This morning I fetched the cnc-punched alu-cases from Johann, who did a great job concerning the mechanical work. Building the frontpanel, involves two main tasks:
- deflashing of the punched holes
- gluing the LED-PCB on the backside of the Frontpanel.
For the 2nd task I am using a transparent hot glue. In order to get a nice and plane look I put the Frontpanels on a glas plate first, mount them together with some handy little tools i don’t know the name of – then I quickly cover all the LED holes with plenty of hot glue (be sure the hotglue-gun is well heated) and in time I press the LED-PCB into the still liquid hot glue – after that I put the glasplate and frontplate into the freezer (-18 °C) for just 5 Minutes, which proved out to be a good number for descent results. It turned out that the results are better if I just swift of the glasplate (instead of using Spiritus), because if the hotglue doesn’t stick to well on the glass the frontpanel comes of more easy. If the finish of the so created light-guides doesn’t look smooth it can be reworked it with a hotair-gun, (but not to long)
Before trying this “hot glue”-technique, I was considering 3D printing the Lightguids with transparent PLA. But I think the hot glue-result is way better than I could print it our Prusa Mendel – Printing a plastic by layers also might have some effects on diffusion. Also the meltingpoint of the used hotglue (200 °C) is siginficantly higher than PLA (130 °C)