Latest revision as of 18:34, 16 February 2014

More detailed documentation on the newly built Prusa Mendel (iteration 2). A PC has been dedicated to run it, below you will find the toolchain used to run it and other details that you may find useful.

Workflow

CAD/Thingiverse -> Netfabb -> STL -> Slic3r -> Pronterface -> PRINT!

See operation section for a tutorial.

CAD: FreeCAD (free, open source) and SolidWorks (expensive, some extra features) offer intuitive sketch and constraint based modeling.; OpenSCAD uses programming code to describe 3D models.; And in case you don't want to model anything and simply want to print stuff, go to Thingiverse.

Netfabb: software for checking the "3D printability" of the model you created. Go to Netfabb and download the Studio Basic option. You can also simply use their cloud offering and have a repaired model emailed back to you.; if your model has issues, run the repair function with default settings and see if that remedies the issues. The repair function can be used by clicking the "first aid" symbol found at the far right on the tool bar.

STL: current format for 3D printing (AMF is coming around the corner).; at this point, your file should be patched up and ready to print.

Slic3r: software for creating 3d printing toolpaths; precompiled binaries can be had from Slic3r.org or be built built from github.; use the profiles already generated for best results.

Pronterface: GUI for controlling the Prusa.; where you will connect to the printer, home, warm up and send print jobs from.; can be built from github or download precompiled binaries for Windows/Mac here.; preview G-Code generated by Slic3r.

Print: File is good to go, toolpaths are generated, time to let the robot do what it does best, PRINT!

Materials

Switching from PLA to ABS, or vice versa, will require purging extruder at with at least one meter of filament at >225C.

Generally, PLA is stronger, better for the environment, and easier to print with. Please use ABS only if there is a specific need for it.

PLA - Polylactic Acid

Extremely ecologically friendly, made from corn starch, smells like waffles/syrup while printing.

Harder than ABS at room temperature.

Needs a fan for parts with overhang/bridging.

Recommended solvent for gluing or vapor polishing is tetrahydrofuran. Slightly more hazardous, much more expensive, and less effective.

Low operating temperature (160C-200C).

ABS

Much less environmentally friendly.

Weaker than PLA at room temperature.

Poorer adhesion to bed while printing, may need polycarbonate bed, paper tape, kapton tape, etc.

Degrades nozzle, forcing more frequent cleaning by an experienced person with blowtorch and acetone.

High operating temperature (225C-240C).

Recommended solvent for gluing or vapor polishing is acetone. Low risk, low cost, highly effective.

Suitable for moderately high-temperature applications like coffee mugs, outdoor fixtures, and certain 3D printer components.

Extra Maintenance

Malfunction

Only grease with PTFE SuperLube, kept at HacDC next to printer.
Grease smooth rods and Z-Axis threaded rod if axes show signs of binding.
Tighten timing belts if not taunt.
Floss the hobbed bolt in the extruder.
Replace linear bearings if they are grinding, slipping laterally, or otherwise ruined.

Replacing filament/changing spools

Turn on the printer, open pronterface, and connect to the printer.
If there is filament sticking out of the top of the extruder, you'll need to remove it.
Set the hotend temperature (175-185 degrees Celsius for PLA)
When extruder is warmed up, raise the extruder (+z axis) so it's not touching the bed.
Click the reverse button while gently pulling upwards on the filament you wish to remove.
Continue gently pulling and pressing reverse until the remaining filament is drawn out from the top of the extruder housing.
Once the filament has been removed, replace the spool.
Feed the new filament into the appropriate hole in the extruder housing.
Gently press down on the filament while clicking "extrude" in pronterface. The extruder should grab the filament as you feed it.
Repeat the previous step until you see the new material being extruded from the tip.
Sometimes it may be necessary to loosen the spring loaded screws on the extruder, and manually unload/load the extruder.

Tips

Always swing fans in during a print. They engage automatically as appropriate.
Time estimate in pronterface's bottom bar is wildly inaccurate. The console printout when a gcode file is loaded will be about 75% accurate.
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.
Bare glass bed is best for quality, tightly grips plastic when hot, releases when cold. Paper tape on glass is generally more tolerant to misalignment. Bare polycarbonate provides extremely strong adhesion, too strong above 45C.
When printing long parts (eg. 150mm*50mm), it it is better to rotate the part, and align its length to the X-axis. The bed is slightly more level along the X-axis than the Y-axis due to a minor design flaw.

Slic3r Settings

Print Settings

Cheap

High speed, low plastic consumption, lightweight part. Also most appropriate for model aircraft parts, as the strength-to-weight ratio is likely approaching that of carbon fiber.

Quality

Maximizes quality, strength, and accuracy. Used for Prusa Mendel Replication.

