The main tube connects the camera mounting plate and the snout on the front, so it’s a structural element of a sort. The ID fits over the non-moving lens turret base on the camera and the inner length is a few millimeters longer than the maximum lens turret extension:
As you might expect by now, the front bulkhead has four alignment peg holes for the snout:
The OpenSCAD code sets the wall thickness to 3 thread widths, but Skeinforge prints two adjacent threads with no fill at all. I think the polygon corners eliminate the one-thread-width fill and the perimeter threads wind up near enough to merge properly.
I assembled snouts to main tubes first, because it was easier to clamp bare cylinders to the bench:
Then glue the tube to the mounting plate using a couple of clamps:
The alignment is pretty close to being right, but if when I do this again I’ll add alignment pegs along the trench in the mounting plate to make sure the tube doesn’t ease slightly to one side, thusly:
You can see the entrance pupil isn’t quite filled in the last picture there, so a bit more attention to detail is in order. A bigger doublet lens would help, too.
The current version of the OpenSCAD source code with those pegs:
// Close-up lens mount & Microscope adapter for Canon SX230HS camera
// Ed Nisley KE4ZNU - Nov 2011
Mount = "LEDRing"; // End result: LEDRing Eyepiece
Layout = "Show"; // Assembly: Show
// Parts: Plate Tube LEDRing Camera Eyepiece
// Build Plates: Build1..4
Gap = 10; // between "Show" objects
include </home/ed/Thing-O-Matic/lib/MCAD/units.scad>
include </home/ed/Thing-O-Matic/Useful Sizes.scad>
include </home/ed/Thing-O-Matic/lib/visibone_colors.scad>
//-------
//- Extrusion parameters must match reality!
// Print with +1 shells, 3 solid layers, 0.2 infill
ThreadThick = 0.33;
ThreadWidth = 2.0 * ThreadThick;
HoleFinagle = 0.2;
HoleFudge = 1.00;
function HoleAdjust(Diameter) = HoleFudge*Diameter + HoleFinagle;
Protrusion = 0.1; // make holes end cleanly
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
//-------
// Dimensions
// doublet lens
LensDia = 25.0;
LensRad = LensDia/2;
LensClearance = 0.2;
LensEdge = 6.7;
LensThick = 8.6;
LensRimThick = IntegerMultiple((2.0 + LensThick),ThreadThick);
// LED ring light
LEDRingOD = 50.0;
LEDRingID = 36.0;
LEDBoardThick = 1.5;
LEDThick = 4.0;
LEDRingClearance = 0.5;
LEDWireHoleDia = 3.0;
// microscope eyepiece
EyepieceOD = 30.0;
EyepieceID = 24.0;
EyepieceLength = 25.0;
// camera
// Origin at base of [0] ring, Z+ along lens axis, X+ toward bottom, Y+ toward left
CameraBodyWidth = 2*10.6; // 2 x center-to-curve edge
CameraBaseWidth = 15.5; // flat part of bottom front to back
CameraBaseRadius = (CameraBodyWidth - CameraBaseWidth)/2; // edge rounding
CameraBaseLength = 60.0; // centered on lens axis
CameraBaseHeight = 55.0; // main body height
CameraBaseThick = 0.9; // downward from lens ring
echo(str("Camera base radius: ",CameraBaseRadius));
TripodHoleOffset = -19.0; // mount screw wrt lens centerline
TripodHoleDia = Clear025_20; // clearance hole
TripodScrewHeadDia = 14.5; // recess for screw mounting camera
TripodScrewHeadRad = TripodScrewHeadDia/2;
TripodScrewHeadThick = 3.0;
// main lens tube
TubeDia = [53.0, 44.0, 40.0, 37.6]; // lens rings, [0] is fixed to body
TubeLength = [8.1, 20.6, 17.6, 12.7];
TubeEndClearance = 2.0; // camera lens end to tube end
TubeEndThickness = IntegerMultiple(1.5,ThreadThick);
TubeInnerClearance = 0.5;
TubeInnerLength = TubeLength[0] + TubeLength[1] + TubeLength[2] + TubeLength[3] +
TubeEndClearance;
TubeOuterLength = TubeInnerLength + TubeEndThickness;
TubeID = TubeDia[0] + TubeInnerClearance;
TubeOD = TubeID + 6*ThreadWidth;
TubeWall = (TubeOD - TubeID)/2;
