Filament Review: PET+ from MadeSolid

28 Sep

Filament Review: PET+ from MadeSolid

Some time ago I posted some tests done with Colorfabb's XT plastic. I'm guessing that the people from MadeSolid read that and wanted me to test their PET+ filament? I love testing new plastics so of course I said yes to getting some samples!

Just like Colorfabb XT, the PET+ material from MadeSolid is made from PET plastic so I expected the two to be kind of similar. PET is the plastic used in drinking bottles and food containers, so just from that you know it's solid. It's much more solid than PLA as it's not brittle at all. It's stronger than ABS and extrudes at temperatures somewhere between PLA & ABS.

More colors

I had actually looked at the MadeSolid materials just the week before as they could offer both transparent, translucent and opaque PET+ filament with a decent range of colors as well. Just last week, Colorfabb also introduced some opaque colors, but at the same time they upped the required temperature from 220-240C to 240-260C making them harder to use for many.

As opposed to Colorfabb, the MadeSolid guys offer extensive printer profiles for their filaments It is quite interesting to see as this highlights how differently the various printers are tuned. A Leapfrog printer should be set to 225C, but a Makerbot should be at all the way up to 255C!


I really like how the final prints look. They come out glossy and the material is very easy to work with. There is a tiny amount of warp, but a brim is sufficient to hold things down on the build surface.

T-Rex at 0.2mm & UltimakerRobot at 0.005mm. One can clearly see that I need to tune the printer a bit more as I have some "wobbly" somewhere, but the prints look really good despite that.

I received about 5 meters of the clear & 10 meters of the white PET+. With this I printed quite a few tests, but I ran out of sample plastic before I got the settings properly dialled in for my printer. That is - I thought that I had it right, but when exposed to pressure it turned out the layers had not bonded fully?

I did some bonding tests and it seems that on my current Hexagon hotend, I need to go to 235-245C to get proper layer adhesion. Oh well...

The transparent PET+ actually seems a little easier to work with than the XT as I'm not getting these tiny blobs along walls that I do with XT. All the walls of the Raaco resistor-box came out looking perfect and the final print is so solid that I need pliers to damage it. When reflecting a light-source it also appears to be more shiny/reflective than the XT, though the transmissive properties are very similar.

Bridging & supports

Bridging was interesting. I had a model that has a decent bridge. It's 29mm so I didn't expect that to work, but initially it looked to be going well. Then the plastic started smearing onto the nozzle and things became really ugly. I set the print to pause, cleaned it up and kept running at a higher speed. That turned out to be a bummer. After a lot of cleaning, I realised that going slower was the best. Next time I'll use Slic3r instead of Cura so I can tweak the speed for bridges.

The print came out fine in the end and I was really impressed by how easy it was to remove the supports? That was of course related to the poor layer adhesion that I discovered later, but after testing some more it seems to be just as easy to remove PET-based support as it is to remove ABS.

I am really liking this plastic, so I just purchased some rolls with the translucent colors (red + blue) as well as opaque white. I wish that MadeSolid had more colors available (like translucent & opaque yellow, orange, purple & more), but I guess that'll come with time.

Next up for this weekend is testing flexible filaments. I have two rolls of NinjaFlex as well as "transparent rubber" from the Italian company PlastInk. Should be fun!

BAM printer settings

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with PET+:

  • Temperature: 225-235C
  • Speed: 50mm/sec
  • Retraction: 2.5mm @ 20mm/sec
  • Extruder tension: screws 0.5mm out (quite solid pressure)
  • Heated bed: 40C
  • Fan: none

Just days after I sent my order, MadeSolid published a lot of new colors. Now they have 15 different colors to choose from. Pretty good!

Making a custom 3D printer controller

20 Aug

Making a custom 3D printer controller

While working on my new printer, I realised how ugly most reprap controllers are. All those I've seen use large SD cards & bulky oldskool LCD's with really poor contrast and viewing angles. Why not use Micro SD & an OLED screen?

You can actually build your own custom controller using any combination of screen, SD reader and encoder, but I couldn't find a good description of how to do it, so here it is. Setting it up with the Marlin firmware can however be a daunting task, so this article aims to document how I went about doing it.


Why I’ll never use Windows Phone again

04 Aug

Why I’ll never use Windows Phone again

It's been a while since I posted a good rant. Here's one that's been brewing for some time. I refuse to belive that ANY Microsoft employes that ever had an iPhone or Android, actually tried to use Windows Phone for a full year. I have and I can tell you - it's utter bullshit. I don't doubt that a lot of talented people have worked hard to make it happen, but without someone capable of telling what is good and bad, you cannot succeed. The whole OS reeks of a lack of interest and use.

I gave it a full year as I figured they'd get som time to fix the major bugs. Despite three fixes delivered over the air, they have not solved anything that could help me like the platform. They have however added a menu with "Extra settings" that I'll never use.

Here's my 6 biggest annoyances:


Project: Makeblock 3D printer

13 Jul

Project: Makeblock 3D printer

Up until now I've had two 3D printers. My first one was the Ultimaker Original and it now has more than 4000 hours of printing behind it. An incredibly solid machine! The next printer was the Printerbot Jr that my son put together. I haven't seen much of it as he's more or less confiscated it, but it's been a great investment into making him try out some real engineering.

The Ultimaker Original is probably the best Open Source 3D printer available today. Now I've built a third printer from scratch, using the Makeblock aluminium extrusions that I've become quite fond of. You can find the build log here, but why did I want to make a new printer?

Makeblock advantage

When you are making a printer based on Makeblock it is really easy to adjust the design as you go. It's also easy to add new elements when you need it. Not only that. When I at some point retire the printer, I can re-use all the Makeblock parts for something else! Makeblock was started as a Kickstarter and they really listen to their customers.

Less hassle!

The single thing that takes the most time for Ultimaker owners is clearing out blockages. They don't happen if you're careful, but every now and then you'll forget turning off the extruder and the heat'll sneak up the pipe to cause a block. When blocks happen this far up in the extruder, it'll take 10-15 minutes to clean it out. The new all-metal hotend from e3d & extruder design solves this completely and changing filament is done in a snap. Over all, I'm REALLY happy with this!

Polulu DRV8825 FTW!

I'm using original Polulu DRV8825 stepper drivers. This gives me 1/32 stepping that is noticeably more silent than the typical A4988 drivers with 1/16 stepping. These are also more powerful, but in reality I'm not using that advantage. If you have a noisy printer, be sure to check this video for a comparison. They're a direct replacement for 4988's on most Reprap hardware, so odd are they'll make your printer more silent too.

More space

The new printer has a bigger print area (31 x 31 x 34 cm). This was one of the goals of the printer and I'm very happy that I managed to go even a little bigger than anticipated. For comparison - it's 32600 cm2 are more than 4 times the volume of the Ultimaker (7700 cm2). It makes levelling the bed a little harder, but it's totally worth it just to have the ability to print larger objects.

More materials

I've changed the design to a Direct Drive Extruder that takes up less space than the original design. This allows a second extruder to be added at a later time. A Direct Drive Extruder it has one major advantage over Bowden-based systems: it supports virtually all the materials I want to experiment with. Flexible plastics, nylon, wood, clay, bronzefill and more. The current setup allows the extruder to go to 300C. With modifications, I can go all the way up to 400C if I want to.


Using Makeblock makes the entire design flexible, but the compact extruder design itself is also quite flexible. One addition I'm working on is adding Dual extrusion as in this video. It's the best approach to dual extruders I've seen to date, so expect an update when I get this working! The design allows me to easily swap out the print head fairly easily so I can play around with extruding chocolate and other fun materials.

So - all in all I'm very happy with the printer! All issues are now resolved, so the design phase is complete. Only minor tweaks remain & the BOM is now online at For now the page contains links to resources & the bill of materials, but I'll also add build instructions to it later.

But - I've got more plans! My Ultimaker with 4000 hours of printing on it's back will soon move to Bitraf and in November I'll (hopefully) receive my first SLA-printer - the Titan 1!

Project: wifi-enabled RGB LED displays

08 Jul

Project: wifi-enabled RGB LED displays

Every now and then there's a project you can't say no to and this was one of them. is sort of Norway's version of Craigslist, a big online market where you can sell just about anything. As a marketing stunt, they opened a physical store downtown Oslo. I was called in via some friends in the agency that handled the project and they needed lots of things quickly. Since I was fully booked, I couldn't say yes to all the projects suggested so I passed some of them to my friend Thomas Winther who did a great job making an in-store Selfie-app using Unity & LeapMotion.

In the store they needed a way to show information from the website and this was the job I couldn't say no to. Apparently it isn't very easy to get hold of a wifi-enabled LED display that can pull data from the web? Also - most commercially available displays are small, monochrome and use tiny LEDs so they're not that visible when mounted high up on a wall. The agency wanted 5 large displays, perferably with more than one color display. Having recently read about Teensy 3.1 and the OctoWS library I promptly said I'd do it!

The Teensy microcontroller is a great alternative to using Arduino's in installations. It has a really fast ARM processor and lots of RAM, but it is still 99% Arduino compatible. This means that pretty much all Arduino code will run on it, but at blazing speeds. After installing a little extra software, you can use the normal Arduino IDE to program it, so it's really an "Arduino compatible". It's so compatible (and affordable @ $20!) that I feel that this is really the path that the Arduino Team should have taken instead of making bigger and more complex boards. Here's how the Teensy 3.1 looks next to an Arduino Nano. It's soo tiny that the Nano looks big!

For the parts, I could have saved some money by picking it up from different places, but I didn't have much time. I picked up tons of Neopixels & Teensy's from Adafruit since they'd ship the parts so I had them within a week. Buying parts from Adafruit really makes a difference since the whole process is completely trouble free. It's a little more expensive, but worth every dollar.

This is how the test-display looked when running the rainbow sketch:

Lovely, isn't it? You can see the neopixel strips lying in front. I stuck these to the back plate using the same clear silicone that I used to fix the panel to the front. The first test showed that we'd have to compensate a little for every 50cm as the neopixels are put together of 50cm segments and loose a few mm in the overlap between these.

Thanks to Jens Dyvik at Bitraf, making the wooden parts was short. Jens is really good at Rhino and CAM software, so the process from sketch to finished product was really swift. His huge Shopbot CNC'd all the lattices and backplates in one go! Nice to have good tools, right? Two things to note about the CNC'd parts:

  • When using MDF as material, make sure each protuding part has a certain minimum size or they'll break off easily.
  • Research carefully what kinds of silicone that will remain fully transparent over time. Most clear silicones will get a yellowish tone over time. The ones that are made for aquariums appear to be the most suited ones.
  • When exposed to heat for a long time, MDF will want to "bend". Make sure you stick it down properly to avoid too much maintenance.

Soldering and gluing together the displays took quite some time, but it was made a lot easier by Paul Stoffergren releasing these neat adapter boards. I added a 2.4Ghz radio to each of these and tucked it away on the back of each display. Here's a photo showing 1920 pixels running at once. Note that the Mac to the left is on full brightness! The displays are so bright that they're visible in daylight as well.

Each sign requires quite a bit of cable and with the amount of current going through them, this was the first electronics project I've made where I've had to calculate the correct diameter of each cable. A good learning experience!

I could have built a Wifi adapter inside each of the displays and in hindsight, that would have been an easier choice if it wasn't for wifi issues. What I went for instead was a server-client solution where a single box would connect to the internet as well as serve up a webserver that could be used to control all the 5 signs. It has a Teensy 3.1 that holds a custom webserver, uses cable for internet access, has a display that shows status and the IP address of the webserver as well as a nrf24l01 radio (2.4Ghz) that sends data to the signs. This is put together in a nice 3D printed box that is wall mounted.

It's a pretty versatile solution and it works rather well. There's two drawbacks to this solution:

  • The NRF24L01 radio's are dirt cheap, but they have a limited range and are affected by other 2.4Ghz radios (bluetooth, wifi & more)
  • The Ethernet library for Arduino is a synchronous API. When the device fetches data from the internet, it'll freeze a short while until the data is received.

None of those issues are big problems, but they're worth noting if you are building something similar. Initially I planned to use a Raspberry Pi to be the webserver, but it turned out to be really hard to make the NRF24 radios work reliably with GPIO on the Pi. I've since noticed that the NRF24 dislikes fast CPUs, so if you're trying to make this readio work on the Pi, make sure to add a delay to your main loop. The Teensy 3.1 is also too fast for this radio.

The final result is that you can use any device such as your phone to control what is displayed on each of the signs. I've also built some remote admin to it as well. Every time the displays power up they'll await instructions from the server. The server fetches API data such as how many tractors are for sale or what are the latest boats available, and sends this to the displays. It's super flexible and a true IOT solution.

Disregarding some (serious) mounting issues beyond my control, I really loved solving this project and you can check it out if you're in Oslo. 


After making this, my wife said that I should start making and selling these commercially. It's probably a good idea, but I really can't see myself selling LED signage. However - if you have some weird project in the Internet of Things domain - feel free to contact me. I love a good challenge!




07 Jul


I really love those squeezed-in weeks of work in between family holidays. It's a rare time to catch up on thing like blogging, reading & updating a few personal projects. I just finished reading The Martian by Andy Weir that I got recommended from @hpeikemo. It's a really thrilling book that I'm sure we'll see as a hollywood movie soon. The story is kind of a "Robinson Crusoe meets McGyver on Mars". After reading it, I gave it to my son who completed it in just two and a half day. Great summer read!


Ultimaker - preventing the extruder from plugging

27 Apr

Ultimaker - preventing the extruder from plugging

If you have an original Ultimaker and have problems with the extruder getting plugged, I have a couple tricks that has saved me completly from plugs after implementing them.

After buying 7 spools of filament from Colorfabb, I was thoroughly disappointed. I kept getting filament plugs both at the top and bottom of the extruder. I contacted Colorfabb support and over a one month period, we tracked the problem down to two things. The filament were delivered in a cardboard box where small bits of cardboard cutoff from the production process, stuck to the filament. Every time one of these tiny bits of paper got into the nozzle, the paper burnt and plugged the extruder. The other thing is that the Colorfabb filament goes soft at a slightly lower temp than PLA from other vendors, causing it to plug more easily at the top if something is blocking at the tip.

Every time this happened, I had to disassemble most of the extruder and use drill bits and other tricks to remove the plug completely before trying again. Colorfabb has remidied the problem now and all their filament are now delivered in clean cardboard boxes with plastic bags around the filament. They also went really far in compensating me for the troubles I had, so I still recommend them and use them as my primary source of filament on spools. Great customer service always pays!

At the top of the extruder

If the entire extruder assembly runs too hot or you have a partially blocked nozzle, you can get plugs at the top of the extruder (between the peek and the white insulator). You'll spot these easily since you can't push any material into the bowden -> even if you unscrew the nozzle. Some time ago, I built an enclosure around my printer so I could do ABS without it cracking up from the material shrinking. The enclosure holds a nice, steady temperature but the increased temperature also increased the amount of plugs since the aluminium mount above the extruder got really hot and so did the peek part.

I've had plugs here on many occasions, but after adding a small fan that blows cold air onto the insulator, peek & aluminum mount I have not had a single one. You may have noticed that almost all new extruders (from makers like E3D, Makerbot & others) have a separate fan that is cooling the upper parts of the extruder. They probably do this because it's required for the new all-metal hotends, but it certainly helps on an Ultimaker too!

