Backyard Turkey Flock

The turkey flock that normally lives along the Wappingers Creek valley, downslope from the back yard, has emerged for the ritual spring foraging:

Turkey flock - 0

Turkey flock – 0

And posturing:

Turkey flock - 1

Turkey flock – 1

And just moseying around:

Turkey flock - 2

Turkey flock – 2

You can match the trees and identify some duplicated birds, but the flock seems stable around a dozen. They used to deploy skirmish lines upwards of two dozen bird and we’ve recently counted 19; we think foxes have been encouraging better control of wandering chicks.

Turkeys are good folks…

Leave a comment

Backyard Deer Herd

One deer might be cute:

Deer Herd - outlier

Deer Herd – outlier

But the rest of the herd makes up for it:

Deer Herd - main

Deer Herd – main

You’ll note the complete lack of understory vegetation; the only remaining plants can withstand continuous deer browsing. Deer have clipped all of the evergreens five feet off the ground, even through they don’t normally eat evergreens…

In fact, there’s no new tree growth in the Hudson Valley, because tree seedlings don’t stand a chance.

,

1 Comment

MakerGear M2: PETG Motor Mount

The M2’s extruder motor mounts in a printed holder that attaches to the X-axis linear rail. The wire guide on the original holder snapped when I installed it, with the fractured end showing poor infill and bonding, but the rest of the mount held together and, my initial misgivings notwithstanding, I never had much motivation to print a replacement. With the PETG settings working pretty well, I fetched the updated STL file, oriented it for printing, and ran off a motor mount:

M2 Motor Mount - PETG on platform

M2 Motor Mount – PETG on platform

That’s at 40% 3D Honeycomb infill, three perimeters and three top/bottom layers, which seems plenty strong enough for the purpose: I can’t bend the wire guide at all, no how, no way!

Despite a few hairs, the nozzle didn’t deposit any boogers. Things are looking up…

A cap should fit over the cable guide, presumably for neatness, but I didn’t see much point in that. Instead, I added a steel rod to support the loom and provide some strain relief beyond the end of the guide, as the wires want to flex at that spot:

M2 Motor Mount - PETG installed - cable brace

M2 Motor Mount – PETG installed – cable brace

Because the V4 hot end mounts to that aluminum plate, rather than the filament drive, the whole operation didn’t disturb the nozzle position at all. Whew!

,

Leave a comment

Sienna Hood Rod Pivot: PETG Edition

Our Larval Engineer reports that the PLA pivot for the Sienna’s hood rod didn’t survive contact with the van’s NYS Inspection. I’m not surprised, as PLA tends to be brittle and the inspection happened on a typical February day in upstate New York. Seeing as how PETG claims to be stronger and more durable than PLA, I ran off some replacements:

Toyota Sienna hood rod pivot - small - PETG

Toyota Sienna hood rod pivot – small – PETG

The square cap fit snugly over the bottom of the post; PETG tolerances seem pretty much the same as for PLA.

A slightly larger loop may be more durable, so I changed one parameter in the OpenSCAD code to get this:

Toyota Sienna Hood Rod Pivot - up-armored - solid model

Toyota Sienna Hood Rod Pivot – up-armored – solid model

Which printed just like you’d expect:

Toyota Sienna hood rod pivot - large - PETG hairs

Toyota Sienna hood rod pivot – large – PETG hairs

Despite the hairs stretching between each part, the nozzle didn’t deposit any boogers during the print. The top and bottom use Hilbert Curve infill, which looks pretty and keeps the nozzle from zipping back and forth quite so much; perhaps that’s a step in the right direction.

Tapping the holes for 6-32 stainless machines screws went easily enough:

Toyota Sienna hood rod pivot - PETG - assembled

Toyota Sienna hood rod pivot – PETG – assembled

She gets one of each and I keep the others for show-n-tell sessions.

