I needed a holder for my dial indicator, I broke the one printed from this source:
https://www.thingiverse.com/thing:4524389

I decided to design it in 2 parts,
it gets stronger, and if broken, you just need to print the one you broke.
Depending on you printing quality, you can experience a little gap between the pin and the holder, it is easy to solve by putting a piece of paper at the same time you assemble the 2 parts.

You can ever change the pin to hold a pen or whatever you need to move with your ender3.

This is a remix from https://www.thingiverse.com/thing:4524389

Creality

Ender 3

No

No

0.4

20%

Any material does the trick.

$fn=50;
roundy=2;

difference(){
union(){

translate([-29,-60.2,-13]) import("/home/Downloads/Print+in+Place+Dial-Indicator!+-+For+easy+Bed+leveling!/files/dial_holder-_Ender3_correct_orientation.stl");

}
translate([0, 0, 14])
color("red") linear_extrude(height = 14)
square([140,140], center = true);

translate([-10, 10, 0])
color("red") linear_extrude(height = 34)
square([22,20], center = true);

}

translate([-7,5,0 ])
difference(){

linear_extrude(height = 14)    minkowski(){        square([(14)-2*roundy,(14)-2*roundy], center = true);        circle(roundy);        }          linear_extrude(height = 14)        square([10,10], center = true);

}
color("blue") translate([-2,-7,14 ]) rotate([0, 90, 0])
linear_extrude(height = 2)
minkowski(){
square([(8)-2roundy,(20)-2roundy], center = true);
circle(roundy);
}

translate([-1, -21.5, 24.5-14]) rotate([15, 0, 0])
color("blue") linear_extrude(height = 5.5)
square([2,14], center = true);

$fn=100;
roundy=3;
DialDiameter=8;
thickness=3;
GripAngle=290;

difference(){
rotate([0, 0, (360-GripAngle)/2])
translate([0, 0, 6])
union(){
rotate_extrude(angle=GripAngle,convexity = 10)
translate([DialDiameter/2+thickness/2, 0, 0])
square([thickness,12], center = true);
translate([DialDiameter/2+thickness/2, 0, 0])
cylinder(d = thickness, h = 12,center=true);
rotate([0, 0, GripAngle])
translate([DialDiameter/2+thickness/2, 0, 0])
cylinder(d = thickness, h = 12,center=true);
}
translate([0, 0, 6.5])
rotate_extrude($fn=200)
polygon( points=[[0,0],[9,9],[0,9]] );
}

translate([-19, 0, 5])
rotate([0, 90, 0])
SquarePin();

module SquarePin(){
linear_extrude(height = 14)
minkowski(){
square([(10)-2roundy,(10)-2roundy], center = true);
circle(roundy);
}
translate([0, 0, -1.5])
linear_extrude(height = 3, center = true, convexity = 10, scale=2)
minkowski(){
square([(5)-roundy,(5)-roundy], center = true);
circle(roundy/2);
}
}

//color("red") cylinder(d = 8, h = 16,center=true);//PseudiDial