This is a little mini-project that I decided to fork into its own narrative because I figured more than I would find it useful. In reality, the build of this thing was kind of interspersed with the dumpster itself, so you’ll see a handful of out-of-sequence photos.

To recap, YWIT version 1 used two first-generation CosClouds smoke effects units for the ‘flaming’ bit of the dumpster. These survived a bunch of abuse in the bot (being left loose to jostle around, accidentally run empty) but had the downside of an inconvenient long-and-skinny form factor and needing to be refilled quite frequently. They’re built to be worn discretely on a costume, and I was looking more for a rolling fog machine.

So I decided to get adventurous and learn more about the literal vape shop (not my memetic, metaphoric vape shop) ecosystem. There’s a whole little miniature landscape built around vape batteries now, with them used to power portable soldering irons, hot knives, and other stuff that requires brief bursts of power to turn into heat in order to cut around sales restrictions on smoking products.

The plan was to appraise the phat cloudz market and see what parts interoperate and can be modified for my purposes. Remember, I don’t inhale anything as a habit. I have the purest, untainted virgin lungs possible… because from a young age I learned smoke that comes off anything I do is usually very irritating (soldering, welding, burning chemicals, hot cutting fluids, etc). So let’s see what kind of damage I can do!

I literally went to a few local vape shops to ask about their product lines! I was very upfront about the fact that I don’t vape, have no idea what’s going on, am using these things for unintended purposes, and they were welcome to upsell me on whatever.

Honestly… a lot of places didn’t even know that much about their own products. But a local XhaleCity was super responsive in laying out the goods in front of me and giving me a rundown of what fits what. The long and short of it is, almost everything I’d care to use has a M7 x 0.5mm thread called “510” for whatever reason, and just about everything else uses a M12 x 0.5mm thread called eGo.

I walked out of there with two Geekvape Z-FLI units with 0.15 ohm stock coils. Geez, I remember when sub-ohm vaping was a meme passing around makerdom and here we are just casually hitting tenth-ohms now. I don’t think you could ever convince me to stick a hundred watts in my face, but here we are.

Oh, yeah, they come with 0.4 ohm “lower power” coils. I’m guessing I’ll probably be running these instead because I’m looking for a little more continuous duty.

I blasted one apart as soon as I got home. These are very intricately manufactured devices, with all the parts featuring mill-turn 4th+ axis action. It took me a little while to understand the airflow path and then to formulate how to tap into it to turn it into a pressurized exhaust path.

The gold assembly on the left is actually the “Coil”. It’s not coil shaped so much as a grid heater made in a cylindrical shape! That explains how it’s so low resistance and not the size of a pencil lead. My only real exposure to the high end vaping market up to this point has been hand-wound helical coils.

Along with these tanks, I picked up a few cheap 510-thread batteries. None of these would remotely hold up the Z-FLI in operation, but I was out to find out which of their connectors were salvageable easily in order to use as a mounting base.

Now, there are plenty of “DIY” 510 threaded bases for sale. However, the vape shop was 5 minutes away and I was trying to get this bot finished before a regularly-occurring end of summer work trip. So for now, I cast Jeff Bezos aside and focused on local resources I could just go get…. multiple times in one day.

All of these pen shaped vape batteries were constructed by means of a thin aluminum or brass tube with the 510 fitting pressed into the end. Not very securely, I might add. The candidate choice came down to which ones had the most metal in the center pin that I could drill out to create the air passage.

These flame-anodized 900mAh jobbies won, as the fitting was solid brass and the center pin was pretty hefty.

Teaching the Chinese to create flame-anodized finishes was a mistake.

The very very skinny wires are just soldered onto a roughed up area of the fitting body (for negative) and the center pin itself, made of nickel plated brass (for positive). Seriously, I think these wires were something like 26 gauge. Probably enough to carry the amp or five for a second at a time.

To pressurize the interior of the vape tank, I had to drill a coaxial hole down the center of the pin (on the battery side) and the receptacle (on the tank side). I chose 2.2 mm as a compromise between airflow and retaining some reasonable wall thickness in the brass for conductivity. The post is 3.5mm diameter.

Likewise, I took the coil contact out of the tank and drilled down its center with the same diameter.

The assemblage of processed parts ready for some test fitting.

Here is the result, a visible straight-through hole that allows me to inject the pumped air into the business side of the coil. One downside here is any unburnt juice that makes it past the coil will probably puddle in whatever container/housing I put these in. That’s just an item on a checklist, I suppose. I’ll just pour it out before every con.

I modeled up a housing where two of the battery 510 bases will be mounted. The base is basically a pressurized air plenum, with the holes on one end to pass wires through as well as to mount a barb fitting for the air hose.

The housing was quickly busted out of my Something-Filled Nylon still remaining from the robot-related print jobs.

An interesting bit of trivia: The M12 x 0.5 thread of an eGo battery happens to be the same thread that a lens locking ring for an S-mount or M12/12mm camera lens. And guess who just happened to have locking rings for S-mount lenses hanging around? That turned the battery connectors into bulkhead mounts real quick and easy!

A small amount of epoxy secures the bulkhead joints as well, since I wanted to beef these up against vibration and my gorilla style overtightening. Same goes for the little 1/8″ barb fitting, since its thread was too short to use a nut with on the other side.

The connectors are wired up independently with 20 gauge silicone wire. I’ll be joining them externally in series to run off approximately 6 volts, which is the supply voltage for the air pump.

Here’s the resulting Double-Barreled Vape Cannon! I was fairly pleased with this 2-day build and it did work very well on the bench. If I had to revise it with more time to spare, I’d definitely use the all-metal “DIY mount” ones because they are more secure.

Final Integration Time

With the Double Barreled Vape Cannon finished, I could actually put the robot together now since they’re kind of a pain to reach otherwise.

I made these drill bit piloting jigs to clamp onto the sides of the Dumpsty so I could locate the holes for the drive pods. They were drilled with a healthy amount of clearance, basically a 1/4″ hole for the #10 screws, so I could make a bit of adjustment to the location if need be. This is not a precision application in any sense.

Here’s one wheel module mounted with some wide-head #10 self-tapping plastic screws going into the nylon body. The “locating feature” built into the bottom of the pod straddles where the center baseplate of the robot was.

And…. honestly, everything else was just loading all the gear in. Remember that this part was basically built and tested on the bench beforehand.

The only new action here was that I whipped up a small snap-fit mount for the air pump, seen in the center. It uses two of the existing inboard motor mounting holes.

And a short test drive that may or may not have set my basement smoke alarms off:

ok they do work… whew

So here it is, in all its glory! Your Waifu Is Still Trash made its debut (sans Miku artwork) at Dragon Con 2024! There’s a short little bit of robot building I did for that involving Susquehanna Boxcar… so stay tuned there. I’m getting some Miku art done for it that will be printed and installed like the world’s most self-aware Itasha wrap.