Better 3D Prints By Mixing Slicing Techniques

Most 3D printing projects start with a 3D model of some kind. Slicing programs transform the model into gcode. The gcode file contains the commands that actually drive your printer. There are different ways to slice a model and sometimes you want to use more than one on a single model. I’ve been working on a way to make that easier.

When you slice a 3D printing model, you can select different attributes for the resulting gcode file. For example, you might set the slicer to produce different infill density, temperatures, or print speeds. These settings can have a big impact on your printing results. For example, a piece that needs high strength might require a denser infill  than some trinket or key chain. You might want an artistic piece to have a finer layer height than some internal part for some gadget no one will ever see.

One Size Fits All?

The problem is that for most open source slicers, these settings will apply to the entire model. Cura has some plugins that can change settings at different Z heights, and Slic3r can vary layer height, but in the general case, what you set for the slicer will apply to the entire model. Of course, a gcode file is nothing more than a text file, so if you are industrious, you can manually merge two or more files into one.

A manual merge is a pain, which is why I wrote gblend. It can stitch together gcode files to get various effects. The program takes multiple gcode files in as inputs and can combine them in different ways. The most useful feature allows you to get a certain number of layers from each source file and combine them into a single print. Measurements are in millimeters, so you don’t have to worry about layer numbers. The entire process is much easier than anything else I’ve come across.

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Review: Microchip Curiosity Is A Gorgeous New 8-bit Dev Board

Microchip has unveiled a new dev board called the Curiosity Development Board. I had my first look at this at Bay Area Maker Faire back in May but was asked not to publicize the hardware since it wasn’t officially released yet. Yesterday I got my hands on one of the first “pilot program” demo units and spent some time working with it.

I requested a sample board out of my own curiosity. As you may know, Microchip is one of the sponsors of the 2015 Hackaday Prize, but that partnership does not include this review. However, since we do have this relationship we asked if they would throw in a few extra boards that we could give away and they obliged. More about that at the end of the post.

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Spools Of Thread For 6,400 Pixel Color Display

This is not an LED display, it’s a thread display. The hardware artists over at Breakfast, a Brooklyn based rapid product and prototype company, built this color display that uses spools of thread for each pixel. 6,400 spools to be exact.

Serious work went into this thing, and the results couldn’t be better. Check out the video after the break to see for yourself. The trick is to increase the surface area of the spools of thread. This is done by using the spool as a pulley which guides a 5.5 foot length of “threaded fabric”. Up close, the fabric looks as if it’s just wrapped around the wooden spool, but the extra length provides enough room for 36 different colors, each blending into the next in a gradient effect. Index the location of the fabric in each pixel system and you have a wide range of color options.

The piece was commissioned by clothing retailer Forever 21 and has even been given its own website. The display pulls Instagram photos with the #F21threadscreen hashtag and displays them. You can watch a live stream for the next week, and the dedicated site has a search feature to find a recording of your own photo by username.

We must once again give credit for producing the kind of advertising we want to see. This is both interesting and awesome. It gave some talented people work producing it, and sharing the details of the build is both interesting and inspiring for us. Want to see some more interesting advertising like this? Check out that Beck’s bottle used as a phonograph cylinder, and the extreme engineering used to separate Oreos.

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No, Mounting A Gun To A Quadcopter (Probably) Isn’t Illegal

Earlier this month, [Austin Haghwout] posted a video on YouTube of a remote controlled quadcopter armed with a semiautomatic handgun. While there are no details of this build, it’s safe to say any reasonably sized quadcopter could be armed in such a manner; just strap a pistol to the frame, add a servo, and connect the servo to the RC receiver. We don’t think this is the first time it’s been done, but has garnered the most attention.

There is nothing novel about mounting a handgun to a quadcopter. Anyone with any experience with RC flying could replicate this build, and the only interesting part of watching a video of a quad firing a gun is seeing how the flight controller reacts to the recoil. However, in the pursuit of the exploitation of a fear of technology, this video has gone viral.

The Verge calls it, ‘totally illegal’, while The Christian Science Monitor asks how it is legal. Wired posits it is, ‘most likely illegal,’ while CNET suggests, ‘surely this isn’t legal.’ In a rare break from reality, YouTube commentors have demonstrated a larger vocabulary than normal, calling the build, ‘felonious.’

With so many calling this build illegal, there should be someone who could point out the laws or regulation [Austin Haghwout] is violating. This information is surprisingly absent. In a Newsweek post, a representative from the Bureau of Alcohol, Tobacco, Firearms, and Explosives is quoted as saying:

“ATF has reviewed the video with local law enforcement and other federal agencies. It does not appear that the device violates any existing firearms regulations…”

The Associated Press reports no state laws were broken by [Austin]. With the BAFTE and Connecticut State Police both signing off on this build, the issue of jurisdiction becomes more pronounced. How, exactly, is a gun mounted on a quad illegal?

