Machines to an End

May 20th, 2014:

To me, one of the coolest things about the ‘maker-movement’ is not the cool stuff people build, but rather the innovative low cost tools they build to enable those projects. Hackerspaces, makerspaces, Techshops, Fablabs and other such community workspaces do an excellent job of providing high end tools to the masses for at reasonable prices, however not everyone is lucky enough to live near a great community space that has the tools they need.

There’s a lot of cool stuff people are building but I’ll just touch on a few that have been on my long term to do list.

SLA/DLP 3d printer. There are a boatload of DIY FDM (fused deposition model) 3d printers, to a fair extent its proven technology and there are enough guides out there to make it a straightforward project.  However the print resolution that FDM machines are capable of pales in comparison to that of SLA. While FDM machines extrude a tiny bead of plastic from a heated print head, SLA (stereolithography) machines use UV light to cure a special resin in a bath. Both technologies build layer upon layer, but the nature of SLA allows for much finer details to be captured (Example SLA Solidator posted above, thank you Tim Fischer at Solidator for the picture). While DIY and low end commercial SLA printing is still in relative infancy, it’s comparable to where FDM was only a few years back. I’ll be surprised if in the next few years we don’t see cheap SLA printers and well established DIY projects catch up to where FDM is now. Until then, for those who like a challenging project a DIY SLA machine is definitely a good one. This instructable does a pretty good job of concisely listing a lot of the difficulties that one will face when building an SLA machine. Another good resource can be found

CNC mill. Not everyone can afford a mill, and for those of us that can’t, if you’re ok with just milling plastic (yes this is a pretty major compromise) there are some super cheap DIY CNC mills out there. I stumbled on the MTM Snap (MTM stands for Machines That Make, and it is a project at MIT made up of a number of different devices for making things) a few years ago. It’s a desktop CNC mill/PCB router that can be built with around $600 in parts and 4 hours of time on a Shopbot. The main structure is designed to be routed out of HDPE and snapped together. FDM printing has largely supplanted the need to mill plastic, but there are instances where you really want the strength of a homogenous material or you want to work with a material that can’t be extruded (machining wax for mold making to name one). PCB routing is another fantastic capability that enables rapid prototyping of circuit boards. It appears that this project eventually evolved into this, but for less money and without the pre-order wait you can build one yourself. See this instructable for more info/details on a very similar desktop mill.

Heat treating oven/kiln. Lastly, and in a completely different direction, a DIY heat treating oven for knife making is not difficult or expensive to build. Basically all it takes is a bunch of refractory fire bricks, a powerful heating element and some sort of control module. This pdf has a decent walk through of it. The concept is simple and the parts for a knife sized oven work out to around $300, however with some creative scrounging, it can be done for less (i.e. pull heating elements from old toaster ovens). I haven’t seen people using Arduino or Raspi control for these, but that’s what Senior Mechanical Engineer Orlando Soto and I are planning on using for ours. Use of a microcontroller or microcomputer gives immense flexibility in temperature control and allows heat treating cycles to be programmed in. In my mind, this is a much more elegant solution than the dedicated PID controllers used by both DIYers and commercial kiln manufacturers. This PDF has some good info on heating elements and this page has links to a bunch of DIY ovens.

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- By Mechanical Engineering Jake Davis, Goddard Technologies