My FREE Tool Turns 3D Scans into CAD feat. Elegoo M1 Ultra

Thanks to @ElegooOfficial for sponsoring this video. Check out the M1 Ultra https://geni.us/ElegooM1Ultra
ScanRuler is FREE and OPEN SOURCE: https://scanruler.com

I built ScanRuler, a completely free and open-source tool that turns 3D scans into something genuinely useful, from precise measurements and deviation analysis to wall-thickness inspection and reverse engineering. With the help of AI, it can even automatically turn a scanned part into a fully editable, parametric CAD model, repair broken features, or design entirely new parts! In this video, I put the new Elegoo M1 Ultra 3D scanner to the test and show how powerful 3D scanning has become when combined with the right software.

🛒 Products from the video (affiliate):
Elegoo M1 Ultra 3D Scanner: https://geni.us/ElegooM1Ultra

Website Article: https://www.cnckitchen.com/blog/scanruler-free-3d-scan-reverse-engineering
ScanRuler - Free 3D Scan Evaluation: https://scanruler.com

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Chapters
00:00 Introduction
02:17 Elegoo M1 Ultra
03:02 Scanner Accuracy (3D Measure Workspace)
06:47 Example 2: Wheel (Markerless Cross Line Scanning)
08:38 Deviation Analysis on 3D Printed ABS
11:38 Wall Thickness Analysis on Vacuum Formed Part
13:40 CAD inside ScanRuler
14:18 Repair Engine Housing (Virtual Kintsugi)
16:24 Manual Reverse Engineering
18:00 ScanRuler MCP (AI Agent)
20:59 Automatic Part Repair
21:23 Automatic TPU Case Generation
21:53 Limitations
22:34 Automatic Scan Analysis
22:57 Agentic CAD Design
23:20 Verdict

#ELEGOO #ElegooM1Ultra #3DScanner
DISCLAIMER: Part of this video was sponsored by PCBWay.
FTC Disclaimer: A percentage of sales is made through Affiliate links

Transcript

0:00 I think my new free tool could change 3D scanning forever. You can give it the mesh from a 3D scan,

0:06 and it can recreate a high-quality, parametric CAD model. And if the original part is broken,

0:12 you can even ask it to fix it for you! But let’s start at the beginning.

0:16 Let's be real: for many people who bought a 3D scanner, that gadget eventually became an

0:22 expensive paperweight. And that wasn't necessarily the scanner's fault, but the software around it.

0:29 3D scanners have become really good and quite affordable compared to what they used to cost,

0:35 but the software they typically come with only lets you capture a part—and not much

0:40 more. You end up with a partially closed mesh of something you'd like to repair,

0:46 but you're missing the tools to do it effectively. Conventional CAD software can load these meshes,

0:52 and you can design around them like a blueprint, but that's tedious and often quite complex. There

0:58 is specialized software for analyzing 3D scans and even assisted reverse engineering. But one

1:04 tool is now behind a registration wall since Zeiss bought GOM, while the others are simply

1:10 really expensive. That’s why I built ScanRuler, a free and opensource tool. No installation,

1:16 no tracking, no cookie banners, and it runs locally on your machine! It's perfect for

1:21 taking measurements directly on your scans, comparing them with reference geometry,

1:26 and analyzing wall thickness. It even includes a full CAD suite designed specifically for reverse

1:33 engineering 3D scans. And the craziest part? If you connect an AI agent, it can handle the

1:38 entire reverse-engineering process for you and create a fully parametric CAD model! And did I

1:44 mention it's free? Let's find out more! Guten Tag everybody, I'm Stefan, and welcome to CNC Kitchen.

1:53 Even though this is a vibe-coded project, I know not everyone is stoked about it. It’s the

1:58 world we live in now, and for me it’s simply a tool to build the tools I’ve always wanted

2:03 and give them back to you completely free. I hope you can appreciate that. I've poured

2:09 weeks of work into this, and it's only possible thanks to all your support and tips, as well as

2:15 amazing sponsors like Elegoo. This is a perfect match, because Elegoo just launched the M1 Ultra,

2:22 an all-in-one 3D scanner with three blue-laser scanning modes, structured-light scanning,

2:27 and even wireless operation, starting at $1,599. I've used it extensively over the last few weeks

2:34 to capture a ton of objects. Those scans didn't just help me develop ScanRuler;

2:40 we'll also use them today to show how powerful the combination of the Elegoo M1 Ultra and ScanRuler

2:47 can be. You can access all the projects shown in this video through the links in the description,

2:52 so you can check out both the M1 Ultra's scan quality and how I processed the scans

2:57 in ScanRuler. Find out more about the Elegoo M1 Ultra using the link below!

3:02 So let’s go through everything that you can do with Scanruler and the right 3D scanner!

3:07 The most important thing if you want to use a 3D scanner as a real workshop tool is accuracy.

3:13 So before using the M1 Ultra for the first time, and at regular intervals afterward,

3:18 you need to calibrate it. Elegoo includes a precision glass calibration plate stored in

3:24 the scanner's beautiful, rugged case. You simply connect the scanner to your PC or

3:28 Mac and open Elegoo Scan. This software is actually really good and if you ever used

3:34 Creality Scan you might find a lot of similarities. It guides you through the

3:40 calibration process as you scan the plate from different angles and distances. Once

3:45 that's done, your scans should be accurate to within a few hundredths of a millimeter.

3:50 Let's test that with my ball bars: precision spheres connected by a carbon-fiber rod. By

3:56 knowing the diameter of the spheres and measuring the overall length, I can calculate the distance

4:02 between their centers. So I scanned the ball bar several times, from different angles, using both

4:08 cross-line and parallel-line laser modes. To find out how accurate and repeatable those scans are,

4:14 let's switch over to ScanRuler at ScanRuler.com. I initially built it as a replacement for GOM

4:20 Inspect, which hobbyists could use for free in the past. But for the past few years,

4:25 after Zeiss bought GOM, accessing it has required registration with a company email address.

4:31 ScanRuler has grown into much more than just a measuring tool, though, as you'll see in a bit!

4:36 After exporting the scan from Elegoo Scan, you simply load the STL into ScanRuler. The first

4:42 workspace is for 3D measurements. The idea is simple: fit geometric features to your scan,

4:48 then use those features to take measurements. For the ball bar, I fitted spheres to the precision

4:54 balls. You click on the surface, and the tool automatically finds and fits the sphere. Next,

5:00 go to Dimensions, where you can take a variety of measurements. Just click the two spheres,

5:05 and the tool gives you the center-to-center distance. I did this for all nine scans,

5:11 and every result was within the scanner's specified accuracy,

5:15 which at this size is 0.035 mm, or about 1.5 thou. My largest deviation was three hundredths of a

5:23 millimeter over a total distance of 257 mm, which is pretty good for most applications!

5:30 But you're not limited to measuring the distance between spheres.

5:33 The 3D measurement workspace is super useful for things that are difficult to measure by hand,

5:40 like draft angles or fillet radii. With a 3D scan,

5:44 those measurements only take a few clicks. You can also export all your fitted features

5:50 as STEP geometry with a single click, if you want to use them as references in CAD.

5:56 One reason semi-professional 3D scanners have become so good is the use of line lasers. These

6:03 thin projected lines allow very precise scanning, and because they're so bright, you can often scan

6:09 shiny metal or black parts without scanning spray. They even work in almost any lighting condition,

6:16 including outdoors! But the scanners I've used in the past had one inconvenience:

6:21 they always needed scanning markers. These are small reflective dots you stick onto the part

6:27 so the scanner can track its position in space. For smaller parts, that's not a huge problem,

6:33 because you can simply put the markers on the scanning table. For larger parts, though,

6:37 it means tediously sticking markers all over the object. So when I discovered that the M1

6:42 Ultra could also do markerless laser-line scanning, I had to try it right away!

