arduino, robots, cameras, and life

To be honest: I posted this to the makerbot forums. I have had limited luck on those forums before so I am also posting here. I’d like to be able to get input from reprappers as well as makerbotters.

I’m rebuilding a late-model cupcake for fablab Boston. It has had some parts stolen, and I’m looking for advice on what route to go.

The two issues are that the motherboard has been stolen and it has a mk4 extruder. I know that the simplest thing to do would be to buy a new motherboard but the direct replacement (1.2) seems to be perennially out of stock.

Then we get to the fact that it still has a mk4 extruder. Since this will be used to teach kids how to print and do 3d design, I would really prefer if it had a bulletproof hot end. I think that generally means stepper-based, either mk6, mk7, or a wades style printed one.

sooooo…
Option 1_ I can get a motherboard v2.4, stepstruder mk7 complete kit, and an arduino mega 2560 from Makerbot for $85+$229+$65=$379

Option 2_ I can get a motherboard v2.4, another stepper driver, a stepper motor, arduino mega 2560 from Makerbot and some printed wades extruder parts for $85+$92+$65+free=$242

Option 3_ I can just get the motherboard v2.4 and an arduino from Makerbot and fight with the old dc extruder for $85+$65=$150

Option 4_ I can get a full reprap-style ramps board from reprapworld.com with stepper drivers, an arduino mega, a stepper motor and printed parts for a wade extruder for $130+$16+free=$146

Am I missing any better options? I’m leaning towards option 4 currently, but I could be persuaded. Am I correct in assuming that I can’t use repg on a RAMPS setup? That would basically be a full reprap toolchain conversion.

I’m honestly fairly excited about moving to a slic3r / pronterface toolchain because repG has always been fairly buggy and I feel like the cupcake is not that well supported in recent versions.

I’m trying to put together a meeting of people interested in 3d printing. It’s called reprap because I think most of the people will come from there, but makerbotters and professional printers alike are more than welcome!

I’ve got a post over on the reprap forums trying to get an idea of how many people are interested and when we should do it. If you want to come out, then post a little bit about yourself over there and hopefully we can meet up!

EDIT: over on the #reprap irc Rhys-jones and a few other helpful folks figured this out for me. Since the endstops aren’t working on my machine yet, the 0,0,0 position was based on wherever it was when it started up. I guess the x and y were similar to that same position, but the z wasn’t. The fix was to add “G92 X0 Y0 Z0;” to the beginning of the gcode. That sets the current position to 0,0,0 on the printer. This can be done in the Start/End Gcode tab in Slic3r. Thanks again all who helped!

I have something weird going on with my reprap where it will take the first z move and scale it dramatically. Then all of the others will behave normally. I made a video to illustrate it.

Machine will jog correctly through pronterface. when it encounters the first .4mm z move it ends up moving significantly farther. It ended up moving around 1 cm.

This is the code for that abrupt z move “G1 Z0.400 F7800.000″

at the end of the video you see it begin the second layer, and it moves the correct amount! This is the code for that z move “G1 Z0.800 F7800.000″

I am very confused.

For those interested, this is a gen6 board running sprinter and controlled by pronterface on my mac. The gcode was a single walled box sliced by slic3r 5.5. The config.h for sprinter is below.

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Ok. A recent move has kept me away from my prusa for a few months now. In that time all of the “cool kid” software has changed. Naturally I want to be running a similar setup with all of the new bells and whistles, so off I go.

I am going to go about uploading marlin onto my gen6 mendel-parts.com board. Installing pronterface on my Macbook running lion, and eventually get to using slicer to generate the stl files.

Step 1: Get marlin on my gen6 main board

I downloaded the most recent version of marlin from github.

https://github.com/ErikZalm/Marlin/tree/Marlin_v1/Marlin

I got the newest version of arduino (23) from here

http://arduino.cc/en/Main/Software

I got the sanguino arduino add-ons from here (Updated to arduino core 0023)

http://code.google.com/p/sanguino/downloads/list

Ok, enough downloading for now. Install the arduino first. There is a driver included with the download called the ftdi driver. Install that as well. That enables usb connectivity for some boards.
Now go here and follow the directions for installing the sanguino add-on. What you are doing is adding support for the specific chipset included in many main boards.

http://sanguino.cc/softwareformac

Now your mac side should be set for marlin. Go into the marlin folder you downloaded and open marlin.pde with arduino. It should open up a sketch with a bunch of other tabs behind it. The main one you will need to play around with is configuration.h. In there you should comment out or in the specific hardware and features you have/want.

