UPDATE: added a bolt+plug as center axis for the table, added a vertical clamping bolt to the smartphone base, improved tolerances.

A rotating platform with scaling and alignment features, designed for photogrammetry-based 3D scanning.

This rotating platform can be used to quickly create an accurate, true sized 3D scan of a small object, by processing resulting photos in Autodesk Remake. It supports a scanning workflow, using a single, stationary camera.
It was particularly designed as a tool for creating a 3D printed spare part for a repair case, from the original part as scan object. It was a result of my graduation project exploring about how to do so.

See my guides on Repair using 3D printing and 3D scanning on Instructables:

Repair using 3D printing, Main guide: https://goo.gl/crshH6
Repair using 3D printing, 3D scanning guide: https://goo.gl/3KEKCd

FUNCTIONS

• Reference image included (PDF): glue the image to your table; it helps the software with camera alignment and you with the scaling of your scan!
• Fully modular; print only the parts you need. Design your own additions if you like!
• Use any camera on a tripod (print only the table, base and centerpin) or use the printable smartphone mount!
• Use either regular marbles (5/8" - 16mm +-0,5mm) or the bearing of an IKEA SNUDDA rotating platform!
• Adjust the smartphone clamp with the knobs, clamp any smartphone (50-80mm wide) in the grip. The entire mount can be adjusted in distance to the platform.
• Align your table in increments of 10deg for each photo; the centerpin snaps in place!
• Scale your scan with a point-to-point dimension, from the corners of the hexagonal table. The table will be included in the scan! All sides are 90mm long, opposing corners measure 180mm apart. Be sure to measure your printed reference before scaling your scan!

ADDITIONAL MATERIALS

• Printed reference image: included as PDF. Cut out and glue to the table.
• M6 bolts, x4, 30mm (or longer, but you'll have to cut them down)
• M6 nuts, x6
• M6 thread or Ø 6mm rod, 300mm or longer
• Regular marbles (5/8" - 16mm +-0,5mm), x10 OR the bearing from an IKEA SNUDDA Lazy Susan

• Rubber band (approx 50mm when it is starting to stretch)

• Featureless background, such as a white wall or large sheet of paper/fabric
• Diffuse lighting. Outdoors on a cloudy day is the easiest way. OR, Use multiple (diffuse) sources (tip: IKEA RYET 1000lum LED bulbs, in a lampshade) on the object, AWAY from the camera. Try using light-diffusing (translucent) materials or white surfaces to bounce light from multiple directions.

BUILD INSTRUCTIONS

• 3D print the parts you need. If you have the option, you can also make the arm and marble cage yourself, for instance by laser-cutting them.
• put the marbles and cage in the designated gutter on the base, OR install the SNUDDA bearing using the self-tapping screws that came with it. Don't forget the center bolt that came with it!
• insert an M6 nut in the designated slot in the base's extension. Feed the threaded rod through the hole in the front and screw it in tightly.
• insert the centerpin in the top of the base's extention. Notice it is slightly tapered; insert it with the narrow side face-down.
• feed an M6 bolt through the table plug and table, with the treaded end down. Secure it with a nut on the underside. Make sure the bolt is no longer than 30mm!
• position the table over the base, drop it with the bolt in the center hole.
• OR: if you are using the SNUDDA bearing; do not use the table plug, but install the nut that came with the SNUDDA instead.
• assemble the smartphone holder, with the bolts fed through the designated holes in the base and smartphone clamp, and nuts inside the knobs. Test the clamping force, add some washers or grip providing material if needed.
• glue a nut in the top hole of the phone base. Slide the phone base over the threaded rod and secure it with a bolt through the nut in the top hole. You can add a third knob on this bolt, if you like!

USE INSTRUCTION
(I will add links to the guides I wrote as soon as I've posted them to Instructables)

• 3D print the parts you need. If you use a camera, just print the base, table, marble cage and centerpin. If you plan on using a smartphone, consider printing the mount! (printing settings and additional building materials are listed below)
• Print the included reference image (A4, 100%!), cut it out and glue it to the table. It helps you, and the software with aligning the photos and scaling the scan afterwards.
• Setup the platform in a well-lit area, with DIFFUSE lighting (no windows or directed lights, which create harsh shadows on your object). The easiest setup is outside, on a cloudy day!
• Provide a FEATURELESS background, which is even, matte and without any interruptions. Use a white wall, or a large sheet of paper/fabric for instance.
• Place your object in the center, fix it using some clay or other material, preferably with the longest side aligned vertically.
• Create full rings of photos, by rotating the platform in increments of 10 degrees for each photo (the centerpin aligns it for you). Use a timed shutter delay, or your earbuds' volume buttons to shoot without moving the phone!
• If needed, adjust the camera altitude angle and shoot another full ring of photos.
• Process the photoset in photogrammetry software such as Autodesk Remake. (I will link my detailed guide on 3D scanning soon!)
• Scale your scan 1:1 afterwards, using the dimensions of the hexagonal table (which scans along with your object!): 90mm sides and 180mm across!