Sandwich200

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Sandwich200

Release status: working

Sandwich200v1.png
Description
A fast, folding, portable aluminum-framed CoreXY printer.
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Author
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CAD Models
External Link


The Sandwich200 is a folding, portable CoreXY 3D printer that uses a 1515 aluminum extrusion frame. Capable of printing at high resolutions and high speeds owing to its CoreXY kinematics, it produces quality parts that are up to 200x200x200mm in size. In its assembled state it is 490mm high x 460 x 410mm (up to around 550mm due to the bowden tube); folded into its box it is 440mm x 420 x 210mm

Goal

To design a folding, portable 3D printer using CoreXY kinematics that offers high speed and quality. The printer must be able to be built without specialized tools.

Features

  • Aluminum structure based on Makerbeam 15x15mm extrusion
  • Stacked variant of CoreXY that eliminates the belt crossing and its associated issues
  • Folds up into its own box, dimensions 440x420x210mm
  • Box halves are used when assembled to contribute to very good rigidity
  • 200x200x200mm build area with heated bed
  • All hardware and electronics (except for filament spool) are integrated within the frame.
  • Capable of 0.05mm layer height and 300 mm/s printing
  • Emphasis on using 3D-printed parts and being easily hackable/upgradeable
  • Geared bowden extruder, giving very high flow-rates (220mm/min - over 20mm3/s - before skipping occurs)
  • Low moving mass — all motors stationary.
  • No specialized tools or equipment necessary for assembly (accessible)
  • LM8LUU linear bearings used throughout, except in the Z-assembly which is dual LM8LUU plus LM8UU for huge (75mm) vertical bed support. Longer bearings means less judder, noise and wear.

Bill of Materials

The BOM is maintained in the source for the CAD model, and is auto-generated (including an accurate count of nuts and bolts required). A copy is here: File:Sandwich200 bom.pdf

Printed Parts

The STL files are auto-generated from pyopenscad (included in the source). Obtain with git clone http://hands.com/~lkcl/foldable3dsandwich200. Build requirements: install git, GNU make, python2 and a recent version of openscad. run "make download" followed by "make".

Tools

Recommended: obtain a geared power drill or a screwdriver with a standard hexagonal toolbit adapter: there are an enormous number of M3 nuts, bolts and screws to assemble (over 300)

  • 1/4in socket (for M3 nuts. lots of M3 nuts)
  • Allen keys: 1.5mm, 2.0mm, 3.0mm, 4.0mm
  • Screwdrivers: electrical (for the EC), flat-head and/or pozidrive (for M3 screws)
  • M3 spanner(s), adjustable spanner(s), or Pincer-nosed pliers with small eye for nuts (M3) (Qty 2 recommended)
  • Another 3D printer capable of 0.20mm layer height (your own or use someone else's)
  • For cutting extrusions to length (from 1m Makerbeam): Metal hacksaw or 10,000 RPM disc cutter with 125mm x 1mm metal-cutting disc (*WARNING: Disc cutting tools are extremely dangerous: they can jump and kick out of your hand and send the metal flying off at high speeds*. If you have a Company Account, purchasing cut-to-order Misumi1515 is a much better idea)
  • Wood saw (if choosing MDF, Plywood or Hardboard for the box sides). Obtaining the panels cut-to-order is recommended (most iromongers / hardware stores can do this for you)
  • Soldering iron, solder, stand and sponge (usual deal for soldering)

Development

Discussion on the reprap forum is here: http://forums.reprap.org/read.php?397,639675,648097

Version 1.0

Initial variant. Uses a non-intersecting CoreXY design to eliminate belt crossing issues.

Issues

  • Z-axis issues—slight wobble
  • Untidy wiring
  • Huge number of nuts and bolts for the box (almost 100 to hold the panels in place)

Todo

  • Cooling fan addition to improve bridging and top speed for small parts
  • Convert to 24V in order to increase speed without back EMF

Gallery

Videos

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