Here is an example:

This is from the top of configuration.h

#define BAUDRATE 250000
//#define BAUDRATE 115200
//#define BAUDRATE 230400

The // that starts most lines tells the arduino to ignore it. These three lines represent a multiple choice for you. In the above example the first line is the one that is currently setting the baud rate. This is an important change. The default marlin firmware has the baud rate set to 250000 for some reason. I don’t think that will work out very well. Change it to 115200 and you ought to see better results.

Some other lines that I changed are:
#define MOTHERBOARD 5
#define THERMISTORHEATER_0 3
#define HEATER_0_USES_THERMISTOR
//#define ULTIPANEL

Feel free to look around and get a grip of all of the options available. There are a lot. Don’t play with the pid settings unless you really know what you are doing, though.

Now you should be ready to upload the firmware to your board. Before you connect your board to your computer, select the board from the pulldown menu in the arduino app. Mine was “Sanguino with atmega 644p” Hit the verify button and wait for it to verify. If it fails, then you need to determine if it is a software issue, or a config issue. Look at the error message and do what it tells you to do. The firmware will check to see if your board in arduino matches the board that you defined. If it doesn’t then it will throw an error.

With a valid verification under your belt, plug your reprap in to the wall, connect it to your computer and turn it on. In the arduino app go to tools / serial port and select your machine. It should begin with /dev/tty.usbserial and not have anything to do with bluetooth in the middle. Once that is successfully uploaded you are done flashing marlin!

Step 2: installing Pronterface on osx Lion

I basically followed the directions here https://github.com/kliment/Printrun and I only had one hiccup. I will paste them below.

Download and install [wxPython2.8-osx-unicode] matching to your python version (most likely 2.7 on Lion, check with: python –version) from: http://wxpython.org/download.php#stable

Download and unpack pyserial from http://pypi.python.org/packages/source/p/pyserial/pyserial-2.5.tar.gz
In a terminal, change to the folder you unzipped to, then type in: sudo python setup.py install

I then tried to run it by typing “python ” (including the space) and then dragging in the pronterface.py file. It gave me an error about not finding any 64 bit resources, so I scrolled down a bit on the github page and found the answer. I typed “export VERSIONER_PYTHON_PREFER_32_BIT=yes” into terminal.

That’s it! Pronterface is installed. Select your port and your speed and hit connect. Now you have the firmware and the front end gui set up. I did a bunch of little tweaks to the firmware because my board was reporting really high temps. I had the thermistor set incorrectly in the firmware, so I would disconnect the machine in pronterface, change the setting in arduino, upload it, and then reconnect in pronterface. That is going to be your loop whenever you change something from here on out.

I don’t remember who tweeted it, but I saw a tweet a week or so ago saying that the makerbot grab bags were a good deal. I looked at them and bought three. I figured that at $9 each they would be a good deal.
even if they had nothing but the ftdi cable.
I got my box today and Wow!

I got two of the grab bag #1 and one #2. Each of the #1′s had TWO ftdi cables, two early nozzles, 5 pfte barrels, 2 brass barrels, a bunch of thermistors, pulleys, a fan, and some plastic build plates. They said that the grab bag could or could not include those items, but I didn’t think it would come close to having them all!

The second grab bag was similarly stocked, with a ton of pulleys, belts, some rods, some wooden build platforms and a ton of fasteners and plastic bearings.

They said it in the description, but I want to reiterate it: If you are a cupcake operator, you should probably get this. It is a great source of spare parts that would have cost you hundreds to buy a few weeks ago from makerbot. It will hopefully keep your bot printing for a long time to come.

If you are not a cupcake operator: it’s still a damn good deal.

Thanks makerbot!