Tour Easy Rear Running Light: LED Heatsink

Because the rear running light will have a higher duty cycle than the front light, I made the (admittedly too small) heatsink slightly longer, with a deeper recess to protect the lens from cargo on the rear rack:

Tour Easy Rear Running Light - boring LED recess
Tour Easy Rear Running Light – boring LED recess

Boring that nice flat bottom is tedious; I must lay in a stock of aluminum tubing to simplify the process.

Drilling the holes went smoothly:

Tour Easy Rear Running Light - drilling LED heatsink
Tour Easy Rear Running Light – drilling LED heatsink

Those two holes fit a pair of pins aligning the circuit plate, with a screw and brass insert holding it to the heatsink. Scuffing a strip across the aluminum might give the urethane adhesive (you can see uncured globs on the pins) a better grip:

Tour Easy Rear Running Light - circuit plate attachment
Tour Easy Rear Running Light – circuit plate attachment

The screw / insert /pins are glued into the plate to permanently bond it to the heatsink. The screw occupies only half of the insert, with the longer screw from the end cap pulling the whole affair together.

The two holes on the left pass both LED leads to one side of the circuit plate, where they connect to the current regulator and its sense resistor.

Micro-Mark Bandsaw: Acetal Blade Guide

The Micro-Mark bandsaw has a metal blade guide below the table that contributes to the awful noise it makes while running, even when it’s not cutting anything. Having recently touched the Delrin = acetal rod stash, a simple project came to mind.

A doodle with the original metal guide dimensions:

Micro-Mark Bandsaw - metal blade guide dimensions
Micro-Mark Bandsaw – metal blade guide dimensions

The 10 mm dimension is non-critical, so I started with a 1/2 inch acetal rod and turned the stub end to match.

A doodle suggested how to carve the slot with a 20.5 mil = 0.52 mm slitting saw, with the offset from a Z touchoff at the top:

Micro-Mark Bandsaw - acetal blade guide - slitting doodles
Micro-Mark Bandsaw – acetal blade guide – slitting doodles

The V block setup required swapping out the overly long OEM screw for a shorter 5 mm SHCS to clear the Sherline’s motor:

Micro-Mark Bandsaw - acetal guide slitting
Micro-Mark Bandsaw – acetal guide slitting

The end result looked pretty good:

Micro-Mark Bandsaw - acetal vs steel blade guides
Micro-Mark Bandsaw – acetal vs steel blade guides

And it looks like it pretty much belongs in the saw:

Micro-Mark Bandsaw - acetal blade guide installed
Micro-Mark Bandsaw – acetal blade guide installed

The 6 mm stud goes into a hole in the frame, where a setscrew holds it in place. You must remove the blade to extract / replace the guide, with the correct position having the end of the slot just touching the back of the blade.

The foam ring apparently keeps crud away from the stud on the backside; I doubt it’s mission-critical.

The saw became somewhat quieter; the ball bearing guides above the table now generate most of the racket. At some point I’ll try replacing them with a block, probably made from UHMW, with a simple slit to guide the blade.

Plastic guides may not last as long as the steel ones, but occasional replacements will be worth it if the saw runs quieter.

Tour Easy 1 W Amber Running Light: End Cap

My initial doodles suggested an end cap with an opening for the Arduino’s USB port and something for the power cable from the Bafang controller:

1 W LED Running Light - internal assembly
1 W LED Running Light – internal assembly

Common sense finally broke out and I made a simple disk cover held in place with an M3 screw:

1 W Amber Running Light - bench test
1 W Amber Running Light – bench test

Unfortunately, I cut the PVC shell flush with the USB port, which meant the cap couldn’t have a little shoulder to stabilize it on the shell. Maybe next time?

Machining the disk required using the scrap of aluminum rod left over from the heatsink as a fixture with a piece of sandpaper stuck to the front surface:

1 W Amber Running Light - end cap setup
1 W Amber Running Light – end cap setup

The live center presses the bandsawed + disk sanded cap against the sandpaper, providing barely enough traction for sissy cuts reducing the disk to the proper diameter:

1 W Amber Running Light - end cap turning
1 W Amber Running Light – end cap turning

It actually worked pretty well, although next time I’ll skip the sandpaper, affix the disk directly to the double sided duct tape, and be done with it.

Line up the center punch dimple and drill a hole for the M3 screw:

1 W Amber Running Light - end cap drilling
1 W Amber Running Light – end cap drilling

The power cable port turned into a little slot bandsawed into the edge of the disk with the sharp edges filed off.

Basically, the thing needs some road testing before I build one for real …

Tour Easy 1 W Amber Running Light: Internal Plate

A semi-scaled doodle laying out an Arduino Nano and the MP1584 regulator board suggested they might fit behind the heatsink with the 1 W LED:

Amber running light - board layout doodle - side
Amber running light – board layout doodle – side

A somewhat more detailed doodle of the end view prompted me to bore the PVC pipe out to 23 mm:

Amber running light - board layout doodle - end
Amber running light – board layout doodle – end

The prospect of designing a 3D printed holder for the boards suggested Quality Shop Time combined with double-stick foam tape would ensure a better outcome.

