invention

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Title says it all. For those so inclined, here’s my very late notice that I’ll be talking about Makerbots, Repraps and Thingiverse this Wednesday 14th in the Science Museum. The event starts at 6:30.

Ignite is an event that asks “Enlighten us, but make it quick”. It was started by Bre Pettis and Brady Forrest as a way for local communities to share ideas and raise the “collective IQ”, and is traditionally composed of a little Make contest first, (like “Best Bridge Made of Popsicle Sticks”) followed by a series of five minute talks.

Each talk covers something interesting, smart and geeky. The format is: 15 seconds per slide, automatically advancing, making for a total of 20 slides. The restrictive format encourages creative presentation and a sustained level of energy in the talks.

As I’m discovering all too late, it also makes it pretty hard to make a presentation if you’re used to ad-hoc! But for my next Ignite talk (he says ambitiously) I’ll know to start much earlier.

My working title at the moment is: “Makerbot, RepRap and Thingiverse: Invent, Share, Enjoy, Repeat“. I’ll be releasing the presentation under a Creative Commons by-sa license so people can play around with it and re-use it.

I’m both looking forward to this, and have a trepidation. I’m packing a really dense talk in here, and the 15 seconds/slide thing is going to drive me a little mad. My only requests of fate are:  1) That I don’t get tongue tied mid-sentence. 2) That I don’t simply confuse the hell out of everyone.

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So, last night (being about 26 hours ago I think) I posted a challenge to the Makerbot User’s Group, asking for a live mousetrap that I could print, use, and award €25 for. Team Makerbot blogged it, and threw in a teeshirt if the winner was released under an open license, which just makes it all the more cool!

Today, I received 5kg of plastic from Reprapsource.com, so I’m ready to start printing tomorrow.

26 hours after the contest opened, there are at least 5 designs, which run the gamut of possible ways to catch a mouse! It’s gonna be fun. I have to close applications here though, as I only have so much time to print and test them.

As mentioned elsewhere, applications are closed unless you have a design in the works already. Please let me know soon if that’s the case.

Thanks to everyone who submitted a design!

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Rapid Prototyping is addictive. I knew it would be when I bought the Makerbot, but I didn’t know just how much. Since the moderate success of Dremelfuge, I’ve gone a step further into multi-part, assembled devices, and I’m proud of the result.

Microlathe is a Makerbot/Reprap printable Lathe that uses a Dremel for rotary power. I spent a day and a half designing the first draft of it in OpenSCAD, another evening printing the parts, and the minutes I could grab over the last few evenings testing it. The result? It’s fairly hazardous, requires careful balancing, and it works just fine on wood dowelling. So on the whole, a big success!

Here’s a link to a video of me demonstrating Microlathe. It’s taken on my HTC in low light, so the quality is poor; apologies! Microlathe draft two will merit High Definition, I think.

One of the reasons I designed and made Microlathe was because I wanted a free lathe. Another reason was to contribute to a pattern of accelerating returns I’ve become aware of and excited about recently, in the sphere of rapid prototyping.

When you give someone a tool, they can use that tool (within its limitations) to make things. You might reasonably expect someone with an axe and some trees to make fuel, but they could in principal master the art of the axe and use it to create lasting works like furniture or a shelter. It’s just really really hard to do with an axe, is all. A clever artisan might use his axe to make a simple mallet, which would enhance his ability to accurately control the force of the axe blade. He might use these to produce still more useful tools and products. This is an example of accelerating returns; tools making better tools to make better tools faster.

Leap forward, and give someone a rapid prototyping machine. These tools, be they laser cutters or 3D printers, are hugely open ended, and because they use CNC control the user can take his or her time in carefully planning each parameter of the final work before beginning, and even share the result if it works with other users. The essence of “Measure twice, cut once” in carpentry and many other crafts boils down to “If you muck up one step of the way, you’ve ruined the end result”. This reliance on expert skill and patience in creative or constructive arts has probably been one of the biggest barriers to people getting involved in making until recently, and with a CNC machine, it is no longer strictly necessary. This means you don’t have to spend years mastering the art of the axe just to make your mallet, you just need to click “print”.

