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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.

Baseboard Radiator Sleds

Cleaning the baseboard radiator fins before moving the houseplants back to their winter abode by the living room window made sense, so I took the trim covers off and vacuumed a remarkable accumulation of fuzz off the top and out from between the fins. The covers had an equally remarkable accumulation of sawdust along their bottom edge, apparently deposited when the previous owners had the floor sanded before they moved in a decade ago.

If you happen to live in a house with baseboard radiators, I’m guessing you never looked inside, because nobody (else) does.

Anyhow, the radiator fins should rest on plastic carriers atop the bent-metal struts also supporting the trim covers, so that they slide noiselessly when the copper pipe expands & contracts during the heating cycle. Over the last six decades, however, the plastic deteriorated and most of the carriers were either missing or broken to the point of uselessness:

Baseboard Radiator Sled - old vs new
Baseboard Radiator Sled – old vs new

The shapes on the bottom are replacements made with a 3D printed base (“sled”) and a chipboard wrap around the radiator preventing the fins from contacting the strut:

Baseboard Radiator Sled - OpenSCAD show
Baseboard Radiator Sled – OpenSCAD show

Although it was tempting to 3D print the whole thing, because plastic, I figured there was little point in finesse: chipboard would work just as well, was much faster to produce, and I need not orient the shapes to keep the printed threads in the right direction.

The Prusa MK4 platform was just big enough for the number of sleds I needed:

Baseboard Radiator Sled - printed
Baseboard Radiator Sled – printed

The sleds along the left and right edges lost traction as the printing progressed, but everything came out all right.

The OpenSCAD program also produces 2D SVG shapes for the chipboard wraps and adhesive rectangles sticking them to the sleds:

Baseboard Radiator Sled - OpenSCAD SVGs
Baseboard Radiator Sled – OpenSCAD SVGs

Import those into LightBurn, duplicate using the Grid Array, Fire The Laser, then assemble:

Baseboard Radiator Sled - assembly
Baseboard Radiator Sled – assembly

The slits encourage the chipboard to bend in the right direction at the right place, so I didn’t need any fancy tooling to get a decent result.

A few rather unpleasant hours crawling around on the floor got the struts bent back into shape and the sleds installed under the fins:

Baseboard Radiator Sled - installed
Baseboard Radiator Sled – installed

Protip: Gloves aren’t just a good idea, they’re essential.

The trim cover presses the angled chipboard where it should go against the fins. The covers carry shadows of the plastic carriers, suggesting the clearance was tighter than it should have been and thermal cycling put more stress on the plastic than expected. We’ll never know.

Although I’ll make more for the other baseboards as the occasion arises, I hope to never see these again …

The OpenSCAD source code as a GitHub Gist:

// Baseboard radiator sled
// Ed Nisley – KE4ZNU
// 2025-10-11
include <BOSL2/std.scad>
Layout = "Sled"; // [Show,Build3D,Build2D,Sled,Wrap,Glue]
/* [Hidden] */
HoleWindage = 0.2;
Protrusion = 0.1;
Gap = 5.0;
Radiator = [25.0,62.0,50.0]; // X = support base, YZ = radiator element
SledBase = [Radiator.x + 10.0,Radiator.y,1.0]; // support under wrap
Runner = [SledBase.x – 2.0,3.0,1.6]; // bars contacting radiator support
GlueOA = [SledBase.x,SledBase.y] – [2.0,2.0]; // glue sheet
Wrap = [SledBase.x,Radiator.y + 1.0,Radiator.z + 1.0]; // chipboard wrap around radiator
WrapFlat = [Wrap.x,Wrap.y + 2*Wrap.z];
WrapThick = 1.2;
WrapSlit = 0.4;
//—–
// Sled base
module Sled() {
cuboid(SledBase,rounding=2.0,edges="Z",anchor=BOTTOM)
position(TOP)
for (j=[-1,1])
fwd(j*SledBase.y/3)
cuboid(Runner,rounding=Runner.z/2,edges="Z",anchor=BOTTOM);
}
//—–
// Glue sheet
// Export as SVG for laser cutting
module Glue() {
rect(GlueOA,rounding=2.0);
}
//—–
// Radiator wrap
// Export as SVG for laser cutting
module Wrap() {
difference() {
rect(WrapFlat,rounding=2.0);
for (j=[-1,1])
fwd(j*Wrap.y/2)
rect([Wrap.x/2,WrapSlit]);
}
}
//—–
// Build things
if (Layout == "Sled")
Sled();
if (Layout == "Glue")
Glue();
if (Layout == "Wrap")
Wrap();
if (Layout == "Show") {
xrot(180)
Sled();
color("Yellow",0.6)
Glue();
up(1)
color("Brown") {
cuboid([Wrap.x,Wrap.y,WrapThick],anchor=BOTTOM);
for (j=[-1,1])
fwd(j*Wrap.y/2)
cuboid([Wrap.x,WrapThick,Wrap.z],anchor=BOTTOM);
}
}
if (Layout == "Build3D") {
Sled();
}
if (Layout == "Build2D") {
left(GlueOA.x/2 + Gap/2)
Glue();
right(Wrap.x/2 + Gap/2)
Wrap();
}

Comments

4 responses to “Baseboard Radiator Sleds”

  1. brentatedsblog Avatar
    brentatedsblog

    Resistance heating? Och. You might want to look into a couple of mini splits.

    1. Ed Avatar

      Nope, it’s old-school hot water baseboard heat from a gas furnace.

      We run the super-whoopie high-efficiency heat pump until the dew point drops into the upper 30s, whereupon the outdoor unit frosts over and the electric resistance heaters cut in. Then it makes much more sense to burn gas, as we found out the hard way last winter.

      1. RCPete Avatar
        RCPete

        (Hi again. The bug in Palemoon that caused a crash when I used it to visit finally got fixed.)

        Our neighbors put in minisplits for AC/heat, but they also found out the hard way that air-to-air heat pumps don’t do well when the temps drop down to “fripp’n cold”. Lodgepole pine in a good woodstove keeps them going.

        For what it’s worth, Amazon sells Schwer anti-cut gloves (not kevlar, but a similar fiber). I used a pair when laying pavers this spring, and the gloves did really well. They are better for delicate(ish) work than leather work gloves. My hands are big, and they have size 10/XLs, too.

  2. Prusa MK4+MMU3 vs. Spool Join: Whoopsie – The Smell of Molten Projects in the Morning Avatar

    […] nobody will ever see the Radiator Sleds, I started a batch with the tail end of the white PETG spool and set up the Spool Join function to […]

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