Posts Tagged Thing-O-Matic
American Standard Elite Kitchen Faucet: Handle Failure
Posted by Ed in Home Ec, Machine Shop on 26-February-2013
Strange though it may seem, the kitchen faucet handle broke while Mary was using it. The rear wall of the socket that fits over the cartridge valve stem fractured:
Having no water in the kitchen is not to be tolerated, so I applied a redneck fix while pondering the problem:
Based on that comment, I called the American Standard hotline (800-442-1920), described the situation, and they’re sending a replacement handle and cartridge. Evidently the new handle won’t fit the old cartridge, which makes me feel better about not stockpiling repair parts, even while I now wonder what the new cartridge part number might be and how you’d tell them apart.
Anyhow, the redneck fix wouldn’t suffice for the next week; I needed something slightly more permanent. The broken wall fit neatly in place on the mount, but:
- It must withstand far more force than a simple glue joint can provide
- I can’t machine square holes
- Wrapping a metal sleeve around the mount seemed like too much work
You undoubtedly saw this coming a while ago:
The mount tapers slightly from the handle body toward the open end to provide draft for the molding process. I applied a hull() operator to two thin rectangles spaced the right distance apart along the Z axis to create a positive model of the mount, which then gets subtracted from the blocky outer rectangle. The hole clears a 10-32 screw that fits the standard setscrew threads (normally hidden behind the handle’s red-and-blue button).
Unlike most printed parts I’ve done recently, the sleeve suffered from severe shrinkage along the outside walls:
The inside maintained the right shape, so I cleared the nubs with a file and pressed it in place around the mount with the rear wall snapped into position. The black plastic socket evidently isolates the handle from the valve stem and I used a stainless 10-32 screw to prevent the nightmare scenario of having the sleeve slide downward along the tapered mount and block the setscrew. Overall, it came out fine:
However, the chunky sleeve didn’t clear the opening in the escutcheon cap, which put the cap on the windowsill for the next week. The result works much better than the redneck fix and looks almost presentable. It’s certainly less conspicuous:
I hope the new handle has a much more robust socket…
The OpenSCAD source code:
// Quick fix for broken American Standard Elite 4454 faucet handle
// Ed Nisley KE4ZNU February 2013
//- Extrusion parameters must match reality!
// Print with +2 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 2.0 * ThreadThick;
HoleFinagle = 0.4;
HoleFudge = 1.00;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
function HoleAdjust(Diameter) = HoleFudge*Diameter + HoleFinagle;
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
Wall = 5.0;
Slice = ThreadThick; // minimal thickness for hull object
ShaftEnd = [11.6,17.8,Slice];
ShaftBase = [12.1,18.8,Slice];
ShaftLength = 19.0;
Block = [(ShaftBase[0] + 2*Wall),(ShaftBase[1] + 2*Wall),ShaftLength - Protrusion];
ScrewOffset = 6.5; // from End
ScrewDia = 5.0; // clearance
//----------------------
// Useful routines
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);
}
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=HoleAdjust(FixDia)/2,h=Height,$fn=Sides);
}
//----------------------
// Model the handle's tapered shaft
module Shaft() {
hull() {
translate([0,0,ShaftLength - Slice/2])
cube(ShaftEnd, center=true);
translate([0,0,Slice/2])
cube(ShaftBase, center=true);
}
}
//----------------------
// Build it!
ShowPegGrid();
difference() {
translate([0,0,ShaftLength/2])
cube(Block,center=true);
Shaft();
translate([0,0,ShaftLength - ScrewOffset])
rotate([-90,0,0])
PolyCyl(ScrewDia,ShaftBase[1],6);
}
Printing Scale Model Concrete Blocks
Posted by Ed in Machine Shop, Software on 24-February-2013
For reasons that undoubtedly make sense to him, my buddy Aitch is moving to coastal NC. Seeing as how we lived in Raleigh for half a decade, I figure he needs some hints on how to blend in…
The solid model looks about the way you’d expect:
The webs are slightly thinner than in real life, but it looks OK to me. The web came out slightly over 3 thread widths = 1.5 mm, to ensure they get a bit of fill rather than being two distinct threads. I originally tried making the web exactly 3 threads wide, which produced tiny dots of fill on the sides and corners. They printed with 0.20 infill; they’d print faster with 1.00 infill or all-solid layers.
