CNC-3018XL Setup: Table Riser Blocks

After fixing the X axis drive, the CNC-3018XL table moved properly again, so I measured its overall alignment:

3018CNC – table height measurement

The +Y side (on the left in the photo, keeping in mind I’ve rotated the axes) turned out to be 0.7 mm too low, so I made a set of riser blocks to level the tabletop:

Table Riser – solid model

The 10 mm height would ram the tip of a Pilot pen about 10 mm below the tabletop surface, were it not for the spring-loaded pen holder:

Pilot V5RT holder – installed

The 0.7 mm difference in height levels the tabletop:

CNC3018XL – table riser positions

The OpenSCAD code produces an SVG outline I intended to use for a foam pad, but then I found a quartet of springs that worked even better:

CNC3018XL – table spring mount

So it’s now aligned within ±0.3-ish mm across the surface, with the unflatness of a slab cut from a 1955-era Formica kitchen countertop accounting for most of the difference in a swale from Quadrant III across the origin to Quadrant I.

Which a check plot using an old file shows will be Flat Enough for my simple needs:

CNC3018XL – test plot

Having the camera alignment remain exactly spot on came as a pleasant surprise:

Camera Alignment check

The faded cross to the left came from the table’s previous position; there’s no positive index between the countertop slab and the underlying T-slots.

Part of the motivation for these blocks was to verify PrusaSlicer automagically handles filament / color changes between two objects, as long as OpenSCAD hasn’t unioned them as part of a common transformation. Not having to cut out the socket around the text simplifies the code from what I’d been doing with previous objects.

The OpenSCAD source code as a GitHub Gist:

	// CNC 3018 table riser blocks
	// Ed Nisley – KE4ZNU
	// 2025-06-29

	include <BOSL2/std.scad>

	Layout = "Show"; // [Show,Build,Outlines]

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;

	BlockOA = [40.0,30.0,10.0]; // riser block size

	SlotBlock = [8.0,BlockOA.y,3.0]; // alignment in slot

	BoltOD = 6.0 + HoleWindage; // central bolt

	LogoFont = "Fira Sans Condensed:style=SemiBold";
	LogoSize = 7.5;
	LogoColor = "Red";
	LogoThick = 0.4;

	//———-
	// Define Shapes

	module Riser(thick=1,matl="Block") {

	LogoText = format_fixed(thick,1);

	if (matl == "Text" \|\| matl == "All")
	right(BlockOA.x/4) zrot(90)
	color(LogoColor)
	up(thick + SlotBlock.z + ((matl == "All") ? 0.01 : 0))
	text3d(LogoText,LogoThick + ((matl == "All") ? 0.01 : 0),LogoSize,LogoFont,
	anchor=TOP,atype="ycenter");

	if (matl == "Block" \|\| matl == "All")
	difference() {
	cuboid(SlotBlock,$fn=8*3,anchor=BOTTOM,rounding=2.0,except=[BOTTOM,TOP]) position(TOP)
	cuboid(BlockOA,$fn=8*3,anchor=BOTTOM,rounding=2.0,except=[BOTTOM,TOP]);
	down(Protrusion)
	zrot(180/6)
	cyl(2*BlockOA.z,d=BoltOD,$fn=6,anchor=BOTTOM,circum=true);
	}

	}




	//———-
	// Build things

	if (Layout == "Show")
	down(SlotBlock.z)
	Riser(BlockOA.z,matl="All");

	if (Layout == "Outlines") {
	projection(cut=false)
	Riser(BlockOA.z,matl="Block");
	}

	if (Layout == "Build") {
	up(BlockOA.z + SlotBlock.z) xrot(180)
	Riser(BlockOA.z,matl="Block");
	up(BlockOA.z + SlotBlock.z) xrot(180)
	Riser(BlockOA.z,matl="Text");

	}