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Posts Tagged M2

More Tommy Bar Handles

Having used a nail for far too long, this is a definite step up for my machinist vises:

Tommy Bar - machinist vise

Tommy Bar – machinist vise

The vise knob has a hole just barely passing a length of 3.4 mm = 9/64 inch mild steel rod from the Small Box o’ Cutoffs.

While I was at it, I made a handle for the parallel jaw clamps:

Tommy Bar - parallel jaw clamp

Tommy Bar – parallel jaw clamp

Those knobs pass a 3.0 mm = 1/8 inch rod, similarly sourced. Inexplicably, one clamp expected no more than a 7/64 inch rod; a brief introduction to Mr Drill Press persuaded it concerning the error of its ways.

I should have made the handles distinctively different, because they’ll get mixed up in the box of vises & clamps. Next time, fer shure!

The Tommy Bar handles use the same solid model as the Sherline Tommy Bars, with hole diameters as noted. Cyan PETG is definitely easier on the eye than red PLA, although it does fade into the background clutter around here.

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Hydrant Wrench

Just because I can:

Fire Hydrant Wrench

Fire Hydrant Wrench

The Slic3r preview shows a bit more detail:

Hydrant Wrench - Slic3r preview

Hydrant Wrench – Slic3r preview

Even an inch-thick handle wouldn’t have enough mojo for the task.

Wikipedia has the equations you need to go from the easily measured “height” (vertex to opposite side) dimension to the pentagon’s “outside radius”, which equals the radius of the circumscribed circle needed by OpenSCAD.

The OpenSCAD source code as a GitHub Gist:

Sorry ’bout that … had to do it.

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Tour Easy Headset Wrench

The headset on my Tour Easy ‘bent worked its way loose, which led to a disturbing discovery: the headset wrench I made from a discarded flat wrench vanished with the shop tools donated to MakerSmiths.

Fortunately, we live in the future:

Tour Easy Headset Wrench - Slic3r preview

Tour Easy Headset Wrench – Slic3r preview

A thin plastic wrench is absolutely no good for torquing down the locknut, but that’s not what it’s for. Adjust the bearing race to the proper preload with this wrench, hold it in place, then torque the locknut with the BFW.

The OpenSCAD source code as a GitHub Gist:

Now, I’d like to say that was easy, but in actual point of fact …

First, I forgot to divide by cos(180/6) to convert the across-the-flats size to the diameter of OpenSCAD’s circumscribed hexagon-as-circle, which made the wrench uselessly small:

Tour Easy Headset Wrench - v1

Tour Easy Headset Wrench – v1

If you have a 28 mm nut with low torque requirements, though, I’ve got your back.

While I had the hood up, I slenderized the handle into a much shapelier figure:

Tour Easy Headset Wrench

Tour Easy Headset Wrench

Trotting off to the garage with a warm plastic wrench in hand, I discovered the blindingly obvious fact that the headset nuts have eight sides. On the upside, the number of sides became a parameter, so, should you happen to need a five-sided wrench (perhaps on Mars), you can have one.

So, yeah, it’s rapid prototyping in full effect:

Tour Easy Headset Wrench Iterations

Tour Easy Headset Wrench Iterations

Remember, kids, never design while distracted …

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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") {
  translate([-BracketHoleOC,0,0])
    PlateBlank();
  mirror(TiltMirror) {
    translate([0,0,ClampOD/2]) {
      rotate([-Roll,ToeIn,Tilt])
        SlotBall();
      rotate([-Roll,ToeIn,Tilt])
        BallClamp();
    }
  }
}

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:

ClampOD*sin(ToeIn/2)

… 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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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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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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