The OpenSCAD source code, which differs from the original by a constant or two:

// Sienna Hood Rod Pivot
// Ed Nisley KE4ZNU November 2013

//- Extrusion parameters must match reality!
//  Print with 2 shells and 3 solid layers

ThreadThick = 0.25;
ThreadWidth = 0.40;

HoleWindage = 0.2;

Protrusion = 0.1;			// make holes end cleanly

inch = 25.4;

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

//----------------------
// Dimensions

ShellOD = 20.0;
ShellID = 8.75;
ShellLength = 10.0;

TaperLength = 1.5;
TaperID = 11.4;

BaseWidth = 20.0;
BaseThick = 3.0;

PegSide = 9.5;					// mounting peg through sheet metal
PegLength = 7.0;
PegCornerTrim = 0.75;
PegHoleOD = 0.107*inch;			//  6-32 tap hole

PegTrimSide = sqrt(2)*PegSide - PegCornerTrim;

ClampWall = 3.0;				// clamping cap under sheet metal
ClampHoleOD = 0.150*inch;		//  6-32 clearance hole
ClampCap = 3.0;					// solid end thickness

PanelThick = 2.0;				// sheet metal under hood

NumSides = 6*4;

//----------------------
// 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);
}

module ShowPegGrid(Space = 10.0,Size = 1.0) {

  Range = floor(50 / Space);

	for (x=[-Range:Range])
	  for (y=[-Range:Range])
		translate([x*Space,y*Space,Size/2])
		  %cube(Size,center=true);

}

//----------------------
// Build it

//ShowPegGrid();

// pivot

translate([-ShellOD,0,0])
	difference() {
		union() {
			cylinder(r=ShellOD/2,h=ShellLength,$fn=NumSides);		// housing
			translate([-ShellOD/2,0,0])								// filler
				cube([ShellOD,(ShellOD/2 + BaseThick),ShellLength],center=false);
			translate([0,(ShellOD/2 + BaseThick/2),ShellLength/2])	// foot
				cube([BaseWidth,BaseThick,ShellLength],center=true);

			translate([0,											// peg
						(ShellOD/2 + PegLength/2 + BaseThick - Protrusion),
						PegSide/2])
				intersection() {
					cube([PegSide,(PegLength + Protrusion),PegSide],center=true);
					rotate([0,45,0])
						cube([PegTrimSide,2*PegLength,PegTrimSide],center=true);
				}
		}

		PolyCyl(ShellID,ShellLength,NumSides);		// central hole

		translate([0,0,-Protrusion])				// end bevels
			cylinder(r1=TaperID/2,r2=ShellID/2,h=(TaperLength + Protrusion),$fn=NumSides);
		translate([0,0,(ShellLength + Protrusion)])
			rotate([180,0,0])
				cylinder(r1=TaperID/2,r2=ShellID/2,h=(TaperLength + Protrusion),$fn=NumSides);

		translate([0,0,PegSide/2])					// screw tap hole
			rotate([-90,0,0])
				PolyCyl(PegHoleOD,(ShellOD + BaseThick + PegLength),6);

	}

// anchor cap

translate([2*PegSide,0,0])
	difference() {
		translate([0,0,(PegLength + ClampCap)/2])					// overall shape
			cube([(PegSide + ClampWall),(PegSide + ClampWall),(PegLength + ClampCap)],center=true);
		translate([0,0,(PegLength/2 + ClampCap + Protrusion)])		// peg cutout
			cube([(PegSide + ThreadWidth),(PegSide + ThreadWidth),(PegLength + Protrusion)],center=true);
		translate([0,0,-Protrusion])								// screw clearance
				PolyCyl(ClampHoleOD,2*PegLength,6);
	}

, ,

Leave a comment

Build Platform Chisel Handle

My father used a little chisel for some unknown purpose while he was an instrument repair tech at Olmstead AFB during the mid-60s. Its homebrew wood handle eventually disintegrated and I made a quick-and-truly-dirty replacement from epoxy putty and heatshrink tubing, promising that I’d eventually do better.

Seeing as how I use it to pop objects off the M2’s build platform and being in need of a tall, skinny object to see how PETG works with towers, that chisel now has a nice magenta handle:

Platform Chisel - PETG handle

Platform Chisel – PETG handle

Well, OK, it may not be the prettiest handle you’ve ever seen, but it’s much better than an epoxy turd, as measured along several axes.

