New Toy!

OK, “toy” might not be the right word (it’s really a powerful tool), but it’s just so much fun to play with!  🙂

UPS delivered a new controller box for my Probotix Fireball Comet CNC router yesterday.  Unlike the PC version that came with the Comet, this one has a BeagleBone inside and will run stand-alone!

The PC configuration for the Comet is a great example of things you can do with HAL.  The Y axis gantry is is controlled by a single step/dir generator using some HAL logic to split the drive pulses into signals for two separate stepper motors with two independent home switches.  But this approach only works with software stepgen, so something else is needed for “outboard” stepgen that is not directly part of HAL (ie: hm2 drivers and the BeagleBone PRU driver).

I have written a gantry HAL component that mimics the behavior of the Probotix HAL file but works with outboard step generation and up to a seven joint gantry axis.  Testing this with a three-joint gantry axis (my linear-delta 3D printer, temporarily re-purposed as a test-bed) was a lot of fun, but I really look forward to getting this working with real hardware and making some chips.  Look for some example configurations using the gantry HAL component in the near future!

NOTE: In addition to working with standard gantry routers (Fireball, Shapeoko, etc), the gantry component will also work well for other multi-motor axis (like the two-motor Z axis found on many Mendel-style 3D printers) as long as each joint (motor) has it’s own home switch.

CRAMPS Kits Available!

I am pleased to announce that I have a limited number of CRAMPS V2.1 DIY Kits available for sale.  This includes a PCB and all the parts required to build a functioning board.  Assembly details are on the RepRap wiki, and the design files are on github.  Please review the known issues, and be sure that you are comfortable soldering 0603 surface-mount chip components prior to ordering a kit.

I apologize in advance for the somewhat clunky shopping cart, but it is the best open-source solution I could find that dynamically calculates shipping rates based on destination (which is required, since the rates for international package shipments vary dramatically).  Yes, you will have to create yet another web account you will likely never use again, but it keeps me from having to charge everyone some obscene amount like $25 for shipping.

I currently have about 20 kits available, and I do not expect to make any more (it is a LOT of work!), so act quickly if you want one.  Also, I am doing this to help with the adoption of the CRAMPS design, so there is a one-kit-per-person limit.

CRAMPS Kits?

The CRAMPS V2.1 circuit boards are fabricated and heading my way.  I am planning to sell the bare boards for a nominal cost (under $5), but I may get motivated and sell some DIY kits that include all the parts needed to assemble your board.  The kit would probably be around $50-60, which is pretty much my cost for the parts in low volume, and I’d only be able to make about 10-20 kits total (before I run out of circuit boards).

So a quick informal poll:  If you are interested in buying a bare PCB or a DIY kit for the new CRAMPS board, send me a direct email and if I get enough interest kits I’ll try to put some together.  Sending me an email places you under no obligation to actually buy anything, nor does it guarantee you’ll actually get a kit should I decide to make some.

I am also working on getting someone to build and sell assembled boards, but that is a process that will likely take another couple months.  The kits would probably be available in 2-4 weeks, depending on how long it takes the PCBs to arrive and if I find any problems with the first prototypes.

CRAMPS V2.1

I finally got around to finishing the updated version of the CRAMPS board.  This version focused on simplifying the design as much as possible, and I really like the end result.  It feels much closer to the original RAMPS for the Arduino Mega in spirit than the previous 1.0 version and the RAMPS-FD.

Changes in this version include:

• No fine-pitch surface mount parts, so the board is much easier to hand assemble
• No servo outputs
• SPI expansion header changed to allow use as extra GPIO if needed
• Expansion headers modified to support an additional 3-axis add-on board (the CRAMP3)

The design files remain on github, and the home page for the design is still the CRAMPS page on the RepRap wiki.  A BOM file including Mouser and Digi-Key part numbers is also available via Google docs.  The boards  have been ordered, and should arrive before the end of May.

While the design is fully open, not everyone wants to build their own boards from scratch.  I am working on getting someone to build and sell completed boards, so stay tuned for updates!

UPDATE: 2014.05.12 – The first batch of 20 boards has shipped, now the 0-30 day wait for a “registered air parcel” begins.

