The XCLIP, a Raspberry Pi (and PCB) mounting solution
by TheKre8Group, published
At Prototype.Asia, we rely extensively on Raspberry Pi computers, Arduino and FPGA prototyping boards to quickly develop and deploy working prototypes with a myriad of capabilities.
As some of our prototypes are destined to enhance the features of existing devices, we often need to deploy our prototypes in retrofitted devices, objects or places such as: televisions, refrigerators, lamp posts, chairs, doors, walls, etc. As such we needed a low profile and cost effective solution to securely mount these PCBs (Printed Circuit Boards) in a way that they would be both shielded from conductive surfaces and non-obtrusive the existing functions of purpose of the device, object or place.
We came up with the XCLIP, a fully parametrisable four corner PCB mounting solution which can be securely mounted on any flat surface without adding more than 2 mm in thickness to the total assembly.
The XCLIP is configured using four parameters: PCB length, width, thickness and component clearance; our XCLIP configurator generates an STL file which can be 3D printed in less than 25 minutes on either our FDM or PolyJet 3D printers (or on any other 3D printer as a matter of fact).
While designing the XCLIP, we needed to ensure that it would provide a firm hold on the PCB without becoming over-engineered or bulky. Furthermore, we needed our device to have an increased retention force the further the PCB is pulled away from the mounting surface.
These features were achieved by centering the mounting plate and by using thin flexible arms to hold each corner of the PCB. When a force pulls on the PCB, the four corners slightly lift from the mounting surface, effectively reducing the plenary distance separating them, thus increasing the force they each exert towards the center of the PCB.
As the force reaches its maximum, the PCB becomes a structural element that limits the arms flex and transfers the load to the center mounting surface, which is held firmly in place by four M3 bolts (zip ties or double sided tape), thus ensuring that the PCB will remain in place.
It can also be purchased on Shapeways : http://www.shapeways.com/shops/PrototypeAsia
Print and enjoy
You might need to file down some parts to give sufficient clearance to components mounted on the edges of the PCB, such as the RJ-45 connector on the Raspberry Pi.
Also, the PCB measurements used to generate these STL are exact to 10 microns, which might make an XCLIP printed with an FDM printer too tight/small. To address this issue we recommend adding an extra 2 mm to the XY plane of the PCB, a Raspberry Pi FDM specific STL is also included.
For those with access to PTC Creo, we've included the PRT file which you can use to customize an XCLIP for your PCBs.
Simply edit the references for the following 3 items
1-PCB_XY_PLUS_3MM (sketch W & L, where W=PCB W+3mm, L=PCB L+3mm)
2-PCB_CLEARANCE (extrusion height)
3-PCB_THICKNESS (extrusion height)