You can download the Fan mount and find instructions at my Youmagine page. It's very minimalistic.

At the bottom of the extruder

Plugs at the bottom of the extruder are much harder to prevent once they have happened, so making sure the filament is clean takes you a really long way in this regard. Just print a copy of this filament cleaner, cut off a bit of foam and place it where the material goes into the extruder.

Use these two tricks and you'll probably never ever get a plug again. I havent! yes

Filament review: Colorfabb XT

27 Apr

Filament review: Colorfabb XT

I've had a few really hectic months with a crazy amount of client projects. Hopefully that'll manifest itself on my bank account, but this weekend was my first few days of calm in two months. Time to play with the 3D printer again and experiment with one of my favorite filaments - ColorFabb's XT!

ColorFabb XT has been one of my favorite materials for a long time. In terms of properties, this PETG is sort of a crossover between PLA and ABS. As opposed to PLA, it is strong and quite flexible and it's much easier to work with than ABS since it barely shrinks at all. I've had varying results with it over time so I thought I'd experiment a bit with what are the best settings.

I first ran a series of tests to see how it's affected by speed (A), flow rate (B) and temperature (C).

I started with a base of 50mm/sec / 235C and the output looks good at both 50 and 100% of that speed. As soon as you go above, you'll see the pillar becoming less transparent. This is due to small bubbles of air and indicates that it's not feeding enough plastic through the extruder. This could be compensated somewhat by increasing temperature, but it seems that 60mm/sec is about as fast as I can go. When it comes to flow, the output looks good even at 90%, but at 80% it suffers (as expected). Nothing really interesting there, and also not when it comes to temperature. The 220-240C that is printed on the box the filament arrives in, looks quite correct.


One of the things I really like about XT is it's transparency. You can't really make it fully transparent, but you can get some very nice effects by calculating your model to have walls that are a multiple of your nozzle size. In the image below, you can see how thickness affects transparency.

The wall thickness is written below the different wall segments. Opacity is quite good when holding the object close to the XT, but as soon as the distance is increased opacity suffers. The upper piece is a shorter model with the same thickness, but it's standing upright. What is interesting is how much the slicer affects transparency. I'm using Cura 14.01 for slicing and it constantly calculates the feed rate for infills incorrectly. To get enough material when filling 100%, I have to increase the Flow Rate to 160%? This must surley be a bug in Cura, but you can work around it by setting the Shell Thickness (= # of outlines) to a very high amount.

Another observation is that you will get the best transparency when you have long, straight lines. Curves & corners will automatically give you less transparency.

A couple tricks and a breakthrough

A hot tip if you get blobs or threads on the walls of your model, is to turn off Combing. This will force retraction on all moves and if your settings are otherwise correct, you'll completely remove the blobs. Another tip is that if the first few layers look good but the object then looses transparency, you can often save things by just slowing down a little as in the image below.

The biggest breakthrough I had in getting the XT to become clear, was after suggesting that Cura did not deliver enough infill. Daid (the maker of Cura) was quick to dismiss this possibility and I spent the whole evening doing more tests. After some cross-comparing with transparent PLA, I realized that Daid was completely right - no errors in Cura:

The first two of these are PLA and the last one is XT - otherwise using similar settings. Why was the XT so much less transparent? There were no difference? I then understood what the problem was.  To get XT fully transparent - you cannot use the fan!

In the image below the first one (A) was printed with the fan turned off until starting on the walls of the box. The second (B) is the best I could do with the fan turned on. The third is the reason I had the fan on - unless the fan is on, you'll get small blobs along the wall (C).

This is easy to solve however - Cura has a brilliant plugin-system that can turn the Fan on after either X layers or X millimeters of printing. Now, these boxes come out nicely every time!