The answer, as with all things involving quadcopters, comes from the FAA. We could find no regulations explicitly banning handguns on remote controlled quadcopters, but of all stories and posts on [Austin]’s handiwork, this is the closest anyone has come to providing the framework for calling this build illegal:

No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.

-FAR Part 91 Sec. 91.15

That’s it. The closest anyone has come to providing a reason why a semiauto quadcopter is illegal: because the cartridge (and bullet), are ‘dropped’ from a quad. The Feds charging [Austin] with “dropping” a bullet from a quadcopter is like taking down [Al Capone] for Income Tax Evasion. The difference being that [Al] was a notorious criminal who had obviously harmed a large swath of people and [Austin] doesn’t seem to be harming anyone.

Although [Austin]’s video of a gun toting quad is only fourteen seconds long, a few reasonable assumptions can be made about his small experiment in flying firepower. The video shows the quad hovering a few feet above the ground. This is surely allowed by the recently published safety guidelines for sUAS users. The gun itself appears to be firing into an offscreen hillside – a sensible precaution. If the only justification for the FAA’s investigation of [Austin]’s video is FAR 91.15, he’s on easy street.

Desktop CNC From Hardware Parts Really Makes The Cut

We love shop made CNC mills, so when [joekutz] tipped us off about the desktop sized CNC he just completed, we had to take a look. Each axis slides around on ball bearing drawer slides, and the machine itself is constructed with MDF and aluminum. And the results it produces are fantastic.

4950561437395360713thumbThe machine’s work area weighs in at 160*160mm with a height of 25mm. Its the table is moved around with a pair of NEMA17 motors and M8 stainless steel threaded rods. Motor control is done with a pair of Arduino’s but they also do double duty with one processing G-code while the other handles the keypad and LCD interface.

The business end is a Proxxon rotary tool whizzing up to 2000RPM, and while [joekutz] hasn’t tried it on soft metals like brass or aluminum, he has successfully cut and engraved wood, plastics and copper clad PCB material.

Be sure to join us after the break for some YouTube videos. [joe] has posted three of a planned five-part-series which aren’t linked to in the project page shown above. to see this machine in action and get a rundown how it all works

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Hackaday Prize Entry: An FPGA’d Propeller

The Parallax Propeller is an exceptionally interesting chip that doesn’t get the love it deserves. It’s a 32-bit microcontroller with eight independent cores that are each powerful enough to do some real computation.  Around this time last year, the source for the Propeller was opened up and released under GPL 3.0, along with the mask ROM and an interpreter for the Propeller-specific language, Spin. This release is not only a great educational opportunity, but a marvelous occasion to build some really cool hardware as [antti.lukats] is doing with the Soft Propeller.

[antti]’s Soft Propeller is based on the Xilinx ZYNQ-7000, a System on Chip that combines a dual core ARM Cortex A9 with an FPGA with enough logic gates to become a Propeller. The board also has 16MB of Flash used for configuration and everything fits on a Propeller-compatible DIP 40 pinout. If you’ve ever wanted to play around with FPGAs and high-power ARM devices, this is the project for you.

[antti] already has the Propeller Verilog running on his board, and with just a bit more than 50% of the LUTs used, it might even be possible to fit the upcoming Propeller 2 on this chip. This build is just one small part of a much larger and more ambitious project: [antti] is working on a similar device with HDMI, USB, a MicroSD, and 32MB of DDR2 RAM. This will also be stuffed into a DIP40 format, making it an incredibly powerful system that’s just a bit larger than a stick of gum.

The 2015 Hackaday Prize is sponsored by:

Robot Control Ties RC Receiver To Motor Controller

[Andrey Nechypurenko] has posted the second part of his robotics ground vehicle design guide. In his first post [Andrey] detailed the mechanical design decisions he faced. [Andrey] now begins covering the electrical components, starting with manual control using a standard radio control system. To accomplish this an RC system was used with an MD22 h-bridge driver and a picoUPS.

The MD22 is a neat motor control board which can take the PWM signals from the radio controller and use this to drive the DC motors. Optionally it can also use an I2C interface, giving a nice migration path to integrate with a microcontroller. Until that happens this can’t really be called a robot — its more of an RC vehicle. But the iterative design and build process he’s using is a good one!

The picoUPS provides on-board battery charging. Due to its UPS heritage it also allows the vehicle to be powered from an external supply, which has proved useful during development. Finally, a 5v regulator was required to supply the on-board digital logic. [Andrey] wanted a quick drop in solution with a budget large enough to allow for future expansion and went with the Pololu D15V35F5S3 which can supply 3.5 amps in a small and easy to use module.

After breadboarding the system [Andrey] fabricated a PCB to integrate all the components. The next step is to add sensors and and embedded computer to the platform.

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