Taming an AnyCubic Kossell Pulley 3D Printer

Quick post to note how I got my Anycubic Kossel Pulley basically working.  It took me forever to find how to do some of this, and I know I will forget it if I do not write it down.

• Use DaHai's configuration video for starters.
• Upgrade the firmware to Marlin 1.1.9.  I ended up using 1.1.9.1 as of this writing.
• Use DaHai's files and modify them to work with stock Steppers.  Use Arduino IDE to load the firware after replacing Configuration.h and Configuration_adv.h (which I did not make changes to).  Here are the changes I made to his Configuration.h:
• Line 624-626: Change these from his upgraded TMC2130_STANDALONE to stock A4988
• Line 705: I got crazy loud stuttering when first descending to the bed during a print.  Lower this to get rid of that.
• Line 868: I and several people online have measured and gotten good resulting prints with the Type 2 Probe Offset at -15.88
• Line 938 to 940: These need to be true for stock steppers.  DaHai's steppers did not need to be inverted.
• Line 1358-1364: Define your temperature presets. I have used PETG to great success with a preheat of 70C for the bed and 230C for the hotend.  This rises to print at 80C and 245C respectively during the print.
• When following the leveling instructions, the video shows a "Set Delta Height" option that is absent in the version of the firmware I loaded.  This caused me no end of headaches later when the method of subtracting the bed distance from both the Z-Height and Probe Offset produced weird math and never worked properly.  Instead, I ran auto-calibration, saved the settings, then:
• Noted my Z after going to Prepare -> Auto Home
• Brought the nozzle to the bed using Prepare -> Move Axis -> Move Z until a business card wouldn't move when squished between the axis and the bed.  I then noted the height
• Changed my Z height only by this amount by subtracting the number from the Z height, and a negative Z Height is thus added.
• Saved and Auto Homed
• Set my Probe Offset to 15.88 per recommendations online.
• Checked it again and only touched the Z Height when it was off.  Repeat the Z height move if this is still not right.
• With the printer calibrated, it was time to print.  I just used Cura because I couldn not get Slic3r or Pronterface to work easily.  Cura does not have the Kossel in it by default, but it can be easily added.  JDHarris on Thingiverse even shared the configuration file they made which can be picked up by Cura after a restart.
• I printed with PETG which has a high temp but no fumes.  I found hairspray for adhesion worked best thanks to several awesome tips by people connected with the PDX hacker community.  Thanks all!

After this, it just worked and keeps working.  It's magical what a little math and open source firmware will do.  That being said, it's my first printer.  It is bound to break in ways I can't even imagine now.  First order of business?  Print things that make the printer better, as is tradition.

Update: Not all is well in Whoville.  I've developed some Heat Creep with this PETG printing at 245C, and I haven't had the time to troubleshoot it.  Wish me luck!

RadioShack LED Strip Driver

I modified the Pololu RGB LED Strip drivers from version 1.2.0 to support Radio Shack's behind the times model that is 30 LEDs controlled in 3-diode sections.  I had to swap the colors around to match this pinout, and I changed the struct to a class (because why not).

The fix was to physically reorder the declaration of red/gree/blue variables in the struct declaration.  This way, when the information is written to the strip, it is sent in a different (and now correct) order.  You can make the fix yourself by changing the file PololuLedStrip.h:

typedef struct rgb_color  {    

   unsigned char red, green, blue;  

} rgb_color;

becomes:

typedef struct rgb_color  {    

   unsigned char green, blue, red;  

} rgb_color;

And here it is on GitHub: https://github.com/RangerDan/RadioShackTricolorLEDStrip

I should probably talk to Pololu on licensing concerns here.  I found the license from the original driver and copied it into my repo.  I couldn't figure out how to fork this properly, so I just re-uploaded it until I understand git a bit better.

C3BO: Proof of Concept using Timbermanbot Schematic

This post is part of a series about building electro-mechnical PIN-cracking robots, R2B2 and C3BO.



This is a proof of concept for @JustinEngler's C3BO (https://github.com/justinengler/C3BO) using transistor controlled relays. It was prototyped by modifying Blink from the Arduino sample project.

The schematic was obtained from Timbermanbot (https://github.com/vheun/ArduinoPlays...) as seen on Hackaday (http://hackaday.com/2014/07/26/pwning...).

In the video, You'll notice I've replaced the touchpad for your finger with a wire to the headphone jack's ground as the circuit ground. The two pieces of copper tape were no longer sticky enough to stay by themselves, so I am holding them down. They press two and 5 with about 8 key presses per second.

R2B2

I built a copy of Justin Engler's Delta Bot R2B2.  Here's how I did it with a revised parts list.

Inspiration

Justin Engler and his iSEC Partners team presented his PIN punching robot at DEF CON 21.  Even though it was, by his own admission, a last resort in cracking phone PINs, it received coverage in Forbes and other outlets. 

Build

The 3D prints from my brother's Replicator came out well.  The dimensions were correct overall, but I had to do some filing to get the mounting bracket to slot together.  The servos I used required me to file out the slots a bit as well.  The spokes from my servo mount were a little large, so I filed those down too.  Overall, it wasn't too tough to fit everything together.  When I build another one, I need to see if my problems were caused by the STL files, how the G-Code was generated or the calibration of the printer itself.

The local RC shop called Hobby People had most of the small and moving parts.  Servos, ball joints and such came in at under $30.  Lowe's had the right sized all-thread to finish the job.  One thing about the construction was that I originally bought 10mm hex cap screws to join the ball joints to the biceps.  The way the bicep is built, though, the joint tends to hit the side of the bicep and limit the range of the effector.  To solve this, I moved the ball joints outward with small washers.  This made the 10mm hex caps too short, so I went with 15's instead.  Redesigning the bicep to free up movement might resolve this problem.  I slipped a metal stylus pen through a rubber grommet and effector.  The stylus was grounded with an alligator clip onto the breadboard.