CRAMPS Update

I have been building up the second CRAMPS board to verify the low-cost PCBs from off-shore really work as expected.  Since I’m doing another build anyway, I have been documenting the process with pictures and have created a CRAMPS 1.0 page with assembly details, ECOs, and other board details on the RepRap Wiki.  Follow along there if you’re interested in tracking progress or are building your own board.  If you are interested in building up a board and can hand-solder the six fine-pitch SMT parts, send me an email and I’ll try to get you a bare PCB.

Meanwhile, work is progressing on the next version of the CRAMPS board thanks to Murry Lindeblom.  Murry has been doing some great with KiCAD getting the schematic whipped into shape while I’ve been busy with other projects.  The main changes are to simplify the design, reducing parts count and making the board cheaper to produce.  See the list of ECOs on the RepRap Wiki for hints about the next version.

tBone Cape

The tBone 3D printer / CNC cape has been announced for the BeagleBone.  It looks like an interesting board with some unique features.  I like the use of more sophisticated stepper driver chips from Trinamic, and the support for higher-current stepper motors.  This board seems to have an Arduino on-board to handle real-time, so it will likely take a bit of coding to get it working with MachineKit which is expecting to control real-time motion with the PRU.

For more details, see the tBone website and their Indiegogo campaign.

CRAMPS Board Working

I have the first CRAMPS board assembled and mostly checked out.  There are a few minor glitches (see the ToDo file on github), but so far no serious problems or anything that makes the current PCB design useless.  I have an example LinuxCNC configuration available if you want to try things out on your own.  The configuration requires you install my new Universal BeagleBone I/O Overlay, which can be used to switch between most “interesting” hardware options for the various I/O pins without having to load multiple overlays or possibly merge several incompatible overlay files by hand.


If you’re a fan of scary movies, I even made a video:

CRAMPS Board

I have finished the design for the first version of the CRAMPS 3D print controller board for the BeagleBone. This “new” design is a rework of the RAMPS-FD board for the Arduino Due, which in turn is a rework of the RAMPS board for the Arduino Mega (isn’t open-source great!). The PCB files are queued at OSH Park meaning I will hopefully have boards around the end of February.

Features & Details:

• 12-24V operation
• 6 Pololu drivers
• 15A driver for heated bed, with dedicated power
• 3 high-current drivers for extruder heaters
• 2 medium-current drivers for fans/lights, always 12V
• 4 Thermistor inputs
• 6 Limit switches (5V tolerant)
• 4 Servo outputs
• SPI and I2C expansion headers (5V tolerant)
• Flexible power options for the BeagleBone (use ‘Bone 5V jack, 5V screw terminals, or add a regulator to generate 5V from 12-24V system power)
• Hardware ESTOP chain
• Stack-through design allows for expansion

If you like living on the edge I’ve shared the board at OSH Park so you can order your own. Design files are on github, and I’ve started a thread on the RepRap forums if you have any questions.

Currently the BOM pretty much doesn’t exist, and please don’t judge me by the lack of assembly drawings in the PCB files.  KiCAD apparently doesn’t have assembly layers or allow creating arbitrary mechanical layers so I can’t make assembly drawings the way I’m used to for the last 15 years.  I’ll get it all sorted out, and add a full BOM once I’ve sourced and ordered all the bits and pieces needed to build the board.

Replicape Available

The Replicape, winner of the BeagleBone cape design contest, is now available for purchase from Thing-Printer.  Congrats to Elias for his cape contest win, and especially for having the follow-through to get the product designed and built!


The Replicape looks like a good board to use for 3D printing, but won’t immediately work with the LinuxCNC/MachineKit images currently available.  SPI and I2C setup is required, which means some coding is needed to get everything working properly.  I have a board ordered, and I am currently reworking the PRU code (to make pin numbering hopefully understandable).  I hope to add Replicape support to the next release of my images, but if you’re willing to try and tackle any of the SPI or I2C configuration tasks, please let me know.  The setup routines can probably be done as user-mode HAL modules written in Python, so it shouldn’t be too hard (unless you’re like me, and grok assembly language better than things like Python and Ruby!).

Don’t forget there is an ever-growing list of capes to do CNC and 3D printing with the BeagleBone.  Choice is a good thing, and I’m excited the Replicape is finally shipping, adding another great choice to the list of available boards.  I can’t wait until mine arrives!

New BeagleBone Cape Available

Alex Joni has finished up his bbb_parport cape and has them available for sale!