6:47 My brother was just changing his tires, so I grabbed one and set everything up for scanning

6:52 in the garage. In the past, that could be pretty painful because these scanners often

6:57 draw more power than a USB port can supply. I'd always have to find a nearby power outlet. The

7:04 M1 Ultra is battery-powered and even comes with a spare battery, which makes it much

7:09 more convenient to use. For the wheel, I chose cross-line laser mode because it captures large

7:14 areas quickly and is great for bigger parts. To my surprise, tracking worked almost flawlessly,

7:21 even when I manually moved the wheel around to reach both sides. My goal was to capture the

7:27 wheel hub from both sides, and that worked great despite the different surface textures and colors.

7:32 Back in ScanRuler, I first aligned the part. I also noticed that my brother's car seems to

7:38 have a camber issue—and that these ten-year-old tires should probably be replaced next year. It's

7:43 crazy how much you can see in a 3D scan! I then created a section and noticed that Volkswagen

7:49 seems to use bolts with spherical seats rather than simple tapered ones. By fitting spheres here,

7:55 I could estimate that the spherical seat has a diameter of around 26 mm. The numbers vary

8:02 a little because this was a fairly rough scan focused on the hub, not on that specific detail.

8:08 By fitting planes to the wheel flange and the inner and outer faces of the rim,

8:12 we can measure the width and offset, or ET. To measure the pitch-circle diameter, I created a

8:18 section through the bolt holes and analyzed it in the 2D workspace. There, I could measure the hole

8:23 diameters, fit a circle through their centers, and determine the pitch-circle diameter. It was

8:29 basically spot-on compared to the specification! I love how easy this whole process has become.

8:35 When you manufacture a part, its dimensions will never match your CAD design perfectly. That's why

8:41 we have tolerances. For simple parts, conventional measurements are usually straightforward. But

8:47 especially with 3D prints that can warp, it's often hard to tell how far a part deviates

8:52 from its ideal shape. And that's exactly the kind of analysis a 3D scanner is great for.

8:59 Let's look at an example. Have you ever wondered whether printing ABS in a heated

9:03 chamber actually reduces warping compared to printing without one? I printed the

9:08 exact same rugged case twice: once with the printer door open and the heater off,

9:12 and once with the chamber heated to 65°C throughout the print. At first glance,

9:18 there wasn't a huge difference. So I scanned both parts with the M1 Ultra in cross-line laser mode,

9:24 which worked flawlessly without any surface preparation—even on the black, glossy plastic.

9:30 To capture the complete part, I took two scans: one from the top and one from the bottom. Both

9:35 scans only took a few minutes. Then I merged them in Elegoo Scan to create a complete model,

9:41 generated the final mesh, and exported it for deviation analysis in ScanRuler.

9:46 The deviation workspace needs two things: a 3D scan and reference geometry—in this case,

9:52 the model I used for printing. The scan doesn't have a defined orientation, so we first need to

9:58 align it with the reference. The auto-align feature handles that, much like the alignment

10:02 of two separate scans. Once the two models overlap, ScanRuler displays a deviation map.

10:09 Red means the scan lies outside the reference surface; blue means it's inside. At first,

10:15 both prints—the one made in the 65°C chamber and the one printed cold—look pretty similar,

10:21 with an average deviation of around 0.3 mm. But when I activate the animation feature,

10:27 one of my favorite parts of ScanRuler because it makes the differences so easy to understand, we

10:33 can clearly see what's going on. The part printed in the cold environment warps significantly,

10:39 especially in the large flat regions, which bow inward. The hot-printed part, on the other hand,

10:44 stays mostly flat but shrinks as a whole as it cools down. And that's something we can correct

10:52 by measuring one of the major dimensions and comparing it with the original STL. I adjusted

10:58 the scaling factor in the slicer, printed the part again, and rescanned it. Now it almost

11:03 perfectly matches the reference geometry! The main deviations left are the corners lifting,

11:08 which can be a problem when the plastic doesn't cool quickly enough. We could even go so far and

11:15 I might implement that soon, that we basically apply the inverse of the warped shape to teh

11:20 stl that we print, so when it warps during printing it warps to the perfect shape - a

11:26 method called pre-defomation. This is one reason I love having a 3D scanner in the workshop:

11:32 it helps me understand what's happening to my prints in a much more visual way!