You’ll want to create a pile o’ blocks at once, of course, although this array took about two hours:
The OpenSCAD source code:
// Scale model concrete block
// Ed Nisley KE4ZNU February 2013
// Extrusion parameters must match reality!
// Print with +0 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 2.0 * ThreadThick;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
Scale = (1/25) * (3*ThreadWidth);
BlockWidth = Scale * 190;
BlockLength = Scale * 390;
BlockHeight = BlockWidth;
WebWidth = Scale * 30;
CoreSize = [(BlockWidth - 2*WebWidth),(BlockLength - 4*WebWidth)/2,BlockHeight];
CornerRadius = WebWidth/2;
//----------------------
// Useful routines
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);
}
//-------------------
// Component parts
module Core(Size,Radius) {
translate([0,0,(Size[2] - Protrusion)/2])
minkowski() {
cube([(Size[0] - 2*Radius),(Size[1] - 2*Radius),Size[2]],center=true);
cylinder(r=Radius,h=Protrusion,$fn=8);
}
}
//----------------------
// Build it!
ShowPegGrid();
difference() {
translate([0,0,BlockHeight/2])
cube([BlockWidth,BlockLength,BlockHeight],center=true);
for (i = [-1,1])
translate([0,i*(CoreSize[1] + WebWidth)/2,0])
Core(CoreSize,CornerRadius);
for (i = [-1,1])
translate([0,i*3*(CoreSize[1] + WebWidth)/2,0])
Core(CoreSize,CornerRadius);
}
Dishwasher Rack Protectors: Into The Maw
Posted by Ed in Home Ec, Machine Shop on 4-February-2013
Three rack protectors have gone missing over the last few months, presumably being digested by the dishwasher’s grinder, so I ran off another batch:
I used the original solid model, shown here with the support structure outside for visibility:
I re-sliced the model to pick up whatever printer config tweakage happened since then. Those ribbed doodads snapped out easily and, in fact, some remained bonded to the platform:
No finishing required: just slide them over the pins atop a blob of acrylic caulk. Despite the few missing protectors, it does a good job of bonding them to the rack and sealing gaps in the worn vinyl coating.
I picked up a jar of ReRack glop on closeout duing my last pass through the Big Box Home Repair Store. It seemed a bit stiff, so I’ve added generous dollops of xylene, acetone, and MEK to thin it out; that’ll take a while to stabilize.
Samsung VAC-9048 Vaccuum Cleaner: Floor Brush Strips
Posted by Ed in Home Ec, Machine Shop on 3-February-2013
After beating the Samsung’s nozzle handle and hose into submission, I made a set of floor brush strips for the hard-floor attachment:
The original brushes had non-woven felt glued to a cleverly molded strip of white plastic, which lasted not very long at all. I’d replaced them (*) with wool fabric glued to hand-hewn strips of polypropylene cut from the usual blister pack material, but that was so labor-intensive as to make no sense at all; it did show that replacement brushes would work, though, which was the whole point. This view looks through a finished strip to the urethane glue and wool fabric:
Fortunately, there’s an easier way to make the strips:
Note that the smaller tab (the one in the front) is not centered on the midline. The openings for the larger tab in the floor brush housing seem to have a small offset, but it’s not worth worrying about. The printed ones are 4 layers thick, but I think 3 layers will work as well; that’s what the OpenSCAD source will produce.
This is one of the few situation where the hand-knitted top surface of a 3D-printed object is an advantage: that, plus the holes, provides enough griptitude for urethane glue to hold the fabric strips firmly in place.
Obviously, you print them in multiples:
A trial fit:
They really are bowed slightly outward in the middle, which ensures there’s more pressure on the middle of the strip against the floor. I think the weird indented pattern in the brush housing under the strips was for a complex spring assembly that never made it into production; the OEM strips looked just like the ones I’m making, minus the perforations.
