Badge Lanyard Reel Mount

A certain young engineer of my acquaintance now carries an ID badge and, so I hear, works in a PCB design & test area. Seeing as how her favorite color is purple, this seemed appropriate:

Badge Lanyard Reel - front - overall

Badge Lanyard Reel – front – overall

The guts came from Circuit Breaker Labs in the form of a recycled PCB trapped in acrylic resin atop a plastic housing with a spring-loaded reel inside.

It arrived with a plastic bullet at the end of the lanyard:

Badge Lanyard Reel - plastic bullet link

Badge Lanyard Reel – plastic bullet link

Which I immediately replaced with brass, because Steampunk:

Badge Lanyard Reel - bullet cross-drill

Badge Lanyard Reel – bullet cross-drill

That made the plastic housing look weak, so, in a series of stepwise refinements, I conjured a much better case from the vasty digital deep:

Badge Lanyard Reel - iterations

Badge Lanyard Reel – iterations

All of the many, many critical dimensions lie inside the case, where they can’t be measured accurately, so each of those iterations could improve only one or two features. The absolutely wonderful thing about OpenSCAD is having it regenerate the whole model after loosening, say, the carabiner slot by two thread thicknesses; you can do that with a full-on relational CAD drawing, but CAD drawings always seems like a lot of unnecessary work if I must figure out the equations anyway.

The back sports my favorite Hilbert Curve infill with a nicely textured finish:

Badge Lanyard Reel - rear - oblique

Badge Lanyard Reel – rear – oblique

It’d surely look better in solid brass with Hilbert curve etching.

Black PETG doesn’t photograph well, but at least you can see the M2 brass inserts:

Badge Lanyard Reel - lower interior

Badge Lanyard Reel – lower interior

The first prototype showed the inserts needed far more traction than the usual reamed holes could provide, so I added internal epoxy grooves in each hole:

Badge Lanyard Reel Mount - show

Badge Lanyard Reel Mount – show

Recessing the screw heads into the top plate made them more decorative and smoother to the touch. Button-head screws would be even smoother, but IMO didn’t look quite as bold.

After seeing how well the grooves worked, I must conjure a module tabulating all the inserts on hand and automagically generating the grooves.

The yellow star holds up the roof of the reel recess in the build layout:

Badge Lanyard Reel Mount - build layout - bottom

Badge Lanyard Reel Mount – build layout – bottom

Slic3r produced the rest of the support material for the carabiner exit slot:

Badge Lanyard Reel Mount - bottom - Slic3r support

Badge Lanyard Reel Mount – bottom – Slic3r support

Those two support lumps on the right don’t actually support anything, but tweaking the support settings to disable them also killed the useful support on the left; come to find out Slic3r’s modifier meshes don’t let you disable support generation.

The top plate required support all the way around the inside of the bezel:

Badge Lanyard Reel Mount - top - Slic3r support

Badge Lanyard Reel Mount – top – Slic3r support

I carved the original plastic housing in half, roughly along its midline, and discarded the bottom section with the belt clip (it’s on the far left of the scrap pile). The top section, with PCB firmly affixed, holds the lanyard reel and anchors the retracting spring in a central slotted peg. No pictures of that, as it’s either a loose assembly of parts or a spring-loaded bomb and I am not taking it apart again.

The lanyard passes through an eyelet that pays it out to the rotating reel. I’d definitely do that differently, were I building it from scratch, because mounting the eyelet in exactly the proper position to prevent the lanyard from stacking up on the reel and jamming against the inside of the housing turned out to be absolutely critical and nearly impossible.

The top plate presses the original housing against the carabiner, with the cut-off section inside the carabiner’s circular embrace, which just barely worked: the PCB bezel is a millimeter smaller than the shoulder of the housing.