11:37 Let's take a quick look at another handy workspace before we finally get to reverse engineering! The

11:43 third workspace is for wall-thickness analysis. On simple parts, you can obviously use calipers. But

11:49 on larger or more complex parts, you might not be able to reach every area, and the wall thickness

11:54 can vary significantly. Vacuum-formed parts are a great example: the more the material stretches in

12:01 certain areas, the thinner it gets. So I scanned the vacuum-formed hood of my INDX. This time,

12:08 I placed markers all over the part, because markerless tracking can be unreliable on flat,

12:13 featureless surfaces, and markers are still the most reliable option. I also placed some

12:18 3D-printed targets with markers around the hood on my desk. Then I scanned everything

12:23 in cross-line laser mode, making sure to capture both sides of the panels,

12:28 especially around the bends. Once the scan was processed and meshed, I went back into ScanRuler.

12:33 Here, I noticed that all the surface normals were somehow flipped. Luckily, that's easy to fix in

12:38 the mesh workspace, where you can also close holes and smooth the part. You can even edit your scan

12:43 and perform Boolean operations using features you fitted earlier—for example, to recreate holes that

12:49 weren't scanned to their full depth. But back to the hood. After correcting the surface normals,

12:54 I returned to the wall-thickness workspace. With one click, I got a beautiful color map showing how

12:59 the thickness varies across the entire part. It's thickest near the edges, where the sheet

13:05 was probably clamped, and I suspect the original stock was 3 mm thick. The top of the hood is

13:11 already more than a millimeter thinner because of the stretching, and it's not even uniform.

13:16 The thinnest areas are around the large lower bends, where the material is less than half its

13:21 original thickness. During manufacturing, these are probably the areas most likely to fail because

13:27 the material has been stretched so much. This information can be incredibly valuable for process

13:33 development or quality control, and you can get it with an affordable 3D scanner and a free tool!

13:40 Now let's get to the part you've probably all been waiting for: reverse engineering!

13:45 The reverse-engineering workspace is a complete CAD system. And if you just want to design

13:50 something from scratch, you can do that here too, without a 3D scan. The nice thing about

13:56 building this myself is that I could add features I've always wanted in conventional CAD software,

14:02 especially for 3D printing. One example is the thread tool. It includes a 45° thread

14:08 profile that's easier to 3D print, and with one click you can add chamfers to

14:12 both ends or give the thread a small offset so printed threads don't bind.

14:17 Reverse engineering is powerful, even for simple repairs like recreating

14:21 this piece that broke off my Vespa's engine housing. I don’t have teh original anymore,

14:27 so we have to design it ourselves. First, let's make a quick scan. Here I'm using the M1 Ultra's

14:33 wireless mode. You still need a PC or Mac, but you don't need a cable between it and the scanner.

14:39 Just switch the little knob on top to activate Wi-Fi mode and connect your computer directly to

14:45 the scanner. As long as you're within Wi-Fi range, you can scan wirelessly, which is especially

14:50 useful for larger components. The screen on the M1 Ultra mirrors your computer's display,

14:55 so you can always see what you're scanning and whether you're at the right distance.

15:00 The downside is that scanning is a little slower because of the reduced bandwidth, and markerless

15:06 laser-line scanning isn't available in this mode. That's why I put markers on the engine

15:10 housing. After only about a minute of scanning in parallel laser mode, I had a beautiful—or maybe

15:16 sad—3D model of my broken engine housing, including the fracture surface itself.

15:22 So let's repair it. First, I fitted a plane to the rim of the housing as a reference for a sketch.