I glued two strips individually to make sure everything lined up, then glued these two in one operation and separated them with a razor knife:
(*) It goes without saying that OEM replacement brushes weren’t available and, in fact, they have never been available at any time when we’ve owned the vacuum cleaner. Maybe I’m not looking in the right place, but so it goes.
The OpenSCAD source code, which you’ll want to print with Multiply set to maybe 8:
// Samsung Vacuum cleaner nozzle floor strips
// Ed Nisley KE4ZNU January 2013
Layout = "Build"; // Show, Build
//- Extrusion parameters must match reality!
// Print with +0 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 2.0 * ThreadThick;
HoleWindage = 0.75;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
Body = [6.0,59.0,3*ThreadThick]; // width, length, thick
Tab1 = [4.5,5.0,0.0]; // width, length, offset from centerline
Tab2 = [3.5,5.0,0.5];
HoleOC = 8.0; // adhesive anchoring holes
HoleDia = 1.0;
HoleSides = 4;
HoleMax = floor(Body[1]/(2*HoleOC));
echo("HoleMax: ",HoleMax);
//----------------------
// 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);
}
module BackingStrip() {
difference() {
union() {
translate([0,0,Body[2]/2])
cube(Body,center=true);
translate([Tab1[2],-1*Body[1]/2,Body[2]/2])
cube([Tab1[0],2*Tab1[1],Body[2]],center=true);
translate([Tab2[2],+1*Body[1]/2,Body[2]/2])
cube([Tab2[0],2*Tab2[1],Body[2]],center=true);
}
for (i = [-HoleMax:HoleMax])
translate([0,i*HoleOC,-Protrusion])
rotate(45)
PolyCyl(HoleDia,(Body[2] + 2*Protrusion),HoleSides);
}
}
//----------------------
// Build it!
ShowPegGrid();
if (Layout == "Show")
BackingStrip();
if (Layout == "Build")
rotate(90) BackingStrip();
Samsung VAC-9048R Vacuum Cleaner: Nozzle Handle Hose Bushing
Posted by Ed in Home Ec, Machine Shop, Software on 2-February-2013
The hose going into the handle of the never-sufficently-to-be-damned Samsung VAC-9048R suck dog has been collapsing for quite some time, but I couldn’t figure out how to take the handle apart. Recently, the lock ring that I would have sworn was glued in place came loose, revealing the secret:
You slide four lugs on the lock ring into the open slots, then turn the ring clockwise to force the lugs over barriers into recesses that capture them and hold the lock ring against the handle. The handle under the lock ring isn’t quite circular, nor is the lock ring, and I think (based on later events) that they expect the ring to deform as it turns in order to let the lugs spring over the barriers.
Anyhow, with the lock ring loose, removing four screws released the two halves of the handle:
The handle includes a switch for the powered floor brush, which we rarely use, and a suction control lever that’s basically a binary leak: on or off. With the handle opened in front of you, remove the innards, unwrap the decorative duct tape, unwind enough of the two power conductor / spring wire ribs to allow for rebuilding the electrical connections, and cut off the damaged part of the hose.
Now, obviously, what that hose needs is a little bit of strain relief, along the lines of the hideous snout I’d affixed to its other end a while ago. The general idea is to replace the lock ring with a little attachment that will hold the heatshrink tubing in place. Something like this:
The bottom view, looking up through the layer of 1 mm cubes defining the Z=0 plane, shows the lugs:
I thought the slit would provide enough springiness to let the lugs bump over the ridges, but it wasn’t quite enough: the relatively stiff ABS isn’t nearly as springy as the original black plastic for about the same thickness. For the next version, I’ll try four slits, all of which must end at different levels to avoid concentrating the stress on a single layer.
In any event, it came out about like you’d expect:
As with many projects, though, I had to make a pair of simpler prototypes to get the measurements correct. The lugs, for example, are not 90° apart, spaced neatly around the handle’s midline seam, as I assumed for Prototype 1 on the right:
Prototype 2, on the left, has a support structure holding up a horizontal step that butted against the handle, which turned out to be unnecessary. The OpenSCAD version substitutes a pair of conical transitions that worked much better; they’re at different levels with a thicker wall section between them.
