misc notes, files for Funmat HT (late, pre-enhanced) 3d printer

a WIP @ the D&M Makerspace

or, skip ahead and declare war on small volume thermoplastics and win back oodles of free time (and also pass go, collect $200, etc etc)

The core of most of our Funmat HT struggles stem from the poor location and quality of the extruder.

It is pretty much a clone of a clone of a mk8 direct drive unit, complete with a standard 11mm copper hobb (~10.6* mm usable diameter). The extruder assembly is directly above the v6 standard hotend (it uses a nice pt100 type optocoupler instead of a sheathed thermistor usually seen on lower temperature machines though, still all within e3d spec) coupled together with a bit of PEEK tube.

All "regular" filaments including Nylons and Polcarbonates inevitably soften (even just a bit can ruin a print!) at the exruder gear after a few dozen layers or so, not helped by the fantastically well insulated and heated chamber. This results in filament getting chewed up / jammed in the extruder assembly / uneven / lumpy extrusion / filament puddling on the hobb --> clogged extruder --> clogged hotend.

The extruder assembly is devoid of any cooling or fans (or even just a breeze), and the hobb itself can get quite hot (it's copper!) in conjunction with the high amperage, high accuracy microstepping (1/16+) stressing the extruder motor.

As a result, here are some observations when printing with the stock hardware and most materials floating around the makerspace:

prints are best sent via octoprint. This provides excellent (and much needed) temperature monitoring, as well as the option for pre / post / whim gcode additions and modifications. Best to send G28 ; homing command before each print among others currently configured for the the D&M's octoprint machine profile.

• make sure the blower is properly addressed- the blower should be fan 0 when slicing. This value usually defaults to 1.

• upload file via "upload" button in octoprint (while on the makerspace network)

• both top and side doors must be completely open

• make sure fans are on again via control tab, best to preheat temps too

• tighten idler. the hot stepper does change the characteristics of the idler's pressure, and should start "almost too tight"

• hope

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Etc-

The D&M machine's firmware should be FUNMAT HT_181126_B.hex. It is unknown if any other pre-enhanced machines shipped with these newer stepper drivers like ours did, but Intamsys has confirmed updating to this version was needed.

See adjacent for setup documents, gcodes and cura profile.