Day: December 3, 2013

While reducing the clutter atop the Electronics Workbench, I ran off four more probe flange reinforcements, just so I’m ready for the next crunch:

They’re almost identical to the previous version, although I tweaked the taper to end slightly inside the cylindrical cup, thereby eliminating the coincident faces and leaving a minute rim that doesn’t matter:

Given that I’ve had the ‘scope for nigh onto two decades and have only broken one probe flange, I think four reinforcements will be a lifetime supply: with any luck, the scope will blow a capacitor before I do.

The OpenSCAD source code:

// Tek Scope Probe Flange
// Ed Nisley KE4ZNU November 2013

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

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

FlangeOD = 16.0;
FlangeID = 8.75;
FlangeThick = IntegerMultiple(1.25,ThreadThick);

DiskOD = FlangeOD + 4*ThreadWidth;
DiskThick = FlangeThick + 4*ThreadThick;

NumSides = 8*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();

difference() {
union() {
translate([0,0,2*ThreadThick])
cylinder(r=DiskOD/2,h=DiskThick,$fn=NumSides);    // cylinder around flange

cylinder(r1=(DiskOD - 2*ThreadWidth)/2,                // flange reinforcing plate
r2=DiskOD/2,
h=(2*ThreadThick + Protrusion),
$fn=NumSides);
}
translate([0,0,(DiskThick - FlangeThick)])                // flange clearance
PolyCyl(FlangeOD,2*FlangeThick,NumSides);

translate([0,0,-DiskThick/2])                            // probe nose clearance
PolyCyl(FlangeID,2*DiskThick,NumSides);
}