This lamp needs a base for its (minimal) electronics:
The solid model won’t win many stylin’ points:
It’s big and bulky, with a thick wall and base, because that ceramic lamp socket wants to screw down onto something solid. The screw holes got tapped 6-32, the standard electrical box screw size.
The odd little hole on the far side accommodates a USB-to-serial adapter that both powers the lamp and lets you reprogram the Arduino Pro Mini without tearing the thing apart:
The sloped roof makes the hole printable in the obvious orientation:
There’s an ugly story behind the horizontal line just above the USB adapter that I’ll explain in a bit.
The adapter hole begins 1.2 mm above the interior floor to let the adapter sit on a strip of double-sticky foam tape. I removed the standard header socket and wired the adapter directly to the Arduino Pro Mini with 24 AWG U-wires:
I didn’t want to use pin connectors on the lamp cable leads, but without those you (well, I) can’t take the base off without un-/re-soldering the wires in an awkward location; the fact that I hope to never take it apart is irrelevant. Next time, I’ll use a longer wire from the plate cap and better connectors, but this was a trial fit that became Good Enough for the purpose.
And then It Just Worked… although black, rather than cyan, plastic would look spiffier.
Bluish phases look icy cold:
Reddish phases look Just Right for a hot lamp:
A ring of white double sided foam tape now holds the plate cap in place; that should be black, too.
The OpenSCAD source code adds the base to the plate cap as a GitHub gist:
| // Vacuum Tube LED Lights | |
| // Ed Nisley KE4ZNU January 2016 | |
| Layout = "LampBase"; // Show Build Cap LampBase USBPort | |
| Section = true; // cross-section the object | |
| //- Extrusion parameters must match reality! | |
| 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); | |
| ID = 0; | |
| OD = 1; | |
| LENGTH = 2; | |
| Pixel = [7.0,10.0,3.0]; // ID = contact patch, OD = PCB dia, LENGTH = overall thickness | |
| //---------------------- | |
| // 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, | |
| $fn=Sides); | |
| } | |
| //---------------------- | |
| // Tube cap | |
| CapTube = [4.0,3/16 * inch,10.0]; // brass tube for flying lead to cap LED | |
| CapSize = [Pixel[ID],(Pixel[OD] + 3.0),(CapTube[OD] + 2*Pixel[LENGTH])]; | |
| CapSides = 6*4; | |
| module Cap() { | |
| difference() { | |
| union() { | |
| cylinder(d=CapSize[OD],h=(CapSize[LENGTH]),$fn=CapSides); // main cap body | |
| translate([0,0,CapSize[LENGTH]]) // rounded top | |
| scale([1.0,1.0,0.65]) | |
| sphere(d=CapSize[OD]/cos(180/CapSides),$fn=CapSides); // cos() fixes slight undersize vs cylinder | |
| cylinder(d1=(CapSize[OD] + 2*3*ThreadWidth),d2=CapSize[OD],h=1.5*Pixel[LENGTH],$fn=CapSides); // skirt | |
| } | |
| translate([0,0,-Protrusion]) // bore for wiring to LED | |
| PolyCyl(CapSize[ID],(CapSize[LENGTH] + 3*ThreadThick + Protrusion),CapSides); | |
| translate([0,0,-Protrusion]) // PCB recess with clearance for tube dome | |
| PolyCyl(Pixel[OD],(1.5*Pixel[LENGTH] + Protrusion),CapSides); | |
| translate([0,0,(1.5*Pixel[LENGTH] - Protrusion)]) // small step + cone to retain PCB | |
| cylinder(d1=(Pixel[OD]/cos(180/CapSides)),d2=Pixel[ID],h=(Pixel[LENGTH] + Protrusion),$fn=CapSides); | |
| translate([0,0,(CapSize[LENGTH] - CapTube[OD]/(2*cos(180/8)))]) // hole for brass tube holding wire loom | |
| rotate([90,0,0]) rotate(180/8) | |
| PolyCyl(CapTube[OD],CapSize[OD],8); | |
| } | |
| } | |
| //---------------------- | |
| // Aperture for USB-to-serial adapter snout | |
| // These are all magic numbers, of course | |
| module USBPort() { | |
| translate([0,28.0]) | |
| rotate([90,0,0]) | |
| linear_extrude(height=28.0) | |
| polygon(points=[ | |
| [0,0], | |
| [8.0,0], | |
| [8.0,4.0], | |
| // [4.0,4.0], | |
| [4.0,6.5], | |
| [-4.0,6.5], | |
| // [-4.0,4.0], | |
| [-8.0,4.0], | |
| [-8.0,0], | |
| ]); | |
| } | |
| //---------------------- | |
| // Box for Leviton ceramic lamp base | |
| module LampBase() { | |
| Bottom = 5.0; | |
| Base = [3.75*inch,4.5*inch,25.0 + Bottom]; | |
| Sides = 12*4; | |
| Stud = [0.107 * inch,15.0,Base[LENGTH]]; // 6-32 mounting screws, OD = ceramic boss size | |
| StudOC = 3.5 * inch; | |
| union() { | |
| difference() { | |
| rotate(180/Sides) | |
| cylinder(d=Base[OD],h=Base[LENGTH],$fn=Sides); | |
| rotate(180/Sides) | |
| translate([0,0,Bottom]) | |
| cylinder(d=Base[ID],h=Base[LENGTH],$fn=Sides); | |
| translate([0,-Base[OD]/2,Bottom + 1.2]) // mount on double-sided foam tape | |
| rotate(0) | |
| USBPort(); | |
| } | |
| for (i = [-1,1]) | |
| translate([i*StudOC/2,0,0]) | |
| rotate(180/8) | |
| difference() { | |
| cylinder(d=Stud[OD],h=Stud[LENGTH],$fn=8); | |
| translate([0,0,Bottom]) | |
| PolyCyl(Stud[ID],(Stud[LENGTH] - (Bottom - Protrusion)),6); | |
| } | |
| } | |
| } | |
| //---------------------- | |
| // Build it | |
| if (Layout == "Cap") { | |
| if (Section) | |
| difference() { | |
| Cap(); | |
| translate([-CapSize[OD],0,CapSize[LENGTH]]) | |
| cube([2*CapSize[OD],2*CapSize[OD],3*CapSize[LENGTH]],center=true); | |
| } | |
| else | |
| Cap(); | |
| } | |
| if (Layout == "LampBase") | |
| LampBase(); | |
| if (Layout == "USBPort") | |
| USBPort(); | |
| if (Layout == "Build") { | |
| Cap(); | |
| Spigot(); | |
| } |
The Smell of Molten Projects in the Morning 