Precision

75micron layer height, for parts with smaller features.

FilamentSettings

HacDC

Optimized for bare glass bed, solid parts, and fast printing. Decrease bed temperature to 45C for bare polycarbonate bed. Decreasing extrusion temperature to 167C may improve bridging but requires slowing down print speed, reduces quality, weakens printout, and may significantly increase extruder wear.

Printer Settings

Leave at "HacDC" unless you feel they need debugging.

Advanced

Entire software load used on dedicated laptop available at github. With these files, one can use their own computer to control the reprap.

WARNING: Slic3r configuration changes made on the dedicated laptop will be reset at reboot. Export your changes from slic3r to save them elsewhere. Alternatively, fork our github repository, make modifications there, and issue a pull request. Failing these options, email blabber.

Credits

digifab	Constructed and donated working PrusaMendel Reprap.
juri	Consultation on maintenance and multiple emergency repairs. Many emergency replacement parts.
nully	Consultation on maintenance and multiple emergency repairs.

Several HacDC members for initial capital.
HacDC members for all Project Awesome funds.
Others.

Technical Specs

This Prusa is fitted with the following:

Melzi - loaded with the latest Marlin firmware (as of 9/1/2012)
12V 30A PSU
Makergear 0.35mm for 3mm filament hot end
LM8UUs
GT2 (2mm) belting and pulleys (5mm bore, 20 tooth)
100K Thermistors (extruder an heated bed)

For FW reference on steps per axis: (80, 80, 2560, 855) {X, Y, Z, E}, this is also assuming 1/16th microstepping and 9/47 gears. Old extruder used 666.67steps/mm.

To Do

Tune trimpots on motor drivers
Print spare parts.
Experiment with higher supply voltages.

Known Bugs

Model holes will print the wrong size. The proper way to manage this is by keeping about 0.25mm per wall or 0.5mm diameter clearance in CAD models.

Additional Resources

"Slic3r is Nicer - Part 1 - Settings and Extruder Calibration" http://richrap.blogspot.co.uk/2012/01/slic3r-is-nicer-part-1-settings-and.html
A guide to calibrating and using slic3r: https://github.com/alexrj/Slic3r/wiki/Calibration