So I bandsawed the remains of a chunky angle bracket into a pair of rectangles, flycut All The Sides to square them up, and tapped a pair of M3 holes along one edge of each:

1 W LED Running Light - baseplate tapping
1 W LED Running Light – baseplate tapping

The other long edges got the V groove that killed the Sherline’s Y axis nut:

Sherline Y-Axis Nut Mishap - setup
Sherline Y-Axis Nut Mishap – setup

The groove holds a length of 4 mm OD (actually 5/32 inch, but don’t tell anybody) brass tubing:

1 W LED Running Light - baseplate trial fit
1 W LED Running Light – baseplate trial fit

The M3 button head screws are an admission of defeat, as I could see no way of controlling the width + thickness of the aluminum slabs to get a firm push fit in the PVC tube. The screws let me tune for best picture after everything else settled out.

A little more machining opened up the top of the groove:

1 W LED Running Light - baseplate dry assembly
1 W LED Running Light – baseplate dry assembly

A short M3 button head screw (with its head turned down to 4 mm) drops into the slot and holds the slab to the threaded hole in the LED heatsink. The long screw is holding the threaded insert in place for this dry fit.

I doodled a single long screw through the whole thing, but having it fall off the heatsink when taking the rear cover off seemed like a Bad Idea™. An M3 button head screw uses a 2 mm hex key that fits neatly through the threaded insert, thereby making it work.

Butter it up with epoxy, scrape off the excess, and let things cure:

1 W LED Running Light - baseplate curing
1 W LED Running Light – baseplate curing

This was obviously made up as I went along …

Sherline CNC Mill: Y-Axis Nut Mishap

The need to gnaw a V groove into the side of two 60 mm aluminum bars led to this Sherline CNC mill setup:

Sherline Y-Axis Nut Mishap - setup
Sherline Y-Axis Nut Mishap – setup

Milling the near end of the bars put the angle plate’s rear lock screw within a millimeter of the column; the vise fits in exactly one spot on the angle plate and that’s where the jaws must be.

While controlling the mill with the Joggy Thing and some manual command entry, because it’s easier than real CNC programming, I overshot the near end and rammed the column with enough enthusiasm to dislodge the Y-axis leadscrew nut. An interlude of utter confusion ended with the backlash preload nut firmly jammed against the leadscrew coupler on the other end of travel:

Sherline Y-Axis Nut Mishap - stuck preload nut
Sherline Y-Axis Nut Mishap – stuck preload nut

The paper shreds show where the bellows formerly stuck on the Y axis stage.

The backlash nut chewed off a few star lock gear teeth on its way out, as seen here just above where they mesh:

Sherline Y-Axis Nut Mishap - chewed star nut
Sherline Y-Axis Nut Mishap – chewed star nut

It’s been quite a few years since I took the thing apart to replace the nuts, so I used the opportunity to lube the otherwise inacessible X axis leadscrew inside its table upside down on the bench.

The setscrew locking the Y axis leadscrew nut in place heaves into view with the X axis table off:

Sherline Y-Axis Nut Mishap - setscrew
Sherline Y-Axis Nut Mishap – setscrew

I thought about jamming it in place with a second 10-32 setscrew, but the ones on hand were just an itsy too long and collided with the X-axis table:

Sherline Y-Axis Nut Mishap - doubled setscrew
Sherline Y-Axis Nut Mishap – doubled setscrew

The thought of having the additional setscrew work loose, grind into the underside of the table, and require major surgery for recovery persuaded me to drop it back in the drawer.

With everything in place, I adjusted the backlash (on both axes) down to a few mils:

Sherline Y-Axis Nut Mishap - backlash test
Sherline Y-Axis Nut Mishap – backlash test

Tweaking the X axis preload nut under the table is not my idea of a good time, but it’s been quite a while since I had to do that.

Folding the new paper bellows and installing them took about as long as repairing the mill.

Milling the second V groove worked fine; all is right with the Sherline again.

Running Light: 1 W LED Heatsink

The general idea: a cylindrical holder / heatsink for a 1 W LED on the end of a tube clamped in a Tour Easy fairing mount, much like a flashlight.

A pleasant evening at a virtual Squidwrench meeting produced the raw shape of the front end from a 1 inch aluminum rod:

1 W LED Running Light - heatsink raw
1 W LED Running Light – heatsink raw

Trace the outline of the LED’s PCB inside the cylinder just for comfort, align to the center, and drill two holes with a little bit of clearance:

1 W LED Running Light - heatsink drilling
1 W LED Running Light – heatsink drilling

For the 24 AWG silicone wire I used, a pair of 2 mm holes 8.75 mm out from the center suffice:

1 W LED Running Light - heatsink fit
1 W LED Running Light – heatsink fit

Gnaw some wire clearance in the lens holder:

1 W LED Running Light - wiring
1 W LED Running Light – wiring

Tap the central hole for an M3×0.5 screw, which may come in handy to pull the entire affair together.

Epoxy the PCB onto the heatsink with the lens holder keeping it aligned in the middle:

1 W LED Running Light - heatsink clamp
1 W LED Running Light – heatsink clamp

Then see how hot it gets dissipating 900 mW with 360 mA of current from a 2.2 Ω resistor:

1 W LED Running Light - heatsink test
1 W LED Running Light – heatsink test

As you might expect, it gets uncomfortably warm sitting on the bench, so it lacks surface area. The first pass will use a PVC cylinder for easy machining, but a full aluminum shell would eventually be a nice touch.

A doodle with some dimensions and aspirational features:

Running Light - 1 W LED case doodle
Running Light – 1 W LED case doodle

Even without a lens and blinkiness, it’s attention-getting!

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 …