I made a vacuum. It sucks.

I have several drawers in my supply closet full of small switches, LEDs, gears, motors, and fans scavenged from various pieces of electronics. This can't be surprising, given the theme and subject matter here. This collection included two crown jewels that I had not yet been able to find a project for; blower motors from hairdryers my wife found ways to destroy. Usually, that destruction came by leaving them on the sink while on, so the hairdryers would vibrate and blow their way free of the porcelain's weak grip, and take that short slide off a long drop to the tile below.

She dropped them. She dropped them all.

Anyway. These fans are great. The fan blades are aggressively angled and stubby, and, knowing nothing about fluid dynamics, I assume that means they're the best fans I've ever laid hands upon. They've never found their way into a project, though. They sat for at least two years, dormant. Waiting to be released on a decent idea.

But I never got one of those, so I decided to make my own dust buster handheld vacuum thing.

Sup, bruh.

Yep. I'm doing this backwards and showing off the final result first.

I also did this whole project backwards, since I started with the part I wanted to use, and designed a project to use it. I started with that fan, and I thought... Man, a super strong fan running in reverse is like... The definition of suck. If I had a way to narrow the airflow coming in, say, through a hose or narrow opening, that creates enough suction to make a little vacuum. Since the fan was the starting point for the project, it was the starting point of the design also.

This was designed in 123D Design from AutoDesk (yes, retired application, use Fusion 360 instead, blah blah). I started off with a measurement of the fan shroud, and sketched a circle with a diameter wide enough to account for 2mm thick walls and a little extra tolerance, then lofted this up to a nozzle end with an outer diameter meant to fit into a dishwasher drain hose that I had on hand.

Face it, ya basic.

I smoothed out the sharp bevels, and at this point, I used the "shell" command to make it hollow.

Got some curves now.

The fan shroud has these little tabs in it to hold it in place. I had to cut out slots for these next.

Down there at the bottom, it's tab slot city.

I figured the next step was figuring out a filter. After all, I can't have debris just plow into the fan. I toyed around with a couple ideas, and at one point, I thought about having it slide into place into the body of the vacuum.

This was going well. Then it got stupid.

Recognizing that this was dumb and would cause 99 problems, I backtracked and created a lip inside to push the filter against. I'll show that off later. 

Next, the bottom, where the exhaust and electronics would live. I started by copying and pasting the top piece, then slicing off the useless nozzle part.

This could also be the story of how I designed a 2-liter bottle of Coke.

I designed this part upside down to make life easier. The back end of this thing was going to end up needing a cap, and some ventilation for exhaust airflow.

The cap is under those nubby deals.

Poor nubbies. They existed only to leave behind little holes. In the model, and in my heart.

Oh, and here's a shot from below to show where the filter rests on that ledge. It also gives a good shot of the cutouts for the power switch and DC power plug on the exhaust cap.

Filtertown, USA.

So, with that, it's time to get printing!

What am I? Why am I allowed to exist?

Okay, that printed poorly. Super poorly. The surface finish is due to printing at large layer heights and extremely fast speeds; at that speed, the acceleration and deceleration of the print head and bed cause artifacts on the surface. The four distinct layer shifts you can see? No idea on those. That's not a common problem on my printer. Although, it could also have something to do with the speed of printing also.

A print like that is mostly useless, but not completely. I can still check the mechanical tolerance for fit. The hose seemed to fit, but I could definitely increase the outer diameter of the nozzle to better create a seal. The bottom, where the fan shroud connects, is a little tight, and so is the fit on the filter. So I make a few changes, and print at significantly slower speeds.

Better.

Now, I did still get lazy and turn up the speed on the print as it got to the last thirty minutes, which shows right up by the nozzle. It was nearly bedtime, and I wanted to finish this thing. As it happens, I still stayed up until almost 4 AM.

After checking fit and finish with the hose, it still wasn't a tight enough seal, so I threw on a bead of PLA using my 3Doodler 3D pen.

It's like you almost can't tell where I ramped the speeds to ridiculous.

When printing the bottom, in particular the exhaust endcap, I used a technique that I had been dying to try. I paused the print halfway through using the M600 advanced pause command, and I stretched some thin tulle mesh across the print and clipped it to the bed. Then, I let the print resume, and it ends up trapping the mesh in the print. It's a little hard to see here, but it's there.

I used the same method for the filter inside. It's not exactly a HEPA filter. It's really just there to catch large solids; dust will just blow right through this thing. That filter is what defines the dust cup, basically. It sits just above the fan, so all the junk it picks up stops right there before blowing through the fan. To empty the cup, I just remove the hose and shake the thing out.

Now. The big question. Does it work?

It sucks. And for once, that was the goal.