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A new reprap printer will built along the lines of the Prusa Mendel.  You can find details of the Prusa design at the [http://reprap.org/wiki/Prusa Prusa Mendel page] on the reprap wiki, or you can [https://github.com/prusajr/PrusaMendel view the sources for the Prusa at github][[File:prusamendelbucket.jpg|250px|right]]
[[Category:PrusaMendel]]


=Intro=
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.
Having another 3d printer in the space will allow us to always have a working machine and to use one machine to help fix another if there are problems.  It will also enable several people to print things out at the same time.  The goal is to document this build so others can make their own printer following our documentation.


=Status=
=Workflow=
We have enough parts to assemble the frame!
The final preparation needed is to cut 4 M8×294mm and 2 M8×210mm lengths from the threaded rod in the box.


=Materials for the build=
CAD/Thingiverse -> Netfabb -> STL -> Slic3r -> Pronterface -> PRINT!
===BOM for Prusa Mendel===
 
{| class="wikitable sortable" border="1"
See operation section for a tutorial.
|-
 
! scope="col" | Quantity
;CAD
! scope="col" | Description
: FreeCAD (free, open source) and SolidWorks (expensive, some extra features) offer intuitive sketch and constraint based modeling.
! scope="col" | Type
: OpenSCAD uses programming code to describe 3D models.
! scope="col" class="unsortable" | Comments
: And in case you don't want to model anything and simply want to print stuff, go to [http://www.thingiverse.com Thingiverse].
|-
 
| 83 || M8 nut || Fastener || READY
;Netfabb
|-
: software for checking the "3D printability" of the model you created. Go to [http://www.netfabb.com Netfabb] and download the Studio Basic option. You can also simply use their cloud offering and have a repaired model emailed back to you.
| 93 || M8 washer || Fastener || NEEDED (the imperial 5/16" ones aren't gonna work)
: 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.
|-
 
| 6 || M8×30 mudguard / fender washers || Fastener || READY
; STL
|-
: current format for 3D printing (AMF is coming around the corner).
| 2 || M4×20 bolt || Fastener || (John) / or use M5x20
: at this point, your file should be patched up and ready to print.
|-
 
| 2 || M4 nut || Fastener || (John) / or use M5
;Slic3r
|-
: software for creating 3d printing toolpaths
| 2 || M4 washer || Fastener || (John) / or use M5
: precompiled binaries can be had from [http://www.slic3r.org Slic3r.org] or be built built from [https://github.com/alexrj/Slic3r github].
|-
: use the profiles already generated for best results.
| 22 || M3×10 bolt || Fastener || READY
 
|-
;Pronterface
| 8 || M3×20 bolt || Fastener || (John) / cut down 25mm or use as is
: GUI for controlling the Prusa.
|-
: where you will connect to the printer, home, warm up and send print jobs from.
| 8 || M3×25 bolt || Fastener || READY
: can be built from [https://github.com/kliment/Printrun github] or download precompiled binaries for Windows/Mac [http://koti.kapsi.fi/%7Ekliment/printrun/ here].
|-
: preview G-Code generated by Slic3r.
| 4 || M3×40 bolt || Fastener || (John) / cut down 50mm or use 35mm
 
|-
;Print
| 70 || M3 washer || Fastener || READY
: File is good to go, toolpaths are generated, time to let the robot do what it does best, PRINT!
|-
 
| 40 || M3 nut || Fastener || READY
=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 [https://github.com/HacDC/PrusaMendel 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=
{| class="wikitable"
|-
|-
| 2 || M3 grub screw / set screw || Fastener || (John) / will the M3 x 8 in the space work?
|digifab
|Constructed and donated working PrusaMendel Reprap.
|-
|-
| 3 || 608 roller skate / inline skate / skateboard bearing || Bearings || READY
|juri
|Consultation on maintenance and multiple emergency repairs. Many emergency replacement parts.
|-
|-
| 4 || ballpoint pen springs || Spring || READY
|nully
|-
|Consultation on maintenance and multiple emergency repairs.
| 6 || M8×370mm || Threaded rod || 3 per side - READY (Thanks Mark!)
|-
| 4 || M8×294mm || Threaded rod || front / rear - READY 4 x 340 (Needs cutting)
|-
| 3 || M8×440mm || Threaded rod || top / bottom - READY
|-
| 2 || M8×210mm || Threaded rod || Z-leadscrew - READY 2 x 300 (Needs cutting)
|-
| 1 || M8×50mm || Threaded rod || or bolt for X idler - READY
|-
| 2 || 8mm×420mm || Smooth rod || X-bar - READY
|-
| 2 || 8mm×406mm || Smooth rod || Y-bar - READY
|-
| 2 || 8mm×350mm || Smooth rod || Z-bar - READY
|-
| 1 || 225mm×225mm print top plate || Thick Sheet || (space)
|-
| 1 || 140mm×225mm print bottom plate || Thick Sheet || space
|-
| 1 || 840mm×5mm T5 pitch timing belt || Belt || READY
|-
| 1 || 1380mm×5mm T5 pitch timing belt || Belt || READY
|-
| 5 || NEMA 17 bipolar stepper motor || Stepper || John
|-
| 50 || small cable binder / ziptie || Misc || READY
|-
| 1 || Wade's Geared Extruder || || (John)
|-
| 1 || Electronics + endstops || || gen3 from John or Tiny G from Alden
|-
| 1 || Printed parts || || READY
|}
|}
*Several HacDC members for initial capital.
*HacDC members for all [http://wiki.hacdc.org/index.php/Category:Project_Awesome 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.


===John===
=Known Bugs=
1x gen3 mobo
* 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.
2x gen3 EC
5x steppers
4x stepper controllers (we'll have to pull these from the cupcake and have the cupcake use the mbi ones)
1x p4ac 4 axis stepper controller carrier board (we'll have to pull this from the cupcake too)
1x wade's extruder (assembled and working)
1x 36mm brass barrel
1x 0.5mm mbi nozzle
1x 0.5mm makergear bighead nozzle
Insulator materials (have to make and document on lathe)
nuts/bolts/washers - I have tons
plywood/mdf for build platform


===Heated Build Platform===
=Additional Resources=
If we want it, can get away with some other hacks if we want, or leave it out altogether.
* "Slic3r is Nicer - Part 1 - Settings and Extruder Calibration" http://richrap.blogspot.co.uk/2012/01/slic3r-is-nicer-part-1-settings-and.html
==Offers==
* A guide to calibrating and using slic3r: https://github.com/alexrj/Slic3r/wiki/Calibration
Alden has a Tiny G board... this is attractive

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

  1. Turn on the printer, open pronterface, and connect to the printer.
  2. If there is filament sticking out of the top of the extruder, you'll need to remove it.
  3. Set the hotend temperature (175-185 degrees Celsius for PLA)
  4. When extruder is warmed up, raise the extruder (+z axis) so it's not touching the bed.
  5. Click the reverse button while gently pulling upwards on the filament you wish to remove.
  6. Continue gently pulling and pressing reverse until the remaining filament is drawn out from the top of the extruder housing.
  7. Once the filament has been removed, replace the spool.
  8. Feed the new filament into the appropriate hole in the extruder housing.
  9. Gently press down on the filament while clicking "extrude" in pronterface. The extruder should grab the filament as you feed it.
  10. Repeat the previous step until you see the new material being extruded from the tip.
  11. 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

Retrieved from "https://wiki.hacdcserver.org/index.php?title=Prusa_Mendel_Documentation&oldid=10311"