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

The New Hotness

  • Helmet Mirror: Smaller Mirror Shaft

    This is the slightly smaller mount corresponding to the OpenSCAD code there for the two-section inspection mirror shaft, hot from the printer:

    Helmet mirror mount on build platform - smaller mirror shaft
    Helmet mirror mount on build platform – smaller mirror shaft

    It’s about the same as the previous version, despite trimming a few millimeters from the diameters and spacings:

    Helmet mirror mount size comparison
    Helmet mirror mount size comparison

    I’ll print the next one in a darker color. At least it’s not pink…

    The OpenSCAD source:

    // Helmet mirror mount
    // Ed Nisley KE4ZNU June 2011
    
    include </home/ed/Thing-O-Matic/lib/MCAD/units.scad>
    include </home/ed/Thing-O-Matic/lib/MCAD/boxes.scad>
    include </home/ed/Thing-O-Matic/lib/visibone_colors.scad>
    
    //-- Layout Control
    
    Layout = "Build";					// Build Fit Show None
    
    Examine = "None";				// AzMount ElMount ElBody ElPlate HelmetPlate None
    
    //-- Extrusion parameters
    
    ThreadThick = 0.33;
    ThreadWT = 2.0;
    ThreadWidth = ThreadThick * ThreadWT;
    
    HoleWindage = 0;			// enlarge hole dia by this amount
    
    //-- Useful sizes
    
    Tap2_56 = 0.070 * inch;
    Clear2_56 = 0.082 * inch;
    Head2_56 = 0.156 * inch;
    Head2_56Thick = 0.055 * inch;
    Nut2_56Dia = 0.204 * inch;
    Nut2_56Thick = 0.065 * inch;
    
    Tap3_48 = 0.079 * inch;
    Clear3_48 = 0.096 * inch;
    Head3_48 = 0.184 * inch;
    Head3_48Thick = 0.058 * inch;
    Nut3_48Dia = 0.201 * inch;
    Nut3_48Thick = 0.073 * inch;
    
    Tap4_40 = 0.089 * inch;
    Clear4_40 = 0.110 * inch;
    Head4_40 = 0.211 * inch;
    Head4_40Thick = 0.065 * inch;
    Nut4_40Dia = 0.228 * inch;
    Nut4_40Thick = 0.086 * inch;
    
    //-- Azimuth Mount
    
    AzMountDia = 12.0;
    AzMountLength = 14.0;
    
    AzFacets = 30;
    
    echo(str("Azmuth mount dia: ",AzMountDia," length: ",AzMountLength));
    
    //-- Mirror sizes
    
    MirrorShaftDia = 3.60;
    MirrorShaftOffset = -1.5;				// vertical offset from center of AzMountBody
    MirrorShoulderLen = 3*MirrorShaftDia;
    MirrorShoulderDia = min(AzMountDia,MirrorShaftDia + 6*ThreadWidth);
    
    MirrorStudDia = Tap3_48;
    MirrorStudLen = 2.0;
    
    //-- Elevation Mount / Body / Plate
    
    ElMountDia = AzMountDia;
    ElMountLength = 2.0 + ElMountDia;
    
    ElMountBase = 2.0;
    
    ElMountRounding = 2.0;
    
    ElMountFacets = AzFacets;
    
    ElBodyWidth = ElMountDia;
    ElBodyBlockLength = ElMountLength + AzMountLength/2 - MirrorShaftOffset;
    ElBodyThick = 8.0;
    
    echo(str("Elevation body overall: ",(ElBodyBlockLength + ElBodyWidth/2)," width: ",ElBodyWidth));
    
    ElPlateTall = ElBodyBlockLength + 0.70*ElBodyWidth;
    ElPlateWidth = 1.25 * ElPlateTall;
    ElPlateThick = Nut3_48Thick + 3*ThreadThick;
    
    ElPlatePlusX = ElPlateThick + (ElMountDia/2 + ElMountBase) + ElBodyThick;
    
    echo(str("Elevation plate tall: ",ElPlateTall," width: ",ElPlateWidth));
    
    ElArcRadius = (3/4) * ElBodyBlockLength;
    ElArcThick = 4*ThreadWidth;
    ElArcHeight = (1/2) * ElBodyThick;
    ElArcAngle = 35;
    ElArcFacets = 32;
    
    ElPlateFacets = 52;
    
    //-- Helmet Interface Plate
    
    HelmetCX = 60.0;
    HelmetMX = 4.0;
    HelmetRX = (pow(HelmetMX,2) + pow(HelmetCX,2)/4)/(2*HelmetMX);
    
    HelmetPlateC = max(ElPlateTall,ElPlateWidth);
    HelmetPlateTheta = atan(HelmetPlateC/HelmetRX);
    HelmetPlateM = 2*HelmetRX*pow(sin(HelmetPlateTheta/4),2);
    
    HelmetPlateThick = ThreadThick*(ceil(HelmetPlateM/ThreadThick) + 1);
    
    //-- Bearing Interfaces
    
    BearingWidth = 3*ThreadWidth;
    
    BearingOverlap = 3*ThreadThick;
    BearingClearance = 1*ThreadThick;
    
    BearingStudDia = min(AzMountDia,ElBodyWidth) - 2*BearingWidth;
    
    //-- Convenience values
    
    Protrusion = 0.1;		// make holes look good
    
    //----------------------
    // Useful routines
    
    module PolyCyl(Dia,Height) {			// based on nophead's polyholes
    
      Sides = ceil(Dia) + 2;
      FixDia = Dia / cos(180/Sides);
    
      cylinder(r=(FixDia + HoleWindage)/2,
               h=Height,
    	   $fn=Sides);
    }
    
    PegSize = 1.0;
    
    module ShowPegGrid(Size) {
    	for (x=[-5:5])
    	  for (y=[-5:5])
    		translate([x*10,y*10,Size/2])
    		  cube(Size,center=true);
    
    }
    
    //----------------------
    // Azimuth Mount
    
    module AzMount() {
    
      difference() {
    	union() {
    	  cylinder(r=AzMountDia/2,h=AzMountLength,$fn=AzFacets);		// body
    	  translate([0,0,AzMountLength/2 + MirrorShaftOffset])
    		rotate([-90,0,0])
    		  cylinder(r=MirrorShoulderDia/2,
    				   h=MirrorShoulderLen,$fn=AzFacets);				// mirror shaft shoulder
    
    	  if (Layout != "Fit")
    		for (y=[0:1])												// shoulder support
    		  translate([-AzMountDia/2,(4*y + AzMountDia/2 + ThreadWidth),0])
    			difference() {
    			  cube([AzMountDia,2*ThreadWidth,AzMountLength/6]);
    			  translate([AzMountDia/2,-Protrusion,AzMountLength/2 + MirrorShaftOffset])
    				rotate([-90,0,0])
    				  cylinder(r=MirrorShoulderDia/2,h=ThreadWidth + 2*Protrusion);
    			}
    	}
    
        translate([0,-Head3_48/2,AzMountLength/2 + MirrorShaftOffset])
          rotate([-90,0,0])
    		PolyCyl(MirrorShaftDia,(AzMountDia + MirrorShoulderLen));	// mirror shaft
    
        translate([0,-(Head3_48/2 - Protrusion),AzMountLength/2 + MirrorShaftOffset])
    	  rotate([90,0,0])
    		PolyCyl(MirrorStudDia,MirrorStudLen+Protrusion);			// mirror stud
    
        translate([0,0,
    	       Head3_48Thick - (AzMountLength - MirrorShaftDia)/2 + MirrorShaftOffset - Protrusion])
          PolyCyl(Head3_48,AzMountLength + Protrusion);					// mounting screw head
    
        translate([0,0,-Protrusion])
          cylinder(r=(Clear3_48 + HoleWindage)/2,
    	  h=(AzMountLength + 2*Protrusion),
    	  $fn=ceil(Clear3_48)+2);										// mounting screw clearance
    
