3D Scanning With Calipers




Introduction: 3D Scanning With Calipers

About: I make things, I break them and I repair them.

In this guide I explain how you can record high quality measurements using your phone and a digital caliper.

The goal is to manually 'scan' an object so that a maker can 3D print the model.

You could call this "manual 3D scanning" because the goal is to record all the important measurements that are needed to make a 3D model out of an existing object just like a 3D scanner but more accurate, easier, quicker and cheaper.

At the end you can send off the object description and photos to a Maker with a 3D printer and he should be able to remake your object.


  • Measuring caliper (preferrably digital).
  • Smartphone with a working camera.
  • (optional) Cutting mat (or another clean background).
  • (optional) Phone standard, selfie-stick or someone to hold your phone for you.

Step 1: Inspect Your Part

Look closely at your part and check the following:

1. Is there any damage to the part that must not copied into the model?

2. How many measurements are needed to replicate the part? Go through all of the relevant measurements in your head and try to estimate the total amount that is needed.

3. If you are confident about making the measurements go to the next step.

Step 2: Setup Your Measurement Station.

Make sure there is enough light, preferably sit down next to a window or a bright light.

Make sure your caliper is set to zero by gently keeping it closed and long pressing the zero button.

Setup your phone standard if you have one and lay down a clean underlay, preferably with a 10x10mm matrix.

Step 3: Take a Couple of Pictures at an Angle.

Make sure to capture the whole object in a 3D isometric view from several angles so that the maker gets a better idea of the geometry of the object.

Step 4: Start 'Scanning' the Part.

Now put the phone in the standard if you have one.

And start taking pictures while measuring with the calipers, this can be tricky with one hand, make sure the measurements don't shift while taking the shot. Get help from someone if it doesn't work.

Make sure to keep the part in the center of the picture and that the screen of the caliper is readable.

Step 5: Create a Collage.

Make a collage from the measurement photos.

You can do this at: https://www.befunky.com/create/collage/

There is also an app: https://play.google.com/store/apps/details?id=air....

Feel free to use other collage making software if you feel like it.

Make sure you don't forget photos, make two or three collages if you have more than 9 photos. Its better to have double measurements than to leave one out.

Zoom in on small features to make them more clear.

Step 6: Describe Your Object.

Add a detailed description of your part with relevant information such as:

  • What the function of the part is.
  • What kind equipment or product it belongs to.
  • What kind of stresses are on the part under normal use?
  • What kind of temperatures does it resist?
  • Point to features in the pictures if necessary.
  • Are there any features or adjustments you want that are not seen in the pictures?
  • Are there any features that have broken off and got lost?

Step 7: Export As PDF

Export the photos the collages and the description as a pdf and send it off to a maker in your area, he should be able to remake your part. If he does miss some info he can always ask for more info later on.

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    2 years ago

    Nice concept, but it would be wildly easier to simply put the phone in video mode. Let it run the entire time, and sound out (speak) the measurements as you make them. This will give the viewer both visual and audio confirmation of the dimensions. No need to make a collage or document. Just push the video up to the cloud.


    Reply 2 years ago

    Good idea! I tried some video recording myself but not with sound. It works but it has its drawbacks too: Its difficult to find certain measurements by scrolling through the video and it produces large files. Maybe we need some software that can make browsing through the video easier or that can extract the measurements with voice recognition.


    Tip 2 years ago

    You could place a ruler next to the object and take an image. By using simple free software (ImageJ for example), you could calibrate the images so that instead of reading the distance between two points in pixels, you can actually measure real distances.
    Of course your method is more accurate :) But the upside of what I said that you only take a couple of images and someone else can measure what ever he likes.


    Reply 2 years ago

    To one up this you could place the item on squared paper with a ruler next to it


    Reply 2 years ago

    Thanks for the tip! It it's indeed faster if you want to make a quick replica, however the accuracy is needed when replicating spare parts with a tight fit. I found that using a reference ruler and a phone camera can produce a pretty high error margin, easily 0.5mm to 1.0mm depending on the quality. Most calipers are accurate to around 0.05mm. If you add the error from a 3D printer (usually around 0.2mm) it makes sense to use calipers in 3D printing for repair scenarios.