Duplicating Parts Using Silicone Molds

[Do As I Do] had a simple task to complete. A couple of small parts needed to be duplicated in some quantity, with good dimensional accuracy and surface finish. There are a number of ways you might go about this, particularly if you have the original tooling or a machine shop on hand. In this case, however, the plan was to duplicate the parts with silicone molds.

The first step, naturally, was to produce the silicone molds. Doing this involved some craft supplies, with glossy paper and hot glue used to create a vessel for casting silicone around the original parts. The silicone itself was mixed carefully and poured into the vessels, and soon enough [Do As I Do] had a pair of negative molds that could be used to produce duplicates of the original. The original parts were removed, and the silicone molds were filled with resin over and over again to make as many duplicates as were needed.

This was a simple enough project with straightforward geometry that suited the process. More challenging parts would require more care in mold prep and more advanced techniques. Depending on material choice for the duplicate parts and other factors like intended final application, extra steps like degassing may be necessary, too. Still, for a quick guide on duplicating a simple plastic part, it’s hard to beat.

We’ve featured other silicone mold jobs before, like these impressive recreated tail light lenses. Video after the break.

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Delta Pen Plotter Draws In Multiple Colors

If you’re building your first plotter, or you just like thinking in right angles, you’d probably consider a Cartesian design for your build. [András Vujovits] went another route with his project, building an impressive delta pen plotter with a useful tool changer, to boot.

The build relies on a unique motion system, wherein two NEMA 17 stepper motors drive either side of the linkage to control the position of the end effector—in this case, a pen carriage. By controlling the position of each side of the mechanism, it’s possible to move the pen through XY space. Running the show is an Arduino Nano, fitted with a GRBL shield and appropriate stepper motor drivers.

The magnetic tool changer is particularly nifty, too. It allows the plotter to grab a different ink at will to add more color to the drawing. It’s well-designed, with the plotter able to change inks without losing accuracy or otherwise fumbling the switchover. The plotter uses Muji ball point pens, which are available in a range of colors and draw with slick, clean lines. It’s also quite a fast plotter, thanks in part to [András]’s efforts to keep the pen carriage light by using a smart mechanism to offload the pen lifting actuator to the main body.

[András] has plans available, but you’re going to have to pay for them. Still, it’s always nice to see a new machine in the wild. Video after the break.

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Building A Fencing Scoring Box

The sport of fencing requires keeping score, just like so many other similar pastimes. When their club’s existing scoring rig broke, [jc0025] stepped up to build a scoring box of their own, using the typical tools of the maker trade.

The brains of the operation is an Arduino Nano, running the venerable ATmega328P. It’s set up to drive a pair of 8×8 WS2812B addressable LED panels. It’s also hooked up to a pair of fencing socket blocks, which hook up to the lamé (jacket), weapon, and guard of each player for electronically scoring hits. The Arduino is thus programmed to respond to various conditions, lighting the LEDs in turn. For example, the tip of one player’s weapon hitting the other player’s lamé will fire a colored light, allowing the hit to be scored. Meanwhile, a tip hitting the floor will fire a white light, indicating off-target. There’s also a buzzer for sonic indication, as well. Everything is wrapped up in a tidy 3D-printed housing, while power is courtesy of a USB-C charger hooked up to the unit.

If you’re looking to replace some old broken fencing scoring gear on the cheap, this project is probably a good place to start. We’ve featured some other great scoreboard projects over the years, too. Meanwhile, if you’re whipping up your custom own gear for your local sporting club, we might like to hear about it on the tipsline.

3D On The Playdate Handheld

The Playdate is a small handheld console with a dedicated fanbase. Among them is [Cristina Ramos], who recently decided to try and push the limits of the hardware by implementing a 3D renderer for the platform.

[Cristina] began by implementing a raycaster. This is a very simple way to do 3D on limited hardware, and this technique was used by some early games like Wolfenstein 3D. However, for [Cristina], it was more a test to get an idea of the performance limitations of the Playdate. After getting her feet wet with that, she stepped up to implementing a renderer that relied on binary space partitioning, which could load map files in the same format used by the classic Quake engine. There was naturally plenty of work to do to handle things like texture mapping and lighting, too, particularly given the vagaries of working with the Playdate’s 1-bit monochrome screen. Using a simplistic, cel-shaded like approach for textures gave things a good look while preserving visual readability on the low-resolution screen.

