by makeme

Lower Entry Barriers For 3D Printing

In Uncategorized on 12, Oct, 2011 at 22:36

The basic technology required to make a 3D printer work isn’t particularly groundbreaking, so it’s nice to see a brand new design as opposed to yet another copy. Origo is a project (company?) started by Artur Tchoukanov and Joris Peels with the goal of producing an $800 mass-produced 3D printer specifically for kids. It looks like they’re planning on using a double swing arm for the X Y motion, which greatly simplifies the physical construction, lowering the cost. They are also integrating the software so that kids can design things in 3DTin and then have their creations automatically printed. Also, a recycler, but I doubt that idea will work.

More 3D printers, particularly cheaper ones, is great. However, I would like to see the cost and complexity drop even farther. Here are some ideas for how that might happen:

  • The printer itself shouldn’t require powerful or precise tools.
The Thing-O-Matic achieves precision with laser cutters, the Mendel achieves precision with another 3D printer, and they both use special steel rods. The designs depend on expensive and difficult-to-maintain manufacturing tools.
I think it’s possible to avoid the use of things like laser cutters, precision ground steel rod, and pre-existing 3D printers. Anything that’s going to be expected to recreate precise movements is going to need some precision parts and assembly, but that’s almost entirely about the layout. For example, instead of laser cut parts one could print a template on a desktop printer, attach it to the wood, and cut/drill by following the guide. The typical solution to linear motion is some kind of bearing riding on precision rod, but some things like aluminum angle and drawer sliders are nearly as precise while being far cheaper.
The real barrier to entry, however, are the precision manufacturing tools. You CAN download the blueprints for a Thing-O-Matic, but they are specifically designed to be produced on a laser cutter. For example, the T-slots aren’t something you can accurately reproduce on your own. Likewise, while you CAN download the parts files for the Mendel, good luck carving them. “Many of the mendel parts are quite difficult to make from wood, and could do with a re-design. They are all created with 3d printing in mind, so there is no consideration for access to internal spaces, or grain or any of the other things to keep in mind when working in wood.” Designs with these requirements create a speedbump which sucks down money, time or luck. Instead, the goal could be for the printer design to require nothing more than a hand saw (cuts) and an electric drill (holes).
  • It doesn’t actually need a .5mm nozzle.
Creating sub-millimeter holes is kind of a problem. The only really reliable way to do it is to put the nozzle blank and drill bit into a lathe. If you allow the nozzle diameter to rise you start to run into pre-manufactured components like needles. Or, at a minimum, things like 1/32th (.8mm) drill bits that are cheaper and easier to obtain than .5mm bits (at least in the States). Even 1/16th (1.6mm) bits would be small enough to do something useful (probably equate to a 2.7mm wide track) and are pretty much free.
More importantly, moving up to something like a 1/16th bit wouldn’t require any special tools to use. Even holding a sub-millimeter bit requires a special tool. A 1/16th will fit into a standard drill chuck. Sure, you CAN get sub-millimeter bits that have expanded shafts, but that’s starting to raise the barriers again as people need to special order them and they can’t be easily replaced.
  • Make each part do more than one job.
The Mendel (and derivatives) is a good example of not doing this. As great a design as it is, there are metal rods being used for the structure and then different metal rods being used for the linear motion. Using the frame material for linear motion would create more synergy (do you have your innovation Bingo card?).
  • Simplify the positioning system.
The reason 3D printers tend to use linear motion is that it’s really simple to program for. 3D files record things in XYZ Cartesian coordinates, so it’s just a matter of calculating the steps. That’s great for the programmers, but not so great for the mechanical engineers. They have to figure out how to create a 3-axis linear motion system on the cheap. Switching to something more like the Origo (a double swing arm) would make the bot a lot easier to build. All you’d have to do is slap a couple arms onto the shafts of a couple motors. The programming would be more complex, and maybe the motors would be more expensive, but the physical construction would be much simpler.
  • Reduce the number of electronic components.
Electronics are expensive, even when you build them yourself. The electronics package is around 1/4 of the cost of a Thing-O-Matic, for example. It might be possible to create a “board on a chip” design inside a Field Programmable Gate Array (FPGA) that would literally do ALL the calculations. It could even replace the stepper boards. FPGA’s, instead of running software, are reconfigurable hardware. You program their logic gates and then they just do what they do. They have hundreds of I/O ports, allowing all the windings of the stepper motors and all of the sensors and all of the heaters to be controlled directly by the FPGA (via some form of amplification). Also, and this is important, they are truly parallel. If something needs to happen on one I/O pin it doesn’t have to wait for the software to get to that part, it just goes in and right back out.
FPGAs aren’t exactly main stream, and there aren’t any open-source solutions yet, but you can get the software you need to program them for free (just sign up for a license). I’m not sure how many gates you would need to replace an Arduino and four Pololus, but seeing as how you could do it with a single chip it’s worth looking in to.
  • Why not design things without a computer?
Origo is on the right track in terms of making it easier for people (kids) to design the 3D models that 3D printers construct. Why not make it even easier? OpenSCAD, a program that has already proven itself in the open-source 3D printing world, already has support for generating 3D models directly from 2D pictures.

openscad 2D to 3D

With just colored lines and some labels OpenSCAD can generate a water-tight 3D model. Kids (anyone) could use crayons or colored pencils to draw a blueprint of their design, scan it, and have it start printing automatically.
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  1. Interesting ideas but I would like to disagree with you on your point that “the printer itself shouldn’t require powerful or precise tools.” I don’t believe that a printer you can make out of wood with a hand saw and an electric drill would really bring the cost or barrier to entry down.