This cape provides support for up to 6 axis, and has an optional ADC for analog inputs.  There is a DB25 connector that should allow direct connection of an existing LPT based CNC machine to a BeagleBone.  If you’re more interested in cutting metal than printing with plastic, this is the cape for you!

Great work, Alex!

BeBoPr-Bridge Purchase Page

To make it even easier to purchase a BeBoPr-Bridge board set, I have added a purchase page complete with nifty PayPal “add-to-cart” buttons.

I have stock levels linked to the buttons, so if PayPal lets you send me money, I have the PCBs and connectors in-hand and ready to ship to you (saving weeks vs. ordering direct from OSH Park).

I also have another BeBoPr and BeagleBone Black coming, so I’ll be putting together my second Bridge board set soon and I promise this time I’ll take lots of pictures and put up some assembly instructions.  When I built the first Bridge board I didn’t realize I would eventually be selling them!  🙂

Bridge Boards Arrive!

Look what came in the mail:

After a long wait (which was sort of the point of ordering boards to have available for sale in the first place), 4-and-10 BeBoPr Bridge board sets finally arrived in the mail!

For those of you who have sent me money, I will be mailing your boards out tomorrow (Friday, Oct. 11).  If you are interested in purchasing a set, let me know.  Prices are in my previous post, and are quite reasonable (you actually save both money and time!).

Now buy some from me so I don’t regret deciding to sell them at cost!  🙂

BeagleBone RAMPS Interface

For a long time now, I have wanted an interface to connect a BeagleBone to a RAMPS board to control a 3D printer.  Wouldn’t you know, all I had to do was seriously start work on designing one, and a finished project would magically appear on Hack-a-Day:

This looks like a great board, and I hope to get one in soon for testing.  The pinout looks to match the BeBoPr-Bridge setup, which means you should be able to run LinuxCNC from my MachineKit image straight “out-of-the-box”.

One potential issue is the thermistors.  The BeBoPr has a different resistor network arrangement than most 3D printer shields/capes (an actual network, vs. a simple pull-up resistor).  It is reasonably easy to compensate for this in the temperature reading python code, but if you used this board without tweaking the temperature code, your temperatures would be precise but not be very accurate.

If you have one of these capes or are otherwise using LinuxCNC on the BeagleBone, please let me know.

BeBoPr Bridge Boards Available

In an effort to help promote the use of LinuxCNC on the BeagleBone Black, I am having a medium run of the bridge boards fabricated by OSH Park.  You can order these boards directly from OSH Park if desired, but it’s about $20 for a set of three boards, with a 2-3 week turn time.  I will try to keep boards on-hand, so I can ship from stock, and I will try to have connectors available so you can buy them at the same time and save on shipping.

Send me a direct e-mail if you’d like to buy a board set.  Pricing is as follows:

• $8 BeBoPr Bridge PCB ONLY via 1st class mail.  You provide connectors!
• $15 BeBoPr Bridge PCB with 2 header and 2 socket connectors via 1st class mail.
• $20 BeBoPr Bridge PCB with 2 header and 2 socket connectors via Priority Mail.

NOTICE: You are buying only the parts!  You will need a soldering iron, solder, and some wire to fully assemble the boards into a working unit!  Assembly is VERY easy, so if you have soldered electronics before you should have no problem.  Assembly details are available on Bas’ github wiki, and you can contact me if you have any problems getting things running.  Bas shows a fancy parallel cable on his wiki, but you can just use plain wire or every other wire in standard 0.050″ pitch ribbon cable (which is what I did).

Hint: If you need a short piece of ribbon cable, you ought to be able to dig up an old floppy-disk or standard IDE cable that isn’t being used and cut a chunk out of that.

What do I get?

Each package comes with one set of BeBoPr Bridge circuit boards, crafted from Bas Laarhoven’s BBR_R1 design which is available from OSH Park.

If you buy the connectors as well, they are from Major League:

• Sockets: SSHQ-123-D-06-GT-LF
• Headers: TSHC-123-D-06-240-GT-LF

Again, remember you are only getting parts!  You will have to solder the connectors to the board and find 10 short pieces of wire (or a small strip of ribbon cable) to use to connect the two boards together.

This is intended for folks in the US, buying the original BeBoPr board from the CircuitCo BoardZoo webstite.  If you are in Europe, you should contact Bas Laarhoven directly.  He is selling the BeBoPr+ with the bridge board functionality already built-in.  If you are interested in purchasing boards for delivery outside the US, please contact me with details and I will figure out shipping costs.

NOTE:  The OSH Park panels just went to fab today (Sept. 10, 2013), so I expect to have boards available in about 2 weeks (around Sept. 24, give or take).

UPDATE: The connectors arrived today (Sept. 19, 2013), and I hope to receive the circuit boards sometime next week.

UPDATE: The PCBs finally arrived (Oct. 10, 2013), so I now have stock of both boards and connectors.  If you have already paid, your order will ship out tomorrow (Oct. 11).  If you are reading this post at some later point in time, I probably have boards and connectors available for immediate shipment, just drop me an e-mail and let me know what you’re interested in.

BeBoPr Boards Available Online!

After about a year (or an eternity in the 3D printer world), the BeBoPr board is FINALLY available for purchase through the folks at Circuitco via their BoardZoo.com site:

http://boardzoo.com/index.php/beaglebone/bone-bebopr.html

With any luck, vendors who have had the BeBoPr listed but unavailable for ages (like Mouser and DigiKey) will also have stock soon.

Note that this is the version of the BeBoPr designed for the BeableBone White (remember that year or so I mentioned?), but these boards will work just fine with the newer BeagleBone Black with a few minor tweaks.  If you don’t need the on-board HDMI, you can get the BeBoPr working with a BBB by cutting two pins and soldering two wires.  If you need HDMI or plan to attach an LCD cape, you have to move a bunch of pins around.  The easiest way to do this is to get a bridge-board and build it up with some wire and connectors.  You can order a set of boards directly from OSH Park, or I will probably be getting a quantity made since you probably won’t need all three, and lead time on OSH Park PCBs is a couple weeks.  Contact me directly via e-mail: charles (at) steinkuehler (dot) net if you’re interested in a set of boards, but note that it will be at least 2-3 weeks until I have any in-hand.

Bas (the BeBoPr designer) has more details on both of these options on his wiki, along with a bunch of other useful information.

The boards from Circuitco  should be exactly the same as the board I got directly from Bas (from an early prototype run) and have been using to drive my 3D printer, so it should work just fine with my MachineKit image.

UPDATE:
Bas has a new version of the BeBoPr, the BeBoPr+, which is a BeBoPr with the bridge board directly soldered on.  These boards are not yet available through BoardZoo or other online retailers, but Bas has a supply available for EUR 117 each.  Contact him directly via e-mail if you’re interested: [email protected]

Oh, you might think the bridge board looks a little funny and I agree.  It looks kind of funny…but when I’m hooking all the wires to my 3D printer, I REALLY appreciate the extra space between the BeBoPr and the BeagleBone.  Not only does it allow me to keep my serial terminal connected, but it keeps the HDMI, USB, and micro-SD cards away from all the wires going to the printer.  Having used the BeBoPr both ways, the extra space provided by the bridge board really helps to keep all the connections more accessible.

K9 SmorgasBoard

A new toy:

While I was on vacation, the great folks over at Practical Micro Design sent me a geeky new toy to play with, the K9 SmorgasBoard!  This awesome board has just about every sort of I/O you might want if you’re working on machine control using a BeagleBone.  There are Pololu sockets for the 3D printer crowd, more traditional DB25/LPT connectors for “legacy” motor drivers as used in LinuxCNC, analog inputs and outputs (including support for thermocouples), RS422/differential encoder inputs, and lots more.

I saw one of these at the LinuxCNC dev-fest in Wichita, but it’s a lot more fun having one to play with!  Not to worry if you have a BeBoPr, however…I am keeping my BeBoPr and bridge board setup as the controller for my MendelMax printer, and I’m going to use the K9 for experiments.  I’m currently planning on building a slightly modified Mini-Kossel, but I’ll have to see how it turns out.  It may wind up being more than just slightly modified.  🙂

If you’re not completely living on the bleeding edge and trying to drive all your machine control applications with a BeagleBone, checkout the other products from the PMDX folks.  They have a lot of stuff that might help you move motors and make some chips.  Also, drop them a line if there’s something you REALLY want to see in a BeagleBone expansion cape, or if you’d like to have them make a BeagleBone product at all.  The K9 is mostly a proof of concept and test platform, so pipe up and let them know if you want to see a real product or it may never happen!

Oh, and if you want to get geeks writing code for you for free, send them some nifty new hardware to play with (hint-hint!).  Let’s see, I could use a…  😉