squirrelitude | Entries tagged with diy

Today's excitement was building and testing an alcohol rocket! (This was inspired by https://www.youtube.com/watch?v=wuz0curb_hg)

Proof of concept: I dug through the recycling and found a discarded 1L plastic water bottle, added a drizzle of 70% alcohol, shook it around, emptied out the extra, and waved a lighter flame past the end -- success! A sizeable jet of flame and a whooshing sound. (The bottle was warm and the top was slightly warped and shrunken, which is to be expected.)

(Safety note: Yes, you can get burned this way. Keep your fingers at least an inch below the line extending out from the nozzle. I believe the safe way to do this is to squeeze the bottle slightly to puff some fuel/air mix out towards the flame. Much safer is to just skip this and go on to electric ignition...)

Second proof of concept: I dug around in my parts bin and found an empty piezo-igniting lighter (rather than the spark-wheel kind) and removed the igniter. I located a long 4P2C (single-line telephone) cord and cut off the ends, then temporarily wired it to the lighter's contacts. I was able to get a spark on the other end, and ignite the bottle that way. Electric ignition confirmed!

(I spent a long while trying to properly solder the wire to the igniter, then broke the igniter... and found I had another igniter that was easier to work with -- one that came from one of those long lighters made for grills or something. I just twisted the wires together this time.)

Horizontal test: I rolled up a newspaper (remember those?) into a tight cylinder with the cord at its center, sticking out a few inches at the end. Once it was about thick enough, I masking-taped it into shape. Launch tube! Launch tube hanging off of a wall with a rock weighing down one end, alcohol in the bottle, launch tube inserted into the bottle about halfway, make the spark. A few false starts until I had the mix right, and then BAM-whoosh! Bottle goes across the yard into the chain link fence.

Refinement: I thickened one part of the launch tube with more rolled paper and tape, so the bottle slides to a stop and lightly pressure-fits into the right position and with the tube centered. Just a few drops of Everclear (95% ethanol) seems to be about right. A little more and it gets more violent. I'm not too concerned about it blowing up (the bottle can slide off the tube freely, and is very light) but I'll switch to a soda bottle before experimenting with that -- bottles intended to hold carbonated liquids are built for higher pressures.

Still to do:

- Make a stand so it can actually launch upright
- Find a park where I can do a proper launch
- Maybe look around for a stronger ignition source so I can use a longer wire, which would make me feel more comfortable having the kid launch it. (The current igniter seemed to have too much voltage drop over a longer wire, but it's also possible I was still having fuel mix issues at the time.)

I put together a new raised bed from some spare materials I scavenged or had lying around:

A 50 gallon plastic tub the neighbors were throwing out because it was cracked
A long flat board someone had used to make a campaign sign, which they then threw out
Some plastic jugs
Used potting soil off of Freecycle
Some old straw that a former upstairs neighbor had intended to use as mushroom substrate
Worm compost

It's a bit unorthodox, but I think it will work well enough. If it all falls apart, it is unlikely to do so catastrophically, and I can always just move stuff into a new container at the end of the season.

Photos and description

The neighbors had thrown out this big 50 gallon plastic tub, presumably because it had a couple cracks on one side. I nabbed it because I saw potential for a large, roughly rectangular, movable raised bed. This is something I've been vaguely wanting.

It also still has a lid. I think I'll be able to put the lid on for the winter, and then if salty sidewalk snow is shoveled on top, it won't contaminate the soil. (Might require some supports, though. Snow is heavy!)

3/4 top view into a long rectangular beige plastic tub. Two pieces of wood have been inserted, running lengthwise, pressure-fit against the far ends.

The main problem was the cracks. The soil pressure would cause the tub to bow out on the sides and would worsen the crack over time. One option I thought of was to tie the long side together via cords running through the tub, crosswise, resisting the bowing effect. Another was to brace the tub against something. What I ended up doing was cutting some boards to fit lengthwise so that they were pressing the narrow ends away from each other slightly. This might just cause new point strains on the ends and new cracks there, but it's worth a shot.

The tub is upside-down and there are about 70 holes drilled in it along the high points

Next I had to provide drainage. I drilled about 70 holes into it along what should be the lowest points. I didn't like all the plastic shreds this generated, but I think I got almost all of it with the vacuum cleaner.

In some places (the last half of the work) I remembered to stagger the holes to avoid creating lines of weakness.

The tub is upright again and has assorted plastic jugs and bottles lying on their sides in the bottom.

This is the silliest part. I didn't have enough material to fill it with, and I didn't actually need something all *that* deep. And I didn't want it to be so heavy it couldn't be moved. So I solicited some empty bottles from neighbors, tightened their lids (or hot-glued when necessary), and laid them down in the bottom. Now there's less space to fill, and less weight, but still something of a deep reservoir space for excess water to sit in before it exits.

