3D printing & CAD modelling
tags: rapid prototyping functional design CAD modelling FDM 3D Print SLA Resin 3D Print Arduino
3D printing technology allows everyone to become an engineer for a moment. For me, a professional mechanical design engineer, it allows to take DIY projects to the next level. Following article records some of my projects created using 3D printing technology.
Fig.1. Ender 3D v2 & DIY resin printer used for presented prints.
Case for telescope electronics
One of my hobbies is astrophotography - you can read about it more here. Due to how unpopular astrophotography is there is not much equipment available on the market. Moreover what is available is not customized hence I needed to attach and hide all of the electronics used to controll the session (power suppy, PC, heater controller, USB hub etc.). This allowed me to make my astro setup handy, protect it from mechanical and atmospheric damages and also reduce number of wires hanging down from the telescope during the session.
As shown on CAD model and pictures below the case consists of two halves shaped around telescope tube. These halves are thin enough to fit into the case of the telesope, lead the wire between devices, fit mount rail at the top and to be easily disassembled if needed.
Fig.2. Telescope electronics case - CAD model.
Fig.3. Telescope electronics case - final print.
Cooling duct for high speed camera
One of my other projects was to implement video magnification algorithms in visual vibrometry - you can read about it more here. That project required high speed camera to be used. Such camera is not delivered with a cooling system and manufacturer recommends to implement it on a customer end. Source of the heat is camera sensor and electronics. Heat is conducted to the camera case and dissipated further to the environment. Natural convection is not enough to keep camera temperature below red flag limits recommended by the manufacturer. In order to cool down the camera customized air duct was designed featuring tripod adapter and fan in order to force air convection and hence dissipate the heat.
Fig.4. Cooling duct - CAD model.
Fig.5. Cooling duct - final print.
Self watering pot
Aim of this project was to familiarize myself with arduino prototyping by designing self watering pot. Below CAD model (Fig. 6) shows section through the pot to visualize internal cavities and ducts. Water is stored inside the walls of the pot (700ml capacity). There is a centrifugal pump with spiral diffuser at the bottom of the tank controlled with arduino based on a signals from moisture and water level sensors. Pot is equipped with RGB LED which indicates moisture level and alerts when to refill the tank. Additionally bluetooth module is implemented in order to be able to monitor exact moisture and water level though smartphone.
FDM printing leaves rough surface due to limitations of the technology (building layers) hence one of challenges was to obtain smooth surface finish of the pot. In order to do that the print was sanded and subsequently covered with paint and coat. Another challange was to prevent any leakages so internal cavities were covered with sealant while it was printed.
Fig.6. Self watering pot - CAD model (section was done to visualize internal cavities).
Fig.7. Self watering pot - final print.
Bracket for PC monitors stand
Due to covid I barely visit the office hence I needed to arrange some office space at home. 1/5 of my desk was occupied by the sand for my LCD monitors. In order to get rid of it I designed a bracket which holds the stand instead - mounted to the back of my desk. In order to smooth out crush stress distribution elastic pads made of TPU filament were printed. Final print holds substantial weight but is stiff enough to hold it and not deform over time (typical issue with 3D prints).
Fig.8. Monitor stand bracket - CAD model.
Fig.9. Monitor stand bracket - final print.
Self made resin 3D printer
Resin 3D printing technology is superior to filament wire printing when it comes to geting smooth surface with a lot of fine details. I hesitated from getting such printer because I don't have a place to put it - due to toxic fumes it is not recommended to be used in a living space. Partial solution to this issue is to get as small printer as possible. The tiniest printer I've found is open source DIY printer Lite3DP. Printer is arduino based project made of the components which are easily available on the market. It is so small it can easily fit on my Ender 3 printbed (fig.1). Additional advantage of such small printer is that you dont need to waste mutch resin while printing small parts. Currently this project is ongoing - soon there will be final prints attached.
Fig.10. DIY resin printer.