Night before Christmas

'Twas the night before Christmas, when all through the house
Not a creature was stirring, not even a mouse;
...
When, what to my wondering eyes should appear, but the BfB RapMan running!

Yes, this relates to the 2008 version 2 RapMan, a Darwin RepRap I never got printing successfully.

Now, with the Geared Brutstruder and a heater construction of my own, it is running. Some additional tweaks in the Firmware and Host for the final printing touch.


Details
Firmware: Gen2OnABoardFiveD_GCode_Interpreter
Extruder: Brutstruder with Wades Gears
Host: ReplicatorG-0009 (patched so that spaces are not removed from cmd string:
SerialPassthroughDriver.java, comment out line #173 clean = clean.replaceAll(" ", "");

For those interested in the final Firmware and hardware design used, leave a comment and I will post the files as well.

Moved

At the time I started this Blog to register my 3D printer stuff in, I thought Blogger was a nice and easy starting point. Now I changed my mind.
Not that Blogger in particular is not the "right thing" to do. It is more the idea of being dependent on one of these "free" services for which you will pay eventually in some way.I just felt like publishing this on my own weblog.

So to keep this a short entry, I moved most of the things I valued worthwhile, to Chaos Geordend. Which is my personal business site which (now) has partly Dutch and partly English content.

Any future Makerbot and/or RepRap stuff I may still log here.

That's it!

PS Yes, it is a matter of paying so either you or your readers are not covered with advertisements. Otoh, eventually we all pay some way or another, if it isn't only Google, to reach content :-)

RepRap revisited

The successfull MakerBot prints gave me enough confidence and motivation to pick up the, last year abandoned, RepRap project. After some days of tough fights with the software, the RR is now in control! Finally I can test the extruder and hopefully the RR will be printing this year :-)

Follows a list of blocking issues:
1. Arduino had a HardwareSerial issue in the Sanguino (Atmega644P) library, solved in Arduino 0018. Mark that you clean up the firmware objects (FiveD_GCode_Interpreter/applet) to ensure a clean object recompiled with the proper libraries;
2. ReplicatorG SerialPassthroughDriver.java removes spaces from the commandstring, patched as follows;

public String clean(String str) {
String clean = str;
// trim whitespace
clean = clean.trim();
// remove spaces
// 2010.04.04 JvO DON'T clean = clean.replaceAll(" ", "");
return clean;
}

3. FiveD Firmware, byte datatype tested for -1 unsigned byte;
4. FiveD Firmware, cartesian_dda.can_step() code is incorrect for Max endstops, patched as follows;

bool cartesian_dda::can_step(byte min_pin, byte max_pin, long current, long target, byte dir)
{
bool canStep = true; // 2009.08.27 JvO
//stop us if we're on target
if (target == current)
canStep = false;
#if ENDSTOPS_MIN_ENABLED == 1
//stop us if we're home and still going
if(min_pin >= 0 && min_pin != 255) // JvO byte datatype is unsigned
{
if (read_switch(min_pin) && !dir)
canStep = false;
}
#endif
#if ENDSTOPS_MAX_ENABLED == 1
//stop us if we're at max and still going
if(max_pin >= 0 && max_pin != 255) // JvO byte datatype is unsigned
{
if (read_switch(max_pin) && dir)
canStep = false;
}
#endif
// All OK - we can step
return canStep;
}

Finite Element Modeling

Reading my way through the "Finite Element Method" by Michael R.Gosz, ISBN 0-8493-3407-1. An excellent book to go with FreeFEM++ and FreeFEM3D.

Finite Element Modeling

My first, modest, steps in modeling the heaterbarrel. Starting with a 2D model. Not taking into account real-life stuff such as convection, radiation and other effects (I am probably not even aware of :-)







First tried to get ElmerFEM to compile on Intel Mac to find out it crashed anyway. Then recently I found FreeFEM++ which is perfectly suited for this purpose.

Before I can add some more sensible comments to this post I have to re-read some old math and physics textbooks first. Partial differential equations, thermal diffusivitiy. All this may take some time ;-)

Please mail me your findings on your 3D printing heaterbarrel FEM approach.

Todays' update; 3D image (FreeFEM3D icw medit) of the heaterbarrel and NiCr Heater coil model.

Oh, the joy of 3D printing

There is calibration to do, and repositioning of the Z-plane rods. Despite all this I printed (a kind of) PTFE retainer.
The first rafts didn't stick at all. Then they did but the extruder would stop or the print would be fudgy so the nozzle got stuck. Then despair came. And today I managed to complete the thing.



And, well err, it does resemble most of the design ;-)

Jim, it's alive!

The MakerBot is built and indeed it prints.



The first print ever, a testcube



Now back to my wishlist of things to print. For tweaking and operational MB stuff I keep an eye on the MakerBot Operators Blog.