Can FOSS CAD compete? Trying out Ondsel (improved FreeCAD)

I prefer to use free and open source options when I can, but when it comes to CAD I use the free but proprietary Onshape. I’ve previously tried but didn’t enjoy FreeCAD, but now we have Ondsel, an improved version that fixes problems and addresses community requests.

In this video, I compare Ondsel to FreeCAD, Onshape and even Fusion360 (this is the most I’ve ever used it). Trying to separate frustrations from being unfamiliar, I make a list of what works well, what is limited, and what still needs to be improved.

I really despise pointing out flaws in something free and open source, but I’ve tried to do so constructively, providing specific examples where these limitations are a problem. I’m sure some FreeCAd advocates will be upset over my conclusion, but the way it and Ondsel approach 3D modelling is quite different from Onshape/Fusion360/Inventor/Solidworks/SolidEdge/etc. They have converged on an intuitive and logical approach. FreeCAD/Ondsel deviates from this, but is it an improvement or hindrance?

Thanks to my patrons Derek and Novaplusplus for their assistance in making this video.

0:00 Introduction

0:47 Ondsel

1:44 Download and installation

2:02 Simple reference shape in Onshape

2:42 Comparison in Ondsel, FreeCAD and Fusion360

5:59 Temporary inconveniences vs actual limitations

6:45 Missing constraints and editing sketches

7:40 Only one shape/feature per sketch

10:38 Manual management of bodies

11:51 No timeline

12:56 Topological naming problem

13:30 The value of open source vs productivity

14:20 Ondsel improvements over FreeCAD

14:49 Ondsel wishlist

15:59 Conclusion

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[TeachingTech]

A considered response to some comments on my Ondsel/FreeCAD video.


I consider this video to be well communicated, fair and honest. Workflows of an experienced user are shown and hard limitations are acknowledged. I thank 4 Axis Printing for making it and I will reference it below.

Firstly, a misconception about my video: I did not do any research when using FreeCAD/Ondsel. As mentioned in the video, I did in fact spend a lot of time looking up things I was frustrated by. I spent time on the wiki trying to understand the different workbenches and why you even need them, and for each individual limitation I identified I went through the forums to double check the feature was actually missing. Whenever I am making a video portraying something in a negative way, I try to be very diligent in making sure the problem is real and also exists for others.

I reject the idea that my criticisms were solely related to my inexperience. Let’s address the specific limitations I identified in my video.

1. No midpoint constraint. A lot of people said I should use a symmetric constraint. The symmetric constraint exists in other CAD packages and can be used in the same way. Doing so is a workaround. My workaround was to use two construction lines, coincident with the geometry I wanted to be centred, and set them to equal. You can get the job done with either of these methods, but the fact remains that a midpoint constraint does not exist and workflow would be easier and more efficient with it. Please see the video I’ve posted at the bottom. Can anyone honestly say FreeCAD/Ondsel would not be improved by adding a proper midpoint snapping/constraint?

2. One shape/feature per sketch. I have yet to see anyone dispute this. In my opinion it is the biggest drawback to FreeCAD/Ondsel. 4 Axis Printing demonstrates a workaround for this (similar to mine but with more skill) but it is clear how much more involved the process is. Modelling the second example is a trivial job in Onshape and other proprietary CAD packages. It is simple and intuitive. In FreeCAD, an experienced user has to jump through multiple hoops to achieve the same thing, but with the risk of parts breaking with future edits. I was also frustrated by many commenting that I needed to use the external geometry tool when this was clearly demonstrated in the video! My gripe with this approach is that the referenced portions are magenta, and not able to be used for pads/extrusions. Therefore, you have to draw what you want again and use constraints to match the externally referenced components. More clicks, more time, needlessly in my opinion.

3. Manual management of bodies. Again, this one didn’t really receive much attention in the comments. Yes, you can handle it yourself, but you don’t have to in almost any other CAD option. More clicks, more time, more complication.

