Casting Car Emblems Via 3D Printing

March 28, 2019 by Lewin Day 10 Comments

Casting is a process that can be quite demanding for the first timer, but highly rewarding once the basic techniques are mastered. It then becomes possible to quickly and reliably produce metal parts en masse, and with impressive tolerances if the right method is chosen. [VegOilGuy] has been experimenting with lost PLA casting, and decided to see if it could be applied to car emblems.

The process begins with 3D models of various car emblems, primarily sourced from Thingiverse. These are printed in PLA, with sprues added to assist with the casting process. The parts are sanded to avoid unsightly print lines on the finished product, and any voids filled with wax. The various emblems are then assembled onto a casting tree, with extra sprues added to improve metal flow with wax and further PLA parts.

The investment mold is then created with plaster, and baked to remove water and melt out the PLA. This is crucial, as any water left in the mold can react explosively with the molten aluminium bronze. The mold is then filled with metal and then allowed to cool. The plaster mold is destroyed, and the parts can then be removed. Final processing involves a trip through a rock tumbler before final polish with sandpaper.

[VegOilGuy] gets impressive results, with the parts looking excellent in their bronze colour. This is an unconventional color for a car emblem, but it’s noted that this material is an excellent candidate for chrome plating to get a more OEM finish.

You might find your lost PLA casting experiments could benefit from the help of a microwave, too. Video after the break.

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Monitor Your 3D Printer With Node-RED And Tasker

March 27, 2019 by Tom Nardi 11 Comments

Anyone with a desktop 3D printer knows that it can be a bit nerve-wracking to leave the machine alone for any extended period of time. Unfortunately, it’s often unavoidable given how long more complicated prints can take. With big prints easily stretching beyond the 20 hour mark, at some point you’re going to need to leave the house or go to sleep. We hope, anyway.

In an effort to make his time away from his printer a bit less stressful, [Mat] from NotEnoughTECH has put together a comprehensive framework for monitoring his machine on the go. After looking at existing remote monitoring solutions, he found none gave him the level of information he was after. His system collects up an incredible number of data points about the printer’s current status and pushes it all to his Android phone as a rich notification. Best of all, he’s documented the entire system in exquisite detail for anyone else who might want to follow in his footsteps.

There’s a considerable amount of hardware and software involved in this system, and getting it up and running won’t be quite as straightforward as using some of the turn-key solutions out there. Octoprint is responsible for controlling and monitoring the printer, and [Mat] is pulling data from its API using Node-RED. That data is formatted and ultimately delivered to his Android device as a notification with Tasker. On the hardware side he’s got a Sonoff POW R2 to not only turn the printer on and off but measure its energy consumption, a USB camera to provide a live view of the printer, and a couple of Raspberry Pis to run it all.

Even if you don’t have a 3D printer, or maybe just don’t leave the house to begin with, the video [Mat] has put together after the break that shows how all the elements of this system are pulled together in Node-RED is a fascinating look at the flow-based visual programming tool. Similarly, it’s a great demonstration on how Tasker can be used to add some very slick Android notifications for your project without having to commit to developing a native application for the platform.

If you like the idea of remotely monitoring your printer but aren’t ready to dive into the deep end like [Mat], there are easier options. With a Raspberry Pi running Octoprint added to your 3D printer and one of the existing mobile monitoring and control front-ends installed, you’ll be well on the way to tackling those big prints without having to pitch a tent in the lab.

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Threaded 3D Printed Part Comparison

March 26, 2019 by Al Williams 25 Comments

If you want to make serious assemblies out of 3D printed parts, you’ll eventually need to deal with threading. The easiest way is to make a nut trap that you can either insert a standard nut into after printing or even during printing. However, there are limitations to this method. If you want a real threaded part you can print the thread, cut the thread with a tap or bolt, or use a threaded insert. [Stefan] ran some tests to see how each of those methods held up to real use. (YouTube, embedded below.) He used fifty test parts to generate data for comparison.

We like the threaded insert method where a brass insert is pushed into the plastic while hot. Special features in the insert cause the brass part to grab the plastic, making it difficult to pull the insert out or twist it within the hole. Another thing we liked was that the tests used holes printed in the horizontal and vertical plane. You can clearly see that the orientation does alter how the holes work and fail to work.

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Volkswagen Tools Turned To The Space Age

March 21, 2019 by Brian Benchoff 36 Comments

The Volkswagen Beetle, and yes the bus and the sexiest car ever made, are cars meant for the people. You can pull the engine out with a strong friend, and you can fix anything in an old Volkswagen. VW realized this, because in the 1950s and ’60s, they came up with plans for tools designed to tear apart an old VW, and these tools were meant to be manufactured in a local shop. That really turns that right to repair on its head, doesn’t it?