These are all HDPE, same as the tub, so they should be *relatively* innocuous. We'll see if they collapse, or float up through the soil, or something else unwanted. They should stay fairly cool and protected, though.

Another option was to cut the tub shorter and raise it on blocks. Height is desirable for two reasons:

We have a low wall around the front yard and I want the plants to get enough light
I want to minimize soil splashup from the yard into the container

But that would reduce the structural integrity of the container even more.

Various bins and buckets with soil components or amendments, described below

This is the material I had to work with:

A half-rotten bale of straw. This is difficult to work into the soil, but will add structure and later carbon.
In the black bin, about 10 gallons of really lovely used potting soil. It's from an organic gardener who always mixes hers down with vermiculite, perlite, and compost each year to rejuvenate it. It had a good deal of structure and cohesion and I hated to break it up.
In the lower white bucket, about 5 gallons of substrate from another person on Freecycle. This is maybe 30% perlite, 20% expanded slate (new to me!), and 50% bark and other mulch. Seems like something you'd grow cactus in.
And in the other white bucket, about 2 years of worm compost, maybe 2 gallons of it. Should be quite rich.

I started by packing straw in around the jugs to create a drainage layer (I hope?) and to use up less-nutrient-rich materials first. (There was also just a lot of straw, although I know it will compress over time.) Then I mixed everything else together, which required quite a lot of elbow grease. I remembered to wear an N95 to avoid breathing rock and soil dust, and it's neat that that's just a thing I have readily at hand these days. :-)

The tub is filled with a straw/soil mixture and in place in our front yard, flush with a low brick wall

I moved the bin to its final location, which required a little re-grading to give it a flat, level surface to rest on. The cracked side is shoved up against the brick wall as additional reinforcement. The exposed side is likely going to get some sun and may get damage from that, so I may just like... lean some plywood up against it or wrap it with some other sun-blocking material. Dunno.

The straw is going to pack down over time, so I'll need to to pit off occasionally with more soil and compost, but that's fine. I may even consolidate some of my other, smaller pots into this one, which will have a similar effect.

Overall I'm pretty happy with this, and I'm interested to see how it holds up!

For some years I've enjoyed the undercabinet lighting that I installed, a very simple arrangement of adhesive LED modules, an adhesive-mounted inline switch, and a 12 volt power supply. But the LEDs reecently started flickering and dying, possibly because the 12v supply has inexplicably turned into a 15v supply. Or it always was, and this is just a cascading failure in the LED modules.

I figure I have to replace more or less the whole setup, and I figured I'd ask if anyone had advice.

The cabinet frontage is about 7 feet, and the front edge of the cabinets are about halfway back above the counter. The bottom is recessed upwards, so long bar lights might be awkward.

Here are my needs and wants:

- About 7 feet of lights under front edge of cabinets (and maybe a little extra to fill in the corner)
- 12 volt DC, although I could be convinced of 24 volt
- Hardwired; prefer something I can link together with barrel connectors or wire nuts/snap-down butt connectors, but will solder wires to pads if needed (now that I know where my soldering iron is)
- 1000 to 1500 lumens, I think?
- Color temperature vaguely around 3000–3500K -- not too glaringly blue for evening use
- High CRI would be nice for being able to evaluate food and ingredient colors properly (would pay a bit extra)
- Dimmable would be nice -- again, would be nice for evening use
- 80+ lumens/watt, ideally 100+ lm/W
- Adhesive mounting preferred, since we rent (does not need to come with adhesive; I can apply something removable)
- Maybe resistant to moisture; we don't currently own an electric kettle or a rice cooker, but I've previously seen the undercabinet lighting subjected to a prolonged steaming from such appliances.
- I'd very much prefer to avoid Amazon, and will pay up to 20% more to avoid it. (For several reasons, including their monopsony status, their treatment of workers, and the high rate of fraudulent sellers.)

Here's what I'm considering so far:

- Ribbon Star 2835 (3 meter roll for $40): LED strip, CRI 90+, 2900-3200K, 1500 lumens and 14.4 W total (105 lm/W), PWM dimmable. I'd have to solder jumper wires from segment to segment or buy connectors. No water resistance.
- Hardwired PWM dimmer with clamps and higher max watts or inline PWM dimmer with barrel connectors and 24 W rating, both $10
- ES4 4-chip Modules (20 modules for $50): 8.4 ft of modules, unknown CRI, 3000–3500K, 1600 lumens and 19.2 W total (83 lm/W), PWM dimmable. IP65 water resistance.
- I guess some kinda 12 VDC power supply!

Anything else I should be looking at? Other sites, other products? How much should I worry about water resistance?

Scamperings

Entries tagged with diy

Alcohol rocket

Improvised raised bed

Advice on LED undercabinet lighting?

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