Archive for category Recumbent Bicycling

Tour Easy Daytime Running Light: Now with Chirality!

In the unlikely event our bikes need two running lights or, perhaps, a running light and a headlight, the solid model now builds mounts for the right side of the fairing, as before:

Fairing Flashlight Mount - Right side - solid model

Fairing Flashlight Mount – Right side – solid model

And for the left side:

Fairing Flashlight Mount - Left side - solid model

Fairing Flashlight Mount – Left side – solid model

Ahhh, chirality: love that word.

Those pix come from a cleaned-up version of the OpenSCAD code that finally gets the 3-axis rotations right, after a rip-and-replace rewrite to deliver the ball model with its origin in the center of the ball where it belonged and rotate the ring about its geometric center. Then the rotations become trivially easy and a slight hack job spits out a completely assembled model:

if (Component == "Complete") {
  mirror(TiltMirror) {
    translate([0,0,ClampOD/2]) {

However, putting the center of rotation directly over the center of the base plate means the ToeIn rotation shifts the bottom of the clamp ring along the X axis, where it can obstruct the mounting holes. Shifting the ring by a little bit:


… keeps the ring more-or-less centered on the top of the plate. That’s not quite the correct geometry, but it’s close enough for the small angles needed here.

Aiming the beam slightly higher makes a 400 lumen flashlight about as bright as any single LED in new car running lights:

Fairing Flashlight Mount - Mary approaching

Fairing Flashlight Mount – Mary approaching

You can just barely make out the snazzy new blue plate on the left side of the fairing.

A bike’s natural back-and-forth handlebar motion sweeps the beam across the lane, so I think there’s no real benefit from blinking.

The OpenSCAD source code as a GitHub Gist:


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Sandisk Extreme Pro MicroSD Card: End of Life?

The Sandisk Extreme Pro 64 GB MicroSD card in the Sony HDR-AS30V died on the road once more, got reformatted, worked OK for a while, then kicked out catastrophic I/O errors after being mounted, so I swapped in the High Endurance card:

Sandisk - 64 GB MicroSDXC cards

Sandisk – 64 GB MicroSDXC cards

The Extreme Pro still passes the f3probe tests, so it’s not completely dead, but if I can’t trust it in the helmet camera, it’s dead to me.

It survived 17 months of more-or-less continuous use, although we didn’t do nearly enough riding for three months early this year. Call it 14 months x five rides / week x 1 hour / ride = 300 hours of recording. Multiply by 4 GB / 22.75 minutes to get 3 TB of video, about 50 times its total capacity.

The never-sufficiently-to-be-damned Sony cards failed after less than 1 TB and 15-ish times capacity, making the Sandisk Extreme Pro much better. However, it’s painfully obvious these cards work better for low-intensity still-image recording, rather than continuous HD video.

Using them as Raspberry Pi “hard drives” surely falls somewhere between still cameras and video, although Octoprint’s video snapshots and streaming media must make ’em sweat.

We’ll see how Sandisk’s High Endurance memory works in precisely the application it’s labeled for.


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Tenergy 18650 Lithium Cells: Initial Capacity

The daytime running lights on the bikes get noticeably dimmer when the 18650 lithium cell voltage drops below 3.6 V, so I picked up a quartet of Tenergy protected cells and ran ’em through the battery tester:

Tenergy 18650 Protected - 2017-08-04

Tenergy 18650 Protected – 2017-08-04

As with the ATX cells, the voltage decreases almost linearly with charge until it falls off the cliff near the end, but these have a higher terminal voltage throughout most of the curve, which is a Good Thing for LED flashlights.

These four seem to have about the same overall capacity as the ATX cells, so we’ll run ’em all in sequence and see how long they last.



Tour Easy Daytime Running Light: Pile of Prototypes

Although I wish I could come up with a finished design in one pass, usually I end up with a big pile of nope before producing the one I want:

Fairing Flashlight Mount - Iterations

Fairing Flashlight Mount – Iterations

The mounts on the left show the progression from large hemisphere balls to the same-size finger ball to the smaller finger ball, with the smaller cyan arch clamp in the foreground still festooned with its support structure. The stack of plates to the right (with the original faded & distintegrating ABS plates in the bag) comes from reprinting in cyan to match the small mounts now on the bikes:

Fairing Flashlight Mount - rounded

Fairing Flashlight Mount – rounded

Hey, it’s time for a ride!