15:27 Then I switched to the reverse-engineering workspace, created the sketch, and drew the

15:32 missing wall with a little overlap. Next, I exited sketch mode and extruded it into the housing. But

15:39 of course, that doesn't give me a perfectly fitting replacement piece yet. So I switched

15:44 to the mesh workspace, where there's a tool called Trim to Scan. I actually call this virtual

15:50 kintsugi! Kintsugi is the traditional Japanese art of repairing broken ceramics, but we're doing it

15:57 with a 3D scanner and ScanRuler! When I enter this mode and select the wall I just created,

16:02 the tool typically finds the fracture surface automatically. I can also choose whether to

16:06 leave a small gap for glue or extra tolerance. Then I select “Trim to the Break,” and the tool

16:11 extends the fracture surface and trims my overlapping wall to match it. The result is

16:16 a perfectly fitting part I can 3D print and glue straight into place! Pretty impressive, isn't it?

16:23 But let's return to the reverse-engineering workspace. What we just did was useful, but

16:28 it wasn't really reverse engineering. Normally, reverse engineering means taking a highly detailed

16:34 3D-scan mesh and recreating the CAD model that could have been used to manufacture the original

16:40 part. And that's exactly what I built this workspace for. Let's start with a part from our

16:45 fridge that recently broke. First, I scanned it with the M1 Ultra in parallel-line mode. Compared

16:52 to cross-line mode, you scan closer to the part, but you can capture finer details. Again,

16:58 I needed to scan from two directions to capture every surface, but that only took a few minutes

17:03 on the scanning table. After merging and exporting the scan, you can see just how much detail the

17:09 laser scanner captured. The first step in reverse engineering is to align the part, because it's

17:15 usually scanned in an arbitrary orientation. The easiest method is the auto-align tool, which

17:20 detects the major surfaces and, in my experience, gets the orientation right about 95% of the time.

17:27 Then I created a section to guide the design. From there, it's much like any other CAD tool. Here I

17:31 created a sketch on the section, drew two rectangles, extruded them to the part's

17:35 dimensions, added a few fillets, and hollowed it out. There are also handy tools that let

17:42 you snap surfaces to the scan or suggest fillet radii based on the mesh underneath.

17:48 You get a full feature timeline, parametric dimensions, and even calculations inside

17:53 dimension fields—everything you'd expect from CAD software, but optimized for reverse engineering.

18:00 That's all nice, but with more complex parts, this process can quickly become tedious.

18:05 So one day I asked myself: if Claude can help build ScanRuler, couldn't it also use the tools

18:12 inside ScanRuler to reverse engineer parts by itself? That's when I implemented an MCP server,

18:19 which acts as an interface between an AI agent and the software. It works

18:24 with a wide range of LLMs, including local ones. The setup is documented on GitHub,

18:29 but the easiest way is to activate the server in ScanRuler's settings and then ask Claude or Codex

18:34 to connect to it. And in no time, the agent can then operate ScanRuler's tools for you.

18:40 My approach is very different to most what has been on the market before. You

18:44 were always able to convert a mesh into a BREP in CAD but that meant often converting

18:50 every triangle to a brep element. That might give you an editable mesh but not something

18:56 to really work with. Using my approach your AI Agent will have the tools with ScanRUler

19:03 to understand the intend of a part trying to filter out the individual design elements of

19:08 a component from a noisy scan to give you clean CAD geometry which is honestly a game changer!

19:17 Here's how I typically use it. I create a folder on my PC and copy the 3D scan into it. Then I ask

19:24 my AI agent to reverse engineer the part. So far, I've had the best results with Opus 5.5. I also

19:31 include a short description of the part and what's important to me. Generally, the more context you

19:37 provide, the better the result. ScanRuler includes guides to help the agent reverse

19:42 engineer parts efficiently. It typically examines the scan, aligns it, fits geometric features,

19:48 and creates sections. From there, it develops a plan for building the model. For simpler designs,

19:54 a run can take anywhere from a few minutes to an hour, and you can follow the process

19:59 in the ScanRuler window. When it's finished, the agent runs a deviation analysis and may flag any

20:05 problems. But most importantly, you get a fully editable CAD model of your part. You can export

20:12 it as a STEP file to continue working in another CAD tool, or refine it directly in ScanRuler.

