Tuesday, August 12, 2008


Multimachine, built by Pat Delany of Palestine, Texas, is an inspiring project. It is...
a humanitarian, open source machine tool project for developing countries... The MultiMachine all-purpose machine tool can be built by a semi-skilled mechanic with just common hand tools. For machine construction, electricity can be replaced with "elbow grease" and the necessary material can come from discarded vehicle parts. What can the MultiMachine be used for in developing countries?
FOOD SUPPLIES: Building steel-rolling-and-bending machines for making fuel efficient cook stoves and other cooking equipment...
The project is open source and thoroughly documented. It uses commonly available pieces. It seeks explicitly to address the needs of the developing world. It recognizes the work people did in this area (1, 2) in years past. Cool stuff. We have all kinds of Industrial Revolution era mill buildings in the greater Boston area and this would fit right in.

Frostbot, the work of Brian Schmalz, is another food fabber. It's designed to frost cookies. The CNC mechanism is from Fireball CNC. Brian's other tinkerings include a cool USB bit-whacking board available at Sparkfun.

Monday, July 21, 2008

3d printer project at Victoria University of Wellington School of Design

There was recently a design contest at VUW School of Design to create inexpensive 3d printers. Apparently Ponoko had some involvment, possibly a sponsorship. I found the prettiest printer to be the Equinox, which also was designed to be environmentally friendly, using a lens to focus sunlight to dry recycled paint as a printing process. I was going to say the printer itself looks like an astrolabe, but it really looks like an armillary sphere, a sort of 3D astrolabe.

There's a high-res photo (low-res version below) that shows some of the mechanics, which were laser-cut on Ponoko. I am very much hoping that the university and/or students will publish the plans for the Equinox. It's very cool that people can use a service like Ponoko to build their own printers.

Very slow progress on my CNC mill. I finally purchased the 3-axis Xylotex controller. It is my hope to connect it this evening and conceivably mill a piece of wood. So I need to move a PC to where the mill is, run a network cable, load the PC with EMC and configure it, and set up the shop-vac to collect sawdust. I'll mount the Xylotex board and power supply and fan on the side of the mill, but that's for later.

Wednesday, July 2, 2008

Penny wise, pound foolish

I got the idea that I should try to design and build my own electronics. I've done electronics design before, including microcontrollers and FPGAs and the like, but I have little experience with power electronics. That, and I'm impatient. The upshot is that after wasting about three weeks and a few hundred dollars in trying to control stepper motors, I'm not much further ahead. Here is the affordable pre-packaged solution (which had been recommended by the guy who sold me the mechanics) which I should have used from the start:
So I'll plan to pick up a 3-axis controller and run it with LinuxCNC. Apparently TurboCNC is also very popular but I'm not about to run DOS on any machine that could be running Linux.

The mechanics cost about $300 including shipping. The steppers cost $75 (I got them from RRRF). This stepper controller will run maybe $225 with shipping, so the whole thing is $600. That's reasonable. Obviously it doesn't include waste.

I'm thinking it would be fun to fool with Python code that generates G code and sends it to the CNC. I could develop a repertoire of programmatically defined shapes.

Friday, June 6, 2008

RepRap replicates, and Will gets a New Toy

On the left is Adrian Bowyer, the University of Bath professor who started the RepRap project. On the right is Vik Olliver, the most active RepRap builder on the planet. The two machines marked "parent" and "child" are RepRap 3D printers with the interesting relationship that the "child" was mostly built by the "parent". This is a HUGE STEP toward Bowyer's vision wherein RepRaps make more RepRaps and humans benefit. This will do for physical goods what the GPL and Linux and Apache have done for software.

My own news is, at least locally, equally exciting. My CNC mill has finally arrived! And I also got an Arduino controller. I've got my stepper motors from RRRF, and a Harbor Freight router is on the way. It's going to take time to put everything together, and of course there's very little spare time in the life of a modern adult.

Once the CNC mill is up and running, I plan to work on a scheme for swapping out the router and swapping in an extruder for thermoplastic. By that time the RepRap guys will be doing even better than they're doing today, so I will benefit from their stuff. Maybe I'll end up making an actual RepRap before I'm through.

