Custom made heat bed for Dremel Idea Builder

thingiverse

As I work on my Dremel Idea Builder project with my brother, we've decided to design a custom heated bed solution since the original doesn't have one. We aimed to make as few changes as possible to the existing printer, avoiding any modifications to the electronics, mechanics, and housing. Our goal was to leave the printer's setup unchanged whenever possible. However, if you want to use print bed temperatures above 60-70° C, the standard print bed holder may be damaged due to its ABS material. To address this issue, I designed a custom print bed holder that can be printed with high temp PLA, such as Multec HT-PLA or extrudr GreenTec PLA. This custom design can be found on Thingiverse: http://www.thingiverse.com/thing:1587208. Additionally, I created an Arduino-based temperature controller since the fully assembled print bed PCB from China includes a 100k Ohm NTC thermistor and 500 Ohm resistor combination for which we couldn't find an off-the-shelf temperature controller yet. If you find one, please leave a comment on this thing: http://www.thingiverse.com/thing:1608602. Post-printing setup is crucial to ensure the heated bed functions correctly. My first prototype was created by my brother using milling machinery equipment he had access to. To process the second prototype myself, I contacted a local FabLab and they suggested building the print bed housing out of laser-cut POM (also known as Delrin) with 3mm thickness. The two SVG files are the result of this approach: => Printbedholder-printable-V3-all-M3-screws.svg - not for laser cutting but for better visibility only, e.g. for printing out on a normal printer => Printbedholder-lasercutter-V3-all-M3-screws.svg - for laser cutting I had the chance to laser cut the print bed holder and tested it with 3mm MDF as well as 3mm POM (Delrin) plates. The design works as expected, heating up above 110° C possible, but for higher temps >80° C fairly slow. The aluminium foil, isolation material (2mm felt), and POM/MDF plate at the bottom reduce heat transfer towards the bottom by approx. 10° C. I.e. if the heat bed itself is heated up to 60° C, the bottom of the heat bed reaches approx. 50° C - good to know when having to think about the heat resistance of the print bed holder. General setup is as follows: Print bed housing: => 3 layers of 3mm thick laser-cut POM or MDF (Printbedholder-lasercutter-V3-all-M3-screws.svg) => 12 2mm diameter spring pins with 8-9 mm length or 12 metall screws 2.9mm * 9mm for connecting the 3 layers of POM or MDF aluminium foil for heat reflection between POM/MDF and felt insulation (keep open spaces where the resistor and plug is connected to the PCB) I also recommend easy-to-use and safe connectors for cabling, such as WAGO series 221, e.g. https://www.amazon.com/dp/B01AF5M5NE/ or http://www.amazon.com/dp/B0107SYYGU/.