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A Quick Progress Update

Wow, it's been a while since I last posted to the site. My intended posting schedule has been blown by a wide margin it seems so I'll be making an extra effort to get back on track.

The next part of the PIC series (on Digital IO) is mostly complete, only the physical construction and testing of the breadboard layout is left to be done. I've ordered a new set of breadboards because of the problems I've been having with my current ones (connections and inductance have become an issue, given that they are nearly 15 years old and have seen a lot of use this isn't surprising). Unfortunately these are taking a lot longer to arrive than I originally anticipated. I have plans for a nice breadboard development setup with a bunch of useful circuitry premade and easy to access - I'll document this on the site once it's done.

Gear Test Prints

In the meantime I've been working with the 3D printer - discovering it's capabilities and limitations as well as determining how well it will perform the task I originally bought it for - making mechanical components for robotic systems. Specifically I've been playing around with gears, wheels and connectors (see the image to the left). After a lot of failed attempts I finally have an OpenSCAD script that actually generates gears that work reliably (they are in the bottom right of the photo). I wound up using a library from Thingiverse that, so far, seems to reliably generate gears even at low resolution. I need to do some more tests to see how well these gears handle relatively high RPM's but it all looks promising so far.

A Simple Paperclip

I've also been working on some simple objects of my own including a very simple paperclip design (the source ``` /---------------------------------------------------------------------------- * A simple paperclip ----------------------------------------------------------------------------/

//--- Default values CLIPWIDTH = 20; // Width of the paper clip in mm CLIPHEIGHT = 40; // Height (length) of the paper clip in mm CLIPDEPTH = 1; // Depth (vertical height) of the paper clip in mm CLIPGAP = 3; // Gap between inner and outer clip parts CLIP_BORDER = 2; // Width of the solid outline on the 'clip' part

// This value controls curved surface accuracy ($fs). You can change this // to match your printer resolution (in mm) if the result is a bit chunky. RESOLUTION = 0.3;

/** Generate a 'pill' shape */ module pillshape(width = CLIPWIDTH, height = CLIPHEIGHT, depth = CLIP_DEPTH) { // Create the basic shape union() { translate(v = [ 0, (height - width) / 2, 0 ]) { cylinder(r = width / 2, h = depth, center = true, $fs = RESOLUTION); } cube(size = [ width, height - width, depth ], center = true); translate(v = [ 0, -(height - width) / 2, 0 ]) { cylinder(r = width / 2, h = depth, center = true, $fs = RESOLUTION); } } }

/** Generate a simple paperclip * * @param width specifies the width of the paperclip in mm * @param height specifies the height of the paperclip in mm * @param gap specifies the size of the 'gap' between the inner and outer * clipping parts in mm. * @param depth specifies the vertical height of the paperclip in mm. */ module paperclip(width = CLIPWIDTH, height = CLIPHEIGHT, gap = CLIPGAP, depth = CLIPDEPTH) { translate(v = [ 0, 0, depth / 2 ]) { difference() { // Create the basic shape pillshape(width, height, depth); // Create the shape to cut out intersection() { difference() { pillshape(width - 2 * CLIPBORDER, height - (2 * CLIPBORDER), depth * 2); pillshape(width - 2 * (CLIPBORDER + gap), height - 2 * (CLIPBORDER + gap), depth * 4); } translate(v = [ 0, -height / 2, 0 ]) { cube(size = [ width, height, depth * 4 ], center = true); } } } } }

// Generate a single paperclip (with default values) //paperclip();

// Generate a 8 paperclips (with default values) // NOTE Make sure the result fits in your printbed area before printing for(y = [ -0.6, 0.6 ]) { for(x = [ -1.8, -0.6, 0.6, 1.8 ]) { translate(v = [ x * CLIPWIDTH, y * CLIPHEIGHT, 0 ]) { paperclip(); } } } ``` ).

This is one of the things I love about 3D printing - the technology can be used to create things that are mundane or profound. This is why I find articles like this really annoying. That particular article concentrates on the mundane side of the technology (the creation of tchotchke type things) and ignore the more beneficial sides (I also find it annoying that the author seems to consider 3D printing an American phenomenon although I think the choice of title was more trying to channel a Matt Taibbi article than anything else).

Look, there are plenty of Yoda heads and toys being printed but there is also a significant number of unique designs (artistic, scientific and mechanical) being generated as well, and these are not just being printed off for some persons unique project - they are being shared, modified, repurposed and shared again. This is something that, if not impossible, is at least very difficult with mass produced items.

Going back to my simple paperclip - yes, you could classify it as a tchotchke and there are certainly plenty of mass produced variations around that I could simply go out and buy from a wide range of retailers. This paperclip however, is mine. It's exactly the right size to clip together my index cards and fit in the box I like to keep them in. It has enough space to put a label on. I don't need 100 of them, I need about half a dozen - if I find out later I need more I can simply print them off as required. And most importantly my simple design is now available to anyone who wants it - they can change the size and shape to suit their needs and make it their paperclip, perfectly suited for whatever specific application they have in mind.

This topic really deserves it's own post but I'll do a quick summary here. The advent of mass production techniques made a large range of products available to individuals at a far cheaper price than previously imagined. Before this items were often made as individual, one off constructions for each purchaser. With the availability of 3D printing you can now design your own item and create it as needed. If you need more of the same item you get the same benefits provided by mass production - the items are very easy to replicate. More importantly you can modify the design to fit your specific needs, something that mass produced items offer in a very limited fashion.

At the moment this is limited to items made of plastic and of a relatively small size - as the technology advances though more and more materials are becoming available and the potential size of individually printed objects is increasing. As this happens there are going to be significant pressures on current manufacturing techniques and IP law. I'm really looking forward to what the next few decades will bring.