@@ Line 1: / Line 1: @@
 [[Category:PrusaMendel]]
-[[Category:RepRap]]
-This is the page on how to use the newly built Prusa Mendel (iteration 2). A PC has been dedicated to run it, below you will find the toolchain used to run it and other details that you may find useful. [[File:PrusaMendel.jpg|thumb|right]]
-=Current Machine Status=
-'''Operational'''
+More detailed documentation on the newly built Prusa Mendel (iteration 2). A PC has been dedicated to run it, below you will find the toolchain used to run it and other details that you may find useful.
 =Workflow=
 CAD/Thingiverse -> Netfabb -> STL -> Slic3r -> Pronterface -> PRINT!
+See operation section for a tutorial.
 ;CAD
-: Any modelling software that can output the file format STL.
+: FreeCAD (free, open source) and SolidWorks (expensive, some extra features) offer intuitive sketch and constraint based modeling.
-: Some programs of interest might be the following: Google Sketchup, OpenSCAD, TinkerCAD, Solid Works, AutoCAD, Rhino.
+: OpenSCAD uses programming code to describe 3D models.
 : And in case you don't want to model anything and simply want to print stuff, go to [http://www.thingiverse.com Thingiverse].
@@ Line 41: / Line 37: @@
 =Materials=
-* PLA
+Switching from PLA to ABS, or vice versa, will require purging extruder at with at least one meter of filament at >225C.
+Generally, PLA is stronger, better for the environment, and easier to print with. Please use ABS only if there is a specific need for it.
+* PLA - Polylactic Acid
+: '''Extremely ecologically friendly''', made from corn starch, smells like waffles/syrup while printing.
+: Harder than ABS at room temperature.
+: Needs a fan for parts with overhang/bridging.
+: Recommended solvent for gluing or vapor polishing is tetrahydrofuran. Slightly more hazardous, much more expensive, and less effective.
+: Low operating temperature (160C-200C).
 * ABS
+: '''Much less environmentally friendly.'''
+: Weaker than PLA at room temperature.
+: Poorer adhesion to bed while printing, may need polycarbonate bed, paper tape, kapton tape, etc.
+: Degrades nozzle, forcing more frequent cleaning by an experienced person with blowtorch and acetone.
+: High operating temperature (225C-240C).
+: Recommended solvent for gluing or vapor polishing is acetone. Low risk, low cost, highly effective.
+: Suitable for moderately high-temperature applications like coffee mugs, outdoor fixtures, and certain 3D printer components.
+=Extra Maintenance=
+==Malfunction==
+*Only grease with PTFE SuperLube, kept at HacDC next to printer.
+*Grease smooth rods and Z-Axis threaded rod if axes show signs of binding.
+*Tighten timing belts if not taunt.
+*Floss the hobbed bolt in the extruder.
+*Replace linear bearings if they are grinding, slipping laterally, or otherwise ruined.
+==Replacing filament/changing spools==
+#Turn on the printer, open pronterface, and connect to the printer.
+#If there is filament sticking out of the top of the extruder, you'll need to remove it.
+#Set the hotend temperature (175-185 degrees Celsius for PLA)
+#When extruder is warmed up, raise the extruder (+z axis) so it's not touching the bed.
+#Click the reverse button while gently pulling upwards on the filament you wish to remove.
+#Continue gently pulling and pressing reverse until the remaining filament is drawn out from the top of the extruder housing.
+#Once the filament has been removed, replace the spool.
+#Feed the new filament into the appropriate hole in the extruder housing.
+#Gently press down on the filament while clicking "extrude" in pronterface. The extruder should grab the filament as you feed it.
+#Repeat the previous step until you see the new material being extruded from the tip.
+#Sometimes it may be necessary to loosen the spring loaded screws on the extruder, and manually unload/load the extruder.
+=Tips=
+*'''Always swing fans in during a print. They engage automatically as appropriate.'''
+*Time estimate in pronterface's bottom bar is wildly inaccurate. The console printout when a gcode file is loaded will be about 75% accurate.
+*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.
+*Bare glass bed is best for quality, tightly grips plastic when hot, releases when cold. Paper tape on glass is generally more tolerant to misalignment. Bare polycarbonate provides extremely strong adhesion, too strong above 45C.
+*When printing long parts (eg. 150mm*50mm), it it is better to rotate the part, and align its length to the X-axis. The bed is slightly more level along the X-axis than the Y-axis due to a minor design flaw.
+=Slic3r Settings=
+==Print Settings==
+===Cheap===
+High speed, low plastic consumption, lightweight part. Also most appropriate for model aircraft parts, as the strength-to-weight ratio is likely approaching that of carbon fiber.
+===Quality===
+Maximizes quality, strength, and accuracy. Used for Prusa Mendel Replication.
+===Precision===
+micron layer height, for parts with smaller features.
+==FilamentSettings==
+===HacDC===
+Optimized for bare glass bed, solid parts, and fast printing. Decrease bed temperature to 45C for bare polycarbonate bed. Decreasing extrusion temperature to 167C may improve bridging but requires slowing down print speed, reduces quality, weakens printout, and may significantly increase extruder wear.
+==Printer Settings==
+Leave at "HacDC" unless you feel they need debugging.
+=Advanced=
+Entire software load used on dedicated laptop available at [https://github.com/HacDC/PrusaMendel github]. With these files, one can use their own computer to control the reprap.
-;PLA
+WARNING: Slic3r configuration changes made on the dedicated laptop will be reset at reboot. Export your changes from slic3r to save them elsewhere. Alternatively, fork our github repository, make modifications there, and issue a pull request. Failing these options, email blabber.
-: Polylactic Acid
-: made from corn starch, smells like waffles/syrup while printing
-: less prone to warping
-: more brittle compared to ABS
-: needs a fan, it remains much more molten after being extruded
-: lower operating temperatures (160C-200C)
