Scientific instruments are expensive. In a lot of cases, really expensive, so if you have spent any time in a well-equipped lab, the chances are that it would have been one backed up by the resources of a university, or a large company. Those experimenters who wish to pursue such matters outside those environments have traditionally had to rely on obsolete instruments from the surplus market. A fascinating endeavor in itself, but one that can sometimes limit the opportunity to pursue science.
It has been interesting then to see the impact of the arrival of affordable 3D printing on the creation of self-built scientific instruments. A fantastic example has come our way, [David H Haffner Sr]’s 3D printable Raman probe. A Raman spectroscope is an instrument in which the light scattered from the sample exposed to an incident monochromatic source is collected, as opposed to that reflected or transmitted through it. Scattered light can be a huge magnitude weaker than other modes, thus the design of a Raman probe is critical to its success. (If you are curious, read this multi-part explanation on Raman spectroscopy.)
This is a work in progress at the time of writing, but it still makes for an interesting examination of Raman probe design. Interestingly the sensor is a standard DSLR camera, which though not a cheap device is possibly more affordable than a more dedicated sensor.
This isn’t the first Raman spectrometer we’ve seen on these pages, we’ve also brought you a Fourier transform spectrometer, and plenty of more conventional instruments.
[madcowswe] starts by pointing out that the entire premise of ODrive (an open-source brushless motor driver board) is to make use of inexpensive brushless motors in industrial-type applications. This usually means using hobby electric aircraft motors, but robotic applications sometimes need more torque than those motors can provide. Adding a gearbox is one option, but there is another: so-called “hoverboard” motors are common and 