Incidentally, epoxy putty bonds to clean steel like there’s no tomorrow. I had to file the last remaining chunks off and sandpaper the residue down to clean steel again.

The solid model shows it in build-a-tower mode:

Chisel Handle - solid model

Chisel Handle – solid model

I think at least one rounded end would improve its appearance. Two rounded ends would make it un-printable in that orientation, although a low-vertex polygonal approximation might have enough of a flat bottom to suffice. Given how long it took me to replace the epoxy, that could take a while.

The central slot fits snugly around the handle, requiring persuasion from a plastic mallet to set in in position.

Once again, the nozzle shed a small brown PETG booger after the first few layers:

PETG Chisel Handle - oxidized plastic

PETG Chisel Handle – oxidized plastic

I’m beginning to think PETG infill needs more attention than I’ve been giving it: that’s 15% 3D Honeycomb combined over three layers.

The OpenSCAD source code:

// Chisel Handle
// Ed Nisley KE4ZNU - March 2015

Layout = "Show";			// Show Build

//-------
//- Extrusion parameters must match reality!

ThreadThick = 0.25;
ThreadWidth = 0.40;

HoleWindage = 0.2;

Protrusion = 0.1; 				// make holes end cleanly

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

//-------
// Dimensions

Shank = [16.0,2.4,59];			// width, thickness, length to arched end

BladeWidth = 27.0;

HandleSides = 8;

//-------

module ShowPegGrid(Space = 10.0,Size = 1.0) {

  RangeX = floor(95 / Space);
  RangeY = floor(125 / Space);

	for (x=[-RangeX:RangeX])
	  for (y=[-RangeY:RangeY])
		translate([x*Space,y*Space,Size/2])
		  %cube(Size,center=true);

}

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);
}



module Handle() {
	difference() {
		scale([1.0,0.5,1.0])
			rotate(180/HandleSides)
				cylinder(d=BladeWidth/cos(180/HandleSides),h=Shank[2],$fn=HandleSides);
		translate([0,0,Shank[2]/2])
			cube(Shank + [0,0,2*Protrusion],center=true);
	}
}

//-------
// Build it!

//ShowPegGrid();

if (Layout == "Show") {
	Handle();
}

if (Layout == "Build") {
	translate([0,0,0])
		rotate([0,0,0])
			Handle();
}

,

2 Comments

Detergent Cap Holder

Although chain mail provides a good test of the M2’s setup and slicing parameters, it doesn’t offer much in the way of infill. To test that, I designed a holder for the cap of the bulk laundry detergent container:

Detergent Cap Holder - in place

Detergent Cap Holder – in place

The container must rest on its side, but if you snap the cap back in place, detergent will ooze out between the cap and the container and drip on whatever’s below. The never-sufficiently-to-be-damned Whirlpool high-efficiency front loading washer vibrates like crazy during the spin cycle, shaking anything from its top to the floor. The cap must sit in a cup to catch the inevitable ooze down its side, the wire shelf already has a bunch of other crap on it, and I needed a bulky test object, soooo ….

We regard that detergent container and its cap as a botched design.

Anyhow.

The holder has pair of holes in its back surface for the copper (!) hangers:

Detergent Cap Holder - solid model - rear

Detergent Cap Holder – solid model – rear

I stripped a length of 10 AWG wire, straightened & annealed it, bent up a pair of hooks, then hammered them just flat enough to work-harden the copper, and they were all good.

Printing that massive block with 20% infill showed that the nozzle collected enough PETG during the first few layers to leave a substantial booger behind:

Detergent cup holder - oxidized PETG

Detergent cup holder – oxidized PETG

Fortunately, that was the only one and it ended up on the inside, tucked out of sight.

The PETG depot on the outside of the nozzle gradually darkens from the original magenta to brown, which I’m pretty sure means that it’s oxidizing / decomposing / going bad. There’s no obvious way to remove the booger during the print; I’ve taken to wiping the nozzle after each object, while it’s still hot and the PETG remains flexible.

