Saturday, February 15, 2014

3D Printer Buildlog #1

For this project, I will be porting my current Printrbot LC 3D printer into a 1 ft3, high speed printer frame. To get the project started, I looked at my current printer as well as some of the best design features "out there" to build the biggest, fastest, and most accurate printer I could possible produce.

I chose to follow a standard Cartesian design and optimize it for speed. As many printer hobbyists know, the best way to increase printer speed without sacrificing accuracy is to reduce the moving mass of the print head. Bowden extruders are a fantastic way to speed up printers, but they're not enough. For this reason, I have chosen to pursue an H-gantry driven XY system. A similar arrangement known as CoreXY has shown promise, and its kinematics have already been implemented in Marlin.

To aid in precision, I have acquired two sets of precision linear rails and their associated carriages. These will form the basis of the X and Y axes. The Z axis will utilize smooth rods with linear bearings for cost reasons. I'd also like to take advantage of the automatic bed leveling that some users have experimented with in Marlin. It looks promising, and if reliable, could be an excellent time-saving feature in the long run.

Since most of my printing is currently in ABS, I will be including a heated bed. Additionally, the build volume will be enclosed to reduce the opportunity for part warping to occur.

 Lastly, the entire printer will be operated by a Raspberry Pi via Octoprint. I've already used the software with my Printrbot LC and it's terrific! A great big thanks to Gina Häußge for developing the project open source! To that end, I would like to include a mount for a webcam so prints may be streamed to the internet. Internal LED lighting will aid that venture.

The tl;dr specs for the project are as follows:

  • 1 ft3 build volume
  • 5/8" steel square tubing frame
  • H-gantry or "CoreXY" kinematics
  • Precision linear rails for x/y movement, smooth rods for Z
  • Bowden extruder w/ opportunity of future expansion to multiple heads
  • Heated bed
  • Fully enclosed printing chamber for heat retention
  • Automatic bed leveling/compensation (recently merged into Marlin main)
  • Internal LED lighting
  • Wireless control via Octoprint
  • Webcam mount for streaming prints
Here's a very primitive conceptual model I developed in Solidworks to gauge scale and position: