One of the projects from a weekend in August 2026 was moving the big HVAC unit in the robotics area. Due to a miscommunication, it had been plunked down in the middle of a space we need. So I went in and helped knock a big dirty hole in the wall. Here's one of the other coaches on a ladder, drilling the hole that the vent goes through.

The prior hole just had a flexible tube jammed through it, but I figured I could do slightly better, so I designed an inside and an outside plate.

I fabbed up the inside plate on Sunday (plasma cutter FTW), then spot welded it together and powder coated it. It's a square steel plate with a rolled, slotted flange around a big round opening, powder coated white.

The outside was the next job: a laser cut grate with our logo on it, which I would also powder coat later in the week. That's the rest of this page.

The big round field is a honeycomb of small holes so the air can get through, with the gear and bulb left solid. That's a lot of holes to cut. Here's the laser head at work, close up and then from farther back.

The sheet on the bed of the laser with the pattern cut, and the bed afterward, with the little cut-out slugs scattered over the bed.

The pattern burned into the firebricks shows how serious a 1200W laser is: it did that even when out of focus by almost two feet!

And the finished cut, bare metal, before any coating went on.

I powder coated it in two stages. First a zinc primer, which should give it even more corrosion resistance than the topcoat alone.

Then the white topcoat.

And here it is finished, lying on the workbench.

It's on the outside wall, in an alley that few people go down, which is too bad. I still enjoy seeing it whenever I do.

It looks especially cool when it's backlit at night. I'll have to get a picture of that one of these days.

On October 22 I started fabbing up a little catch basin. Sheet metal is fun. Here's the folded tray on the bench. I just cut the shape with some metal shears by hand, and spot welded the corners.

The drain needs a conical recess, so I 3D printed a one-off punch and die to make one. This is the design, in cross-section.

I already have a Harbor Freight 20-ton hydraulic press, like everyone has in their garage, but this is only 26 gauge steel, so a clamp or a bolt and nut is plenty.

It worked even better than I expected. Here's the clamp squeezing the printed die into the tray.

And the formed drain: a nice smooth conical recess.

The drain parts are 3D printed too. This is the drain fitting seated in the recess.

From underneath, the drain passes through the table via a printed hex nut fitting, with a clear braided hose attached below.

Here's the finished product (the photo at the top of the page), just waiting for the silicone to cure. I tilted it up ever so slightly so everything runs to the drain. I might need to add some bumpers at the edges to make sure the mill doesn't vibrate the whole thing loose. For obvious reasons I didn't want to fasten the pan down, although I could; a neoprene washer under the screw would probably work fine.

Here's the mill running with the pan in place. Working like a champ.

This is where it started: my first attempt at a sheet metal project, in January 2022. Meh. But it's a start.

Achievement unlocked: spot welding. The spot welder itself is in the background. These units aren't too expensive, and versions that run off of 120 are available, so this capability is pretty accessible even to a modest home shop.