The rest of the robot (as you can see in the pic) are an Arduino Uno, a small breadboard and a four-legged stand I put together from a 1x2 and some angle braces.  The robot is held to the frame by a fender washer through the central hole of the mounting bracket.  The sketch had to be modified with the correct measurements on the actual robot.  Most everything matched, so that built my confidence.  Once I uploaded the sketch, I played around with the machine code and made it dance.  This is when I found out the ball joints were binding against the bicep.  I also dropped the robot, and the short hex caps made it go eveywhere.  D'oh!

I forked and cloned Justin's github to prep for writing some code and tidying up the notes.  Rather than cracking phone PINs, I plan to use this to punch card PINs on PIN Pads used in credit card processing.  I don't think I'll need the OpenCV code, so I'll have a blind version of R2B2 up in my own repository once I learn enough Python to be dangerous.

Finally, Marginally Clever has a new version of the delta bot that uses laser cut parts.  The R2B2 that Justin demoed at SXSW seems to have been made from this version out of acrylic.  Snazzy!  This comes with its own platen and looks mighty sturdy.  I might have to grab one and give it a spin.

New parts list

Count	Cost Each	Name	Description
2	$1.94	Du-Bro 2123 3.0 mm x 10mm Socket Head Cap Screw (4-Pack) P/N 2123	Screws to connect effector to ball joints
2	$1.94	Du-Bro 2124 3.0 mm x 15mm Socket Head Cap Screw (4-Pack) P/N 2124	Screws to connect bicep to ball joints
2	$1.98	Traxxas 5347 Rod Ends with Hollow Balls Large Revo (12)	Ball joints to form the arms from threaded rod
6	$1.04	The Hillman Group 44817 8-32 x 6-Inch Threaded Rod, 10-Pack	Threaded rod for ball joints to connect bicep to effector.
3	$7.99	The Hillman Group 44817 8-32 x 6-Inch Threaded Rod, 10-Pack	Servos that connect to bice. Most will work, but Hobby People has adequate ones for cheap
As needed	Varies	Washers,Flat,3mm DUB2109 and The Hillman Group 36-Count #6 x 3/8-in Zinc Plated Standard (SAE) Flat Washer	Washers to separate arm from bicep and effector. Used to give arms maximum freedom.
1	$2.00	Like Hillman Rubber Grommet (5/16x5/8x5/8x7/16)	Rubber grommet for effector to hold stylus
1	$4.00	Like Stylus pen	Stylus for effector
1	$1.13	1 x 2 x 8 Spruce-Pine Furring Strip	Body for robot
1	$1.13	1-in Zinc Corner Braces	Braces to hold shape of robot
X	$2	Bolt, fender washers and wingnut	Bolt to hold robot to body

Arduino and Other Electronics Projects

Miscellaneous electronics and microcontroller projects:

Make and RadioShack's Drawdio:

Initial test of this 20x4 character screen.  Notice the Haiku

Small Screen Blues

Screens 20 by 4

Focus encoded messag

As haiku does

 First fully custom project.  Writing a 'guessing' game that uses a RadioShack RGB LED Strip, the screen, LEDs, and 6 buttons.  Already maxed out the memory of the little chip on the Uno R3.

 Moving my dev environment to Raspberry Pi.  The borrowed laptop I was using is going to be repurposed and will live in an inaccessible place.  Here is the Pi running the Arduino IDE.

 Used Google, and knowledge from a class at SYN Shop, the local Hackerspace, to remove and troubleshoot this module.  It is a Blower Motor Speed Controller from my car's AC.  I found out the transistor in it is bad, but replacing it would take more effort than it is worth.

DEFCONbots - Genetic Al-Gore-isms v.01 Test

Video of the laser+servosx2 test rig.  Not enough granularity for the contest, but it's a start.

Bench Power Supply Complete!

Thanks to SYN Shop, the Las Vegas Hackerspace, I completed a bench top power supply.  I took a class that helped me build one from a kit.  The kit itself produced a 5v out and a configurable out that I ended up making 8.5 for Arduino.

One of the challenges of the class was to take that kit and enhance it.  I removed the resistor on the configurable channel and replaced it with a 10K Ohm potentiometer from Radio Shack.  This allows me to configure it for between 2 and 14.5 volts!

Some time later, I got tired of the alligator clips I used to connect to the two rails.  I replaced them with a barrel connector and switch.  My initial schematic was woefully flawed, however.  If I had completed it, I would have shorted the rails to ground through the switch, blown the fuse, and possibly smoked the voltage regulators.  Yeesh.

Thanks again to SYN Shop and Javid, the teacher who's kit made this possible.

Pivoting from Planning to Doing

You know what's awesome? When people go from "somebody ought to", to "I ought to".

— Dan Kaminsky (@dakami) November 8, 2013

The above tweet by Dan Kaminsky really got into my system.  As someone who makes lists of things to do, I often get trapped planning more than doing.  Since DEFCON 21, I have tried to focus on doing.  Here is a list of my successes so far:

• Rooted my Sony Ericsson Xperia Play and installed Cyanogenmod 9.
• Studied Arduino and created a few basic projects.
• Started following security wonks on Twitter and have become fairly well-versed in the conversation.

Where to go from here?

• Hack Skylanders and Disney Infinity using tag writers and custom code.
• Help Ethan get through Scratch manual.  He has had a blast so far.
• Creating a product in Arduino.  Planning a card swipe emulator to apply my skills to real world annoyance.
• And probably most important: settle on a handle.  VegasVic?