Bits from Bytes Darwin RepRap

This is a Darwin RepRap that was built by WJT from a kit from Bits from Bytes. It was started in May 2009, and first successfully printed on 27 November 2009. A heated bed was added in May 2010, built in the Czech Republic by Josef Prusa.

About This Build

• Build: May 2009 – June 2009
• Tuning: June 2009 – December 2009
• First successful print: 27 November 2009
• Tuning with heated bed: May 2010

Contents

1. Image Gallery
2. Useful Links
3. Skeinforge Settings for Unheated Bed
4. Skeinforge Settings for Heated Bed

Image Gallery

Go to the image gallery at Flickr.

Useful Links

• RepRap.org
• RepRap machine genealogy
• Bits from Bytes build information
• Bits from Bytes user forum
• Bits from Bytes blog
• Bits from Bytes RepRap v3
  • About the extruder
  • Extruder build video clips
  • Forum entry on new extruder parts
  • Skeinforge settings
  • Printing
  • More about printing
  • Diagnosing print problems
  • G code reference
• Useful pictures of other builds
  • Batist Leman
  • Unfold
  • Bogdan Kecman
  • Rapman electronics closeup
  • Rapman in use
• Required tools
  • Ball-end allen keys (1.5mm, 2.5mm, 4mm, 1/16″, 3/32″)
  • Metric wrenches (4mm, 5.5mm, 8mm, 13mm x 2)
• Specs
  • M8 threaded rod has 1.25mm pitch
  • Torque for tightening screws in acrylic plates 0.5-0.75 Nm / 4.4-6.6 in lbs / 0.3-0.55 ft lbs max

Skeinforge Settings for Unheated Bed

• Material: ABS from MakerBot.com
• Start with Rapman ABS default settings
• No extruder fan for any prints
• Smaller parts (less than 50mm on a side with raft)
  • Feed Rate 12 mm/s
  • Raft Temp 235 C
  • First Layer 230 C
  • Next Layers 240 C
  • Raft Margin 5 mm
  • Extrusion 270 (27 RPM)
• Medium parts
  • Feed Rate 8 mm/s
  • Raft Temp 233 C
  • First Layer 228 C
  • Next Layers 238 C
  • Raft Margin 10 mm
  • Extrusion 250 (25 RPM)

Skeinforge Settings for Heated Bed

• Test Raft
  • Started with 500 W power supply
  • Test raft breaks free when thermistor temp is 46 C (infrared temp around 62 C)
  • Test raft sticks when thermistor temp is 61-63 C (IR temp around 77-80 C)
  • Feed Rate 20.7 mm/s
  • Head Speed 4.0 mm/s
  • Raft Temp 235 C
  • Bed Target Temp 100 C
• Raftless Object
  • Still having problems getting a raftless object to stick to the bed (with kapton tape on aluminum). Current ratio of flow rate to feed rate is 17.86
  • Bed Temp 100 C
  • Feed Rate 28.0 mm/s
  • Flow Rate (Extrusion) 500 (50 RPM)
  • Temp of Raft 238
  • Temp of First Layer 238
  • Temp of Shape 238 C
  • Raft Base Layers 0
  • Raft Interface Layers 0
  • Things to Try Next…
    • Replace Power Supply with 750 W unit
    • Update Skeinforge
    • Increase temp a little bit (240 C?)
    • Increase feed rate while keeping flow:feed ratio the same or raising it slightly
    • Up flow rate to feed rate ratio a bit
    • Install Raftless plug in?