. The notes on rebuilding the carbon disk rheostat and conjuring a Hall effect sensor show the innards, but here’s what you need to know to get there.
The pedal has a pair of pivots on the side closest to your foot, held in place with a small screw inside the two feet:
Kenmore 158 – Pedal pivot screw – in place
The screw fits into a notch in the unthreaded pin inserted from the side:
Kenmore 158 – Pedal pivot screw – disassembled
And that’s all there is to it!
Now, as happened to my correspondent, the pin can go missing, perhaps after the screw worked loose. Worst case, you’re looking at replacing both parts.
Being made in Japan (as ours were), the pedal has metric sizes: the unthreaded pin is 4 mm in diameter and 18 mm long and the setscrew has an M4×0.7 thread. You could replace the pin with an 18 mm (down to maybe 15 mm) long M4 screw. The threads would make a gritty pivot, but better than no pivot at all.
Better to get a longer M4 screw with an unthreaded section near the head, hacksaw it to the proper length, file to tidy up the cut end, maybe file a notch for the setscrew, and pop it in place. For tidiness, file off the slot / Philips / hex socket to eliminate the temptation to turn it out.
Worst case, a pair of plain old USA-ian 6-32 screws 3/4 inch long would make a sloppy fit. Don’t tell anybody I said so; that’d be barely better than nothin’ at all in there.
Lowe’s claims to have M4×0.7 setscrews (with a hex socket, not a slot) to secure the pin.
If my experience around here is any guide, however, Lowe’s / Home Depot / Walmart may claim to have metric hardware in stock, but the only way to know is to actually go there and rummage around in the specialty hardware section, inside the big steel cabinet with slide-out drawers filled with a remarkable disarray of ripped-open bags and misfiled parts.
The Smell of Molten Projects in the Morning 