Solid Tips For Casting Colored Silicone Tires

April 5, 2021 by Donald Papp 13 Comments

For people who work with wheeled robots or RC vehicles, sooner or later one gets interested in making custom tires instead of dealing with whatever is available off the shelf. [concreted0g]’s preferred method is to design and 3D print wheel hubs, then cast some custom silicone tires to fit over them. Of course, the devil is in the details and this process can be a bit messy, so he’s shared useful tips on how to get reliable results with simple materials.

The casting material is cheap silicone caulking from a hardware store, and color can be added with a small amount of cheap acrylic paint. A few drops of glycerin added to the silicone thins it out slightly and helps it flow into a mold better. Mix well (the paint will also serve as a visual indicator of how well it is mixed), then scoop the mixture into the mold while trying to avoid creating air pockets. If your mold is in two pieces, assemble the mold and remove any overflow, then let it sit undisturbed for at least several hours while it cures.

Mounting the resulting tire to a wheel hub can be done with a thin film of super glue, which seems to work perfectly well for small tires and is easy to apply.

The rules are going to be a bit different for big objects. We know that silicone caulking can have difficulty fully curing when it’s applied thickly, especially when sealed into a mold with little to no airflow. In such cases, adding cornstarch (in about a 5:1 ratio of silicone to cornstarch by volume) is all that it takes to cure even thick wads of goop in less than an hour. Stirring cornstarch in tends to introduce more air bubbles into the mixture, but for larger pieces that can be an acceptable tradeoff. Cheap silicone caulking is versatile stuff, one just needs to know what to expect, and take a few steps to deal with the messiness.

Need something tougher? Maybe check out using slices of automotive silicone hose for robot wheels to get something that works just as well, but is a lot more durable.

Serial Silicone Molding

March 26, 2021 by Chris Lott 5 Comments

The techniques for making single-digit quantities of custom molded parts don’t scale well when you need to make dozens, as [Kevin Holmes] discovered. He needed to make 80-some sets of a silicone motor mount, and the one-up mold process was not going to work. He explores several solutions, which he rejects as being too complicated. Finally [Kevin] comes up with the idea of daisy-chaining banks of molds clamped together with rails of stock metal bars. It’s a pretty nifty process to watch and you can check the video out below, which is not unlike a very slow 7495 four-bit shift register.

Even though the silicone he uses is clear, pay attention and you can still see the carry-out as it propagates from mold to mold. He manually performs the nibble carry operation from one bank to the next — we wonder if he could cascade these banks, and inject all 80 in one really big squeeze?

Why would someone need 80 sets of silicone rubber motor mounts, you may ask? Well, you may remember the 4-mation 3D zoetrope that we wrote about back in 2018. [Kevin] is one of the founders of this mesmerizing project, and it would seem that their Kickstarter project has been successful. As he demonstrates in the video below, without some type of noise dampening mounts, a rumble from the motor is amplified through the stage of the zoetrope. If you have any favorite mold-making tips for small batch manufacturing, let us know in the comments below. Thanks to [George Graves] for sending this tip our way.

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Digital PlayStation 3 Purchases May Only Live As Long As Your PRAM Battery Without Sony Servers

March 23, 2021 by Drew Littrell 105 Comments

Word of Sony shutting down PlayStation storefront servers for PS3 this summer spread like wildfire on the internet Monday. The discourse in comment sections were filled with anti-DRM rhetoric and renewed pledges of physical-only game collections, because without content servers to connect to, your digital PS3 purchases will eventually become unplayable. Even if legitimate purchases are installed to the console’s hard drive before Sony “flips the switch”, they may only live on as long as the internal clock stays in sync. Which is why this guide to replace a PS3 PRAM battery written by [Andrew] has renewed importance. After a battery replacement the internal clock needs to be reset and this requires validation from the PlayStation network (you know, the one that’s soon to be shut down).

Game preservationist group [Does it play?] drove home the impact of such a business decision by Sony on Twitter. The thread is quick to point out that even if users are quick to re-download all of their purchases to a PS3 system before the purported July 2nd deadline, those games will eventually become unplayable if the system clock becomes desynchronized. Replacing the PRAM battery and reconnecting to the PlayStation Network prior to Sony shuttering their servers should buy the user some more playtime. However, without any further changes to Sony’s licensing policy little else can be done physically to ensure those digital PS3 games will work in perpetuity.

Sony isn’t the only one to have drawn the ire of digital rights advocates in regards to terminating their online services. Nintendo shuttered the DSI-Shop in 2017 and Microsoft turned off access to the original Xbox LIVE servers in 2010. The big three console makers have all let their consumers down by removing the ability to reacquire purchases in some way, but the fact that so many PS3 exclusives were only ever available digitally just further exacerbates issues with digital rights. Dropping in a fresh coin-cell may not be the permanent solution everyone is looking for at the moment, but it couldn’t hurt to re-familiarize yourself with the Cell processor.

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Build-It-Yourself LC Meter

March 22, 2021 by Stephen Ogier 31 Comments

A basic digital multimeter (DMM) is usually the first measurement tool the aspiring electronics tinkerer buys. Even a bargain-bin DMM will happily measure voltage, current, and resistance; check continuity; and may even have a mode to measure transistor gain. Every toolbox needs at least one DMM, but most have an crucial limitation— they can’t measure two of the fundamental electrical quantities: inductance and capacitance. On Hackaday.io, [core weaver] has developed an open-source LC meter to allow you to build your own tool to measure inductance and capacitance.