While working on his van, [Justin Miller] came across a reference to one of these tools meant to be made at home. The VW 681 is a seal puller, designed to be manufactured out of bar stock. It’s an old design, but now we have interesting tools like 3D printers and parametric CAD programs. Instead of making one of these DIY seal pullers with a grinder, [Justin] brought this tool from the space age into the modern age. He took the design, modelled it in OpenSCAD, and printed it out.

The VW reference book that lists this tool is Workshop Equipment for Local Manufacture, and for this seal puller, it gives perfectly dimensioned drawings that are easily modelled with a few lines of code. The only real trouble is filing down the pointy bit of the puller, but a bit of boolean operations fixed that problem. After 15 minutes of printing and a few hours finding the right documentation and writing fifteen lines of code, [justin] had a plastic VW 681 in his hands. Yes, it was probably a waste of time as a regular seal puller could have done the job, but it’s an excellent example of what can happen when manufacturers support their local repairman.

3D Printing A Combination Lock

March 21, 2019 by Lewin Day 2 Comments

Combination locks! They’re great if you’re skilled at remembering arbitrary strings of numbers, and have a dramatic flair that’s made them a famous part of many a heist movie. They come in a wide variety of styles, and are vulnerable to a different set of attacks than the more typical pin-tumbler locks used on a household basis. If you fancy tinkering with a combination lock, why not 3D print one yourself?

It goes without saying that any lock you 3D print is going to have issues with strength. Such a lock should not be used to protect anything of real value, but it could be handy to prevent the kids getting at the Halloween candy you’re saving for October.

Regardless, 3D printing and assembling your own combination lock is a great way to learn about how they work. It’s a fun project that is also much easier than sourcing and disassembling the real thing. For a greater understanding of the underlying mechanism, this video should make the basic operation clear.

That’s not all 3D printing can offer to the locksport community, of course. You can always print your own keys, too. Video after the break. Continue reading “3D Printing A Combination Lock” →

Dancing Arrows To Break Your Brain

March 20, 2019 by Brian Benchoff 8 Comments

Last year, mathematician and professional optical illusionist [Kokichi Sugihara] came up with an arrow that only points one way. Technically, it’s ‘anomalous mirror symmetry’, but if you print this arrow and look at it juuuussst right, it appears this arrow only points one way.

[Ali] had the idea to turn this arrow illusion into something motorized, and for that he turned to 3D printing. The models for the illusion arrows were already available, but there had to be a way to turn a single arrow into an art installation. For that, you just need a few 9g servos. [Ali] slightly modified his servos so they would turn a full 180 degrees, and designed a magnetic mount to allow easy swap-out of these arrows.

The servos are attached to a 3D printed frame with heat-staked threaded inserts, and driven by a Pololu servo driver. The effect is great, with multiple arrows twisting and turning but still only appearing to point to the right. [Ali] put together two videos of this arrow illusion, one that’s effectively a build guide, and of course all the STLs are available in a link in the description.

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A 3D Printed Blooming Rose For (Next) Valentines Day

March 17, 2019 by Ted Yapo 7 Comments

Inspiration runs on its own schedule: great ideas don’t always arrive in a timely manner. Such was the case with [Daren Schwenke]’s notion for creating a 3D-printed blooming rose for his valentine, a plan which came about on February 13. Inspired by [Jiří Praus]’s animated wireframe tulip, [Daren] figured he could make a rose from clear printed petals colored by RGB LEDs. 24 hours seemed tight but sufficient, so he diligently set to work, but – after a valiant effort – finally had to extend the schedule. It’s now more than a month later, and tweaks to the design continue, but the result is nothing short of spectacular.

We first saw a discussion of the idea over on Hack Chat, and followed as it evolved into a project on hackaday.io. There, you can read the full details of the trials and tribulations that had to be endured to make this project happen. From a printer that wouldn’t boot, through testing PLA, TPU, and nylon filament, trying a number of different approaches for springs and hinges to operate the petals, and wiring the delicate DotStar LEDs with magnet wire, you can get a really good sense of the amount of experimentation it takes to complete a project like this. If you know anyone who still thinks 3D printing is as easy as clicking a button, send them over to read the logs on this project.

What finally materialized is a terrific combination of common hacker technologies. The petals are printed flat in nylon, then formed over a hot incandescent chandelier bulb. The stem and leaves are also printed, but the side stem has a piece of magnet wire embedded in the print as a capacitive touch sensor; when the leaf is touched, the rose blossom opens or closes. Magnet wire for the LEDs and a connecting rod for the mechanics run through the main stem to the base, where a 9g servo is responsible for controlling the bloom. The whole thing is controlled, naturally, with an Arduino. To move the project along a little more quickly, [Daren] enlisted the help of another Hack Chat denizen, [Morning.Star], who did an amazing job on the software without any access to the actual hardware.

Be sure to check out the video of the rose in action, after the break.

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