All in all, I think it came out really well for a 3D printed object made by a guy who usually builds brackets:

Badge Lanyard Reel - front - oblique

Badge Lanyard Reel – front – oblique

I hope she likes it …

The OpenSCAD source code as a GitHub Gist:

 

Advertisements

,

3 Comments

Eneloop AAA Cells: First Charge

With an AAA-to-AA adapter in hand, the Eneloop AAA cells looked like this:

Eneloop AAA - as received - Ah scale - 2017-04-20

Eneloop AAA – as received – Ah scale – 2017-04-20

The glitch comes from a not-quite-seated cell, showing that a poor connection matters.

The package touts “up to 800 mA·h, 750 mA·h min”, with asterisks and superscripts leading to “Based on IEC 61951-2(7.3.2)“, access to which requires coughing up 281 bucks. So it goes.

A full charge made them happier:

Eneloop AAA - first charge - Ah scale - 2017-04-22

Eneloop AAA – first charge – Ah scale – 2017-04-22

The as-delivered 530 mA·h capacity represents 73% of the 725 mA·h after the first charge, so I suppose they’re more-or-less within the “Maintains up to 70% charge after 10 years of storage” claim. The 16-10 date code suggests they’re hot off the factory charger, so they must ship with somewhat less than a full charge.

Comparing the capacity in W·h makes more sense, because most devices (other than the Planet Bike blinky light these will go into, of course) use a boost converter to get a fixed voltage from the declining terminal voltage.

They arrived bearing just over 600 mW·h:

Eneloop AAA - as received - Wh scale - 2017-04-20

Eneloop AAA – as received – Wh scale – 2017-04-20

After charging, that went a bit over 850 mW·h :

Eneloop AAA - first charge - Wh scale - 2017-04-22

Eneloop AAA – first charge – Wh scale – 2017-04-22

Call it 71% of full capacity on arrival. Close enough.

The Planet Bike blinky will be somewhat dimmer with two NiMH cells delivering 2.3-ish V, compared with the initial 3-ish V from a pair of alkaline cells. I generally burn the alkalines down to 1.1 V apiece, so perhaps they’ll be Good Enough.

Now, if I were gutsy, I’d install a rechargeable lithium AAA cell, with a dummy pass-through adapter in the other cell socket, and run the blinky at 3.7 V. At least for a few moments, anyhow …

6 Comments

Tour Easy Front Fender Clip

We rode the Feeder Canal trail during a recent bike vacation in exotic Glens Falls NY:

Feeder Canal Park Trail - Branches

Feeder Canal Park Trail – Branches

The numerous downed branches along the trail and countless twigs on the trail came from a brush-clearing operation:

Feeder Canal Park Trail - Brush Clearing

Feeder Canal Park Trail – Brush Clearing

As luck would have it, a twig snagged between my front tire and fender, snapping the clips holding the fender in place:

 

Tour Easy front fender mount breakage

Tour Easy front fender mount breakage

Should it not be obvious, each ferrule formerly had two parallel jaws (on the left) gripping the fender, with the tiny screw digging into the fender. I affixed the fender to the broken clips with copious amounts of duct tape and we continued the mission.

It should be obvious why those ferrules are not suitable for 3D printing.

However, with the recent rear fender clip serving as inspiration, this didn’t take long:

Tour Easy - Front Fender Clip - Slic3r

Tour Easy – Front Fender Clip – Slic3r

The front fender fits a 20 inch wheel and is somewhat wider and flatter than the rear fender (I think they bent the same plastic strip around a smaller mandrel), so I did a quick copy-and-paste hack job on the OpenSCAD source code, rather than trying to parameterize the daylights out of the previous model.

The posts around the wire stays are 6 diameters deep and reamed to fit; the stays won’t be flopping around even without fiddly mechanical hardware retaining them. The holes extend about halfway into those posts to mimic the dimensions of the original ferrules.

All of us can predict where the next break will occur, right? That’s OK: I want this to break, instead of wrecking the fender, so the only question is how much abuse those simple joints can withstand. The printing orientation wraps the perimeter threads from the posts around the clip, making it about a strong as it can be.