    	translate([0,0,AzMountLength/2 + Head3_48Thick + MirrorShaftDia/2 + MirrorShaftOffset - Protrusion])
    	  cylinder(r1=(Head3_48/cos(180/7) + HoleWindage)/2,
    			   r2=Clear3_48/2,
    			   h=(3*ThreadThick + Protrusion),
    			   $fn=7);												// overhang support
    
        translate([0,0,AzMountLength/2 + MirrorShaftOffset])
          rotate([0,90,0])
    		PolyCyl(Tap2_56,AzMountDia/2 + Protrusion);					// setscrew hole
    
        translate([0,0,AzMountLength - (BearingOverlap + BearingClearance)])
    	  PolyCyl(BearingStudDia,
    			  BearingOverlap + BearingClearance + Protrusion);		// bearing surface
    
      }
    
    }
    
    //----------------------
    // Elevation Mount
    
    module ElMount() {
    
      difference() {
    
    	union() {
    
    	  translate([(ElMountDia/4 + ElMountBase/2),0,(ElMountLength/2 + BearingOverlap)])
    		rotate([0,90,0])
    		  cube([ElMountLength,ElMountDia,(ElMountDia/2 + ElMountBase)],
    			  center=true);											// mounting block
    
    	  translate([0,0,BearingOverlap]) {
    //		color([0.4,0.3,0.3,0.7])
    		cylinder(r=ElMountDia/2,
    				 h=ElMountLength - ElMountDia/2,
    				 $fn=ElMountFacets);								// cylinder to Az
    
    //		color([0.3,0.4,0.3,0.7])
    		translate([0,0,ElMountLength - ElMountDia/2]) {				// curved interface
    		  intersection() {
    			cylinder(r=ElMountDia/2,h=ElMountDia/2,$fn=ElMountFacets);
    			translate([0,ElMountDia/2,0])
    			  rotate([90,0,0])
    				cylinder(r=ElMountDia/2,h=ElMountDia,$fn=ElMountFacets);
    		  }
    		}
    
    	  }
    
    	  cylinder(r=(BearingStudDia - HoleWindage)/2,h=BearingOverlap);	// bearing stud
    	}
    
    	translate([0,0,-Protrusion])
    	  PolyCyl(Tap3_48,(3/4)*ElMountLength + BearingOverlap + Protrusion);	// AzMount screw
      }
    }
    
    //----------------------
    // Elevation Body
    
    module ElBody() {
    
      difference() {
    	union() {
    	  translate([-ElBodyBlockLength,-ElBodyWidth/2,0])
    		cube([ElBodyBlockLength,ElBodyWidth,ElBodyThick]);
    	  translate([0,0,ElBodyThick])
    		cylinder(r=(ElBodyWidth - 2*BearingWidth)/2,h=BearingOverlap);
    	  cylinder(r=ElBodyWidth/2,h=ElBodyThick,$fn=ElMountFacets);
    	}
    
    	PolyCyl(Clear3_48,ElBodyThick + BearingOverlap + Protrusion);
    
    	translate([0,0,-Protrusion])
    	  PolyCyl(Head3_48,Head3_48Thick);
    
    	translate([-ElArcRadius,0,ElBodyThick - ElArcHeight/2])
    	  rotate([0,-90,0])
    		PolyCyl(Tap2_56,ElBodyBlockLength - ElArcRadius + Protrusion);
    
    	translate([0,0,ElBodyThick - (ElArcHeight + BearingClearance)])
    	  difference() {
    		cylinder(r=ElArcRadius + (ElArcThick/2 + BearingClearance),
    				 h=ElArcHeight + BearingClearance + Protrusion,
    				 $fn=ElArcFacets);
    		cylinder(r=ElArcRadius - (ElArcThick/2 + BearingClearance),
    				 h=ElArcHeight + BearingClearance + Protrusion,
    				 $fn=ElArcFacets);
    	  }
    