The 3D engine and associated game remain a work in progress for [Cristina] — we look forward to seeing where the project goes next. We’ve seen similar projects on resource-limited platforms before, too.

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Repairing A RED Cinema Camera On The Cheap

[ALT CINE] took a punt recently when purchasing a damaged RED Komodo camera online. In functional form, the 6K-capable camera sells for several thousand pounds (or dollars, or euros), whether used or brand new. However, [ALT CINE] was able to score the damaged unit for just £700. The question was—could it be repaired and turned back into a functional camera?

Things looked promising from the drop. The camera had just 3 hours of usage recorded in the firmware, and the casing seemed to suggest it had little use. However, the problem was soon revealed to be serious as the image sensor itself appeared to be damaged. Some research provided hope though—that the damage could be limited to a glass layer in front of the sensor itself that had delaminated.

Thankfully, disassembling the camera was easy enough thanks to its modular design, and [ALT CINE] soon had the sensor block on the bench for further examination. The cause of the issue was apparent—overzealous cleaning leading to fluid getting stuck to the rear of the filter in front of the sensor. Simply popping off the filter, cleaning and drying it properly, and reassembling, was enough to get the camera back to fully operational status.

RED’s repair service quoted $695 for a glass filter swap and $1,395 for a full sensor change. In contrast, [ALT CINE] was able to demonstrate that this repair was something easily within the realm of an intermediate camera tinkerer and it cost almost nothing to achieve. The video also covers an alternative potential repair route, wherein a DSMC2 filter can be subbed into a Komodo camera if the damage to the filter glass is otherwise unrecoverable.

It’s rare to get this lucky when it comes to repairing big-dollar cinema cameras like this one. We’ve featured some other great deep-dive camera repairs before, too. Continue reading “Repairing A RED Cinema Camera On The Cheap”

3D Printed Go Kart Designed To Fit In A Suitcase

[Ivan Miranda] is famous for his large-scale 3D printed vehicles. They’re pretty fun, but they’re also pretty big and heavy—which can make transporting them around rather impractical. Hence, when he had reason to travel with a 3D printed go kart, he went back to the drawing board to create something light enough to pack in regular plane luggage.

The build started with some major compromises compared to [Ivan]’s previous go kart build. Notably, there are only three wheels instead of four, and a simplified control layout that eschews a regular steering wheel. These decisions were made to save weight and allow the design to be more compact. The kart uses a set of handles either side of the rider to handle steering. Drive is via a brushless motor, with power supplied from a series of 18 V drill batteries. Parts were produced on [Ivan]’s massive printer which comes in handy on large-scale projects like these.

All in all, the final build weighed around 20 kg. That’s light enough to be broken down across checked luggage and carry-on for a typical flight. We’d consider the project a success on that basis, even if quite a bit of assembly was required upon arriving at the destination. [Ivan]’s other builds in this realm are pretty fun too, from the printed scooter to the ride-on tank.

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Hands-Free Mouse Uses Eyes And Muscles Instead

The standard computer mouse is a perfectly useful peripheral if your hands work. If you’ve got some trouble in that area, you might appreciate an alternative input solution. To that end, [Varun Adinath Patil] created a neat hands-free solution for moving a cursor around a screen.

The build is based on the Neuro PlayGround Lite, a board built for physiological signal acquisition in the Feather form factor. It’s hooked up to an IMU sensor—both a MPU6050 or BMI270 work—which tracks head movements to allow the cursor to be panned around the screen. Other biological signals are then used to activate other standard mouse functions. Clenching the jaw fires off a left click, while a triple blink fires a right click. Clicking and dragging is achieved by a double-blink. The jaw muscles are sensed via EMG signals picked up with gel electrodes on the skin, while the blinks are detected via EOG signals via the same contact points.

Commercial solutions in this realm exist, but it’s great to see how such a device can be built from the ground up. We’ve looked at other neat applications of head-tracking before, too. If you’re working on your own innovative accessibility tools, don’t hesitate to let us know via the tipsline.