As you read in my last post about the pet-feeding device project, there was an issue with the fill sensors. The lines from the 3d-print transferred the light directly to the sensor and made a useful measurement impossible.
One of the solution to this problem is a small gap between the LED and the sensor.
Here you can see the slots. These already work fine, the measurement results are looking great. The only disadvantage about the slots is the mechanical one. Crumbs will fall into this slots and it makes the turntable hard to clean.
To solve this problem, I fill the slots with black epoxy. I use a syringe to be able to use tiny amounts and fill the slots flush with the surface. You can see the process in the following video:
I use epoxy with a low viscosity with a drop of black colour: Epoxy resin L + hardener L from R&G. You see in the video, how the epoxy flows easily into all cracks and levels itself.
The result is an almost perfectly flat surface.
I hope you found this update interesting. Currently, I am testing the platform using different fill angles at the sensors. If you have any questions, missed information, or simply want to provide feedback, feel free to comment below. 😄
Get Blog Updates With the New Mailinglist
Three Ways to Integrate LED Light Into the Modular Lantern
The Importance of Wall Profiles in 3D Printing
Better Bridging with Slicer Guides
Large Update to the Circle Pattern Generator
The 3D Printed Modular Lantern
2 thoughts on “Adding a Light Barrier using Epoxy”
I wonder if it would be a good idea to simply cover the whole top (food-contacting) surface in epoxy (letting it flow into slots as well) to minimize grinding, dust, the food getting stuck between printed layers, and the bacteria breeding there.
Yes, indeed, this is an excellent idea, and I will most likely do this in the final device. I did not write about this in my series because working with epoxy requires quite an amount of experience and preparation – so not everyone will be able to do this. It’s the reason I still search for a solution that does not require using epoxy.
Also, I am not sure what effect it has on the light transmission issue I had. 🤔
If I coat the platform with epoxy, I will take photos and publish this as an addition to the instructions. Thank you very much for bringing this up. 😄