[core weaver]’s design is all through-hole, so even just assembling one would be a great exercise for someone getting started in electronics. However, he didn’t just release a design, in a series of videos he goes through the theory of the device’s operation; explains the design of the circuit, firmware, and case; and shows you how to put it all together. For times when you need to measure a lot of parts (e.g. if you have to sort a bag of cheap capacitors looking for specific value), he’s even developed a desktop program to save you some trouble!

The finished meter looks incredible! If you want to build one for yourself, he’s put all of the files up on GitHub, and we highly recommend you check out his first video after the break. If you’d like to build yourself a 6.5-digit DMM to go with our LC Meter, consider this one which even has a home-built ADC.

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Lost A Lightweight Quadcopter? Here Are The Best Ways To Find It

March 6, 2021 by Donald Papp 24 Comments

Lost aircraft are harder to find when they are physically small to begin with. Not only are they harder to see, but the smaller units lack features like GPS tracking; it’s not normally possible to add it to a tiny aircraft that can’t handle much more than its own weight in the first place. As a result, little lost quads tend to be trickier to recover in general.

Fluorescent tape adds negligible weight, and will glow brightly at night under a UV light.

The good news is that [Eric Brasseur] has shared some concise tips on how to more easily locate and recover lost aircraft, especially lightweight ones. Recovering aircraft is something every aircraft hobbyist has had to deal with in one way or another, but [Eric] really has gathered an impressive list of tricks and techniques, and some of them go into some really useful additional detail. It occurs to us that a lot of these tips could apply equally well to outdoor robots, or rovers.

Even simple techniques can be refined. For example, using bright colors on an aircraft is an obvious way to increase visibility, but some colors are better choices than others. Bright orange, white, and red are good choices because they are easily detected by the human eye while still being uncommon in nature. Violet, blue, and even cyan on the other hand may seem to be good choices when viewed indoors on a workbench, but if the quad is stuck in dark bushes, those colors will no longer stand out. Another good tip is to consider also adding a few patches of fluorescent tape to the aircraft. If all else fails, return at night with a UV lamp; those patches will glow brightly, and be easily seen from tens of meters.

Some of the tips are used while the device still has power, while others don’t depend on batteries holding out. [Eric] does a great job of summing up those and many more, so take a look. They might come in handy when test flying quadcopters that are little more than an 18650 cell, motors, and a 3D-printable frame.

Elegant And Portable DIY Nightlight Becomes A Fixture For Hacker’s Kids

March 5, 2021 by Kristina Panos 11 Comments

When [itzikdiy]’s kids asked for a night light for their room, he got the bright idea to build something that straddles the line between portable and permanent. This fixture-less fixture plugs directly into a wall socket and is turned on and off with a handsome rocker switch on the bottom.

This lovely little lamp is mostly made from scrap — the oak on the front appears to have come from an old cabinet door, and the other two ring-shaped pieces are made from pine. [itzikdiy] even took the acrylic from broken panel lamps. Everything was cut with a Dremel and a circle-cutter attachment except the oak, which required a jigsaw. We think it looks great, especially with the different grain directions — call it art deco woodworking.

When it was all said and done, [itzikdiy] found it was too heavy to hang by the plug alone, so he added an L-shaped support beneath the power supply that holds it more evenly against the wall. [itzikdiy] also made a pair of hooks that snap into a pair of slots on the sides of the outlet itself. The solution is simple, sturdy, and effective without disrupting the lines of the lamp at all. Carve out a little bit of time to watch the build video after the break.

We know that someone of your hulking intelligence has no fear of the dark. But if you think you could use a nightlight in the bathroom for those 2 AM trips, look no further.

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The 70s Are Calling To Shed Some Light

March 2, 2021 by Kristina Panos 24 Comments

Remember when phones didn’t all look the same? We had a good thing going in the early cell phone days, which seemed like a brief holdover from the Western Electric (et. al) era where you could get a phone that suited your inner minimalist or princess, and choose the color to boot.

[Dubchinsky] found a beautiful phone from this bygone era and saved it from one of two likely fates — the landfill, or else a life languishing as a piece of vintage technology that’s just sitting around for looks. Instead, this phone found a second calling as a lovely desk lamp with secret goose neck flexibility. The lamp itself is an inexpensive LED module from ebay that’s wired up to mains power through a push button switch in the phone’s base.

We absolutely love that [Dubchinsky] wrapped the curly cord around the goose neck, but were a bit disappointed that he didn’t use the hook switch to turn the lamp on and off. In the comments, he says that the plastic felt like it was too brittle to stand up to repeated actuation of such a heavy switch. That’s understandable. [Dubchinsky] also thought about using the rotary dial as a dimmer, and we think that’s a bright idea.

Between the guide, the pictures, and the build process video after the break, this is pretty much a complete how-to. We think that is commendable given that [Dubchinsky] is selling these lamps on etsy.

Do ya miss spinning the rotary dial and long for somewhat simpler days? Hook your finger into this rotary cell phone.

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