Because the nozzle didn’t accumulate any more PETG during the rest of the print, it’s not a constant problem, but I have seen boogers several times so far.

Perhaps continued refinement of the slicing parameters will help? One can always hope…

The OpenSCAD source code:

// Detergent Cap Holder
// Ed Nisley KE4ZNU - March 2015

Layout = "Show";			// Show Build

//-------
//- Extrusion parameters must match reality!

ThreadThick = 0.20;
ThreadWidth = 0.40;

HoleWindage = 0.2;

Protrusion = 0.1; 				// make holes end cleanly

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

//-------
// Dimensions

RecessX = 45.0;								// cap recess
RecessDia = 55.0;
RecessDepth = 10.0;
RecessSides = 16*4;

BaseThick = 5.0;							// block thickness below cap

PinDia = 2.5;
PinLength = 20.0;
PinOC = 65.0;
PinInset = 7.0;
PinZ = BaseThick;

Block = [RecessX,PinOC + 2*PinInset,30.0];	// overall block size (X to cap center)

FairingRadius = Block[2] - RecessDepth - BaseThick;

//-------

module ShowPegGrid(Space = 10.0,Size = 1.0) {

  RangeX = floor(95 / Space);
  RangeY = floor(125 / Space);

	for (x=[-RangeX:RangeX])
	  for (y=[-RangeY:RangeY])
		translate([x*Space,y*Space,Size/2])
		  %cube(Size,center=true);

}

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);
}

module Holder() {
	difference() {
		union() {									// main shape
			translate([-Block[0]/2,0,Block[2]/2])
			cube(Block,center=true);
			cylinder(d=Block[1],h=Block[2],$fn=RecessSides);
		}
		for (j=[-1,1])								// mounting pin holes
			translate([-(Block[0] + Protrusion),j*PinOC/2,PinZ])
				rotate([0,90,0]) rotate(180/6)
					PolyCyl(PinDia,PinLength + Protrusion,6);
		translate([0,0,Block[2]])					// fairing arc
			rotate([90,0,0])
				cylinder(r=FairingRadius,h=2*Block[1],center=true);
		translate([Block[0]/2,0,Block[2]/2 + RecessDepth + BaseThick])	// flat top
			scale([1,2,1])
				cube(Block,center=true);
		translate([0,0,BaseThick])
			cylinder(d1=RecessDia,d2=1.1*RecessDia,h=Block[2]);
	}
}

//-------
// Build it!

//ShowPegGrid();

if (Layout == "Show") {
	Holder();
}

if (Layout == "Build") {
	translate([0,0,0])
	rotate([0,0,0])
	Holder();
}

6 Comments

MakerGear M2: PETG Chain Mail

After the initial slicing parameter setup, I ran off several chain mail patches for fine tuning; they test platform adhesion, first layer thickness, bridging, and general quality.

The first layer started out a bit squashed:

Chain Mail - PETG on nozzle - platform switch clearance

Chain Mail – PETG on nozzle – platform switch clearance

The clearance under that switch lever doesn’t amount to much…

The patch came out looking pretty good, though:

Chain Mail - 4-wide - PETG hairs - bridging

Chain Mail – 4-wide – PETG hairs – bridging

The small red blob on the right side of the nozzle in the first picture tells a tale: the nozzle tends to pull fine hairs from one perimeter to the next, despite 1 mm of retraction. Fiddling with the retraction on subsequent patches didn’t improve matters.

Even though the infill isn’t overstuffed, the nozzle tends to collect and redeposit small amounts of PETG as it travels over the surface. Those small blobs turn into fine hairs when the nozzle moves from one island to the next.

Reducing the bars from six threads to four threads shows that bridging (at 25 mm/s and 0.9 flow rate) seems messier than PLA:

Chain mail - 4 strand PETG bridging

Chain mail – 4 strand PETG bridging

Despite that, all the links came out OK and the sheet was reasonably flexible. After some fiddling with speeds and patterns, these small-link patches popped off the platform easily and were just as flexy as the PLA sheet below them:

Chain Mail - PETG patches atop PLA patch

Chain Mail – PETG patches atop PLA patch

So far, so good.

Leave a comment