TubeSides = 48;
echo(str("Main tube outer length: ",TubeOuterLength));
echo(str(" ID: ",TubeID," OD: ",TubeOD," wall: ",TubeWall));
// camera mounting base
BaseWidth = IntegerMultiple((CameraBaseWidth + 2*CameraBaseRadius),ThreadThick);
BaseLength = 60.0;
BaseThick = IntegerMultiple((1.0 + Nut025_20Thick + CameraBaseThick),ThreadThick);
// LED ring mount
LEDBaseThick = IntegerMultiple(2.0,ThreadThick); // base under lens + LED ring
LEDBaseRimWidth = IntegerMultiple(6.0,ThreadWidth);
LEDBaseRimThick = IntegerMultiple(LensThick,ThreadThick);
LEDBaseOD = max((LEDRingOD + LEDRingClearance + LEDBaseRimWidth),TubeOD);
echo(str("LED Ring OD: ",LEDBaseOD));
// alignment pins between tube and LED ring / microscope eyepiece
AlignPinOD = 2.9;
SnoutPins = 4;
SnoutPinCircleDia = TubeOD - 2*TubeWall - 2*AlignPinOD; // 2*PinOD -> more clearance
// alignment pins between tube and base plate
BasePins = 2;
BasePinOffset = 10.0;
BasePinSpacing = BaseLength/3;
//-------
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,$fn=Sides);
}
module ShowPegGrid(Space = 10.0,Size = 1.0) {
Range = floor(50 / Space);
for (x=[-Range:Range])
for (y=[-Range:Range])
translate([x*Space,y*Space,Size/2])
%cube(Size,center=true);
}
//-------
//- Camera body segment
// Including lens base and peg for tripod hole access
// Z=0 at edge of lens base ring, X=0 along lens axis
module CameraBody() {
translate([0,0,-CameraBaseThick])
rotate(90)
union() {
translate([0,0,(CameraBaseHeight/2 + CameraBaseRadius)])
minkowski() {
cube([CameraBaseWidth,
(CameraBaseLength + 2*Protrusion),
CameraBaseHeight],center=true);
rotate([90,0,0])
cylinder(r=CameraBaseRadius,h=Protrusion,$fn=8);
}
translate([0,0,(TubeDia[0]/2 + CameraBaseThick)])
rotate([0,90,0])
rotate(180/TubeSides)
cylinder(r=(TubeDia[0]/2 + CameraBaseThick),
h=(CameraBodyWidth/2 + Protrusion),
$fn=TubeSides);
translate([CameraBodyWidth/2,0,(TubeDia[0]/2 + CameraBaseThick)])
rotate([0,90,0])
cylinder(r=TubeDia[0]/2,h=TubeLength[0]);
translate([(TubeLength[0] + CameraBodyWidth/2),
0,(TubeDia[0]/2 + CameraBaseThick)])
rotate([0,90,0])
cylinder(r=TubeDia[1]/2,h=TubeLength[1]);
translate([(TubeLength[0] + TubeLength[1] + CameraBodyWidth/2),
0,(TubeDia[0]/2 + CameraBaseThick)])
rotate([0,90,0])
cylinder(r=TubeDia[2]/2,h=TubeLength[2]);
translate([(TubeLength[0] + TubeLength[1] + TubeLength[2] + CameraBodyWidth/2),
0,(TubeDia[0]/2 + CameraBaseThick)])
rotate([0,90,0])
cylinder(r=TubeDia[3]/2,h=TubeLength[3]);
translate([0,TripodHoleOffset,-BaseThick])
PolyCyl(TripodHoleDia,(BaseThick + 2*Protrusion));
}
}
//- Main tube
module Tube() {
difference() {
cylinder(r=TubeOD/2,h=TubeOuterLength,$fn=TubeSides);
translate([0,0,TubeEndThickness])
PolyCyl(TubeID,(TubeInnerLength + Protrusion),TubeSides);
translate([0,0,-Protrusion]) {
if (Mount == "LEDRing")
cylinder(r=LensRad,h=(TubeEndThickness + 2*Protrusion));
if (Mount == "Eyepiece")
cylinder(r=EyepieceID/2,h=(TubeEndThickness + 2*Protrusion));
}
for (Index = [0:SnoutPins-1])
rotate(Index*90)
translate([(SnoutPinCircleDia/2),0,-ThreadThick])
rotate(180) // flat sides outward
PolyCyl(AlignPinOD,TubeEndThickness);
for (Index = [0:BasePins-1])
translate([0,-(TubeOD/2 + Protrusion),
(TubeOuterLength - BasePinOffset - Index*BasePinSpacing)])
rotate([-90,90,0]) // y = flat toward camera
PolyCyl(AlignPinOD,(TubeWall + 2*Protrusion));
}
}
//- Base plate
module BasePlate() {
union() {
difference() {
linear_extrude(height=BaseThick)
hull() {
translate([-(BaseLength/2 - BaseWidth/2),0,0])
circle(BaseWidth/2);
translate([ (BaseLength/2 - BaseWidth/2),0,0])
circle(BaseWidth/2);
translate([0,(0.75*BaseLength),0])
circle(BaseWidth/2);
}
translate([0,0,BaseThick])
CameraBody();