So my magic settings for getting ColorFabb XT as transparent as possible - 35 mm/s, 235C, 105% flow & no fan for the transparent area. If you have a heated bed - crank that up as well as it'll help the layers blend by keeping the XT as hot as possible, so it blends better the next time the nozzle passes. Then you can crank up speed to 50 mm/s and turn on some careful fan cooling.

The reason I played around with this was to make a cutlery basket for my kitchen. Below you can see how it turned out and you can download and print the model here.

What platform next?

20 Feb

What platform next?

In 2013, Adobe completely dropped the ball on the Flash Player and AIR. All further development has been moved to India. This normally means that the software has been put in what is referred to as "Maintenance mode". Any serious bugs will be fixed, but don't expect much in terms of new features. If you take a look at the Release Notes for AIR 4.0, you'll see what I mean.


X/Y robot with MakeBlock (Part 4)

17 Feb

X/Y robot with MakeBlock (Part 4)

Have spent a couple evenings on getting GRBL up and running now. Here's my notes from setting it up.

Compiling GRBL on OSX

At Oslo Maker Faire, I finally met Simen Svale Skogsrud from the Oslo firm Bengler. One of their/his many cool side-projects is GRBL - a machine control software used for CNC, laser and 3D printers. As soon as I saw the Makeblock X/Y gantry, I knew that I had to make it run GRBL. Since most of the guides available seem to think that getting GRBL onto an Arduino is difficult, I thought that I'd write a small guide/tutorial for how I did this.

Start by copying / clone the source files from the Github repository to your machine. The precompiled versions could work, but I'll need access to the source later.

Download what we'll need

If you don't have the Arduino IDE installed, go get it from This contains all the command line tools we'll need, including avrdude (used for uploading code to the Arduino) and the avr-gcc compiler (converts source code to something the Arduino can use). The Terminal application is in the Utilities subfolder on your Mac /Applications/Utilities/Terminal. Open the app and type avrdude. If you get an error message along the lines of "command not found", we will need to setup the Mac to know where the AVR software are.

Adding the AVR tools to PATH

My original intent was to use LadyAda's tutorial ( for setting up AVR, but it's unfortunately quite outdated. Some of the external links are dead and I think it's possible to do this a little easier given that all the required tools are in the Arduino download.

Add your AVR-dude to the OSX path according to this tutorial. The AVR tool location on your machine will vary, but it will probably be somewhere inside your Arduino app folder like this:


After adding to the path, you'll need to close that terminal window and open a new one for the PATH to refresh. Typing "avrdude" in this new terminal window should now list all the options instead of "command not found". If not, go back to the tutorial above and try again.

Compiling the source

Now that we have the AVR tools in our path, we can go to the GRBL folder. I placed mine along with other Arduino code at /Users/jensa/Documents/Arduino/grbl/. Open open a terminal window and go to that folder:

cd /Users/jensa/Documents/Arduino/grbl/

To generate a .HEX file from the source code, simply type "make" and hit Enter.

If all goes well, you will now get a compiled program that you can upload to your Arduino. If something goes wrong, type "make clean" to remove the generated files. To see what other options are available, have a look at the "makefile" in the grbl folder. this is also where you'll adjust the compilation options if you're compiling for something other than an Arduino UNO (or other Atmega 328p-based devices).

AVR adjustments

To upload the hex file to the Arduino, you'll use "make flash". As long as the path has been set properly, that will compile just fine, but uploading it didn't go as planned. After figuring this one out, I found this official guide that could have helped me. To help others in the same situation, I'll leave how I got it working without this guide and the errors I got:

avrdude -c avrisp2 -P usb -p atmega328p -B 10 -F -U flash:w:grbl.hex:i
avrdude: can't open config file "/usr/local/etc/avrdude.conf": No such file or directory
avrdude: error reading system wide configuration file "/usr/local/etc/avrdude.conf"
make: *** [flash] Error 1

