Let's Make Robots!

Nord, a Reprap Mendel

This is an additive rapid prototyping machine that can print lots of its own parts, it replicates!

   This is my build of a Reprap v2 3D Printer, called a Mendel.  Since 2005, the inventors of the Reprap have been leading a now worldwide movement to create a self replicating open source 3D printer.

   It works by laying lines of molten plastic down in layers and builds them up in the physical shape of a 3d model that you can make on your computer using open source software.

   There are several open source 3D printers going around, some are available in kit form and others like the Mendel are open designs that you need some help to make yourself, i.e you need to find a way to source the parts that are printed by another machine.  I got mine printed by a frined with a Makerbot and we built our Mendels at the same time. We also tried to buy as many parts as we could locally which saved some cash in the process and developed local interest in the idea of home 3D printing.

I found building this machine to be one of the best and most fun learning experiences I've ever had in my adventures in DIY. I started calling it my "Intro to Everything" because it covers mechanical fundamentals to interfacing with embedded electronics and finally fabricating my own 3D designs and others available for personal use from websites like thingiverse.com and the Reprap Object Library. People have designed and made everything from better Reprap parts (that help in the evolution of these printers) to household objects and *robot parts* and school supplies.


I just took it for its first stress tests today and since everything worked fine, I'll mount the extruder and go big...

Notes on the Software:

I design with free software called Blender or Google Sketchup, then export to a program called Skeinforge which generates GCode for the printer, then finally print the gcode file in a program called ReplicatorG. 

Update, 5/21/2010: Just finished re-installing a Wade's NEMA17 extruder and configured it into the ReplicatorG control panel via the machines.xml file in the RepG folder. Also made some mods on my major wiring issues. This was by far the most challenging thing for me to date. I seem to do well with all things mechanical, but at software, files and code I balk at its seeming complexity sometimes. Anyway, it was easy in the end.  Now that I have a complete machine, I'm onto some test extrusions to tune my settings and then I'll put up some video of a print!

UPDATE 10/21/10 Printing officially!  Didn't need to take this long, but with work and daily life, it did :)

Pics of the calibration blocks and a turtle I made for my daughter...

This was all in one night, so I'm glad to have gotten this foothold and am ready to say I completed the Mendel!

Now let's make more Mendels...

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Oooh! I always wanted one of these printers. Very cool to see one on LMR

this is "the proyect" the main reason, the best of all.... dream come true......whatever...

In a short time i will be able to make, buy or borrow an extruder, in order to make a reprap machine......

Finally printing calibration blocks! 

Last few weeks (months?) was such a big learning curve. I've built and rebuilt an extruder at least five times and fell into a lot of dead ends and rabbit holes concerning getting a stepper motor to work with the extruders and stuff. But I did get it working so cheers to that.  Anyways I'm sensing the home stretch here ( I know I've said that before but it's for real this time I swear! ;))


These pics are of the first three blocks being printed, yeah I know they look less than desirable, but yours will too at first. ;)

The next two were just missing a corner but had solid walls all around.

Seems like the next hurdle to conquer is driving the extruder properly with a dedicated stepper driver and that will help with making objects that look good.

So that's where I'm at today, functional but still ironing out the aesthetic of prints and configuring the settings in skeinforge.

More soon I hope.

Here's a break down of what I spent and where, plus some things that might make a better cost outline.

-RP parts were free for me, I run a shop where we hold workshops and my friend made a batch for me so that we could tag team other batches in the future. On ebay these are $200-400, lasercut is sometimes cheaper. You can mold or mill parts at home as well, so that would be in the free bracket.

-Electronics were GEN3 electronics from Makerbot store. Total was about $250.

Alternatives have since come out from Pololu for the stepper drivers, and you could find Motherboard and extruder controllers for about $100. The motherboard is a customized Sanguino and the extruder is a custom Arduino 168, so if you want to hack a bit, then you can shave cost there.

- I bought my nuts and bolts hardware locally for about $40 and got my

-Belts from Mcmastercarr.com. they were about $20 including shipping, I got extras.

-Bearings cost $48 plus shipping from ultimachine.com

-Extruder parts were $30 and I got those from the Makerbot store. But there are plenty of avenues in the Forums on Reprap as well.

-Motors were about $50 total from Alltronics.com, I've made three separate orders there and all of the Lin Engineering Motors work great.

That puts me at just under $450 raw cost.  I've also spent some time and money on milling legacy stepper drivers, getting other motors, and lasering out build beds and stuff.  All in all I've matched that to about $600 since January. I'm glad I don't go out much or I'd be broke.

Reprap.org has a cost analysis of 520 euro, that's currently about $640.

Kits are being sold at around $850 because, I assume, that labor is being tacked on.

I'd be glad to help out with parts in the future, I've been slammed at work lately so I haven't been able to publish any pics or vids of calibration blocks...soon enough..

Hi, congratulations on building the repstrap mendel! can you please elaborate a bit on where those $600 where spent? i'm trying to build one as well and would like to know as much as i can so that i can spend the least possible :)

You're probably best off asking the CNC guys I guess. This is a Dutch site you could try (they all speak English down there) http://www.cnczone.nl/ Probably some sites local to you also exist.

Update on firmware troubleshooting:

Gotta edit the configuration for both 5D and Reprap firmware for control of a stepper driven extruder, so I'm running into those foxholes as I write.

Each firmware has its own set of simple mods in the code depending on the author, which is sort of nice for me, being of more analog roots than coding and microcontrollers, so its a good intro to embedded systems.

So far I've done some test extrusions and have done a "dry" print to see how Nord behaves, but when it actually should be printing, there is no call from the GCode to drive the extruder.

If anyone who is more familiar with Gcode and has adivce or insight, I'd love to hear it!


Basically the RepRap (Mendel) uses special M codes to control the extruder, have a look here: 


The thing is that the G-code you generate must include those codes to drive the extruder, AFAIK the RepRap software does that, Skeinforge should also do so... but that piece of software is really complex. 

BTW: Which firmware are you working with? I have found several have a look at my post here: http://letsmakerobots.com/node/9006 (the 03 - Mar - 2010 update)

Should have updated sooner. but got it figured out!  Since I have little experience running any sort of toolchain for CNCs and 3D printers, I have been using gCode generated from Skeinforge and the Reprap host, and experimenting with the new files to see what flows best with the printer.

In the Mendel User manual, you'll see that the line M108 controls the motor speed, but is labelled as deprecated since "Sxxx" is a PWM.  I replaced that with something like "Rxxx" since the stepper is controlled via a setting for RPM instead. It works!

I'm running modified Makerbot firmware with version 1.6 on the motherboard and 1.8 for the extruder.  I haven't had any luck with the newer versions thus far, but I'll keep trying.

Hey, nice work on the reprap. These things take a ton of work.

I'm building a repstrap (I'm about halfway done, I'd say) and, if anyone needs parts, I can help too when I'm done.