4. No timeline. In my video I said that the Ondsel/FreeCAD tree view was not strictly in chronological order because some items were nested. That is still correct. I did search for timeline functionality for FreeCAD, but came up empty. Forum posts said it was missing. Commenters, however, pointed out that you can right click and use ‘set tip’ in FreeCAD. Not only did I not come across this when searching, but it is only present if you have the ‘Part Design’ workbench selected, not the ‘Part’ workbench. That one is on me, but in my defence the implementation is counterintuitive and obscure. The visual slider found in other options is easier to use and understand.

5. Topological naming problem. This is an acknowledged problem for which I showed the wiki article. I’m glad to hear fixes to the underlying architecture are in the works.

Besides the ‘set tip’ workflow, I stand by all of my criticism of Ondsel/FreeCAD communicated in the video. If you still disagree, please consider two specific questions:

1. All of the industry standard CAD programs conform to an ‘industry standard’ workflow. FreeCAD/Ondsel is different, but is that better?

In my opinion, the other options have converged on this workflow because it is the best one. That is why it is easy to switch between them with only temporary inconveniences. As explained in the video, that is the most I’ve ever used Fusion 360, but it was simple to pick up and create what I wanted. Ondsel and FreeCAD were the opposite. So where is the advantage in how FreeCAD/Ondsel modelling is approached? How will the user accomplish more, or do so in a more intuitive and efficient way? I see in 4 Axis Printing’s video that workarounds are possible, but the process takes longer and is more complex. Why choose this alternate path if the end result is diminished? Why do the Ondsel or the Realthunder variations exist if vanilla FreeCAD has no problems?

Consider this situation in a different way. If a 3D printer was launched that required the user to jump through hoops, read manuals and tinker a lot, but didn’t print any better than other options on the market, it would be rightly criticised for being inferior. When people were frustrated, no one would say it was a skill issue, they would expect the product to improve.

2. Why is FreeCAD/Ondsel not so much more popular?

Although not a dealbreaker for me, I acknowledge the legitimate concerns many people have about Onshape and Fusion360 being tied to the cloud, and the risk of them removing features without notice in future. This should mean that a CAD option that is 100% free and can run 100% locally should be the easy winner, but in reality it is not. Some commenters were upset by the video, but there were just as many who shared my conclusion. The like ratio for the video is still above 96%, so I am confident that my opinion on the state of Ondsel/FreeCAD is not an anomaly. It is also shared by my fellow Youtubers in Angus Deveson and Tom Sanladerer.

Could the reason that the free and open source option is not popular is because it is simply not as good? That users are expected to jump through extra hoops, read wikis and troubleshoot cryptic errors, whereas in other options, you just design and model stuff? That it is so frustrating and limited that the vast majority of people will seek other solutions, if they are tied to corporate entities.

I expect and accept others won’t always have the same view as me, but I would hope they do so constructively and fairly. There were too many commenters who clearly didn’t watch the video, or were disingenuous in their responses. Some people were commenting the same thing repeatedly to try and flood the comment section. Others acted as if the symmetric constraint workaround negated everything else I said. When I was reading through the FreeCAD forums, as I mentioned in the video, it was not uncommon to find responses to reasonable questions like ‘read the manual’, or ‘it’s open source so make whatever changes you like yourself’. A less than welcoming community might be another reason the free options are not more popular. Not to say there aren’t generous and talented people in these communities. The trouble is the bad ambassadors tend to leave a stronger impression.


I tried to keep the same pacing: efficient, no unnecessary pauses, but not rushing and still with some commentary. What takes 70 seconds in Onshape takes three and a half minutes in FreeCAD (6:00 to 9:30), with many extra little steps and gotchas. Even if we ignore the time taken, watch each video and make a list of the steps required. Ask yourself how the final model, or the user experience is improved by all of the extra steps and nuances. Now imagine an inexperienced user who doesn’t know those workarounds. Then consider this is just a very simple part, with only one body. The differences and nuances will only be exaggerated from here.