Looks like avrdude needs some custom configuration. Let's have a look at what's required. By typing "avrdude" on the command line, you'll get an overview of what's possible. From this, we can see that the "-C" flag allows us to set a custom configuration file. Since we are using the Arduino supplied version of AVR, we should probably use that config file as well. I found this file by using the find command in the terminal window:

sudo find / -name "avrdude.conf"

In my case, the path was:


so you're will probably be something similar. I added this to "makefile" after the other parameters for "PROGRAMMER" so that the line was now:

PROGRAMMER ?= -c avrisp2 -P usb -C /Applications/

Running "make flash" now returned a different error message:

avrdude: usbdev_open(): did not find any USB device "usb"

Right... That makes sense. In the Arduino IDE you're always specifying paths that start with /dev/ and such. You can find the correct port using the command

ls -l /dev/cu.*

This returns a list of possible devices and it's the same you'll find in the Arduino IDE. In my case it was /dev/cu.usbmodem411. Note: do not have the Arduino IDE open while doing this as it can cause trouble.

My "PROGRAMMER"-line in the makefile was now like this:

PROGRAMMER ?= -c avrisp2 -P /dev/cu.usbmodem411 -C /Applications/

I still got errors though:

avrdude: stk500v2_ReceiveMessage(): timeout

Ok. I've seen this one before. It basically means that your config is correct, but something is incorrect with the programmer. The programmer is set with the "-c" flag and here it's set to "avrisp2". That's the same as using "AVRISP mkII" in the Arduino IDE and that won't work with an Arduino UNO board. How about removing the number 2 so we get this:

PROGRAMMER ?= -c avrisp -P /dev/cu.usbmodem411 -C /Applications/ -carduino

Note the addition of -carduino at the end there? It helps with defining the right board. Ohhh! It's uploading! Now let's see if this works. We should be able to log onto the GRBL installation using the Arduino serial monitor. Bingo.

For figuring out the rest, I looked a lot at this tutorial that details how to use GRBL for a laser engraver. It's a little outdated, but has tons of good info!

For some defaults, I tried what is found on the GRBL wiki. That didn't work too well with the MakeBlock setup I have. Instead I ended up on using something like this:

$0=12.650 (x, step/mm)
$1=9.000 (y, step/mm)
$2=25.000 (z, step/mm)
$3=5000.000 (x v_max, mm/min)
$4=5000.000 (y v_max, mm/min)
$5=500.000 (z v_max, mm/min)
$6=500.000 (x accel, mm/sec^2)
$7=500.000 (y accel, mm/sec^2)
$8=10.000 (z accel, mm/sec^2)
$9=200.000 (x max travel, mm)
$10=200.000 (y max travel, mm)
$11=200.000 (z max travel, mm)
$12=10 (step pulse, usec)
$13=2500.000 (default feed, mm/min)
$14=192 (step port invert mask, int:11000000)
$15=25 (step idle delay, msec)
$16=0.050 (junction deviation, mm)
$17=0.005 (arc tolerance, mm)
$18=3 (n-decimals, int)
$19=0 (report inches, bool)
$20=1 (auto start, bool)
$21=1 (invert step enable, bool)
$22=1 (soft limits, bool)
$23=0 (hard limits, bool)
$24=1 (homing cycle, bool)
$25=224 (homing dir invert mask, int:11100000)
$26=100.000 (homing feed, mm/min)
$27=500.000 (homing seek, mm/min)
$28=100 (homing debounce, msec)
$29=2.000 (homing pull-off, mm)

An error that had me stumped for a long time was that the limit switches would be hit all the time causing the GRBL error:

ALARM: Hard/soft limit. MPos?

I searched and searched until I found this post regarding testing of homing in 0.9. Oh my... GRBL wan't to work with a 3 axis setup? How on earth could I know that... Well. I guess I could change the Z-axis a bit. That way I could even fit a Dremel on there? Hmmm! That sounds interesting...