-: Preferred plastic of choice
-;ABS
+=Credits=
-: same plastic in which LEGOs are made of
+{| class="wikitable"
-: flexible
+|-
-: higher operating temps (220C-240C)
+|digifab
-: smells like death, can release carcinogens at higher temps
+|Constructed and donated working PrusaMendel Reprap.
-: requires a heated bed (110C) or warping occurs
+|-
-: requires kapton/PET tape on heated print surface for best adhesion. Possibly a light sanding of the surface and slurry of dissolved ABS in acetone for further warp prevention.
+|juri
+|Consultation on maintenance and multiple emergency repairs. Many emergency replacement parts.
+|-
+|nully
+|Consultation on maintenance and multiple emergency repairs.
+|}
+*Several HacDC members for initial capital.
+*HacDC members for all [http://wiki.hacdc.org/index.php/Category:Project_Awesome Project Awesome] funds.
+*Others.
-=Machine Setup/Specs=
+=Technical Specs=
 This Prusa is fitted with the following:
@@ Line 72: / Line 136: @@
 * 100K Thermistors (extruder an heated bed)
-For FW reference on steps per axis: (80, 80, 2560, 666.67) {X, Y, Z, E}, this is also assuming 1/16th microstepping.
+For FW reference on steps per axis: (80, 80, 2560, 855) {X, Y, Z, E}, this is also assuming 1/16th microstepping and 9/47 gears. Old extruder used 666.67steps/mm.
-=Maintenance=
+=To Do=
+* Tune trimpots on motor drivers
-==Malfunction==
+* Print spare parts.
-*Check for loose wires.
+* Experiment with higher supply voltages.
-*Grease smooth rods and Z-Axis threaded rod if axes show signs of binding.
-*Only grease with PTFE SuperLube, kept at HacDC next to RepRap.
-*Floss the hobbed bolt in the extruder.
-*X/Y endstops. Manually push X/Y axes to test the switches.
-==Bed Cleaning==
-*Polycarbonate bed should be kept flat, without excessive protrusions. Scrape excess plastic off, and trim deep cuts.
-*Glass bed must be clean, but not too clean. Best practice seems to be wiping with a paper towel, and then gently brushing dry fingers across the glass.
-*Use paper/kapton tape on the polycarbonate bed, not the glass bed.
-==Print Depth==
-*First-layer depth. For polycarbonate beds, this must be <0.4mm below the bed surface. For glass bed, exactly 0.2mm above the bed surface is required.
-*Z-axis height. Z-axis endstop position sets depth for entire bed.
-*Z-axis level. The dual threaded rods must be kept aligned.
-*Bed leveling. Place Z-axis just above bed, then move X/Y axes. Place thin paper strips under bed until level.
-=Operation=
-# Check for loose wires, you don't want anything shorting out or coming undone while printing
+=Known Bugs=
-# Make sure that all endstops are lined up and will be triggered upon homing. Do so by manually pushing X/Y axes into their switches. For the Z axis, make sure nothing is obstructing its descent to the switch and that is at a safe distance where the hot-end will not crash into the print surface
+* Model holes will print the wrong size. The proper way to manage this is by keeping about 0.25mm per wall or 0.5mm diameter clearance in CAD models.
-# Check the print surface for any signs of fingerprints or residue that would prevent good adhesion. Clean if necessary.
-# Ensure that the filament feed is not tangled and can freely unwind itself for the duration of the print.
-#Assuming that you already have your STL file of choice either made from whatever CAD program you used or downloaded from Thingiverse, generate the G-Code via Slic3r (either using the profile already generated there or one that you customized).
-#Depending on your file size/complexity, Slic3r can take awhile. Use this time to connect to the printer by opening the Printrun folder and running Pronterface.py (run in terminal when asked).
-#If you are printing from a microSD, save the g-code file generated to the SD card and insert it into the SD port on the Melzi board. At this time, also switch the jumper for power selection from USB to the Vreg option. This will enable the board to be powered from the PSU instead of your laptop.
-#Once open, connect to the printer. Make sure the baudrate is set to the 250000 and the correct port is selected, should read "...USB0". You will know when it is connected when it spits out some basic stats of the firmware loaded. Check the box that read "Monitor Printer," this will spit out current temp readings, make sure they are reasonable (~20C at room temp).
-#Double check all wires for correct placement and secureness, you may now power on the PSU by turning on the power strip it is plugged into.
-#Set your heated bed to 60C for PLA or 110C for ABS. Do not turn on the heater yet!
-#Click "Load" and load the G-Code file you have created. A preview of the first layer should appear in the middle of Pronterface. You can click on the preview and walk through the layers by holding shift and scrolling on the trackpad. In the console, a time estimate for the print should also appear.
-#At this point, you can turn on the heater. Set to 180C for PLA and 220C for ABS. Wait for it to hit temp and prime it. You can do this by either manually turning the large extruder gear or pressing the "Extrude" button. Do so until there is a nice and steady flow.
-#Once all temps are hit and stable, file is loaded and extruder is primed...you can now hit print! If you are printing from SD, at this point you will click on the SD Print option, browse the SD card and select the file to run.
-#Sit back and watch as the printer homes itself and sprints off to print your file!
-=To Do=
+=Additional Resources=
-* Tune trimpots on motor drivers
+* "Slic3r is Nicer - Part 1 - Settings and Extruder Calibration" http://richrap.blogspot.co.uk/2012/01/slic3r-is-nicer-part-1-settings-and.html
-* Binder clips for glass surface
+* A guide to calibrating and using slic3r: https://github.com/alexrj/Slic3r/wiki/Calibration
-* Kapton tape for 2nd glass plate (for ABS)
-* Acetone/Cotton balls (for cleaning Kapton surface)
-* Spool System (mount printed Sky Hooks)
-* Cable Management (Spiral wrap loose wires and ziptie down)

Prusa Mendel Documentation: Difference between revisions

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