Category: Recumbent Bicycling

Cruisin’ the streets

Tour Easy Rear Running Light: First Light!
The rear running light definitely has an industrial look:

Tour Easy Rear Running Light – installed

The front of the light has plenty of clearance from the seat mesh:

Tour Easy Rear Running Light – installed side view

Out on the road, the 1 W LED appears about as bright as automotive running lights:

Tour Easy Rear Running Light – tunnel

The blink pattern makes it perfectly visible in sunlight, although I’d prefer somewhat larger optics:

Tour Easy Rear Running Light – sunlight

In shaded conditions, it’s downright conspicuous:

Tour Easy Rear Running Light – shade

At any reasonable distance, the 10° beam covers much of the road behind the bike:

Tour Easy Rear Running Light – distant

You may not know what the occulting red light represents, but something ahead is worthy of your attention.

The Arduino source code producing the two dits:
```
// Tour Easy Running Light
// Ed Nisley - KE4ZNU
// September 2021

#include <morse.h>

#define PIN_OUTPUT  13

// second param: true = active low output
LEDMorseSender Morser(PIN_OUTPUT,true,(float)10.0);

void setup()
{
    Morser.setup();

    Morser.setMessage(String("qst de ke4znu "));
    Morser.sendBlocking();

//    Morser.setWPM((float)3.0);
    Morser.setSpeed(75);
    Morser.setMessage(String("i   "));
}

void loop()
{
    if (!Morser.continueSending())
        Morser.startSending();

}
```
Looks good to me, anyhow.
2021-09-27
Beaver Lodge II

The beaver family living in their pond along the Dutchess Rail Trail near Titusville Rd is doing so well they’ve erected a second lodge:

Second Beaver Lodge – near Titusville Rd – 2021-09-23

It’s 500 feet (-ish) upstream from the first lodge and seems somewhat smaller, so perhaps it’s for the kids.

2021-09-26
Why LED Lamps Fail

Spotted over a fast food emporium’s parking lot:

Disemboweled parking lot light

It’s hard to be sure, but I think there’s a paper wasp nest around the bundle of wires just above the transformer / ballast / whatever. Perhaps the repair tech departed with the job unfinished?

As with traffic signals, flashlights, and automotive lighting, the LEDs surely work long after the driver circuitry has given up.

2021-09-25

Tour Easy Rear Running Light: Circuit Support Plate

Building the circuit support plate for the amber front running light was entirely too fiddly:

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

This was definitely easier:

Running Light Circuit Plate - solid model — Running Light Circuit Plate – solid model

Two pins fit in the small holes to align it with the LED heatsink, with an M3 stud and brass insert holding it in place:

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

The rectangular hole around the insert let me glop urethane adhesive over it to lock it into the plate, with more goop on the screw and pins to unify heatsink and plate.

The LED wires now emerge from the heatsink on the same side of the plate, simplifying the connections to the MP1584 regulator and current-sense resistor:

Tour Easy Rear Running Light - regulator wiring — Tour Easy Rear Running Light – regulator wiring

The paralleled 5.1 Ω and 3.3 Ω resistors form a 2.0 Ω resistor setting the LED current to 400 mA = 1 W at 2.6 V forward drop. They’re 1 W resistors dissipating a total of 320 mW and get barely warm.

The resistors and wires are stuck in place with clear adhesive, so things shouldn’t rattle around too much.

The OpenSCAD source code as a GitHub Gist:

	// Circuit plate for Tour Easy running lights
	// Ed Nisley – KE4ZNU – 2021-09

	/* [Hidden] */

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	Protrusion = 0.1; // make holes end cleanly

	function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

	ID = 0;
	OD = 1;
	LENGTH = 2;

	inch = 25.4;

	//———————-
	// Dimensions
	// Light case along X axis

	LightID = 23.0;

	WallThick = 2.0;

	Screw = [3.0,6.8,4.0]; // M3 OD=washer, length=nut + washers
	Insert = [3.0,4.2,8.0]; // splined brass insert, minus splines

	InsertOffset = 10.0; // insert from heatsink end

	PinOD = 1.6; // alignment pins
	PinOC = 14.0;
	PinDepth = 5.0;

	Plate = [50.0,LightID,Insert[OD] + 4*ThreadThick]; // overall plate size

	WirePort = [10.0,3.0,2*Plate.z];

