Weed Eater String Made From Plastic Bottles

For those who don’t mind constantly adding tiny but measurable amounts of microplastics to their landscaping, string trimmers are an excellent way of maintaining edging around garden beds, trimming weeds, or maintaining ground covers on a steep hill. One problem with them, though, is that not only is the string consumable but it can be expensive. Plus, if you have a trimmer with a proprietary spool you need to hope the company never goes out of business. Or, you can simply refill your string spool with this handy tool.

The build uses plastic bottles to create the string from what would likely become garbage anyway. First, a sharp roller-style knife slices the plastic into a long thin strip. Once cut, it is fed through a heater similar to a hot end on a 3D printer which allows the plastic to be deformed or forged into a cylinder. From there the plastic is added onto a spool, which also has the motor in it that drives the entire mechanism. In this case it is using an old variable-speed drill.

From the comments on the video, there is some discussion about the economics of using this string in a weed eater. It’s likely the plastic won’t last as long as specialty string trimmer string, and the time and expense of making the plastic may never save much money. But we have to give credit to the ingenuity nonetheless. And, if you’re really into recycling plastic just for the sake of keeping it out of the landfill, there are plenty of other ways to go about accomplishing that goal.

I will NEVER buy weed whip line again! from landscaping

You Can Turn Soft Drink Bottles Into Handy Solar Lamps

Solar lights are a popular garden decoration. Of course, they’re available cheaply from most hardware and garden stores, but if you’re more of the DIY type, you might like to build your own. [opengreenenergy] has done just that, using recycled materials for a cheap and simple design.

The design was inspired by the Moser bottle, which is a water-filled bottle used to diffuse sunlight into a room during the day. Instead of sunlight, however, this design uses an LED to provide the light, for decorating a garden or for use when out camping or traveling.

In this design, a solar panel is used to charge a lithium-polymer battery during the day using a LP4060B5F charge controller IC. It’s paired with a AP6685 battery protection IC to ensure the battery is not overly discharged or otherwise damaged in use. When the solar panel stops putting out power when it gets dark, the LED is automatically switched on. It can be set to a low or high brightness to provide more runtime or more light as needed.

All the circuitry is wrapped up in a neat 3D-printed case that allows the hardware to be screwed directly on top of a regular soft drink bottle. Paired with some water in the bottle, and perhaps a little bleach to stave off algal growth, the result is a handy, portable light that also has enough mass to avoid it being blown over easily.

It’s interesting to compare the design to commercial versions that aim to pare costs down to a minimum. Video after the break.

Continue reading “You Can Turn Soft Drink Bottles Into Handy Solar Lamps”

RC Sub Built With A Water Bottle

Submarines are one of the harder modes of transport to build in radio-controlled form. Doing so involves tangling with sealing electronics from water ingress and finding a way to control the thing underwater. It’s a challenge, but one relished by [Project Air] in his latest build.

The body of the sub was built from a drink bottle, serving as a stout container upon which could be mounted all the necessary hardware. Filling the bottle with water allowed buoyancy to be adjusted to a neutral level. Twin brushless motors were used for drive, while servos were waterproofed using a combination of rubber gaskets, olive oil, and sealing spray.

Control was via a floating 2.4 GHz receiver, as high-frequency radio signals don’t penetrate water very far. The floating box also carries an FPV transmitter to allow the sub to be piloted via video feed. Rather than using a ballast system, the sub instead dynamically dives by thrusting itself beneath the water’s surface.

Unfortunately, water sloshing around in the partially-filled drink bottle meant controlling the sub in pitch was virtually impossible. To fix this, [Project Air] filled the bottle completely, and then used some plugged syringes on the outside of the body to adjust buoyancy. The long heavy tether was also replaced with a much shorter one, and the sub became much more fun to drive around under water.

The build was actually built for a friendly contest with [DIY Perks], a fellow Youtuber whose efforts we covered recently. It also bears noting that better results can be had by using lower-frequency radio gear. Video after the break.

