The PS:One ShopBot is a great CNC machine that has the benefit, among other things, of being huge, allowing for a lot of cuts on large pieces of material. One of the difficulties working with the machine, however, is getting the bit at exactly 0,0,0 in the X, Y, and Z axis so that if you need something cut at exactly six inches from the edge of the material, it will be exactly six inches. There is already a built-in method for setting the Z axis, using a metal plate and clip and running a specific program on the ShopBot, but there is no such program for setting the X and Y, requiring the user to manually position the bit. This can lead to inaccuracies and wasted work.

To help everyone with accurate setting of the the X, Y, and Z axis, I made a thing:

The front of the plate, looking down on a test piece of wood for calibration

This is an aluminum plate that is milled to be as precise as I could make it (read: probably a lot of room for improvement) where it sits on the lower left hand corner of the piece to be cut, with the corner of the work sitting directly in the middle of the circle.

With the piece placed on the work, the cable is plugged into the back (I had originally drilled two holes on the front left and bottom of the plate, forgetting that is where the bit has to touch so as to not push the plate off the work, so I drilled a new hold on the back and wrote “Do not use this hole” on the other two) and attached via the alligator clips (ToDo: make a better cable) to the Z plate.

The cable connects the XYZ plate to the Z plate that comes with the Shopbot for finding the Z axis.

The user should position the bit somewhere over the top part of the plate, where doesn’t matter. The user loads xyz-zero-finder.sbp (the code is available at this GitHub repository) into the ShopBot software and runs it. Assuming the bit is somewhere over the top, it will then slowly move the bit down until it touches the top, at which point it will move to the side (visually this appears to be moving towards the front of the machine, but in reality the side of the machine with the power switch is technically the bottom, or X axis). The program will move the bit inside the circle at what it believes is exactly 0,0,0 and, after displaying a message, will move the bit up two inches to allow the user to remove the plate and put it away.

The bit at the corner of the work after the plate has been removed and the bit put back to 0

The plate is in the drawer under the ShopBot in the Arduino box (ToDo: Make a real box for the plate). Feel free to use it and report back how it worked for you, so that we can make it better.

I want to thank Dean, Everett and Todd for giving me valuable advice about how to mill the plate on the Bridgeport; it was tricky because both sides of the plate are milled and getting it to sit properly in the vice was very worrying to me. I also want to thank Eric for suggesting the project in the first place.

Thursday 8/6/2015 @ 7;30pm we will be doing a Chilipeppr Presentation

Here is a link to the Meetup page on it.

Chilipeppr is full featured, web based, GCode sender.  GCode senders basically send your CNC toolpath files to the micro controller running your CNC machine.

Chilipeppr takes that concept to the max.  It more like a full featured front end to your CNC machine.  It visualizes the GCode, shows the status of your machine, helps with work offsets and jogging.  It also has some cool tricks it can do to deal leveling and Z probing.  It is currently compatible with machines running Grbl and TinyG.

John Lauer, the creator will be conducting the presentation via Google Hangout.  We hope to expand the presentation.  I’ll tweet out a link on @buildlog and post it here when we work that out.

We will have a machine or two for a physical demo.

Here is a link to the hangout.

This month’s CNC Build Club meeting will be a demo night.  Bring something to show.  It can be a project you finished, something you made, a work in process or something we might think is cool.

I will be bringing several things I have recently completed.

The bipolar ORD Bot: This is a CNC machine I built for 2015 ORD Camp.  It is a super simple drawing machine with some fun math behind the motion.

The DC Power Supply Interface: This is something I did for Inventables that we will be selling soon.   It really cleans up the wiring when you use a DC power supply on a CNC machine.

The TB6600 Stepper Driver Shield:  This is another Inventables project.  The TB6600 can do a ton of cool CNC stuff.  Now you can interface it to the free grbl CNC controller.

The CNC Club is a monthly meeting of Chicago area people passionate about learning, building and using digital fabrication equipment.  It is held at the Pumping Station One Hackerspace.  It is open to non members.  We also have a Google Group called CNC Build Club.

Each meeting we talk about, build, train on and use CNC machines.  We have 3D printers, laser cutters, CNC routers and vinyl cutters.  Come out and join the fun.

Please RSVP on Meetup.  I will have a CNC or Inventables related door prize to a random person who RSVPs and is present at the meeting.

Scotland is a place that, for the average American, provokes strong reactions. Single malt Scotch whisky. Haggis. And bagpipes. At least in America, the thought of 3D printed bagpipes may inspire fear in some people. Bagpipes were considered weapons of war, and commonly thought to be banned following the unsuccessful Jacobite Rising of 1745. (The Act of Proscription 1746 doesn’t directly mention them, though.) Personally, I’m quite a fan of pipe music, as well as other Scottish folk music, such as the Corries, and the music of Nova Scotia, especially Mary Jane Lamond.

I bought a Highland bagpipe practice chanter years ago, only to discover that the angle I had to hold it to keep my fingers in the right position was torture on my wrists. I figure it would be more comfortable to play when attached to an actual bag. But acquiring a full set of Highland bagpipes wasn’t terribly practical, and that would probably lead to my neighbors breaking down my door and coming after me with torches and pitchforks should I try to practice indoors. Or at least they’d complain to the condo association. So I forgot about that for a while.