Thursday, May 29, 2008

RepRap: Big step up in print quality!

This posting on the RepRap blog shows the massive progress these guys have made recently in their printing quality. The progression is clearly visible in this photo of some door handles. The most recent incarnation is the work of a guy known as "Nophead", with his own blog describing his work. His machine uses a RepRap extruder on a purchased CNC table rather than the RepRap 3D platform, which made me think that the RepRap platform must be the reason for the less-than-commercial-grade print quality. I asked him about this in a comment, and he replied that the improvements were:
  • his extruder has a shaft encoder to control the speed precisely
  • he has temperature control to +/- 3C
  • he doesn't have any comms delays (I don't know the architecture well enough to know exactly what he means here)
  • he runs his head faster so as to stretch the filament down to 0.5mm.
  • careful choice of printing material
To conclude, he says "All these things can be sorted out on Darwin [the current RepRap prototype] so I expect its prints to be this good in a month or two." That's a very cool thing. It's wonderful to see such progress.

Within just a year or two, RepRap will be much further along in terms of both quality and ease of use, and it will be affordable for small clubs in high schools and colleges all over the world, and large numbers of individual hobbyists. By then it will probably print multiple materials including conductive ones, so you'll be able to embed circuitry in a widget. Today one of the big killer apps for 3D printers is little action figures based on avatars from Second Life and similar games, but when 3D printers really are ubiquitous, people will move on to far more interesting apps that I can hardly imagine.

Let me not forget this very nice list of a lot of different commercial and hobbyist 3D printers.

Still waiting for my CNC mill platform, the eBay fellow has been getting a huge volume of business and his shop is a bit swamped. I've been getting a bit more organized with the electronics, including resuscitating an old FX2 board design, and I've ordered some stepper motor driver parts that should arrive soon.

Wednesday, May 7, 2008

Affordable CNC gadgets

CNC has existed as a hobbyist pursuit much longer than 3D printers have been. I finally broke down and purchased one of these on eBay. It will take a couple weeks to arrive, and the one I got did not include stepper motors, couplers, or motor drive electronics. Those are things I'd enjoy doing myself anyway, so no problem.

I like this project which is along similar lines.

For my own gadget, I need to order stepper motors, think about couplers, and start planning how the electronics will go together. I'm thinking about being lazy and using the parallel port.

I got to see a real RepRap up close!

This evening I went to a presentation and demonstration of a real live RepRap by Bruce Wattendorf and his son. It was very cool to meet somebody who's built a real one and is totally up to speed on every aspect of the project. I asked some questions about the long-term future of the RepRap project.
  • Can they get much better spatial resolution without compromising the social goal of serving the developing world? Yes: better spatial resolutions can be gotten with finer nozzles, which would print slower. You could build a duel-nozzle gadget with a wide nozzle for fast clumsy printing, and a narrow fine nozzle for slow elegant finishing.
  • Will they bump into patent problems as they move toward the state of the art currently occupied by commercial 3D printers? A number of patents will expire in about three years and the RepRap guys will then be much freer in this area.
He wrapped up his presentation by showing the nanofactory video, "Productive Nanosystems: from Molecules to Superproducts". I came to 3D printers from an interest in nanotech, and he came to nanotech from working on 3D printers. It was gratifying to see that the similarity is clear to people on the other side of the fence.

It was a heck of a lot of fun. I took some pictures. Bruce also has many more pictures on his blog. Interestingly, the parts that are normally plastic in a RepRap are made of wood in Bruce's machine, and he's in the process of printing a set of plastic parts.

Bruce's talk was sponsored by a group called DC401, a bunch of Rhode Island folks who enjoy going to DefCon. They are working with a woman in real estate to arrange a lab space in a building in downtown Providence where they can do electronic and mechanical tinkering. It was fascinating to hear her talk about how she's making it all work by using the other floors for businesses and residential space. This reminds me a lot of MITERS, and it warms my heart.