With the ring and somewhat preshrunk heatshrink tubing slipped along the hose, rewiring proceeds in reverse order. Next time, I’ll add a QD fitting in the hose-to-socket wire so I can take the whole thing apart again without cutting that wire:
Assemble the handle, snap the glaring white strain relief fitting in place, shrink the tubing, add a cable tie mostly for show:
I cut a few slits in the tubing’s end to improve its bendiness, but it’s already Much Better than it was.
A few things I’d do differently:
- Add a recess for the cable tie, with a flat spot for its latch
- Four slits, not just one
- Ribs on the snout to help anchor the tubing
- Longer snout?
The OpenSCAD source code for the final version, with a module for the support ring that you won’t need:
// Samsung Vacuum cleaner hose bushing
// Ed Nisley KE4ZNU January 2013
// Layout options
Layout = "Build";
// Overall layout: Show Build
// Parts: Ring Sleeve
//- Extrusion parameters must match reality!
// Print with +1 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 2.0 * ThreadThick;
HoleWindage = 0.75;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
HoseOD = 47.0; // spiral tube diameter
TubeWall = 1.4; // heatshrink tubing wall thickness
HandleRingLong = 8.5; // length of ring stub on handle
RingID = 51.0; // lock ring over handle end
RingOD = 58.0;
RingLong = 12.0;
Locks = 4; // bumps inside lock ring
LockLength = 4.0;
LockWide = 4.0;
LockThick = 0.75;
LockAngleOffset = 52.0; // offset of lock bump from handle top dead center
LockAngleIncluded = 102.4; // between first and second lock bump (also 3 & 4)
LockAngles = [-LockAngleOffset,
-(LockAngleOffset+LockAngleIncluded),
-(LockAngleOffset+180),
-(LockAngleOffset+LockAngleIncluded+180)];
BushID = HoseOD + 1.0; // over spiral hose
BushOD = RingOD - 2*TubeWall; // allow flush heatshrink fit
BushLength = 15.0;
SlitWidth = 2*ThreadWidth; // allow expansion of lock ring, sorta kinda
SlitHeight = 20.0;
SlitAngle = 0;
SlitLength = max(RingOD,BushOD);
RingSides = 4*8;
RingAlign = 360/(2*RingSides);
$fn = RingSides;
//----------------------
// 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);
}
//-------------------
// Component parts
module Ring() {
union() {
difference() {
union() {
cylinder(r=RingOD/2,h=(RingLong + Protrusion));
translate([0,0,RingLong])
cylinder(r1=(RingOD/2),r2=(BushOD - Protrusion)/2,h=(RingOD - BushOD));
}
translate([0,0,-Protrusion]) {
PolyCyl(RingID,(HandleRingLong + Protrusion),RingSides);
cylinder(r=BushID/2,h=(2*RingLong));
}
translate([0,0,(HandleRingLong - Protrusion)])
cylinder(r1=((RingID/2) / cos(180/RingSides) + HoleWindage),
r2=BushID/2,
h=(RingID - BushID)/2);
}
for (i=[0:Locks-1])
rotate(LockAngles[i] + RingAlign)
translate([(RingID/2),0,LockWide/2])
cube([2*LockThick,LockLength,LockWide],center=true);
}
}
module Sleeve() {
difference() {
cylinder(r=BushOD/2,h=(BushLength + Protrusion));
translate([0,0,-Protrusion])
cylinder(r=BushID/2,h=BushLength + 3*Protrusion);
}
}
module Bushing() {
difference() {
union() {
Ring();
translate([0,0,RingLong])
Sleeve();
}
rotate(SlitAngle)
translate([SlitLength/2,0,(SlitHeight - Protrusion)/2])
cube([SlitLength,SlitWidth,(SlitHeight + Protrusion)],center=true);
}
}
// This turned out to be unnecessary after tapering the transitions
module Support() {
SuppHeight = RingLong - ThreadThick;
color("Yellow")
union() {
difference() {
cylinder(r=(RingID/2 - LockThick - ThreadWidth/2),h=SuppHeight);
translate([0,0,-Protrusion])
cylinder(r=(BushID/2 - ThreadWidth),h=2*RingLong);
for (i=[0:RingSides-1])
rotate(i*2*RingAlign)
translate([RingID/4,0,SuppHeight - ThreadThick/2 + Protrusion/2])
cube([RingID/2,(LockLength - 3*ThreadWidth),(ThreadThick + Protrusion)],center=true);
}
}
}
//----------------------
// Build it!