Then in spring of 2014 I saw the Dreaming Pipes Kickstarter posted by Donald Lindsay of Glasgow. He was creating a 3D printed chanter with a customized extended range for the Scottish smallpipes, which are, as their name suggests, smaller, and designed to be played indoors. But he was also creating plans for a full set of smallpipes modeled off a 17th century design that could be 3D printed, with a laser cut bellows. And he was also designing 3D printed Highland bagpipe drones. I’ve got access to four 3D printers and a laser cutter at Pumping Station: One. It looked like fun to build. So I backed it.

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My knitted-circuit artwork, Electronic Damask, was in a gallery show, NoFi, at Chicago Artists Coalition, October 24 – Nov 13. The piece was a collaborative effort, put together through the volunteer efforts of close to two dozen PS:One members. PS:One really represented at the Oct 24 opening, and I managed to drag most of us in front of the camera for a group photo with the artwork. (Thanks to Everett for the photo!)

If you missed the fun that night, you’re in luck. Electronic Damask has already been tapped for another show, and with an opening tonight in Pilsen, from 6 – 10pm.

This show should be of particular interest to PS:One members. It’s called Technologic and it “celebrates making art through technology”. It features some amazing stuff made with 3D printers, LCD screens, CNC watercolor painting, and of course a certain knitted e-textile.

The gallery, Chicago Art Department, is located at 1932 W Halsted in East Pilsen’s Chicago Art District (#8 Halsted bus runs right past it). Tonight’s opening coincides with the district’s 2nd Fridays gallery night, so there will be other openings all over the neighborhood.

You can find preview photos of the show on the facebook page. Full info is below. The show runs until December 6.

TECHNOLOGIC
curated by Chuck Przybyl
Friday, Nov 14, 6-10pm

Inventables donated a ShapeOko 2 CNC Router “The Works” kit to Pumping Station:One, and we’ve been doing a group build over four sessions so far. It’s been a chance for people to learn about open hardware and CNC firsthand from the ground up, and participate in making PS:One’s next machine. We’ve had participants with various levels of experience working together, and I think everyone learned something new.

During the first session, we assembled wheels and bearings, and attached them to plates for the x, y,and z axes. We started the next session with parts that looked like this:

The instructions describe the z-axis assembly as the most intricate, and they’re not kidding. It took a lot of fiddly work and some mistakes to get here:

Here are some of the participants, planning what to do next:

We assembled the carriages, then the gantry and machine frame. The machine came together well during this session:

I think #1177 (“Minion”) the ShapeOko1 is jealous of its newer, larger, and shiner sibling #5549 (so far unnicknamed):

During the third session, we squared and wired the ShapeOko and installed the drag chain (“e-chain”) with some help from Zach from Inventables.

During the fourth session, we nearly finished the wiring and made a custom holder for the emergency stop button:

Thank you to everyone who helped so far! Our next build session will be Thursday, August 28th at 7pm in PS:One’s shop. We’ll be testing the motors, troubleshooting, and sending the “hello world” job. Come see the machine move!

Thank you Ron (I think) for the Session 2 photos and Allen for the Session 3 photo.

Stepper motor drivers are the things that power most of our DIY CNC projects.  There are dozens of choices.  What makes a good driver?  We will talk about that.

I will bring as many as I can find, which could be a dozen or more. Gecko’s, Leadshine DSPs, Pololu, Panucatt, Allegro, TI and others. I even have a three phase closed loop driver and motor.

Special attention will be given to the Trinamic TMC261. This is a new-ish driver chip that has a lot of cool new features. The most interesting is it’s sensorless load detection. This means the driver can sense the load on the motor. This allows it to do a few new tricks. One is to dynamically adjust the current. You can set the maximum current quite high, but it will only go that high if the load on the motor requires it. This keeps the driver cool, yet allows it to power through higher loads and accelerations. The other trick is stall detection. If the motor totally stalls this is sensed and a fault pin is activated. This is being used by people to eliminate end stop switches. Rather than using pots and pins to set these values, you use and SPI bus. The driver also has a very high voltage range for a chip this size of 9-60VDC. Stepper motors love higher voltages

I have a eval board we can play with.  This board has a motion controller on board and can take the steppers up to ludicrous speeds.

The CNC Club is a monthly meeting of Chicago area people passionate about learning, building and using digital fabrication equipment.  It is held at the Pumping Station One Hackerspace.  It is open to non members.  We also have a Google Group calledCNC Build Club.

The adventure continues! We had a great turn out at the last ShapeOko build event. Now it’s time to assemble the gantries and do some wiring. Join us this Wednesday July 30 from 7-10PM in PS:One’s shop to see the machine really take shape, and maybe we’ll get to see it move, too. Learn about open hardware and the ShapeOko 3D carving machine. This event is open to the public and is great for newbies and experienced CNC’ers, too.

Here is my latest creation

In wax before it is to be cast

This is a turkey vulture pendant that I created as per request of a member here for a birthday present. The recipient is a Naturalist for the Nature preserve here in IL.

So how I went about creating this: created the design through Adobe Illustrator, laser cut the pendant out with our Epilog  laser engraver, and did a lost wax cast to get the final piece in sterling silver, then added a patina to the metal for the shading.

To check out my website or contact me for collaborations see www.ellagentz.squarespace.com.