Wednesday, 6 February 2013

Recommending a 3D printer

In a previous entry I wrote about the technology of additive manufacture and the use in printing three dimensional objects.

My Prusa Reprap printer, not recommended for new builds
It is now almost two years since I built my own 3D printer and I keep getting asked by colleagues and friends about the technology and often what printer to buy.

I will answer the purchase question first and then describe my experiences which have lead to the conclusion in another post. This may seem a bit backwards but the explanation is long and is not necessary if you are happy to learn from my mistakes.

Of all the options available right now, and there are many, I would choose a Mendal90 kit from Chris Palmer. The complete kit including everything to build the machine is £499 plus shipping. If I could afford it this is what I would buy myself to replace my current machine.

This is a Fused deposition modelling (FDM) printer similar to my Prusa Reprap but better engineered to produce repeatable results without the numerous issues of the other models. In Europe I would also recommend faberdashery as a materials source as their product is first rate every time.

Yes the kit requires some assembly but the commonly available commercial printers either cost many times more to deliver equivalent results, use an SLS or other print strategy requiring very expensive consumables or are from a company with dubious track record with the community.

If forced to recommend one, the 3DTouch from Bits From Bytes is not awful, but really do not be afraid of the kit, you will learn more about how it all fits together and save lots of money for your materials.

A 20mm high pink dump truck toy
One thing anyone buying a 3D printer right now should understand is that this technology is nowhere near as polished as the 2D equivalent. With the exception of the SLS systems like shapeways and the like use (and have price tags to match) The output will have clear "layering" and some objects simply cannot be created using the FDM process.

I guess what I am saying is do not expect a thousand pound machine to produce output that looks like that of a hundred thousand pound printer. To be clear you will not be printing complex moving machines on an FDM process more simple things that need assembly.

Having said that I have some pretty good results my favourite has to be the working recorder though, I might have said the whistles except my sons have them and they are way too loud.

You will spend a lot of time designing your things in 3D CAD packages and fair warning they all SUCK and I mean really, really badly. Add to that all the rest of the tools in the workflow are also iffy and I do wonder how anyone every gets anything printed.

My (open source) workflow is:


Which is probably a case of "least bad" tool selection though I warn you now that OpenSCAD is effectively a bad editor (I wish I could use emacs) for a 3D solid macro language with visualisation attached and definitely not a graphical tool.





7 comments:

  1. Hi Vincent,

    You can use emacs to edit openscad files.

    In openscad, turn off the editor: View/Hide Editor
    also turn on auto recompile: Design/Automatic reload and compile.

    In emacs check out scad-mode. It is available vial ELPA and the Marmalade repo.

    Then simply edit the in emacs. Openscad will notice when you save the file and automatically recompile.

    Jason

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    Replies
    1. Interesting, the openscad packaged in Debian does not have these features.

      I note that a new release was made in January so I guess a backport of that edition would solve my problems.

      Thanks for the suggestion.

      Delete
  2. Hey Vincent,

    Great blog posts. I've been looking extensively into 3D printers in the last few months. I'd like to know what you think about the MendelMax design, and if you heard of the lulzbot AO 101. It's my top choice at the moment...
    There's also the Tantallus printer which looks great, boasting 300mm/s speeds with 8 micron X/Y details and 10 micron layer height..
    The makerbot replicator 2 looks good too, but I don't like the closed source aspect of it, and it's too expensive compared to the others.
    Let me know what you think!

    KaKaRoTo

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    Replies
    1. I have indeed looked at the mendalmax but it simply does not solve the fundamental issues with the A frame design.

      Indeed the lulzbot is the A frame design once again implemented in aluminium extrusion with huge braces to try and add stability.

      All these designs still has a lot of mass (the motors) at the top of the frame and still tries to solve the x axis rigidity a long way from the centre of mass.

      My experience with subtractive manufacture process, where these are solved issues, leads me to believe that all these type of solutions will continue to suffer from vibration and calibration issues.

      The Tantallus and the makerbot are a better design but are generally more expensive than the Mendal90 solution.

      I politely alluded to the Makerbot issues in my posting and most definitely do not want to start such an argument in this forum.

      Delete
    2. Thanks for the reply!
      From the review I've seen of the lulzbot, it seems to be stable and has excellent repeatability and quality. I didn't realize though that the A frame design was such an issue and it couldn't truly be fixed. Even though lulzbot are saying that they tested it on the back of a jeep in a dirt road in the mountains and it still printed.

      I hadn't heard of the mendel90 until your blog post, suddenly I seem to see it everywhere!
      It looks like the 90 degree design is better and is being widely adopted. The Prusa i3 for example, as well as lulzbot's next printer, the TK-O : http://devel.lulzbot.com/TK-0/
      http://forums.reprap.org/read.php?1,157703

      Considering the reputation of lulzbot and their efforts in making TK-O better, and their tests, and after reading thir DfX document (http://devel.lulzbot.com/TK-0/Documents/AO-100%20DFx%20Presentation.pdf) I'm convinced in buying the TK-O once it becomes available! Hopefully it will be cheaper than the AO 101.

      Thanks again for your input!

      p.s: I'm not good with hardware so I need to get an assembled/pre-calibrated machine. I'm ready to pay the extra price if it saves me from building it myself.
      p.p.s: Let me know what you think of the TK-O if you hadn't seen it before.

      Delete
  3. To run this printer need to good command over CAD/CAM.

    ReplyDelete
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