ShowPegGrid();
if (Layout == "Build")
union() {
Bushing();
// Support();
}
if (Layout == "Show")
Bushing();
if (Layout == "Ring")
Ring();
if (Layout == "Sleeve")
Sleeve();
if (Layout == "Support")
Support();
Hall Effect Current Sensor: Winding and Armoring the Toroid
Posted by Ed in Electronics Workbench, Machine Shop on 22-January-2013
Winding a slit ferrite toroid poses no challenge, so putting 25 turns of 26 AWG wire on it didn’t take long at all:
However, a ferrite toroid doesn’t take kindly to being dropped and I figured that a slit toroid would crack under a stern look, so I decided to wrap some armor around it. A small squeeze bottle offered a cap just slightly larger than the winding, so I used that slitting saw to cut off a suitable ring. The first step was to grab it in the 3 jaw chuck and align its axis parallel to the spindle:
I wanted to cut off a slightly taller ring, but the clamping screw on the saw arbor just barely cleared the chuck for a 5 mm ring. I jogged around the chuck jaws to cut two slits in the cap that eventually joined near the back:
That was about 1000 rpm, no coolant, and slow feed, but also a totally non-critical cut in plastic.
I put a snippet of foam rubber in the slot, put the ring on a Kapton-covered build platform from the Thing-O-Matic, filled it with hot-melt glue, gooshed the toroid in place, and waited for cooling. Trimming and cleaning out the slit produced a hideously ugly, but (I hope) much more durable assembly:
I’m reasonably sure I didn’t crack the ferrite while cleaning out the slit; that hot-melt glue is tenaciously gummy stuff!
Now, to find out whether it actually works…
Improved OXO Can Opener Knob
Posted by Ed in Home Ec, Machine Shop on 14-January-2013
We recently replaced a defunct can opener with an OXO opener that removes can lids without creating razor-sharp edges. Unfortunately, the knob doesn’t agree well with Mary’s hand, so I laid out a prototype doorknob-shaped cap (and also removed all the can lids that confronted her):
It prints in four parts: the flat cover and three pillars, with two filament snippets aligning each pillar. The internal openings of this model do not fit the OXO knob’s lobes correctly; a Dremel sanding drum worked wonderfully well to make it fit. The next version should have much smaller pillar bases with a bit more clearance at the top: measurements from the as-adapted pillars will be in order.
Gluing everything together once again justifies having Too Many Clamps:
I intended to secure cap to knob with 2-56 screws in those recessed holes and even went so far as to flatten the top of the knob’s lobes in preparation for drilling:
However, Dragorn of Kismet gave me a few packets of only slightly outdated Sugru (a great idea that’s far too spendy and short-lived for my shop) that solved the problem:
The silicone tape wrap greatly improves the griptitude.
Early returns indicate this works reasonably well, but the top should be more rounded and tapered. It goes without saying that black filament would be much less ugly…
The OpenSCAD source code, with the caveat that the as-printed knob won’t fit without considerable abrasive adjustment:
// OXO Softworks Can Opener
// Enlarged & rounded knob
// Ed Nisley KE4ZNU December 2012
include </mnt/bulkdata/Project Files/Thing-O-Matic/MCAD/units.scad>
include </mnt/bulkdata/Project Files/Thing-O-Matic/Useful Sizes.scad>
// Layout options
Layout = "Cap";
// Overall layout: Build1 Build2
// Parts: Cap Knob
//- Extrusion parameters must match reality!