The ferrules should splay outward by a few degrees to match the angle from the fender to the fork eyelets, but that’s in the nature of fine tuning.

The arch accommodates a strip of double-sided foam tape holding the clip in place along the fender curve, with those cute little hooks capturing the fender to keep the tape in compression:

Tour Easy Front Fender Clip - installed

Tour Easy Front Fender Clip – installed

I really must get some black foam tape …

The picture shows the fender sitting well away from the tire, due to the upper fender mount bending in response to the splash flap snagging on curbs and random debris; the wire stays didn’t seat completely into the posts.

The extender I made during the cracked fork episode remained perfectly straight, though:

Tour Easy - new fork - fender extender

Tour Easy – new fork – fender extender

So I re-bent the upper fender mount (not the extender!) to its original angle, thereby moving the bottom of the fender much closer to the tire. Now the stays seat fully, the clip holds the fender firmly in place with no rattles, and it’s all good.

The OpenSCAD source code as a GitHub Gist:

 

 

,

2 Comments

Microscope 60 LED Ring Light Adapter

The Barbie-themed microscope light I built from an angel eye LED ring worked fine for the last six years (!), but a much brighter ring with 60 aimed 5 mm LEDs for $17 delivered from a US seller caught my eye:

Microscope 60 LED ring light - in use

Microscope 60 LED ring light – in use

Although this ring looks much more professional, it didn’t quite fit the microscope, being designed for a round snout rather than a squarish one. This snout has a 47-ish mm threaded ring intended for filters & suchlike, so I built an adapter between that and the 60 mm ID of the LED ring:

Microscope 60 LED Ring Light Adapter - top - Slic3r

Microscope 60 LED Ring Light Adapter – top – Slic3r

The ring came with three long knurled screws which I replaced with much tidier M3 socket-head screws going into those holes:

Microscope 60 LED ring light - assembled - top

Microscope 60 LED ring light – assembled – top

The part going into the snout threads is deliberately (honest!) a bit small, so I could wrap it with soft tape for a good friction fit. The Barbie Ring didn’t weigh anything and I wound up using squares of double-sticky foam tape; it could come to that for this ring, too.

The adapter features a taper on the bottom for no particularly good reason, as the field-of-view tapers inward, not outward:

Microscope 60 LED Ring Light Adapter - bottom - Slicer

Microscope 60 LED Ring Light Adapter – bottom – Slicer

Seen from the bug’s POV, it’s a rather impressive spectacle:

Microscope 60 LED ring light - assembled - bottom

Microscope 60 LED ring light – assembled – bottom

The control box sports a power switch and a brightness knob. Come to find out the ring is actually too bright at full throttle; a nice problem to have.

That was easy!

The OpenSCAD source code as a GitHub Gist:

 

,

4 Comments

Cylindrical Cell Adapters

An octet of Eneloop AAA cells arrived, I wanted to measure their as-delivered charge (the package says “Factory Charged With SOLAR ENERGY”, so you know it’s good), and discovered I’d given away my AAA cell holders. You can actually get inter-series adapters on eBay, but what’s the fun in that? Plus, I didn’t want to delay gratification for a month; you know how it is.

Soooo:

AAA to AA Adapter - top - Slic3r

AAA to AA Adapter – top – Slic3r

It’s basically an AA-size sleeve that fits over the AAA cell, with a lathe-turned brass post conducting juice from the + terminal of the inner cell outward:

AAA to AA Adapter - parts

AAA to AA Adapter – parts

Not much to look at when it’s assembled:

AAA to AA Adapter - assembled

AAA to AA Adapter – assembled

The AAA cell fits deliberately loose, because this goes into a metal clip holding everything firmly in place for the battery tester:

AAA to AA Adapter - in use

AAA to AA Adapter – in use

The source code tabulates the sizes of several cylindrical cells, exactly zero other pairs of which have been tested; I expect most won’t work correctly. In particular, the table entries should include the contact button OD and thickness for each cell, so that I can turn out the proper terminal for each pair of cells. If I ever need a different adapter, I’ll beat some cooperation out of that, too.

