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Turndrawble Pen Holder

Pen Holder

If you remember reading about my Turndrawble, the turntable-based drawing machine, you may remember that I use Fine Point Sharpies with it. The last time I used it in public I just had the pens in a jar, which is not ideal.

The original design was going to have the pen holder built in, but I changed things and decided against that, so I needed something else, and this is it.

If you want to see this thing in person, and make some art with it, I’ll be at the Hidden River Art Festival at the Sharon Lynne Wilson Center for the Arts on September 19th & 20th, 2015.

Wood

The wood pieces are cut from 1/4″ Baltic Birch plywood. The blue parts are set to cut before the black parts. You usually want to cut the insides of things first. (Often this leads to many colors if you nest objects.) Not all laser cutter software requires you to do this manually. Some software is smart enough to always cut the inside objects first.

Acrylic

I also cut some rectangular acrylic panels to go on the inside. Two red, and two black, to match the Turndrawble acrylic colors used.

Pen Holder

I glued the wood pieces together with wood glue, sanded them, and did a stain and polyurethane coat. (Next time it would be better to sand everything completely before assembly. The sanding removed some of the burned wood look, which I wanted to preserve.

Pen Holder

The acrylic pieces fit nice and snug, but just to be safe I put a few small dabs of hot glue on the before putting them in place. There’s also four rubber feet on the bottom to prevent sliding around on the table.

Pen Holder

Pen Holder

(You can read more about this thing on the Turndrawble project page..)

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HDPE Disaster

HDPE Sheet

My most recent HDPE adventure did not turn out well. While I got a nice sized sheet, I managed to slice my finger open and wasn’t sure why, until I investigated more closely…

HDPE, now with glass!

If you can see those shiny pieces, those are pieces of glass. But since I’m personally cutting up all the HDPE scraps and putting them in the oven, where did this glass come from?

Glass, damaged...

Oh yeah, I put it in the oven in a glass baking pan. The HDPE actually tore some layers from the bottom of the pan when I was removing it! The HDPE doesn’t exactly fall out of the pan, and requires some coaxing to come out. I typically pry it out with a screwdriver, then pull it out. (I wear gloves the entire time, as that stuff is HOT!)

Obviously the glass baking pan isn’t ideal for this. I’ve gone back to using the smaller glass loaf pan. I’m hoping the smaller surface area will help prevent this from happening again.

Baked to Hell!

The glass pan is pretty beat anyway, and with pieces missing from the bottom, I guess I’ll just scrap it. (Unless someone wants to melt it down!)

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Maker Faire Milwaukee

Maker Faire Milwaukee

While I’ve been posting a lot lately about plastic and other odd things, pretty much all of my time these days has been filled with planning Maker Faire Milwaukee.

If you’re not familiar with what a Maker Faire is, here’s a quick description from the history page of makerfaire.com

Part science fair, part county fair, and part something entirely new, Maker Faire is an all-ages gathering of tech enthusiasts, crafters, educators, tinkerers, hobbyists, engineers, science clubs, authors, artists, students, and commercial exhibitors. All of these “makers” come to Maker Faire to show what they have made and to share what they have learned.

What I love about Maker Faires (I’ve attended about eight of them in various cities the past few years) is that the people who share their work (or play) are passionate about what they do, and they love sharing it with others. I find this inspiring, and I usually leave excited about what I saw, and eager to learn new skills and make new things.

I’m planning to do a talk about The Power Racing Series, and help out showing off tiny electric vehicles built for under $500, but most of my time will probably be spent working with the folks from Betty Brinn Children’s Museum and Milwaukee Makerspace just making sure everything runs smoothly. (The two organizations are co-hosting the event, and I’m an employee and member of them both, respectively.)

I hope to see you at Maker Faire. If you’ve got kids, it may inspire them, and if you’re a kid at heart, you’ll love it too. (Don’t get me wrong, adults are welcome too!) And, Maker Faire Milwaukee is FREE to attend, thanks to our great sponsors! (And yes, there are still sponsorship opportunities, so get in touch with me if interested!)

If you want a preview of what you’ll see, check out some of the blog posts I’ve been writing.

(Oh, Maker Faire Milwaukee takes place at State Fair Park on September 26th & 27th, 2015, and Harvest Faire is also happening at that time, and also free, so really, there’s something for everyone… Come on down!)

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Raspberry Pi auto login

Linux

Occasionally I post things here because I may need them in the future… this is probably one of those things, which is setting a Raspberry Pi to auto-magically login to the shell (not the desktop) on boot.

Install and configure Raspbian as you normally would, setting it to boot up to the command line, not the desktop.

Boot the Pi and login as the user pi, and then run the following command:

sudo nano /etc/inittab

Find the following line:

1:2345:respawn:/sbin/getty --noclear 38400 tty1

and comment it out by adding a # to the front:

#1:2345:respawn:/sbin/getty --noclear 38400 tty1

Just under it, add this line:

1:2345:respawn:/bin/login -f pi tty1 </dev/tty1 >/dev/tty1 2>&1

Save the file, quit nano, and reboot.

Obviously this can pose a security risk, just like any other auto-login procedure. If you’re using a Raspberry Pi that is not connected to the network, and doesn’t have a keyboard attached, and is secured in a case, there’s a bit less of a concern.

(Most of this info is from the post Auto Login and Auto Start in Raspberry Pi. Thanks!)

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Milling Recycled HDPE – Workflow

Make

I wanted to document how I did the artwork and toolpaths for the MAKE thing I make on the Shapeoko CNC router at BAMspace recently…

Make

I started with my old MAKE design in Inkscape and set it to the size I wanted. I also placed it on the canvas as if it were on the piece of stock, knowing that the lower left corner would be the home position on the CNC router.

Make

After I saved out my SVG file, I loaded it into MakerCam. Now, you can go to www.makercam.com and use that, or you can load up the SWF, and save it locally to run on your own machine. (Flash is required either way. I guess the source code is also available, but you probably need Adobe’s Flash development tools to do anything with it.)

If you’re using Inkscape, you need to set the prefs to 90ppi instead of 72ppi before you open your SVG file. Oh, make sure you check out the MakerCam tutorial, help, and about pages.

Make

In MakerCam I created two profiles, one to cut the inside pieces, and one to cut the outside of the entire piece.

Make

These setting worked fairly well. I would up the feedrate or the step down on our machine if using 1/2″ HDPE. This job definitely took a while to run…

Make

Once I had the toolpaths all set in MakerCam I exported the G-Code into a single file, and then loaded that file into OpenSCAM to run a simulation. (Looks like OpenSCAM recently rebranded as CAMotics… guess I should grab the latest version!) Running the simulation allows you to see the toolpaths and check how many passes it will take to cut through the material. I guess you could also use math, but sometimes I prefer visualizations…

That’s pretty much my workflow for 2.5D toolpaths; create art in Inkscape, load it into MakerCam and generate G-Code, load G-Code into OpenSCAM (CAMotics) and see how it looks.