Continue reading “RC Sub Built With A Water Bottle”

Deceptively Simple Process Turns Bottles Into Filament

If you know that most soda bottles are made from PET plastic, you’ve probably thought about how you could make filament from them and have an endless supply of cheap printing material. [Mr3DPrint] says he has a method and shares a few videos that make it look easy. We wonder if the quality of the filament is up to par with commercial products, but assuming the videos are accurate, it appears that the resulting filament gets the job done.

The details are a little sketchy, but it looks simple enough. THe first step is to get any indentations out of the bottle. He has several demonstrations of this some using pressurized air in the bottle and some without. In each case, though, a drill holds the bottle through the cap and spins it over a flame until the surface is smooth.

Continue reading “Deceptively Simple Process Turns Bottles Into Filament”

“Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)

A story that passed almost unnoticed was that the Coca-Cola company plan to run a limited trial of paper bottles. Wait, paper for a pressurized beverage? The current incarnation still uses a plastic liner and cap but future development will focus on a “bio-based barrier” and a bio composite or paper cap tethered to the vessel.

Given that plastic pollution is now a major global concern this is interesting news, as plastic drinks bottles make a significant contribution to that problem. But it raises several questions, first of all why are we seemingly unable to recycle the bottles in the first place, and given that we have received our milk and juice in paper-based containers for decades why has it taken the soda industry so long?

Plastic soft drink bottles are made from Polyethylene terephthalate or PET, the same polyester polymer as the one used in Dacron or Terylene fabrics. They’re blow-moulded, which is to say that an injection-moulded preform something like a plastic test tube with a screw top fitting is expanded from inside in a mould by compressed gas. As anyone who has experimented with bottle rockets will tell you, they are immensely strong, and as well as being cheap to make and transport they are also readily recyclable when separated from their caps.

Continue reading ““Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)”

Learn The Secrets Of Matching Bottle Cap Threads To One Another

Do you want to design something to match existing threads on a bottle, or a cap? It turns out there’s an easier way than reaching tiredly for the calipers and channeling one’s inner reverse-engineer. Bottle cap threads — whose industry term is the neck finish — aren’t arbitrary things; they are highly standardized, and [Noupoi] researched it all so that you don’t have to! The Bottle Cap Thread Calculator takes a few key measurements and spits out everything needed to model exact matches. Need some guidance on how exactly to use the information the calculator spits out? There is a handy link to a Fusion360 tutorial on creating bottle threads (YouTube video) to demonstrate.

This all came from [Noupoi] wanting to model an adapter to transfer the contents of one bottle to another, smaller bottle. By identifying which thread was used on each bottle, the job of modeling a matching adapter was much easier. It turns out that the bottle necks were an SP 28-415 (larger) and a 24-415 (smaller), and with that information the adapter was far simpler to design. If you want to check the adapter out, it’s available on Thingiverse.

If truly reverse-engineering bottle threads is needed, here’s a method we covered that involves making a simple cast and working from that.

[via Reddit]

Forget Printing Labels For Your Bathtub Hooch, Why Not Engrave The Bottle?

[BlueFlower] sends in this cool wine bottle engraver. It’s a simple machine that reminds us of the infamous EggBot. One axis can move in x and z while the other axis rotates the work piece. The EggBot works in spherical coordinates while this one lives in a cylindrical world.

The base of the device appears to be an older project of [BlueFlower]’s an XY-Plotter/Cutter. The plotter itself is a very standard twin-motor gantry design. In fact, it looks like when the machine is converted to bottle engraving, the drivers which previously moved the Y-axis are re-purposed to move two rollers. The rollers themselves are suspiciously similar to those found inside 2D printers. We all have them kicking around our junk drawers, but it’s rare to see them actually being used. The spindled is just a DC motor with a ball grinder coupled to the end.

As for the final result, we have to admit that the engraved bottles are quite fetching. Catch a video of the engraving process after the break.

Continue reading “Forget Printing Labels For Your Bathtub Hooch, Why Not Engrave The Bottle?”