The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Tag: M2

Using and tweaking a Makergear M2 3D printer

Laser-cut Profile Test Pieces

A new battery for my electrified Tour Easy recumbent arrived. It has newer 21700 lithium cells in the same overall box, but the baseplate requires new blocks adapting it to the frame:

UPP Battery Mount – solid model

The top profile fits snugly into the battery mounting plate, with clearance on the sides for the latches:

UPP Battery Mount – trial fit

However, I had enough trouble measuring those recesses that I broke down and added a projection() view to the OpenSCAD code:

UPP Battery Mount – profile

Exporting that as an SVG image and importing it into LightBurn let me cut it out of chipboard:

UPP Battery Mount – laser cut profiles

Obviously, it took several iterations to fit the top profile to the baseplate, particularly after finding slightly different measurements at each block position. On the other paw, laser cutting the profiles proceeded much more quickly than 3D printing just a few millimeters of the block, so it was a net win.

The new battery baseplate doesn’t have an internal space for the buck converter feeding the running lights, so there’s more construction ahead.

2024-06-10
Sillcock Faucet Alignment Wedge: Getting the Angle Right
A pair of frost-free sillcock faucets arrived to replace the house’s leaky and un-repairable hose bibs. The faucet must be mounted at a 5° angle to let the water drain out when it’s closed:

Everbilt Frost-Free Sillcock faucet – installation

One might expect the Alignment Wedge included with the faucet to have a 5° angle. Because I can both measure and math, it has a 1° angle.

Well, I can fix that.

Start by scanning the bottom (widest side) of the wedge and apply GIMP’s Select by color tool:

Sillcock faucet alignment wedge – GIMP color selection

After a little manual cleanup in Quick Mask mode, apply a 1 mm inset to ensure it snaps around the pipe, convert the selection to a path, export it as an SVG image, and import it into OpenSCAD to cut the angle:
```
// Sillcock faucet alignment wedge
// Ed Nisley KE4ZNU - May 2024

MaxThick = 5.0;
Tilt = -5.0;

PlateOA = [60,40,MaxThick];   // XY = original angle plate size

difference() {
  linear_extrude(height=MaxThick,convexity=5)
    offset(r=-1.0)
      import("/mnt/bulkdata/Cameras/2024/Shop Projects/Sillcock Faucets/Sillcock faucet angle washer - outline.svg",
             center=true);
   translate([-PlateOA.x/2,-PlateOA.y/2,MaxThick])
     rotate([Tilt,0,0])
        cube(PlateOA,center=false);
}
```
The solid model goes into PrusaSlicer for duplication & slicing:

Sillcock faucet alignment wedge – PrusaSlicer layout

And comes off the printer looking just about like you’d expect:

Sillcock faucet alignment wedge – OEM vs printed

The far side of both wedges are 5 mm tall, but you can see the difference four more degrees makes in the front.

It’s even more obvious from the edge:

Sillcock faucet alignment wedge – on pipe

The wood siding where these will fit is perfectly vertical, so getting the wedge angle right isn’t really optional.

I must drill the existing hole in the sill plate out to 1-1/8 inch to clear the pipe fittings, plus the wood around the screws holding the current bibs to the wall will surely need some buttressing, but all that’s in the nature of fine tuning.

FWIW, this was the first 3D print after the move and I’m happy to say the M2 had no any need of adjustments.

The WordPress AI image generator apparently ignored the post text and produced a stylin’ picture of an arched bathroom faucet over a rimless sink, which I shall leave to your imagination.
2024-05-30

Under-shelf Kitchen Light Bracket

Quite a while ago I’d added another LED strip to the under-cabinet light array, because the little cutting boards & suchlike on a wire shelf blocked the light, but fastened it in place with ugly wire ties.

Finally I found a Round Tuit on the desk for brackets mounting the strip directly to the shelf:

Kitchen Light Bracket - shelf blocks - solid model — Kitchen Light Bracket – shelf blocks – solid model

Ram a pair of brass inserts in the holes, screw the strip in place, snap the brackets between the wires, and it’s much better:

Kitchen Light Bracket - installed — Kitchen Light Bracket – installed

Stipulated: those wire ends look awful. Fortunately, they’re normally hidden by the cutting boards and suchlike on the shelf.

Although it looks precarious, the rounded sides (seem to) have enough grip on the wires to hold the LED strip in place. We’ll see how well that works in practice, but the idea was to avoid anything sticking up above the wires to collide with the stuff on the shelf.