20:18 But one of the most powerful features might be something you don't notice right away:

20:23 the notes tool. It lets you attach notes directly to your part and communicate with the agent. So

20:29 if you don't like how it created a feature, just add a note and ask it to change it. You

20:34 can do this before, during, or after a run. For example, my fridge bracket has a broken

20:40 connection on the inside that I want the agent to repair. So I simply add a note asking it to

20:46 recreate that connecting bridge. About a minute later, I have not only a reverse-engineered CAD

20:51 model but one where Claude has also repaired the broken feature, ready for 3D printing!

20:56 And this doesn't just work with the simplest parts. I have another fridge holder that broke,

21:01 and I promised my aunt a year ago that I'd fix it. But I never got around to reverse engineering

21:07 it to make a replacement. Now I can simply ask Claude to reverse engineer the part and fix the

21:13 broken section at the top. The more information I give it, the better it performs. Pointing out

21:18 exactly where the fracture surfaces are helps it create a much better replacement part.

21:23 And the possibilities don't stop there! For example, I had ScanRuler and Claude reverse

21:28 engineer my bike computer. The agent struggled a little with the geometry along the way,

21:34 and it took some back-and-forth to get this result. But from there,

21:38 I simply asked it to design a 3D-printable protective sleeve that I could make from TPU,

21:44 including the necessary cutouts. And this is what I got! Somehow,

21:47 it figured out how to do it with the tools available, and the printed sleeve fits perfectly!

21:53 I also want to be completely open about the limitations: the tool isn't perfect. With

21:58 more complex parts, freeform surfaces, or very rough castings, the results often aren't great.

22:04 That's partly due to ScanRuler's limitations and partly due to the AI agent itself. I've

22:10 had the best results with Opus 5.5 so far. Less capable models sometimes do a terrible job. I also

22:17 tried a few local models, but with my limited hardware, the results were pretty poor. Still,

22:22 I expect things to improve—and hopefully get cheaper—over time. I'd also love to hear your

22:28 feedback. Since ScanRuler is open source, you're welcome to contribute to the project yourself!

22:34 Every ScanRuler workspace can be controlled by an agent. So AI isn't limited to reverse engineering;

22:40 you can also use it for a complete 3D-scan analysis. Remember the ball bars from the

22:45 beginning? I simply put all the scans into a folder and asked Claude to analyze them and create

22:50 a full report. That's pretty neat, and it saves me from having to do all that repetitive work myself.

22:57 There are so many more things you can do with this tool, and I'd love to see what you come

23:01 up with. Just to be clear, connecting an agent is completely optional and you can use the complete

23:07 tool obviously without it for every task as well. It's only a demonstration how this novel approach

23:13 could potentially automate many tasks that you previously didn’t have the time or the skill for.

23:20 I hope I've shown you how software like ScanRuler

23:23 is making 3D scanning more and more powerful. It's turning something that

23:27 used to be a nice tech demo—or required expensive professional software—into a

23:32 practical way to solve real problems in your workshop, hobby, or small business.

23:38 I've also had a really good time with the Elegoo M1 Ultra. Its three laser

23:42 modes make it versatile for a wide range of applications,

23:46 and it lets you scan parts that previously needed painstaking preparation with scanning spray. The

23:52 structured light mode is a great addition if you especially want to scan people or large

23:57 objects! The swappable batteries and wireless operation also make it really convenient,

24:03 especially away from your desk. At $1,599 during the early-bird sale, it's definitely not the

24:09 cheapest scanner on the market. But compared with alternatives from Creality, Revopoint, or Einstar,

24:15 I think the M1 Ultra offers a lot for the money. You'll find a link with more information and where

24:20 to get the M1 Ultra in the description. Thanks again to Elegoo for sponsoring this video!

@tomulinek This is the BEST 3D free project for years. 👏👏👏 Stephan killed it. 6 likes

@JeffBradway Really cool stuff. I bet you could have a AI agent reverse engineer using Scan Ruler then once youre happy with it, ask the agent to build the part natively in FreeCAD using the same feature structure. 2 likes