translate([0,(TubeOuterLength + CameraBodyWidth/2),
(BaseThick + TubeDia[0]/2)])
rotate([90,0,0])
PolyCyl(TubeOD,TubeOuterLength,$fn=TubeSides);
for (Index = [0:BasePins-1])
translate([0,(CameraBodyWidth/2 + BasePinOffset + Index*BasePinSpacing),
3*ThreadThick])
rotate(90) // flat toward camera
PolyCyl(AlignPinOD,BaseThick);
translate([0,0,3*ThreadThick])
PolyCyl((Nut025_20Dia*sqrt(3)/2),2*Nut025_20Thick,6); // dia across hex flats
translate([0,0,-Protrusion])
PolyCyl(Clear025_20,(BaseThick + 2*Protrusion));
translate([TripodHoleOffset,0,3*ThreadThick])
PolyCyl((Nut025_20Dia*sqrt(3)/2),2*Nut025_20Thick,6); // dia across hex flats
translate([TripodHoleOffset,0,-Protrusion])
PolyCyl(Clear025_20,(BaseThick + 2*Protrusion));
translate([-TripodHoleOffset,0,-Protrusion])
PolyCyl(TripodScrewHeadDia,(TripodScrewHeadThick + Protrusion));
}
translate([-TripodHoleOffset,0,0]) { // support for tripod screw hole
for (Index=[0:3])
rotate(Index*45)
translate([-ThreadWidth,-TripodScrewHeadRad,0])
cube([2*ThreadWidth,TripodScrewHeadDia,TripodScrewHeadThick]);
cylinder(r=0.4*TripodScrewHeadRad,h=(BaseThick - CameraBaseThick),$fn=9);
}
}
}
//- LED mounting ring
module LEDRing() {
difference() {
cylinder(r=LEDBaseOD/2,h=LensRimThick,$fn=48);
translate([0,0,-Protrusion])
PolyCyl((LensDia + LensClearance),
(LensRimThick + 2*Protrusion));
translate([0,0,LEDBaseRimThick])
difference() {
PolyCyl(LEDBaseOD,LensThick);
PolyCyl(LEDRingID,LensThick);
}
translate([0,0,LEDBaseThick])
difference() {
PolyCyl((LEDRingOD + LEDRingClearance),LensThick);
cylinder(r1=HoleAdjust(LEDRingID - LEDRingClearance)/2,
r2=HoleAdjust(LensDia + LensClearance)/2 + 2*ThreadWidth,
h=LensThick);
}
for (Index = [0:SnoutPins-1])
rotate(Index*90)
translate([(SnoutPinCircleDia/2),0,-ThreadThick])
rotate(180) // flat sides outward
PolyCyl(AlignPinOD,LEDBaseThick);
rotate(45)
translate([0,LEDRingID/2,(LEDBaseThick + 1.2*LEDWireHoleDia/2)])
rotate([0,-90,0]) // flat side down
rotate([-90,0,0])
PolyCyl(LEDWireHoleDia,2*LEDBaseRimWidth);
}
}
//- Microscope eyepiece adapter
module EyepieceMount() {
difference() {
cylinder(r1=TubeOD/2,
r2=(EyepieceOD + 8*ThreadWidth)/2,
h=EyepieceLength,
$fn=TubeSides);
translate([0,0,-Protrusion])
PolyCyl(EyepieceOD,(EyepieceLength + 2*Protrusion));
for (Index = [0:SnoutPins-1])
rotate(Index*90)
translate([(SnoutPinCircleDia/2),0,-ThreadThick])
rotate(180) // flat sides outward
PolyCyl(AlignPinOD,6*ThreadThick);
}
}
//-------
// Build it!
if (Layout != "Show")
ShowPegGrid();
if (Layout == "Tube")
Tube();
if (Layout == "LEDRing")
LEDRing();
if (Layout == "Plate")
BasePlate();
if (Layout == "Camera")
CameraBody();
if (Layout == "Eyepiece")
EyepieceMount();
if (Layout == "Build1")
translate([0,-BaseLength/3,0])
BasePlate();
if (Layout == "Build2")
Tube();
if (Layout == "Build3")
LEDRing();
if (Layout == "Build4")
EyepieceMount();
if (Layout == "Show") {
translate([0,TubeOuterLength,TubeDia[0]/2]) {
rotate([90,0,0])
color(LTC) Tube();
translate([0,(Gap/2 - TubeEndThickness - Protrusion),0])
rotate([-90,0,0])
for (Index = [0:SnoutPins-1])
rotate(Index*90)
translate([(SnoutPinCircleDia/2),0,0])
rotate(180) // flat sides outward
PolyCyl(AlignPinOD,(TubeEndThickness + LEDBaseThick));
translate([0,Gap,0])
rotate([-90,0,0]) {
if (Mount == "LEDRing")
color(OOR) LEDRing();
if (Mount == "Eyepiece")
color(OOR) EyepieceMount();
}
}
translate([0,-CameraBodyWidth/2,0])
color(PG) CameraBody();
color(PDA)
render()
translate([0,-CameraBodyWidth/2,-(BaseThick + Gap)])
BasePlate();
for (Index = [0:BasePins-1])
translate([0,(BasePinOffset + Index*BasePinSpacing),
-Gap/2])
rotate([180,0,90]) // flat toward camera
PolyCyl(AlignPinOD,BaseThick/2);
}
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