A 3D Printer is a Ruler

What is a 3D printer for? Well, it can do things that are difficult to do other ways, or would take a long time. This morning I was looking at fitting drawer fronts to a table. I needed to hold the drawer front with a fixed gap around the edges so that there was a uniform clearance. I had a quick think and knocked up some wooden shims using the bandsaw. They were OK, but then I found that the gap at the bottom of the drawer front was a bit different to the sides. So I needed a couple more. So I made some more on the bandsaw. Then I found I needed two more to make the front stable while shimming it up. OK, off to the 3D printer. Some SCAD later (10mins or so):

//
// Marking aid for table shelf runners
//
//

// 25mm height for runners

if (0)
{
difference()
{
cube([40, 10, 30], center=true);
    translate([0, 2.55, 30.2/2-25/2])
cube([45, 5, 25], center=true);
}

}

// shim to keep distance consistent when attaching sides to drawer front
if(1)
{
    ov = 7;
    th = 3.5/2;
    th =1;
    d= 100/2-ov/2+th;

difference()
{
cube([20, 7, 30], center=true);
    translate([0, d, 30.2/2-25/2])
cube([25, 100, 25], center=true);
}

}

Quick and dirty. Note the shim distance of 3.5/2. That's tricky on the bandsaw, or in wood at all. Not a problem on the 3D printer.
A bit of printing later (two printers now, so simultaneously on both) and we have shims:

The two different sizes look like this when they are resting:

Of course, you can do other things. Also printed this morning were two pin vice holders:

(The sharpie holder was done weeks ago).