Fabr is a RepRap

July 14th, 2008 § 4 comments

I became intrigued by the concept of ‘renewable manufacturing’ – owning the life-cycle of everyday things. This idealism was captured by the RepRap project; who’s tag line is ‘Wealth without money’.

In the early phases of the construction of Fabr, I ran into the classic RepStrapping problem – how do you build a device intended to be built using a 3D Printer without a 3D printer? I had attempted to use the printing services at the TechShop in Menlo Park, but was unsuccessful. After that failure, I decided to designed and build Fabr using commonly available materials and few custom parts.

Over the last year, the RepRap organization has made changes independently which amusingly coincide with some Fabr design decisions, and Fabr has changed to be more like the RepRap in order to better leverage the software and firmware from the RepRap team.

In essence, Fabr is a RepRap.

Since my last post, I’ve been working on the following parts of the project:

  • The TextMate plugin was nearly rewritten in order to remove the Processing toolchain, and require the AVR MacPack from Objective Development.
  • Using the new Mill & Lathe, I’ve improved some of the articulation points
  • Implemented a multi-screw Y axis to compensate for unacceptable racking. I wish I could say that 80/20 is an asset, but the linear motion bearings are woefully inadequate and excruciatingly expensive. 
  • I smoked my motor shield while debugging a stepper problem, and switched to using 4 EasyDrivers from SparkFun.
  • Started building a ‘Super Driver’ which can drive steppers to 2.5A, as well as software configurable Full Step or Microstepping.
  • Ported the RepRap gcode interpreter to the TextMate toolchain and adapted it for the EasyDrivers (Need to unify this work with the trunk, and submit my updates to the RepRap team).
  • Implemented a Ruby gcode uploader; hopefully to be used in the Sketchup exporter.
  • Acquired materials and Building RepRap Opto Endstops for home positioning
  • Acquired materials and Building the Temperature controller for the extruder

§ 4 Responses to Fabr is a RepRap"

  • Oliver says:

    What, no pictures? 🙁

    And how the hell are bearings expensive? They’re made by the million 😀

  • Louie says:

    I need to grab a shot of the controller breadboard. Otherwise, not much has changed.

    As for the ‘bearings’ – 80/20 uses a UHMW tslot profile in a 3 way sandwich between the 80/20 rod and a ‘h’ shaped bracket. It’s not a roller bearing.

  • Very cool. (And as a reprapper, glad to hear it). I’d seen 80/20 discussed as a way to build routers, but this is the first 3D printer I’ve seen built this way.
    You must know of it, but your readers may want to see CNCzone’s ‘building a 80/20-based CNC router’ subforum.

    1) Now that you’ve had a go with 80/20, would you do it again? (And how much did it cost?)

    2) You may be interested in the Bay Area RepRap User Group. It’s still booting up, but may be big some day, especially as people join up.

    3) What kind of mill are you using? Can you slap an extruder on it?

  • lou.amadio says:

    Hello Sebastien,
    Thank you for the pointer to the CNC forums. Having read through the posts, I was relieved to hear I wasn’t the only one having problems with binding and racking using the linear bearings. I compensated for the racking using two screws with a sync chain connected to a stepper.

    1) I posted tonight with a full rundown. If you have further questions let me know 🙂

    2) I moved back to Seattle about 8 months ago. I’m in the Bay area from time to time, so I’ll keep an eye out for events. It looks like there are several people in seattle who are in various stages of building a reprap, and looking to get an event togehter.

    3) I’m using a non-CNC sherline. I love the mill and want to convert it to CNC. I had hoped to leverage my ‘super driver’ motor controller and the software built for the reprap (bass ackwards I know).

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