The Value of Closeout Pictures

With the Bafang BBS02 and all its gimcrackery on the Terry Symmetry buttoned up and ready to go, I took a few closeout pictures for future reference.

The motor has a sheaf of wires sticking out of the bottom crying out for a protective covering:

Bafang BBS02 - wire bundle cover
Bafang BBS02 – wire bundle cover

Although cameras tell only the truth they’re allowed to see and can be made to lie by omission, sometimes their latent truth was completely invisible to eyewitnesses in real time.

I only noticed the mis-routed shift cable when I looked through the last set of pictures.

It should pass through the plastic channel under the metal tab holding the cable guide to the bottom bracket shell:

Bafang BBS02 - wire bundle vs shift cable
Bafang BBS02 – wire bundle vs shift cable

Normally, aiming the cable into the channel is no big deal. In this case, I had to undo the shift cable, remove the left crank, loosen the motor and rotate it out of the way, nudge the cable with a small screwdriver, then reinstall in reverse order.

Dang, that was close …

Microscope Stage Positioner: Rigid MakerBeam Edition

Rebuilding the XYZ stage positioner with MakerBeam aluminum struts, but without the steel brackets, produce a much more rigid result:

Microscope Stage Positioner - rigid Makerbeam
Microscope Stage Positioner – rigid Makerbeam

This requires drilling holes through the extrusions:

Microscope Stage Positioner - Makerbeam drilling
Microscope Stage Positioner – Makerbeam drilling

Running the center drill down until it just nicks the sides produces enough of a pilot hole through the center section to capture the 3 mm drill. If I had to drill enough holes to make a fixture worthwhile, I could probably eliminate the divots.

Two more holes + epoxied M3 brass inserts attached the 60 mm beam directly to the Z Axis stage, thereby eliminating the vertical beam and a steel bracket:

Microscope Stage Positioner - Makerbeam joints
Microscope Stage Positioner – Makerbeam joints

The M3 SHCS attaching the 100 mm beam goes through both beams. I think you could get the same result with a Tee Nut or a 12 mm Square Head bolt, should you have those lying around and don’t want to drill another hole. The Corner Cube screwed into both beams prevents rotation and helps ensure perpendicularity.

The Y stage now attaches directly to the beam, rather than through a pair of Corner Cubes, because I realized I wasn’t ever going to adjust its position.

The Z Axis stage stands on the plastic plate through a hellish mixture of metric and USA-ian screws. Basically, the 6-40 screws into the stage were long enough, the 6-32 screws through the plate fit the existing holes, and M3 screws are for MakerBeam:

Microscope Stage Positioner - Z Axis base
Microscope Stage Positioner – Z Axis base

To my utter astonishment, the threads in the end of the vertical beam had the proper alignment to let a Square Head bolt snug the beam against the 40 mm beam on the plate. As a result, the L Bracket just prevents the vertical beam from turning on the screw and the combination is as rigid as you (well, I) could want.

The 40 mm beam has two spurious holes, because I thought I could avoid drilling another hole in the baseplate. Nobody will ever notice.

After squaring and tightening everything, the 100 mm beam along the Y Axis is now horizontal within 0.2 mm and the X Axis is horizontal to better than I can measure.

It’s definitely Good Enough™ for me:

Microscope Stage Positioner - in use
Microscope Stage Positioner – in use

Remember, nothing exceeds like excess …

Microscope Stage Positioner: MakerBeam Rebuild MVP

Over the course of half a decade (!), the 3D printed arm on the XYZ positioner I use with the stereo zoom microscope sagged:

Microscope Stage Positioner - PETG creep angle
Microscope Stage Positioner – PETG creep angle

It’s about what you’d expect from a plastic beam carrying a big lump of brass and steel:

Microscope Stage Positioner
Microscope Stage Positioner

The near side of that arm (the -Y end) drooped about 5 mm below than the side nearest the Z axis slide, so it was time for an update.

Having some MakerBeam ready to hand, this didn’t take long:

Microscope Stage Positioner - Makerbeam overview
Microscope Stage Positioner – Makerbeam overview

Protip: before dismantling a fitted slide, mark one end so you know how to put it back together. Bonus points for taking a picture:

Microscope Stage Positioner - slide marking
Microscope Stage Positioner – slide marking

Double bonus points for writing a blog post.

Rather than fight with the existing fine-pitch USA-ian screws, I drilled out their threaded holes:

Microscope Stage Positioner - Y slide drilling
Microscope Stage Positioner – Y slide drilling

And epoxied 3 mm brass inserts in their place:

Microscope Stage Positioner - Y slide M3 inserts
Microscope Stage Positioner – Y slide M3 inserts

Those holes match up with a pair of corner cubes normally appearing on the end of the beams:

Microscope Stage Positioner - BHCS mods for Makerbeam
Microscope Stage Positioner – BHCS mods for Makerbeam

It turns out M3 button head cap screws will slide into the beams if you file the slightest angle on opposite sides of the button, although a small bag of tiny tee nuts should arrive in a while.

Then a variety of brackets spliced everything together:

Microscope Stage Positioner - Makerbeam detail
Microscope Stage Positioner – Makerbeam detail

Although it looks strictly from industrial, it actually wasn’t much better than the plastic edition and, in fact, the beam supporting the XY slides sagged about the same 5 mm. The plastic upright post also contributed a bit of wobble.