    For starters the RP (3D printed) parts for a Prusa are only a fraction of the cost of the rest of the printer. If you have a friend with a 3D printer they will usually give you the parts for the cost of a roll of plastic. Even buying them from ebay or an online store is still usually only the cost of two or three rolls of plastic. Some hacker spaces will even give away RP parts if you promise to print two complete sets when your printer is up and running.

    Another issue is that most of the people who are doing the innovating in the RepRap space already have a 3D printer and so their designs can be more rapidly tested, and therefore allowed to evolve, in the form of RP parts. If every iteration of the design has to be built from wood, even if it’s only with a hand saw and electric drill, it severely limits the process.

    I think what you’re proposing is already available in the 1X2 printer:

    http://reprap.org/wiki/1X2

    1X2 is really a RepStrap, i.e. a device from which RP parts for a “proper” printer can be made. The nature of RepStraps is that they are usually temporary and are built using the components and skills that the builder has at their disposal. People who build RepStraps usually do so because they can’t get hold of RP parts.

    I have no statistics on RP part availability but from what I’ve seen from #reprap, forums and browsing auction sites, RP parts are not the biggest barrier to building a printer. There are sufficient numbers of RepRaps (and other 3D printers) out in the wild that RP parts must be available on every continent in the world. This is only going to improve as more people get hold of the technology and help it to spread.

    I know it has always been a chicken and egg problem but the answer to lowering the barrier to entry for 3D printers really is more 3D printers, especially the kind that are designed to self-replicate. This has been the goal of the RepRap project since its inception but it really is becoming a reality that more and more people are able to achieve for themselves.

    • Thanks for spending the time to compose such a thoughtful and informative response! I will now respectfully disagree 🙂

      The overall trust of your argument seems to be that anyone who doesn’t have a 3D printer yet should simply rely on a person who does. Basically, “…the answer to not enough 3D printers is more 3D printers…” seems to sum it up. From a RepRap perspective that makes complete sense. Dr. Bowyer specifically invented his printer not as an engineering project, but as a biological experiment. The overarching goal of the RepRap project is to maximize the population of self-replicating printers. That is a laudable goal, but that goal is not the first priority expressed in this post. In the same way that the Mendel/Prusa are optimized for self-replication, newer designs like the Mosaic and Ultimaker are optimized for performance. The design (more of a design philosophy really) I advocated in this post places ease of acquisition & assembly first. As soon as you make acquisition & assembly the first priority, one look at the 1×2 printer and you realize it doesn’t save you much compared to a Mendel/Prusa for exactly the reason you pointed out: the plastic parts themselves aren’t all that large a percentage of the cost/time of the total printer.

      You pointed out that getting the plastic parts isn’t the biggest barrier, and I absolutely agree. However, the plastic parts are an integral piece of a design paradigm that optimizes self-reproduction rather than low entry barriers. By definition, if you already have access to a 3D printer (whether your own or someone else’s) then you are already 3D printing. It’s like if someone already has any other expensive tool; of course they don’t have as many barriers to actually reach their goal! The Makerbot guys already had a laser cutter, so they were able to start prototyping the Cupcake as soon as they had the idea. Maybe when hackerspaces are as common McDonalds it will make sense to rely on them, but at the moment they’re rare and esoteric.

      My focus, and the reason I suggested prioritizing entry barriers (over self-reproduction or performance), is on getting 3D printing into the hands of school kids. They don’t need something that can print in 20 micron layers, they just need something that shows them what 3D printing is. However, schools and teachers are poor (in time and money) and, for the most part, not tech savvy. I’m tech savvy, with time/money to blow, and I had a hard time putting together a Thing-O-Matic and a Mendel, let alone troubleshooting them when they didn’t work. The existing paradigms only work for dedicated hobbyists and the emerging paradigms are profit focused (Origo). I want to see a design that’s so cheap (including the cost of the tools required) it can simply be given away. No one’s going to give away large numbers of any of the existing 3D printers. Not when they cost $500+ and require an entire weekend to assemble. However, get that down to, say, <$250 and one afternoon and you're in the ballpark of what could conceivably be given away in quantity.

  2. I’m wondering why they don’t combine 3D printers and laser cutters in one device. A multiple purpose device can convince teacher and less tech savvy people to buy one.

    Here is an example:
    http://hackaday.com/2010/09/09/laser-cutter-doubles-as-a-3d-printer/

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