The blocks emerge from a chunk of code glommed onto the original OpenSCAD program:

ShelfWireDia = 3.2;
ShelfWireOC = 1*inch;
StrutWireDia = 6.3;

ShelfBlock = [ShelfWireOC,LEDEndBlock.y,(0.8*ShelfWireDia + StrutWireDia/2)/cos(180/8)];
echo(ShelfBlock=ShelfBlock);

LEDHoleOffset = [ShelfBlock.x/2 - (6.0 + ShelfWireDia/2),6.0];  // from Y+ and X±
LEDHoleDia = 3.0;

ID = 0;
OD = 1;

M3Insert = [3.0,4.0,4.2];   // short M3 knurled insert

<<< snippage >>>

module ShelfBlocks(Side=1) {

  difference() {
    translate([0,ShelfBlock.y/2,ShelfBlock.z/2])
      cube(ShelfBlock,center=true);
   translate([Side*LEDHoleOffset.x,ShelfBlock.y - LEDHoleOffset.y,-Protrusion])
      rotate(180/8)
        PolyCyl(M3Insert[OD],M3Insert[LENGTH] + 2*ThreadThick,8);
    translate([-2*ShelfBlock.x,-StrutWireDia/4,0])
      rotate([0,90,0]) rotate(180/8)
        PolyCyl(StrutWireDia,4*ShelfBlock.x,8);
    for (i=[-1,1])
      translate([i*ShelfWireOC/2,-ShelfBlock.y,(StrutWireDia/2 + ShelfWireDia/2)/cos(180/8)])
        rotate([-90,0,0]) // rotate(180/8)
          PolyCyl(ShelfWireDia,3*ShelfBlock.y,8);
  }
}

<<< snippage >>>

if (Layout == "ShelfBlocks")
  for (i=[-1,1])
    translate([i*(ShelfBlock.x/2 + 3.0),0,0])
      ShelfBlocks(i);

Should’a done that years ago …

2023-10-26

Tour Easy: DPC-18 Display Controls

The Bafang 500C display I installed on Mary’s Tour Easy recumbent has assist level buttons along its left edge:

Bafang display – clamp bushing

This required her to take her left hand off the handlebar to fiddle with the assist level and, as it turned out, used her thumb in position causing some distress. Given that changing the assist level happens a lot as we ride, it was time for a change.

So I replaced the 500C with a DPC-18 display like the one on my bike, with the key advantage of putting the buttons on the handgrip:

Tour Easy Bafang Controls – DPC-18 buttons

She preferred a higher position for the buttons than I do, with the PTT button for the Baofeng amateur radio below the housing.

After a few iterations, the throttle moved from the right handgrip to the right end of the handlebar crosspiece on a lengthened version of the mount I conjured for Tee’s Terry Symmetry upright bike:

Tour Easy Bafang DPC-18 – throttle mount

That location requires a bit of dexterity, but let us move the twist-grip shifter upward on the handgrip where it is more comfortable. She rarely uses the throttle, so we’ll try this for a while.

The DPC-18 has an awkward portrait-mode display with an incredible amount of wasted space, with the side detriment of displacing the blue Camelbak hose. After a few iterations, we settled on a receptacle to catch the mouthpiece without requiring any fancy snaps / clips / fasteners:

Tour Easy Bafang Controls – Camelbak nozzle catcher

The solid model descends from the Zzipper fairing mounts on that same aluminum bar, with the bottle simply jammed into the big hole:

Zzipper Fairing – Camelbak nozzle catcher – show layout

There being no real forces on the holder, I omitted the aluminum load-spreading plate across the top and just epoxied four threaded brass inserts into the bottom part.

Early reports suggest a happier thumb and no problems stashing the hose, so it’s all good.

2023-09-13

Laser Cutter: Mirror Pin Wrench

After struggling with pin pliers again, I finally made a pin wrench for the laser cutter’s mirror retaining rings:

Laser Mirror Pin Wrench - in use — Laser Mirror Pin Wrench – in use

The odd grayish tint toward the flat end of the knob comes from residual black filament in the hot end after switching to retina-burn orange PETG.

The solid model looks about like you’d expect:

Mirror Pin Wrench - Solid Model — Mirror Pin Wrench – Solid Model

The pins are snippets of 3/32 inch = 2.4 mm steel rod with ground-round ends to fit the 2.5 mm pin sockets in the retaining ring.

They’re rammed into place with a drill press to keep them aligned with the holes:

Laser Mirror Pin Wrench - pin insertion — Laser Mirror Pin Wrench – pin insertion

Pressed flush with the central boss that aligns the wrench with the ring:

Laser Mirror Pin Wrench - pin leveling — Laser Mirror Pin Wrench – pin leveling

Then put the ring on the bench, set the wrench atop the ring with the pins in the sockets, and press firmly to seat the pins to the proper depth. The end results should look like this:

Laser Mirror Pin Wrench - mirror ring test — Laser Mirror Pin Wrench – mirror ring test

The next time I clean the mirrors, there will be less muttering.