It turns out that the extruded aluminum beams have plenty of longitudinal and torsional stiffness, but all those flat steel fittings don’t.

There’s a way to work with the beam strengths, rather than against them, but that’s a story for another day …

A New Rabbit Appears

Mary chased a small rabbit out of her garden a few days ago, whereupon we up-armored a few vulnerable parts of the fence. The culprit turns out to be insufferably cute:

Young Rabbit - at the gate
Young Rabbit – at the gate

You cannot be annoyed with something like this:

Young Rabbit - alert
Young Rabbit – alert

Oh, yes, you can. Rabbits are basically eating machines:

Young Rabbit - grazing
Young Rabbit – grazing

They’re welcome to all the greenery in the yard, just nothing in the garden:

Young Rabbit - overcompressed A
Young Rabbit – overcompressed A

It’s known as a 2×2 Bunny, because it can fit through that size opening in a chain link fence while traveling at a dead run.

This one has yet to learn about being wary around the Big People:

Young Rabbit - overcompressed B
Young Rabbit – overcompressed B

The alert reader will have noted the crappy quality of the last three pictures, at least in comparison with the first two. It’s the difference between digital zoom on my Pixel 3a phone applied to a zoomed-all-the-way image and optical zoom on a “real” camera (admittedly, an old Sony DSC-H5). On the other paw, I had the phone in my pocket when Mary spotted the bunny on the driveway, which counts for everything in similar situations.

JPG compression doesn’t handle hair particularly well, so the low-res bunny wears a rather artistic brush-stroke coat; it’s OK if you like that sort of thing.

Bicycle Helmet Mirror: Stalk Repair

The mirror on my bike helmet snagged on a mesh fence while walking the bike to Mary’s garden:

Helmet Mirror - bent stalk
Helmet Mirror – bent stalk

One of the good things about building your own stuff is that you have all the parts when something breaks:

Helmet Mirror - damaged parts
Helmet Mirror – damaged parts

The decorative M2 screw and insert pulled out of the ball. The rim of the nail set punch (intruding from the top) just barely caught the edge of the stub inside the ball, so a few taps could extract it. A Dremel cutoff wheel peeled the crumpled end off the stalk.

Reassembly proceeded without incident:

Helmet Mirror - installed
Helmet Mirror – installed

The bizarrely blurred mirror over on the left comes from the Pixel phone camera app deciding this was a Portrait, applying a background blur, and running into trouble with those hard edges in the foreground. The camera app has a distinct Portrait mode that, perhaps, I inadvertently engaged while fumbling around.

Another Nice Doggy

We’re riding southbound on the recently opened section of the Empire State Trail, just south of Hopewell Junction, and are approaching a dog walker totally face-sucked by her phone in the middle of the path:

Empire State Trail - Dog Lunge - 2021-05-12 - 0
Empire State Trail – Dog Lunge – 2021-05-12 – 0

Mary has been dinging her bike bell for the last few seconds and finally manages to break through:

Empire State Trail - Dog Lunge - 2021-05-12 - 1
Empire State Trail – Dog Lunge – 2021-05-12 – 1

The dog walker leans against the fence while pulling on the leash as hard as she can, as if she knows the dog poses a threat:

Empire State Trail - Dog Lunge - 2021-05-12 - 2
Empire State Trail – Dog Lunge – 2021-05-12 – 2

Which it does:

Empire State Trail - Dog Lunge - 2021-05-12 - 3
Empire State Trail – Dog Lunge – 2021-05-12 – 3

The leash is too long for close-quarters work:

Empire State Trail - Dog Lunge - 2021-05-12 - 4
Empire State Trail – Dog Lunge – 2021-05-12 – 4

Nice teeth, doggie:

Empire State Trail - Dog Lunge - 2021-05-12 - 5
Empire State Trail – Dog Lunge – 2021-05-12 – 5

Surely, the dog just wants to lick me to death:

Empire State Trail - Dog Lunge - 2021-05-12 - 6
Empire State Trail – Dog Lunge – 2021-05-12 – 6

Tell me again how well-trained this dog is:

Empire State Trail - Dog Lunge - 2021-05-12 - 7
Empire State Trail – Dog Lunge – 2021-05-12 – 7

Seven seconds after the first picture:

Empire State Trail - Dog Lunge - 2021-05-12 - 8
Empire State Trail – Dog Lunge – 2021-05-12 – 8

The dog also lunged at the pair of bicyclists following us, so perhaps this is how she makes sure it get its exercise during the walk.

I hate dogs.

Vultures Sunning

Spotted after pre-season prep at Mary’s Vassar Farms garden:

Vultures sunning
Vultures sunning

It must feel really good up there atop the old barn, even if they’re sunning themselves to kill off parasites.

Taken with the Pixel 3a zoomed all the way in at 7× from a bit over 200 feet:

Vultures sunning - photo range
Vultures sunning – photo range

Then cropped and sharpened just a smidge. Not a great picture, but good enough for practical purposes; the Good Camera + Big Glass takes better pix and is too awkward to carry in my pocket.