What is the best way to approach 3D scanning and printing something large?

Discussion in 'Technologies and Hardware' started by tempusr4089_a3fddcc971a4, Apr 23, 2013.

  1. I have some very custom instruments that I would like to recreate, full size, from 3D printing... if that's possible. I realize that there are many important decisions to made around materials, feasibility and so on. What I'm wondering is whether such a thing as achieving a quality 3D scan of a guitar or parts of a guitar is possible and then how best to approach recreating those parts with 3D printing.

    I realize there are many guitar-specific issues to address... so just information about if and when this might be possible, regardless of expense, would be really valuable.

    Thank you for your help!

    Jeff Titus
  2. Roy_Stevens
    Roy_Stevens New Member
    Sure it's possible. If your budget is unlimited then there are several scanning methods available from the free service that (sortof) recreates things from multiple photos, there are also pointmap arms and laser scanners. But I have found the best 3D scanner for non-organic parts like a guitar is a set of calipers and a little patience. Items drawn using this method are much easier to manipulate than the pointmap fields that you get from a typical 3D scanner.
  3. ThreeForm
    ThreeForm New Member
    Printing something the size of a guitar would cost several thousand dollars easily. In that price range you can certainly get a quality scan done as well. To begin with, you can rule out the photo-scanning thing (photogrammetry) because the output has holes and is usually very lumpy and distorted. That might work if you are printing a miniature instrument as a novelty, but would not create an accurate record of the form.

    I have tried scanning an instrument (and many other things) with a laser scanner (a hand-carved flute), and the results were ok but not great. The hole sizes and locations were not captured with enough accuracy for a full-size recreation. The spot size of the laser limits feature size, so lasers are better for very large objects.

    For professional work I use a structured-light scanner. They capture what is basically a 3D photo, with a very accurate range measurement for each pixel. Multiple range image are aligned and merged to create the final object. Structured-light scanners (also called white-light scanners) typically range in price from $10,000 to $150,000, so you would probably have the parts scanned as a service. On a well calibrated device, you could expect a range accuracy of about 50 microns (2 thousanths of an inch) over a meter, with 0.25mm-0.5mm sample spacing (pixel size). That detail might drop to 100-500 microns or less depending on how well the alignment and reconstruction is done.

    Here is a random slice (single view) from a recent body scanning project (I make custom 3D-printed clothes).
    Note the texture of the cloth is picked up perfectly. Each scan captures about 1-3 million polygons, and a typical scene or object might take 10-30 scans. This type scanning is also adept at capturing surfaces with variations in brightness, glossiness, translucency, and even fur.

    Let me know if you have any other questions.