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Tour Easy Daytime Running Light: Annotation

The flashlight mount need not be symmetric after applying all the rotations, so recording how it’s aimed and which end goes forward seemed appropriate:

Fairing Flashlight Mount - Mount Annotation

Fairing Flashlight Mount – Mount Annotation

Optionally, with rounded ends just for pretty:

Fairing Flashlight Mount - Mount Annotation - rounded

Fairing Flashlight Mount – Mount Annotation – rounded

Because the rounding comes from resized spheres, the plate gets a ridge along the top to (maybe) lock the nylon screws / wing nuts in place:

Fairing Flashlight Mount - Mount - rounded

Fairing Flashlight Mount – Mount – rounded

Or discourage them from turning, which would be OK, too. After the second tightening, they don’t seem to come loose, so this may be overthinking the problem.

All in all, they look pretty good in cyan PETG:

Fairing Flashlight Mount - rounded

Fairing Flashlight Mount – rounded

Believe it or not, that’s aimed so the top edge of the beam is roughly horizontal to keep the hot spot out of oncoming traffic. They’re plenty bright, even on the “low power” setting.

The flashlight mounting balls produce a decorative brim that ought to be useful for something:

Slotted ball on platform

Slotted ball on platform

Maybe earrings?

The OpenSCAD source code as a GitHub Gist:



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J5 V2 Flashlight: Switch Tightening

From the start, the (second) J5 V2 flashlight had an erratic switch that flickered the LED at the slightest pressure. Not enough to switch modes, as it does with a half press, but enough to show something’s not quite right inside.

Taking it apart requires a pin wrench, which I have, but the deeply recessed ring required more reach than any of the tips I’ve made over the years. Introducing a pair of stainless steel 10-32 screws to Mr Grinder added two more pins to the collection:

J5V2 Flashlight - custom pin wrench

J5V2 Flashlight – custom pin wrench

The lock ring in the flashlight cap turned out to be finger-loose, certainly contributing to the problem. Removing the lock ring, peeling the rubber dome out of the cap, and poking with a punch sufficed to drive out the guts of the switch assembly:

J5V2 Flashlight - switch parts

J5V2 Flashlight – switch parts

Which is, as you’d expect, the cheapest possible parts that don’t immediately fail.

The (steel) tab sticking out of the actual switch (in the upper right) contacts the inside of the (aluminum) cap. I bent it slightly outward, added a trace of DeoxIT Red, reassembled everything in reverse order, and it’s all good for the first time in its brief life.

I’d rate J5’s QC as Below Average, given that the first light arrived with built-in dirt and its replacement (this one) had an alien egg next to the LED, plus this loose switch lock ring + crappy tab contact.

The J5 V2 light claims 750 lumen output, but the spot is nowhere near twice as bright as the LC40 lights on the bikes and much dimmer than the LC90 light (which is too big for the bikes), all tweaked for equivalent-size illuminated areas. Given that lumens measure total output and candela measure lumen/steradian, there’s some wiggle room for misinterpretation.

Won’t buy another, for sure.


Tour Easy Daytime Running Light: Improved Ball Mount

The original ball around the flashlight consisted of two identical parts joined with 2 mm screws and brass inserts:

Flashlight Ball Mount - flattening fins

Flashlight Ball Mount – flattening fins

Providing enough space for the inserts made the ball bigger than it really ought be, so I designed a one-piece ball with “expansion joints” between the fingers:

Fairing Flashlight Mount - Finger Ball - solid model

Fairing Flashlight Mount – Finger Ball – solid model

Having Slic3r put a 3 mm brim around the bottom almost worked. Adding a little support flange, then building with a brim, kept each segment upright and the whole affair firmly anchored.

Fairing Flashlight Mount - Finger Ball - solid model - support fins

Fairing Flashlight Mount – Finger Ball – solid model – support fins

Those had to be part of the model, because I also wanted to anchor the perimeter threads to prevent upward warping. Worked great and cleanup was surprisingly easy: apply the flush cutter, introduce the ball to Mr Belt Sander, then rotate the ball around the flashlight wrapped with fine sandpaper to wear off the nubs.

The joints between the fingers provide enough flexibility to expand slightly around the flashlight body:

Flashlight Mount - finger ball

Flashlight Mount – finger ball

I made that one the same size as the original screw + insert balls to fit the original clamp, where it worked fine. The clamp ring applies enough pressure to the ball to secure the flashlight and prevent the ball from rotating unless you (well, I) apply more-than-incidental force.

Then I shrank the ball to the flashlight diameter + 10 mm (= 5 mm thick at the equator) and reduced the size of the clamp ring accordingly, which made the whole mount much more compact:

Flashlight Mount - LC40 - finger ball - side

Flashlight Mount – LC40 – finger ball – side

Here’s what the larger mount looks like in action:

The flashlights allegedly puts out 400 lumen in a fairly tight beam. The fairings produce a much larger and brighter glint in full sunlight than the flashlights, so I think they’re about the right brightness.

The OpenSCAD source code for the new ball as a GitHub Gist:

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