Saturday 13 May 2017

Project: Proteus Delta, part 8

Proteus Delta with Prometheus System installed
     Last time with the Proteus Delta I'd just installed the heat-bed, then left it sitting for a few months while waiting on delivery of the Prometheus System by Distech Automation, which is a dual extruder/single hot-end printing system that allows for the use of 2 different materials or different colours of the same material in a single print.


Prometheus System half assembled with parts of effector platform
     After receiving the parts for the Prometheus system at the beginning of April, assembly took a week or so of evenings working on assembly, partially because I got the parts for both the original design and the revisions that occurred after the 'early-bird/beta' system feedback was received. So, since I had the original PEEK feed pipe, the splitter fork got assembled as per the original design instructions, and the extruders are using the revised design with the reinforced Bowden clamps.


Prometheus hot-end installed in effector
     For actually mounting the Prometheus system on the Proteus, I'd designed a custom raised effector shell back in November, after giving it a final polishing pass, the parts got printed and bolted together. I'm still working on the part-cooling fan ducting but the rest of the parts are here.


Effector installed on Proteus for initial testing
     After installing the completed effector on the Proteus, I started moving the motion system around by hand to check for any issues, and it immediately became apparent that the clamps that were holding the print-bed in place where going to cause issues with the effector since the hot-end tip is only slightly below the effector ring. 


Proteus print-bed with new mounts
      After some revising, reprinting and reassembly, the problem was mostly solved by switching to a new mounting bracket design for the print-bed, the STL is here, it's designed to grip the glass along the side and recess the mounting screw flush with the upper surface, allowing for a 28cm maximum printing diameter, although I would recommend printing it in a high-temperature resistant plastic, otherwise the bed will start drifting when you go past the glass-transition temperature.


Effector mounting plate and spool holder hardware waiting for assembly
     Originally, I was planning to mount the ProStruders in a flying configuration, but after February's experiments, I've decided to put them on an independent pylon, roughly 46 cm down from the top, mostly level with the effector when it's homed. For holding the spools, I'm using one of the leftover sections of 1/2inch EMT from building the towers, it's the perfect length for sticking a pair of spools on, one on each side above the extruders. Add some printed caps and a clamp to keep things in place, and that finishes the assembly process.


Extruders mounted to Proteus with spool holder above
Proteus Delta ready to print
     With all that finished, the next step was calibration and a couple of test prints. Leveling the bed was mostly the same as I've covered previously, only real change was initial setup of the SD card for the Duet 0.8.5, most of the files are linked through the Duet wiki, but one really useful tool is the Reprap Firmware Configurator, it has a couple of quirks, specifically the default thermistor for heatbeds is wrong, but makes most of the configuration process fairly painless overall. I'm still getting the hang of using it, but the few prints I've done so far are fairly good for PLA without a part cooling fan. Overall, a fun build and I'm looking forward to trying some dual colour prints in the near future.

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