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:
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:
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.
This requires drilling holes through the extrusions:
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:
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:
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.
Protip: before dismantling a fitted slide, mark one end so you know how to put it back together. Bonus points for taking a picture:
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:
And epoxied 3 mm brass inserts in their place:
Those holes match up with a pair of corner cubes normally appearing on the end of the beams:
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:
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 …
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:
You cannot be annoyed with something like this:
Oh, yes, you can. Rabbits are basically eating machines:
They’re welcome to all the greenery in the yard, just nothing in the garden:
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:
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.
One of the good things about building your own stuff is that you have all the parts when something breaks:
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:
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.
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:
Mary has been dinging her bike bell for the last few seconds and finally manages to break through:
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:
Which it does:
The leash is too long for close-quarters work:
Nice teeth, doggie:
Surely, the dog just wants to lick me to death:
Tell me again how well-trained this dog is:
Seven seconds after the first picture:
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.