	NumSides = 234;

	//———————-
	// Useful routines

	module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes

	Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
	FixDia = Dia / cos(180/Sides);
	cylinder(r=(FixDia + HoleWindage)/2,
	h=Height,
	$fn=Sides);
	}

	// Circuit plate

	module Plate() {

	difference() {
	intersection() {
	cube(Plate,center=true);
	rotate([0,90,0])
	cylinder(d=LightID,h=2*Plate.x,$fn=NumSides,center=true);
	}

	rotate([0,90,0]) rotate(180/6)
	translate([0,0,-Plate.x])
	PolyCyl(Screw[ID],2*Plate.x,6);

	rotate([0,90,0]) rotate(180/6)
	translate([0,0,-Plate.x/2 – Protrusion])
	PolyCyl(Insert[OD],Insert[LENGTH] + InsertOffset + Protrusion,6);

	translate([-Plate.x/2 + InsertOffset + Insert[LENGTH]/2,0,Plate.z/2])
	cube([Insert[LENGTH],Insert[OD],Plate.z],center=true);

	for (j=[-1,1])
	translate([-Plate.x/2,j*PinOC/2,0])
	rotate([0,90,0]) rotate(180/6)
	translate([0,0,-PinDepth])
	PolyCyl(PinOD,2*PinDepth,6);

	for (j=[-1,1])
	translate([0,j*(Plate.y/2 – WirePort.y/2),0])
	cube(WirePort,center=true);


	}

	}

	//- Build it

	Plate();

view raw Running Light Circuit Plate.scad hosted with ❤ by GitHub

2021-09-24

Tour Easy Rear Running Light: LED Lens Assembly

Having discovered the need for careful alignment of the LED PCB with the lens, I paid more attention to detail this time around.

The LEDs arrive soldered to PCBs atop aluminum star heat spreaders, but the one I picked out of the bag looked slightly misaligned. Unsoldering it showed a smear of solder paste had melted across the central pad:

1 W LED PCB – errant solder

The LED has a die contact slug on the bottom which, I suppose, could be directly soldered to the spreader. For my simple needs, removing the errant solder, plunking the LED atop a layer of heatsink compound, and resoldering the leads should suffice:

1 W LED PCB – wire layout

The LED holder has a pair of slots aligning it with the LED leads on the PCB. The base of the holder sits flush against the PCB, so the wires must attach directly to the LED pads.

I ran the wires for the amber light through holes close to the pads:

1 W LED Running Light – heatsink fit

Which required chewing two passages in the base of the holder:

1 W LED Running Light – wiring

It turns out the 5° and 10° lenses are strongly conical and leave plenty of room around the LED to run a wire around the inside of the holder, so I drilled a pair of holes to put both wires on the same side of the circuit plate:

Tour Easy Rear Running Light – circuit plate attachment

The holder required minor surgery to let the wire double back on itself over the LED pad:

1 W LED Holder – wire passage

The wires thread through two holes drilled in the plastic holder:

Tour Easy Rear Running Light – clamped LED assembly

More urethane adhesive glues the PCB to the LED holder, with the clamp applying pressure to the lens to ensure the lens seats properly around the LED. It turned out that worked well and the light has a nicely rounded beam.

With the optics bonded together, metal-filled JB Weld epoxy attaches the heat spreader to the heatsink with good thermal conductivity:

Tour Easy Rear Running Light – clamped LED heatsink

The LED holder is a slide fit in the heatsink, so the clamps can keep the PCB flat on the bottom of the recess while the epoxy gets a good grip on all parts.

Now it’s just a matter of wiring everything up!

2021-09-23
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

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

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

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.

2021-09-22
Rear Running Light: Too-aggressive Turning

The same lathe fixture and double-sided duct tape trick I used for the amber running light’s end cap should have worked for this one, but only after I re-learned the lesson about taking sissy cuts:

Tour Easy Rear Running Light – end cap fixture – swirled adhesive

Yet another snippet of tape and sissy cuts produced a better result:

Tour Easy Rear Running Light – end cap

Protip: when you affix an aluminum disk bandsawed from a scrap of nonstick griddle to a lathe fixture, the adhesive will grip the disk in only one orientation.

2021-09-21