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
- 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!
- 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!
(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!
Layer height of 0,2mm, 0,1mm for small parts
The parts are designed with a particular orientation in mind! This way, they can be printed without support material and handle forces best.
They are oriented correctly already, see the parts overview image if you are uncertain.
Print the parts with a Brim for improved bed adhesion (prevent warping!). I printed the larger parts with a layer height of 0,2mm, the smaller parts in 0,1mm. The small parts can be printed on one bed, the parts of the platform have to be printed separately.
I printed in PLA, though any rigid material might work. Keep in mind that the centerpin requires very slight flexing, but is thin enough to do so already.
I've designed this platform to be optimized for 3D printing, requiring no support structures and saving material where possible. Modularity was key; to reduce cost and optimize compatibility with common materials. It was designed to fit a print bed of 200x200mm.
I designed the entire thing in Autodesk Fusion 360.
The included images are rendered in Luxion Keyshot.
I used the standard M6 nut-bolt combinations:
- thread with a pitch of 1mm
- hex bolts: heads of 10mm side-to-side and 4mm thick. Nuts are 5mm.
All holes are overdimensioned with a +0,125mm tolerance. Thus, the holes for the bolts are in fact 6,25mm in diameter. Part clearance was overdimensioned with a +0,25mm offset.
The arm was designed to capture objects up to 200mm tall, with a maximum autitude angle of 60 deg, at 225mm distance (which makes the object fit the 48deg field of view of an iphone 5).
- the arm is 24mm wide, 9mm thick and the clamp slot is 6,25mm wide. Chamfers of 1mm were added to prevent sharp corners.
- Redesign the arm to above specs if you like, or consider laser-cutting it!