// Print with +1 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 2.0 * ThreadThick;
HoleWindage = 0.2;
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
TriLobeRad = 37.5; // radius: center to end of lobe
TriLobeOD = 2*TriLobeRad;
TriLobePeakRad = 23.0; // radius: center to peak height
TriLobeHeight = 22.5;
WingArcRad2 = 48; // Arc between knob lobes, top
WingArcRad1 = WingArcRad2 - 5; //
WingArcOffset = 14.0; // Knob center to arc2 radius
KnobOD1 = 70; // maximum dia without chamfer
KnobOD2 = 65; // top dia
KnobSides = 3*4; // maintain 3-side symmetry
DomeHeight = 8; // dome shape above lobes
KnobHeight = DomeHeight + TriLobeHeight;
DomeOD = KnobOD2 + (KnobOD1 - KnobOD2)*(DomeHeight/KnobHeight);
DomeArcRad = (pow(KnobHeight,2) + pow(DomeOD,2)/4) / (2*DomeHeight);
ScrewDia = Tap2_56;
ScrewHeadDia = Head2_56;
ScrewBase = 0.6*DomeHeight - Head2_56Thick;
AlignPinDia = 3.0;
AlignPinCircleRad = 0.55*(WingArcOffset + KnobOD2/2);
AlignPinDepth = 3.0;
//----------------------
// 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,
$fn=Sides);
}
module ShowPegGrid(Space = 10.0,Size = 1.0) {
Range = floor(50 / Space);
for (x=[-Range:Range])
for (y=[-Range:Range])
translate([x*Space,y*Space,Size/2])
%cube(Size,center=true);
}
//-------------------
// Component parts
module TriKnob() {
intersection() {
difference(convexity=3) {
translate([0,0,-Protrusion])
cylinder(r=TriLobeRad,h=(TriLobeHeight + 2*Protrusion));
for (i=[-1:1])
rotate(i*120)
translate([(WingArcOffset + WingArcRad2),0,-TriLobeHeight/2])
cylinder(r1=WingArcRad1,r2=WingArcRad2,h=2*TriLobeHeight);
}
translate([0,0,TriLobeHeight/2])
cube([2*KnobOD1,2*KnobOD2,TriLobeHeight],center=true);
}
}
module KnobCap() {
difference() {
intersection() {
translate([0,0,(KnobHeight-DomeArcRad)])
rotate(180/KnobSides)
sphere(r=DomeArcRad,$fa=180/KnobSides);
difference(convexity=4) {
rotate(180/KnobSides)
cylinder(r1=KnobOD1/2,r2=KnobOD2/2,h=KnobHeight,$fn=KnobSides);
TriKnob();
}
rotate(180/KnobSides)
cylinder(r1=KnobOD2/2,r2=KnobOD1/2,h=KnobHeight,$fn=KnobSides);
}
for (i=[-1:1])
rotate(i*120) {
translate([-TriLobePeakRad,0,0]) {
PolyCyl(ScrewDia,KnobHeight);
translate([0,0,TriLobeHeight + ScrewBase])
PolyCyl(ScrewHeadDia,KnobHeight);
}
}
for (i=[-1:1]) for (j=[-1,1])
rotate(i*120 + j*(270/KnobSides))
translate([AlignPinCircleRad,0,(TriLobeHeight - AlignPinDepth - Protrusion)])
PolyCyl(AlignPinDia,2*(AlignPinDepth + Protrusion));
}
}
//----------------------
// Build it!
ShowPegGrid();
if (Layout == "Cap")
difference() {
KnobCap();
cylinder(r=KnobOD1,h=Protrusion/2,center=true);
}
if (Layout == "Knob")
TriKnob();
if (Layout == "Build1")
translate([0,0,-TriLobeHeight])
difference() {
KnobCap();
translate([0,0,(TriLobeHeight - Protrusion)/2])
cube([2*KnobOD1,2*KnobOD2,TriLobeHeight+Protrusion],center=true);
}
if (Layout == "Build2")
translate([0,0,TriLobeHeight])
rotate([180,0,0])
difference() {
KnobCap();
translate([0,0,(TriLobeHeight + TriLobeHeight/2)])
cube([2*KnobOD1,2*KnobOD2,TriLobeHeight],center=true);
}


































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