So with this one starting tool, you can imagine a situation where a person can design/download and assemble a plethora of relatively complex tools in short order given only the cheap feedstock needed to run the Rapid Prototyper. That’s what I’m looking forward to and trying to drive forward, because this accelerating return is going to help push innovation to new heights at a grassroots level.

A Makerbot cost me about €750, all told (Of which €110 was shipping!). A full suite of tools might cost me that much or more, easily, but if they were printable it’d cost me a few extra euro. Probably less than 20. Given enough feedstock, I can even make the structural parts of another printer, and give that to my friend, who can make a fab lab of his own, etc. etc.

Obviously the Makerbot can’t make everything. For example, it can’t make its own heater barrel, which needs to be made out of metal. That task calls for a lathe. And now, you can print one of those. And because it’s open-source and available online, if it doesn’t work right or suit you as-is, you can just improve it.

Someday I’m hoping to see a printable CNC Router and Lathe on Thingiverse, so that I’ll be able to have my computer-controlled robot fablab build me almost anything I can desire or imagine, fast. The first thing I’ll probably make when it’s ready? Another Fab Lab!

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Long Overdue Update: I’m very proud to say that, some time back, I updated the Dremelfuge design with better tolerances and a better shape to handle tubes. When I tested it (only once so far) at full speed on a dremel with two tubes full of fruit smoothie, it didn’t eject or break the tubes at all.

So there you go, Dremelfuge can now be considered the world’s cheapest midi-ultra-centrifuge, capable of putting about 52,000g on up to six 1.5ml eppendorf tubes. Warning; Lots of risk, don’t use this thing unless you have taken some serious precautions. Try to stay outside the plane of rotation.

Back to the original post:

Since my last post, I’ve been a very busy person.

Dremelfuge is now available for purchase on Shapeways from my shop there. There are two versions, one with an axle for chuck-fitting machines, and another with a bore into which the cutting-disc-holder from a standard dremel can be fitted. Price varies by location, but even at the $65 price which includes shipping to Ireland plus VAT, you could buy a Dremel to match it and still come in under €100 for a functioning centrifuge. I gather the price falls to $55 for American buyers.

Here’s a video of me demonstrating Dremelfuge. I tested it with standard microcentrifuge tubes, and found that it stably spins them anywhere from 5000g to somewhere above 20000g. I say “somewhere above” because the tubes shatterd somewhere between the third speed setting and the fifth on the dremel.
The math shows that the average force on a microcentrifuge tube quickly exceeds that of the commercial centrifuges I use in the lab. They go as high as 14,000g. Dremelfuge plus a Dremel 300 can put over 50,000g on a sample. Except that’s too much for the tubes so they shatter.

One nice bonus is that it seems to be very stable on a Dremel 300; there’s little to no vibration or rattling, even with highly unbalanced loads.

So here I have it: A centrifuge attachment for drills or rotary tools which spins them with even more power than the official thing, and costs a tiny fraction of the price to make and operate. I call that a success by every metric!

Thanks to Makerbot for making this possible in the first place, and my fiancee and family for their patience.

As always, I don’t endorse use of Dremelfuge as anything but an ornament, for reasons of liability.

Update: I’ve tested Dremelfuge in my lab with E.coli cells and HL60 human suspension cells. It pellets both excellently! I’ve already shown it to spin down Miniprep columns, and the math shows it hugely exceeds the power of a standard lab centrifuge when used with a Dremel 300 (€89 in Argos and useful for just about everything else, too).

So that’s it as far as I’m concerned: Dremelfuge is a fully functioning centrifuge. Can’t wait to see it in use on some cool projects!

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