Discovered I needed an adapter after breakfast, started testing cells after lunch. Life is good!

The OpenSCAD source code as a GitHub Gist:

The original doodle:

AAA to AA Adapter - sketch

AAA to AA Adapter – sketch

4 Comments

Some Things Last: 100 W Incandescent Bulb

The light switch for our attic turns on a single ceramic socket at the top of the stairs. The bulb burned out a few days ago:

Long-lasting 100 W Incandescent Bulb

Long-lasting 100 W Incandescent Bulb

To the best of my knowledge, that bulb has been in service since we moved in almost two decades ago. Most likely, it was installed when the house was built in 1955, because it matches several new-old-stock bulbs in a battered box that Came With The House™.

To be fair, the attic light doesn’t see much service, but … it’s been a great cost-performer!

The attic temperatures range from well below 0 °F in the winter to well above 120 °F in the summer, so it’s no place for CFL or LED bulbs. I swapped in a 60 W bulb from my heap, although I doubt it’ll be good for another half-century.

Leave a comment

Sharing the Road on NYS Bike Route 9: Right Hook

I’m towing a trailer of groceries southbound on Rt 376 (a.k.a. Hooker Avenue in this section), intending to turn right onto Zack’s Way for a library stop.

T=0.00 s, car @ 26.4 mph, me @ 19.8 mph

The transverse cracks through the asphalt are a convenient 60 ft apart, with the last one 20 ft from the stop line, and the frame numbers tick along at 60 frame/sec, so you can easily compute distances, times, and speeds.

I’ll be turning right at the intersection. The light is green.

Zacks Way - Right Hook 2017-04-11 - 0624

Zacks Way – Right Hook 2017-04-11 – 0624

 

T= 2.07 s, car @ 26.7 mph, me @ 19.7 mph

Now I can see the car’s right turn signal, so this might not end well. I can’t jam on the brakes and avoid a collision by dumping the bike at speed; I’ll slide under the car in the middle of the turn.

Zacks Way - Right Hook 2017-04-11 - 0748

Zacks Way – Right Hook 2017-04-11 – 0748

T=4.15 s, 15.2 mph

I’m 20 feet from the stop line and, suddenly, the driver also realizes this might not end well.

What he doesn’t know is that my trajectory must use the traffic lane: the shoulder around the corner is deteriorated, with several potholes, and vanishes completely where the intersection paving ends.

Zacks Way - Right Hook 2017-04-11 - 0873

Zacks Way – Right Hook 2017-04-11 – 0873

T=5.05 s

The driver is turning wide, into the opposing traffic lane, but if I weren’t lining up for the turn, we’d be on a collision course. My line will take me just to the left of the seemingly tiny, but very deep, pothole just ahead.

Zacks Way - Right Hook 2017-04-11 - 0927

Zacks Way – Right Hook 2017-04-11 – 0927

T=7.15 s

Leaning hard into the turn, but our paths won’t cross.

Zacks Way - Right Hook 2017-04-11 - 1053

Zacks Way – Right Hook 2017-04-11 – 1053

T=7.37 s

I’m back upright in the middle of the lane, with the shoulder ending in a pothole to my right.

Zacks Way - Right Hook 2017-04-11 - 1066

Zacks Way – Right Hook 2017-04-11 – 1066

T=8.31 s

Remember, I’m wearing a fluorescent (“safety”) orange shirt, running a blinky light (which is also the rear camera), and towing a trailer with a fluttering flag: I am not inconspicuous!

Zacks Way - Right Hook 2017-04-11 - 1123

Zacks Way – Right Hook 2017-04-11 – 1123

In case there’s any question:

Zacks Way - Right Hook 2017-04-11 - rear

Zacks Way – Right Hook 2017-04-11 – rear

The rest of the ride proceeded without incident …

Leave a comment