Maker on jverkamp.com

Undergravel Filter

Tue, 02 Dec 2025 00:00:00 +0000

Four years / a day? What’s really the difference.

I was asked to design an undergravel filter. Let’s do it.

Prototype

Here’s the original prototype:

Not much to go on.

Version 1

And here’s where we ended up:

// Units
inch = 25.4;

// Requested dimensions (converted to mm)
box_x = 9 * inch;
box_y = 6 * inch;
box_z = 0.75 * inch;

// Piece thickness of walls and bottom (top?)
wall = 2;
bottom = 2;

// Size and space between centers for grid holes
hole_d = 2.5;
spacing = 10;

// Size of the larger tube hole in the corner
tube_hole_d = 18.4;

// --- Don't change anything below this line ---

// Derived cavity size
inner_x = box_x - 2 * wall;
inner_y = box_y - 2 * wall;
inner_z = box_z - bottom;

// Centered hole grid counts
nx = floor((inner_x - hole_d) / spacing) + 1;
ny = floor((inner_y - hole_d) / spacing) + 1;

// Offset to center hole grid
start_x = wall + (inner_x - (nx - 1) * spacing) / 2;
start_y = wall + (inner_y - (ny - 1) * spacing) / 2;

// Tube hole in the corner
tube_hole_x = start_x + spacing;
tube_hole_y = start_y + spacing;


difference() {
 // Outer box
 cube([box_x, box_y, box_z]);

 // Hollow interior (cut from top)
 translate([wall, wall, bottom])
 cube([inner_x, inner_y, inner_z + 0.01]);

 // Hole for the tube
 translate([tube_hole_x, tube_hole_y, -1])
 cylinder(h = inner_z + 2, d = tube_hole_d, $fn = 64);

 // Hole array through bottom
 for (i = [0:nx-1]) {
 for (j = [0:ny-1]) {
 x = start_x + i * spacing;
 y = start_y + j * spacing;

 // Skip grid hole if too near tube hole
 dist = sqrt( (x - tube_hole_x)*(x - tube_hole_x) +
 (y - tube_hole_y)*(y - tube_hole_y) );

 if (dist - 1 > tube_hole_d/2) {
 translate([x, y, -1])
 cylinder(h = bottom + 2, d = hole_d, $fn = 32);
 }
 }
 }
}

Aquarium Lid Clips

Mon, 01 Dec 2025 00:00:00 +0000

Okay, here’s another (wow, has it really been four years…)

We’ve been ~~slowly~~ acquiring fish tanks. In order to make custom lids which fit each tank and allow for growing plants in them, we need little clips which can hold the lid of the tank. Most of them, we get the right size for, but there’s one tank which is a bit different.

Rather than the 5mm side walls all the rest have, this one has 4mm on the sides and back and 3mm on the front.

New Baby Shirts!

Sun, 10 Oct 2021 00:00:00 +0000

We’re going to be parents (again)!

Last time around, we made adorable big brother/big sister/little sister shirts with dinosaurs, this time we wanted to go with FLOWERS! It’ll be wonderful.

Board Game Cup

Wed, 30 Dec 2020 00:00:00 +0000

I play … a lot of board games. This year has been hard to do that in person¹, but I still get a chance from time to time. Most recently, I played Century: A New World.²

One component I really love that came with that game was a set of four small plastic bowls that hold the various goods (colored wooden cubes). It’s… kind of brilliant. There are a few other games that could use something like that (cough cough Lords of Waterdeep)… and I have a 3D printer. Let’s make some!

Links:

3D COVID-19 Ornament

Thu, 24 Dec 2020 00:00:00 +0000

So. This was actually what I originally intended to make when I made the 2d ornaments:

Full 3D coronavirus!

Unfortunately, what I kept getting was something more like this:

No matter how I tweaked the support settings, I could not get the little knobs to print. I even tried printing it in halves, but only half of it came out still. So it goes. Perhaps next year. ¹ Eesh that’s a terrible picture too.

Links:

Original STL model (original source, licensed under CC BY-NC)²
With hangler
With hanger and year
Fusion 360 file
Tinkercad file

2D COVID-19 Ornament

Tue, 22 Dec 2020 00:00:00 +0000

This… has been quite a year. As I’m sure everyone is well aware. But hey, it gave me the perfect chance to make a unique ornament for my mother (she’s always asking) that really represents the year.

Links:

Christmas Tree Leg

Mon, 21 Dec 2020 00:00:00 +0000

This is exactly why I got a 3D printer:

Kids are hard on just about everything. This time around, they managed to lose one of the three legs for their smaller Christmas tree. It’s not the sort of thing that’s particularly easy to find replacements for and even if you can it would probably cost about the same as the entire tree for shipping.

So of course I had to model and 3D print my own!

Links:

MtG Seperator

Sat, 15 Aug 2020 00:00:00 +0000

Finally getting around to the ‘more of this’ I mentioned.

A little while back, I got a 3D printer (a Creality Ender 3, they’re a really good budget option). It took forever and a day to tune it, but now that it’s working, I’ve been printing various things I’ve found online. One of those things was some 3D Magic the Gathering (MtG) boxes. With those, I really wanted some dividers (like these), but instead of by color, I wanted them by set.

I know, I know.¹²

Links:

Sock and Underwear Drawer

Sat, 22 Feb 2020 00:00:00 +0000

One thing that I’ve been meaning to do for a long time is make more things. To that end, when my family needed a new set of containers to hold socks and underwear and the like, I designed one!

It has been a long time since I’ve used CAD programs, but it’s all starting to come back to me.

It’s actually two seperate halves (helps a bit with the weight) and could be stacked, although we have them side by side.

Files: