Building MakerBot 00018

The MakerBot Cupcake is a RepRap-derived 3D printer. I built machine number 00018 between 24 April 2009 and 18 February 2010.

About This Build

• Machine number: 18
• Build: 24 Apr 2009 – 15 Feb 2010
• Tuning: 15 Feb 2010 – 18 Feb 2010
• First Successful Print: 18 Feb 2010

Contents

1. Image Gallery
2. Useful Links
3. Testing the Electronics
4. Tuning
5. Thermistor Settings
6. Skeinforge Settings

Image Gallery

Go to the image gallery at Flickr.

Useful Links

• MakerBot Lineage Page
• Flickr Photo Pool
• Google Group for MakerBot Operators
• Construction Tips and Tricks
• Build Wiki
• Plastruder Build Wiki
• Electronics
  • Electronics Fabrication Guide
  • Hotplate Reflow Technique for SMT Soldering
  • Electronics Assembly
  • RepRap Generation 3 Electronics
• Electronics Build Sequence
  • Endstops
    • N.B. placement of some connectors different from standard RepRap build
    • RepRap OptoEndstop v2.1 build instructions
    • Four endstops using the RJ45 connectors for X and Z axes
    • Two endstops using 3 pin connectors for Y axis
  • Stepper drivers (large SMT components, smallest is SOIC)
  • RepRap motherboard (fairly spaced out, but the TQFP can be tricky)
  • Extruder controller (pretty dense, with TQFP)
  • USBTinyISP

Testing the Electronics

• Opto-endstops
  • Checked all connections with dissecting microscope set at 0.7 x 10x
  • Re-soldered one loose joint
  • Used PB-503 proto-board to build a little test rig for both kinds of connection
  • All endstops seem to be working correctly
• Stepper motor drivers
  • Checked all SMD and through-hole connections with dissecting microscope
  • Had to ground the sense line of the ATX power supply unit to get it to power on without a computer attached (following Masked Retriever’s hack)
  • Checked that green power LED comes on for all stepper motor drivers
• Burning the bootloader
  • Used Arduino 0017 on Mac OS X with Sanguino 1.4-r1 support
  • USBTinyISP needs to have jumper across two pins near cables in order to provide +5V to Sanguino
  • Power LED on Sanguino doesn’t light up even though Arduino software claims that bootloader burns successfully
• Firmware
  • Using RepRap Gen 3 Firmware 1.2
  • Don’t forget to copy reprap-r3g-firmware-1.x/libraries/* to arduino-00xx/hardware/libraries/ (otherwise you will get an error that it can’t find simplepacket.h)
• Debugging
  • The power LED never lights up on the Sanguino
  • Unfortunately I am now getting the following error: “avrdude: stk500_recv(): programmer is not responding”
  • Tried connecting LED to Pin 13 and resetting. It doesn’t flash, which suggests something may be wrong with bootloader. When I power with the ATX power supply and hit the reset button, the Debug light flashes 4 times; the power light doesn’t come on at all.
  • Tried putting a low voltage through the SMD LEDs that indicate Power and Debug (on the LEDs, cathode is marked with green stripe). Both LEDs work.
  • Replaced motherboard.
  • Once motherboard replaced, extruder controller and stepper motor drivers work perfectly
  • Invert Y axis in ReplicatorG

Tuning

• First mini mug is eye-shaped when looking down at it from above. Loose belt on X axis.
• ABS sticks to foamcore but object pops loose halfway through build. Made an acrylic plate to cover the build platform, covered one side with kapton tape and roughed the other with sandpaper.
• Natural ABS extrudes smoothly at 220 degrees C
• Difficult to get ABS to stick to the platform
• Part way through a full day of tuning, realized that the idler wheel had slipped sideways off of the bearing and the filament was jammed beside it. Disassembled extruder and rebuilt idler wheel and bearing with Special T cyanoacrylate. Johnny Russell also suggested using a zip tie as a filament guide, shown in this photo. If the problem recurs, might try double-thick idler wheel or machining new one out of some other material.

Thermistor Settings

• Assume I have older (1mm) thermistor – didn’t measure it before building extruder
• Beta=4881, r0=93700, t0=24

Skeinforge Settings

• Material: MakerBot Natural ABS
• Start with Configuring Skeinforge page
• N.B. These settings are pretty good, but could use a little more tuning; see the “Fundamental Settings” section of the Configuring Skeinforge page to get them perfect
• Carve
  • Layer Height: 0.4
• Raft
  • Temperature of Raft: 220
  • Temperature of Shape Next Layers: 220
  • Temperature of Shape First layer Outline: 220
  • Temperature of Shape First Layer Within: 220
  • Temperature change times: 0
  • Interface Layers: 0
  • Base Layer Thickness over Layer Thickness: 1.7
  • Raft Outset Radius Over Extrusion Width: 10
• Speed
  • Flowrate Choice: PWM
  • Flowrate PWM Setting: 255
  • Feedrate: 25
• Fill
  • Solid Surface Thickness: 3
  • Extra Shells On Sparse Layers: 2
  • Extra Shells on Base Layers: 3
  • Extra Shells On Alternating Solid Layers: 1
  • Infill Pattern: Grid Rectangular
• Deactivated modules
  • Cool
  • Hop
  • Oozebane
  • Stretch
  • Unpause
  • Comb
  • Multiply
  • Polyfile
  • Wipe