The OpenSCAD source code as a GitHub Gist:

	// OMTech laser cutter mirror pin wrench
	// Ed Nisley – KE4ZNU – August 2023

	// From https://www.thingiverse.com/thing:4146258
	use <knurledFinishLib_v2_1.scad>

	/* [Hidden] */

	ThreadThick = 0.20;
	ThreadWidth = 0.40;

	HoleWindage = 0.2; // extra clearance

	Protrusion = 0.1; // make holes end cleanly

	inch = 25.4;

	//———————-
	// Dimensions

	/* [Knob] */

	PinDia = 2.4; // pin diameter
	PinOC = 20.5; // … on-center spacing
	PinDepth = 10.0; // … hole depth

	LocDia = 14.5; // central stud
	LocLength = 3.0;

	ShaftDia = 26.0; // un-knurled section diameter
	ShaftLength = 15.0; // … length

	KnurlDia = 30.0; // diameter at midline of knurl diamonds
	KnurlLen = 20.0; // … length of knurled section

	/* [Hidden] */

	KnurlDPNom = 32; // Nominal diametral pitch = (# diamonds) / (OD inches)

	DiamondDepth = 0.5; // … depth of diamonds
	DiamondAspect = 2; // length to width ratio

	KnurlID = KnurlDia – DiamondDepth; // dia at bottom of knurl

	NumDiamonds = ceil(KnurlDPNom * KnurlID / inch);
	echo(str("Num diamonds: ",NumDiamonds));

	NumSides = 4*NumDiamonds; // 4 facets per diamond

	KnurlDP = NumDiamonds / (KnurlID / inch); // actual DP
	echo(str("DP Nom: ",KnurlDPNom," actual: ",KnurlDP));

	DiamondWidth = (KnurlID * PI) / NumDiamonds;

	DiamondLenNom = DiamondAspect * DiamondWidth; // nominal diamond length
	DiamondLength = KnurlLen / round(KnurlLen/DiamondLenNom); // … actual

	TaperLength = 0.75*DiamondLength;

	KnobOAL = ShaftLength + KnurlLen + 2*TaperLength;

	//———————-
	// 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);
	}


	//- Build it

	difference() {
	union() {
	render(convexity=10)
	translate([0,0,TaperLength])
	knurl(k_cyl_hg=KnurlLen,
	k_cyl_od=KnurlDia,
	knurl_wd=DiamondWidth,
	knurl_hg=DiamondLength,
	knurl_dp=DiamondDepth,
	e_smooth=DiamondLength/2);

	color("Orange")
	cylinder(r1=ShaftDia/2,
	r2=(KnurlDia – DiamondDepth)/2,
	h=(TaperLength + Protrusion),
	$fn=NumSides);

	color("Orange")
	translate([0,0,(TaperLength + KnurlLen – Protrusion)])
	cylinder(r2=ShaftDia/2,
	r1=(KnurlDia – DiamondDepth)/2,
	h=(TaperLength + Protrusion),
	$fn=NumSides);

	color("Moccasin")
	translate([0,0,(2*TaperLength + KnurlLen – Protrusion)])
	cylinder(r=ShaftDia/2,h=(ShaftLength + Protrusion),$fn=NumSides);

	color("Brown")
	translate([0,0,KnobOAL – Protrusion])
	cylinder(r=LocDia/2,h=(LocLength + Protrusion),$fn=NumSides);
	}

	for (i=[-1,1])
	translate([i*PinOC/2,0,KnobOAL – PinDepth])
	rotate(180/6)
	PolyCyl(PinDia,PinDepth + Protrusion,6);
	}

view raw Mirror Pin Wrench.scad hosted with ❤ by GitHub

It descends from a long line of similar things dating back to the OG Sherline Speed Wrenches.

2023-09-05

Tour Easy Running Lights: Anodizing Sun Fade

After six years, the anodizing on the Anker LC40 flashlights I repurposed as daytime running lights shows some radiation damage:

Tour Easy Running Lights fading – mount top view

The bottom side looks pristine:

Tour Easy Running Lights fading – mount bottom view

It turns out they were clamped in slightly different positions on our two bikes:

Tour Easy Running Lights fading – top view

The side view shows a gentle color transition:

Tour Easy Running Lights fading – bottom view

Apparently I had swapped the caps from the two lights when I noticed the fading after only the first year.

2023-09-04
Onion Maggot Fly Sticky Trap Repair
One of the sticky traps absorbed a mighty blow during the season and its ski-pole mount snapped off. Rather then rebuild the whole thing, I decided to just epoxy the pieces together and stick a reinforcing plate on the bottom.

I added a pair of screw holes to the OpenSCAD model and produced a projection of the bottom layer:
```
if (Layout == "Projection") {
    projection(cut=true) {
        Attachment();
        Cap();
    }
}
```
Which looked like this:

Sticky Sheet Cage – projection

Cutting that shape from an adhesive sheet looks the same:

Onion Maggot Fly Trap – adhesive sheet

The somewhat raggedy large hole seems to come from OpenSCAD’s somewhat low-res SVG outline conversion.

Fill the broken part with epoxy:

Onion Maggot Fly Trap – epoxy ready

Clamp it together on a plate to keep the bottom aligned:

Onion Maggot Fly Trap – clamping

Cut an acrylic baseplate:

Onion Maggot Fly Trap – acrylic cut

Apply adhesive sheet to acrylic, stick it on the bottom of the cage, add a pair of stainless steel screws, and declare victory:

Onion Maggot Fly Trap – bottom view

We’ll see how long that lasts out in the garden next year …
2023-08-30