As the Dremel Idea Builder has no own heated bed my brother and myself decided to design our own custom made solution and publish its design so everybody interested can rebuild it by himself.
Our main target for the design was to change as little as possible to the existing Dremel i.e. no tinkering with the electronics, mechanics and housing.
The change to the printer itself may only be required if you want to use print bed temperatures above 60-70° C. as the standard print bed holder is made out of ABS and my be damaged by such high temperatures.
If you want to use such high print bed temperatures, I've designed a custom made print bed holder which can be printed with high temp PLA (e.g. Multec HT-PLA, extrudr GreenTec PLA). The design of this print bed holder can be found here: http://www.thingiverse.com/thing:1587208
Additionally I've designed my own Arduino based temperature controller as the fully assembled print bed PCB from China already includes 100k Ohm NTC thermistor and 500 Ohm resistor, for which combination I did not 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
My first prototype was created by my brother who has direct access to milling machinery equipment.
In order to process the second prototype myself I've decided to get in contact with a local FabLab. The guys over there suggested to build the print bed housing out of laser cut POM (also known as Delrin) with 3mm thickness.
The two SVG files are the result of that 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. I tried it with 3mm MDF as well as 3mm POM (Delrin) plates. I did a fair share of testing, 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 the heat tranferred 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.
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 at the PCB)
1-2mm thick insulation (e.g. felt) between print bed holder and PCB (keep open spaces where the resistor and plug is connected at the PCB)
print bed PCB
3mm thick aluminium cover
- 10 x M3x8 counter-sunk screws for attaching the print bed to the holder
I've created a better view of the general setup via Tinkercad: https://www.tinkercad.com/things/evLoup2Buhj/
Parts for assembly