If you aren't familiar with 'OpenSCAD The Programmer Solid 3D CAD Modeller', it's software to generate 2D and 3D surfaces.

I wanted to make a mount for corrugated tube to run Ethernet through for a pair of APs, and so I took a few measurements and below is what I got;

// SRJ 2026-09-21  Smurftube Clip
$fn=100;

module SmurfTube(){
cylinder(h=60, d=24, center=true);
// Ribs on 3.52mm centers.
for (z = [-30 : 3.52 : +30]){
    translate([0,0,z]) cylinder(h=2.5, d=27, center=true);
    }
}

module LathScrew(L){
    // #8 has an 11mm d/Head
    translate([0,0,15]) cylinder(h=30,d=11.75,center=true);
    // 4.5mm for clearance
    cylinder(h=60,d=4.75,center=true);
}

difference(){
    cube([40,50,20],center=true);
    translate([0,-20,2]) SmurfTube();
    translate([0,5,0]) rotate([90,0,0]) LathScrew();
}

The image looks like;

Not only does OpenSCAD make it easy to design parts, it has the ability to directly send the model to OctoPrint.