Prusa Mendel Operators Log

When you use the Prusa Mendel, please add notes here. Newest at top.

• Some problems may be ambient temperature related. When the room is 52F (11C), plastic curling, extruder jams, and Z-axis endstop malfunction are more likely. Placing a space heater on medium heat (~750W) at least four feet from the RepRap helps. Usual concerns about space heaters apply, be safe. (mirage335, 12-31-2012)

• Found loose bolts on end stops. Tightening the bolts and greasing part of the Z-axis endstop switch resolved previously mentioned homing issue. (mirage335, 12-28-2012)

• Machine needed grease. Donated officially recommended grease. Re-greased linear bearings and Z-axis threaded rods. (mirage335, 12-24-2012)

• Z-axis end stop occasionally deviates from its typical 'double click' homing. This puts it too far above the printbed. Fortunately, this occurs rarely, and may be a software glitch. The workaround is to restart the print job until it works correctly. (mirage335, 12-23-2012)

• Polycarbonate beds provided for RepRap. Glass bed still available. First layer adhesion vastly improved, bed leveling issues now far less critical. Enables easy printing of large (180x180mm) parts. Spare polycarbonate beds are exist, so users need not be too concerned about fouling. Paper tape may be used if necessary. (mirage335)

• Thin paper provided for leveling. Place small strips under print bed to adjust height. (mirage335)

• Existing power supply spontaneously failed in the middle of a job. Cautiously wired up new ATX 12V power supply, with help from juri_ . Also added 120mm fans, with cable ties (semi-permanent attachment) and gator clamps (to allow swinging the fans out of the way). Finally, achieved successful bridge tests, finding lower extrusion temperatures (165C vs 185C) improved print quality. (mirage335, 11-19-2012)

• A user found the PLA filament almost entirely used up.

• The Z-axis endstop has been moving slightly downward every time it is used. (mirage335)

• Found printer bed deleveled again. Releveled, and now machine is happy-go-lucky. (mirage335)

• Found the glass detached from the heater bed, Z-axis badly askew, and Z-axis end-stop repositioned. Performance degraded to worse than the old makerbot, but was repaired after much wasted plastic and lost time. Also added paper tape to front of printing bed for safety. (mirage335, 9-23-2012)

• Vastly better printing than makerbot. High precision, fast, easy to use, configurable. Extreme objects were tested successfully. (mirage335)

Most minor glitches were on account of provided USB fan. Overhang is best reduced by filleting[1] sharp edges and placing fan a few inches from to printer. However, strong wind may cause unusually tall and thin parts (ie. pencil-like) to print crooked; the fan should be placed at least a foot away in these cases. Fan itself should be externally powered, unplugging it from the laptop USB port disconnects the printer. Unplugging other devices (USB sticks) has no effect. Fan must rest on high-friction (eg. rubber) surface, or will slowly blow itself away. (mirage335, 9-15-2012)