Friday 25 June 2010

Heater board complete

I've completed and soldered my heater board.

There are 8 PWM outputs from my reprap shield which are boosted using 54A MOSFETS. These should happily drive my extruder heater, heated bed, fans, extra motors, whatever.

I've posted the files to thingiverse. I've also added my single-sided stepper driver files to a thing as well.

I now have four working stepper drivers, one mega shield, and a completed heater PWM board. Only a couple of thermistor sensors, and I'll have a complete set of electronics for a mendel :-)

Saturday 19 June 2010

RepRap host software on Mac

Just a quick note to anyone trying to get the RepRap host software to run on a new Mac (Mac OSX 10.6.3).
I downloaded the software from the wiki and unzipped it.

To get it to work, I had some problems trying to make it accept a classpath. Eventually I did the following:

Make a directory ~/Library/Java/Extensions
Copy any files with *.jar and *.jnilib extensions to that directory.

The librxtxSerial.jnilib file supplied in the reprap software didn't seem to work. I found one at and I replaced it with this newer one.

Go to the reprap host software directory in a terminal window (you need to be in a directory with the rr-logo-green-url.png file in it).

type 'java org.reprap.Main'

This brings up the main reprap windows on my mac, and I was able to load and slice a .stl file. YMMV :-)

As pointed out by Tony, this is not the most elegant solution. It doesn't help that I was looking at the 'mac-experimental' version from last year, rather that re-building from source :-( oops.

I also found out why I was having problems with the classpath :
java org.reprap.Main -cp $CLASSPATH 
is NOT equivalent to
java -cp $CLASSPATH  org.reprap.Main 

This is usually true of any other command-line program, but any arguments AFTER the classname are passed to the class Main() method. I blame late-night programming :-)
Ignore all the java/extension rubbish, just use instructions from

A command line that also works is
 java -cp "*" org.reprap.Main 

Wednesday 9 June 2010

Monday 7 June 2010

Apple service and board PDFs

A few weeks ago, I bought myself an Apple MacBook Pro :-) and I've been really happy with it. However, a few days ago, I had terrible trouble trying to load the Ardunio software - segment faults and Kernel Panics (serious errors!) all over the place.
After a bit of debugging, I tracked it down to a single command - 'java -d32' which would cause a segmentation fault or bus error straightaway. A bit more investigation led me to the Apple Hardware test - which reported a 4MEM error, indicating a bad stick of ram :-(.

I dropped into the apple store today, expecting a delay as they had to send my nice new MacBook off, or at least swop out the ram. The apple 'Genius' was very helpful, and confirmed the bad ram - or possibly a logic board - and went off to speak to the manager.
However, 10/10 for service - despite the fact that I'd been using it for 6 weeks, they arranged a swop for a brand new machine right away! They even copied everything over to the new machine! I picked up my 'new' pc, opened the lid and everything was exactly as it had been on the old machine. I am now a very happy Mac customer :-) - that is an excellent example of customer service.

Also produced some PDF files for the Mega shield - available with the eagle files on the
Eagle files for Renoir's RepRap Mega Shield Page.

Friday 4 June 2010

Renoir's Mega Shield built

I've been soldering and building and I've finished my mega shield!
From RenoirsMegaShield
The build went well. I 'tinned' the copper pads (using some plumbing flux and a tiny bit of solder), which made the soldering a bit easier. Using a tip (from ladyada?) I converted some standard header pins to some through-pins by pushing them through using the flat on a pair of pliers, three or 4 at a time:
From RenoirsMegaShield
Once I'd fixed the pins, I could put them through into the arduino and check the alignment - OK. I left the pins partially pushed in to maintain the position, and soldered a single pin from each row:
From RenoirsMegaShield
This held them in place when I removed the mega and soldered the rest.
From RenoirsMegaShield
I've now got 10-pin IDC headers for X,Y,Z, and extruder (A) - and a spare (B) using header pins as I ran out of sockets. There's a space for the 20-pin interface connector from the generation 4 designs, and a whole set of +5v/GND/analog in headers for temperature probes, extra sensors, etc. Along the top is an I2C 4-pin header, and similar +5v/GND/digital I/O headers for servos, TX/RX comms, and some PWM pins. 8 PWM outputs are taken to a separate 10-pin IDC header that is intended to go to a MOSFET power driver board to drive the heater and heated bed (coming soon).