      }
    
    }
    
    //----------------------
    // Elevation Plate
    
    module ElPlate() {
    
      union() {
    	difference() {
    	  translate([ElBodyWidth/2 - ElPlateTall/2,0,0])
    		scale([ElPlateTall,ElPlateWidth,1.0])
    		  cylinder(r=0.5,h=ElPlateThick,$fn=ElPlateFacets);
    	  translate([0,0,-Protrusion])
    		PolyCyl(Tap3_48,ElPlateThick + 2*Protrusion);
    	  translate([0,0,ElPlateThick - (BearingOverlap + BearingClearance)])
    		PolyCyl(BearingStudDia,(BearingOverlap + BearingClearance) + Protrusion);
    	  translate([0,0,-Protrusion])
    		cylinder(r=Nut3_48Dia/2,h=(1.1*Nut3_48Thick + Protrusion),$fn=6);
    	}
    
    	translate([0,0,ElPlateThick])
    	difference() {
    	  cylinder(r=ElArcRadius + ElArcThick/2,
    			   h=ElArcHeight,
    			   $fn=ElArcFacets);
    	  cylinder(r=ElArcRadius - ElArcThick/2,
    			   h=ElArcHeight + Protrusion,
    			   $fn=ElArcFacets);
    	  rotate([0,0,90 - ElArcAngle])
    	    translate([ElArcRadius + ElArcThick,0,ElArcHeight/2])
    		  cube([2*ElArcRadius + ElArcThick,
    				2*ElArcRadius + ElArcThick,
    				ElArcHeight + Protrusion],
    				center=true);
    	  rotate([0,0,-(90 - ElArcAngle)])
    	    translate([ElArcRadius + ElArcThick,0,ElArcHeight/2])
    		  cube([2*ElArcRadius + ElArcThick,
    				2*ElArcRadius + ElArcThick,
    				ElArcHeight + Protrusion],
    				center=true);
    	}
      }
    }
    
    //----------------------
    // Helmet Interface Plate
    
    module HelmetPlate() {
    
      difference() {
    	scale([ElPlateTall,ElPlateWidth,1.0])
    	  cylinder(r=0.5,h=HelmetPlateThick,$fn=ElPlateFacets);
    
    	translate([0,0,HelmetRX + HelmetPlateThick - HelmetPlateM])
    	  sphere(r=HelmetRX,$fn=256,$fs=0.1);
    
      }
    }
    
    //----------------------
    // Lash it together
    
    if (Examine == "AzMount")
      AzMount();
    
    if (Examine == "ElMount")
      ElMount();
    
    if (Examine == "ElBody")
      ElBody();
    
    if (Examine == "ElPlate")
      ElPlate();
    
    if (Examine == "HelmetPlate")
      HelmetPlate();
    
    if ((Layout == "Build" || Layout == "Show") && Examine == "None") {
      translate([-10,-20,0])
    	rotate([0,0,90])					// mis-align top fill from ElMount
    	  AzMount();
    
      translate([-10,20,ElMountLength + BearingOverlap])
    	rotate([0,180,-90])
    	  ElMount();
    
      translate([0,0,0])
    	rotate([0,0,0])
    	  ElBody();
    
      translate([10,15,0])
    	rotate([0,0,215])					// mis-align top fill from ElBody
    	  ElPlate();
    
      translate([20,-20,0])
    	rotate([0,0,-45])
    	  HelmetPlate();
    
      if (Layout == "Show")
    	ShowPegGrid(PegSize);
    
    }
    
    if ((Layout == "Fit") && Examine == "None") {
      translate([0,0,-(AzMountLength/2 + MirrorShaftOffset)])
    	color(MFG) AzMount();
    
      translate([0,0,AzMountLength/2 - MirrorShaftOffset - BearingOverlap])
    	color(DHC) ElMount();
    //	color([  0/255, 204/255, 204/255,0.5]) ElMount();
    
    	translate([ElMountDia/2 + ElMountBase,0,0])
    	  rotate([0,90,0])
    		color(DFC) ElBody();
    
    	translate([ElPlatePlusX,0,0])
    	  rotate([180,90,0])
    		color(LHC) ElPlate();
    
    	translate([ElPlatePlusX,0,ElPlateTall/2 - ElBodyWidth/2])
    	  rotate([0,90,0])
    		color(LWM) HelmetPlate();
    }