Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Tag: Improvements
Making the world a better place, one piece at a time
Mary wanted to convert some old tomato cages into flower supports and deer protectors (until the flowers get big enough), by the simple expedient of flipping the cages over with the large end down. She figured we could chop off the wire ends that normally anchor the cages to the ground, then bend them into hooks for secure ground anchors.
I deployed the linesman’s pliers, which only showed that my wire size estimation is grossly underdeveloped. The high-carbon steel wires required bolt cutters… but a few minutes of twang effort scattered two dozen really stiff wires across the patio.
I ran a marker across the pile at the bend point, grabbed two random steel rods in the vise and, in short order, bent up a stack of ground anchors.
I carry around an ancient Zire 71, from the time before PDAs merged with phones and PCs to become fashionable objects of desire.
Anyway, it turns out that the buttons on the front are remarkably easy to squash in your pocket: the poor thing spends a lot of time turning itself on and off. I machined a plate with two holes for the four buttons and a lengthwise recess with two notches for the joystick selector. The whole affair slides into the pouch Mary made for it and works fine.
I tweaked the thing a bit when I got a replacement Zire a few months ago; the grippy tape I put on the sides seemed to be just large enough to force the joystick against the protector while sliding it into the pouch. Now that’s not a problem.
Zire 71 protector in place
This is in the nature of documentation, just in case I need something like this ever again. I found these pix while looking for something else …
You’ve seen bits & pieces of this in the previous weeks and months: now it’s up and running!
Admittedly, this is brassboard hardware; I must now build three final versions for our bikes incorporating all the tweaks & adjustments. But it’s time to write this stuff down so I can find it again … and perhaps you can use some chunks, too.
I don’t have an instruction manual to go along with this, nor is there a parts kit available. You’ll certainly want to modify everything for your own purposes; the circuit board and case certainly won’t fit whatever HT you’re using!
Over the next several days, I’ll be describing & documenting the tricky parts… in no particular order, because I’m not going to sort my notes & photos ahead of time.
I favor a small cylindrical earbud with a good seal inside my ear for use with the amateur radio on my bike. These things come with back vents that allegedly improve their bass response; that’s not a concern for communications-grade audio and, worse, the vent produces a tremendous amount of wind noise.
Earbud with back vent
The solution is straightforward: put some tape over the vent!
Kapton tape over vent
I used Kapton tape, because I have it, but in point of fact the snippet of duct tape I applied on the first ride (having forgotten to do it on the bench) worked just fine. A drop of epoxy would be fine, too, if you were a bit careful about not letting it ooze down inside the case while it cured.
Despite the fancy appearance, this is a random pick from the assortment of earbuds I’ve bought at $10 or less over the last few years. According to my golden-eared assistant, the audio quality varies dramatically among the assortment, but they all work reasonably well between 300-3000 Hz. I suspect the insanely cheap ones on eBay are essentially the same things, although IMO they’re intended to collect large quantities of high positive ratings: caveat emptor.
Speaking of caveats, insert the usual safety caveats here.
Note that we’re using one earbud for tactical comm, not boppin’ to the music, and the audio level is low enough we (well, I) can’t hear diddly at speeds over 15 mph. Your jurisdiction may prohibit “headphones” or “earphones” or some such, so behave accordingly.
All the officers I’ve met think the radios are a great idea, if that means anything.
The Third Eye Hardshell Mirror was designed back in the day when Bell Helmets had actual hard plastic shells over a foam core, with a lip around the shell’s edge. These days, helmets consist of an elaborate foam structure with a paper-thin plastic covering. Mary’s helmet is like that, but it has a visor and I figured the mounting clamp might grab onto that.
It almost worked, but the edge of the clamp tapered the wrong way: tightening the screw tipped the clamp away from the visor lip.
Solution: chop off the offending part of the clamp, file off the sharp edges, and screw it in place. Works like a champ.
I’m not convinced this mount will survive the test of time, though. We already know that the clever ball joint will eventually lose its griptivity, but that’s fixable.
This pic shows that the mirror attaches to the boom through a clever ball joint that allows both rotation around the mirror’s long axis and a slight amount of tilt. Unfortunately, after a few years, the ball stem breaks and at least one of the socket petals snaps. It’s a nice plastic design that’s totally unsuited to a few years of more-or-less daily bicycle travel.
The repair was easy enough, particularly because I think the boom has enough adjustment range to handle the job on its own (and I don’t care about how it looks). I filed off the stem stub and milled a slot for a 2-56 machine screw along the back edge.
Milling slot for screw
Then you just slide a brass tube from the cutoff box over the end of the boom around some JB Weld epoxy, shove the screw into the blob, align the mirror with the boom, and let it cure.
Reinforced attachment
Although it’s not shown here, the helmet attachment is aligned with the mirror at right angles to the helmet bracket. That puts it in roughly the proper position with the boom bent as usual.
I don’t actually plan to use this one for anything, but if I need a somewhat scuffed mirror in a pinch, well, it’s in the box!
I’m in the process of reworking the interface box between the amateur radio HTs on our bikes and our helmet-mounted earbud & mic lashup. Mary needed a new helmet before I got the new interface ready, soooo there’s an adapter cable in the middle.
This time around, the helmet cable uses a male USB-A connector, rather than a female 6-pin Mini-DIN PS/2 keyboard connector. Either one is cheap & readily available as assembled cables, which gets me out of soldering teeny little connector pins. These days, though, USB cables are more common.
The motivation for a non-latching, low-extraction-force connector at the helmet is that when (not if) you drop the bike, the helmet doesn’t tie your head to the bike and snap your spine. Falls on a recumbent are much less exciting than on an upright bike, but you still want the bike to go that-a-way while you go this-a-way. Been there, done that.
The old helmet cable connector: female 6-pin mini-DIN. The wire color code is not standardized. Viewed from rear of female connector or the front of the male connector, with the key slot up:
ear com - Gn 5 |_| 6 K - ear hot
mic com - Or 3 key 4 Y - mic hot
gnd - Bn 1 2 R - gnd
The new helmet cable connector: male USB-A. Mercifully, they standardized the wire colors. Looking at the front of the male USB-A connector with the tab down and the contacts up, the pins are 4 3 2 1:
1 – R – ear hot
2 – W – mic hot
3 – G – mic com
4 – K – ear com
The female USB-A connector is exactly the same.
That arrangement should produce the proper twisted pairs in a USB 2.0 cable, but all the USB cables I’ve seen so far lay all four wires in a common twist inside the shield. Maybe it’s the cheap junk I buy, huh?
It’s worthwhile to scribble some color in the background of the trident USB symbol so it’s easier to mate the connectors.
Easy-align USB connectors
Memo to Self: verify the connections & proper operation before shrinking the tubing!
The Smell of Molten Projects in the Morning 