Series Heating and Other Developments

After a long break spent graduating, moving furniture into/around our flat, and lots of other such messing around, I finally got around to permanently solving my heated printbed problem, while getting a sturdy desk to set the printer on.

First of all, I had a problem with the way my heated-bed power-supply was connected, as the circuit was fixed with solder, that meant that the adapter block was physically connected to my reprap by its cable, and that I couldn't easily change it for another power supply.
My solution to the problem of wanting to quickly connect/disconnect a DC power supply was to take some bits of electrical screw-terminal:

sometimes referred to as a 'chocolate block' connector, cheap in long blocks

...and bolt it to one of Nicoll's bolted PLA bushings for Prusa Mendel.

Testing ABS on Mendel Parts Heated Bed

It has been suggested that you can't print ABS on a RepRap Mendel built with the current kits supplied on mendelparts.com, since they include a power supply for the heated bed that only delivers 70W at the highest voltage, and that isn't enough to produce temperatures high enough to keep the parts stuck down.

Recently, I have been trying to challenge that claim with a few tests of my own. Firstly I taped some cotton wool under each of the heating resistors to provide a bit of insulation, hoping that would conserve some of the heat, and then pre-heated the printbed using an iron again, turning the thermostat up to the setting for cotton and leaving it for a few minutes, which brought the bed up to a temperature of around 110C.

Kapton tape hugs makeup removal pads over heating resistors under the printbed.