One more thing to consider: my background and perspective. I have been using CAD for over twenty years, from back when I started studying Industrial Design at University in 2001, using Solidworks. I also spent eleven years as a primary and secondary school teacher, and at each school one of my jobs was to implement 3D modelling into the curriculum. Therefore, I have spent a lot of time over the years testing and evaluating free CAD options, as well as seeing how easily they were picked up by students and my fellow teachers. Judging through that lens, Ondsel/FreeCAD would be a long way down the preference list when selecting CAD to teach in a school. Teachers and students want to spend their precious time working creatively and actually designing their ideas, not searching for workarounds to obscure and counter intuitive software. I think it’s pretty clear that the average hobbyist feels the same way.

To repeat what I said in the video, when FreeCAD/Ondsel is developed a lot more to the point where it can compete, I will gladly throw my weight behind it and promote it on the channel. I applaud the commitment and effort of the developers, and I hope in time an outcome is achieved that is satisfactory for all.

[Ondsel]

Hi Michael, thanks a lot, this is really useful feedback! Most complaints you have are perfectly valid and many are on the TODO list. Some are easier to implement, some are inherited deeply ingrained design decisions, and we need to tread carefully there (e.g. one shape/feature per sketch). The toponaming issue is being actively worked on, you will likely see real results around late spring.

A few quick notes. The same Tasks panel on the right where you start a sketch from scratch has commands specific for a selected object or geometry. For example, when you select a face, the topmost option is to start a sketch from it. That's a major workflow notion in FreeCAD and Ondsel ES.

We already implemented the quick measure feature a few weeks back, it's coming in the next release.

Thanks again :)

[dana]

I was at the FreeCAD conference at FOSDEM 2024, seems like they're finally adressing the topo naming issue, hope that'll be fixed soon.
I wish great luck to all FreeCAD and Ondsel contributors.

[ydoucare]

FreeCAD is what you get when software is designed from the inside out instead of the outside in. This is something Steve Jobs figured out very early. Determine what the ideal user experience should be, then build the software under that. FreeCAD is what happens when you build the functions first and the interface last, which is why we have a wall of buttons and the interface is constrained by the logical structure of the underlying software. Ondsel looks like it's making an effort to improve that and I hope they continue to make progress. It certainly looks promising.

[Inventorsquare]

I’ve used FreeCAD for so long that I’ve grown so proficient around it’s flaws that I prefer it to my recent introduction to Solidworks lol. Eventually that might change as I alter the settings and set up all the key bindings, but I’ll be cheering for the free program all the way.

[valeriyproklov]

This is pretty much a documentary of my experience with Ondsel. Watched the announcement video the day it came out, downloaded the zipped file, eventually found the executable, got frustrated at the lack of a midpoint constraint, worked around that by using two construction lines with equal lengths, tried extruding (took a while to find "pad") and failed because of the selection issues you mentioned. I gave up immediately after that. You clearly have more patience.

I also really hope that the Ondsel team manages to sand down all of the many remaining rough edges. In the meantime, an interesting use case is importing STEP files from other programs and using Ondsel for free FEA. Haven't tried it myself though.

The Ondsel team is doing great work, for free, for everyone. That should recieve a standing ovation together with constructive criticism that will help Ondsel improve. I hope one day this turns into and open project like blender but for parametric CAD.

[MarkFraserWeather]

Mid-point is done using the symmetry tool and you can use external geometry to refer to the previous shape.

[FowlerAskew]

I've got to say that your experience with FreeCAD is not too dissimilar from mine, although I've powered through and continued using it as my main CAD tool, thanks in large part to MangoJelly.

While there are some points where the limitations you've found do actually have solutions, I see an attitude in some of these comments that I find a lot on freecad forum posts, which is that because there is *an* existing workflow to do something, it does not warrant improvement or streamlining.
I run into this the most with constraints, where having a built-in constraint for something like bisecting an angle would be very useful, but instead you have to build a bunch of construction geometry to get what you want.

There are also a lot of operations where FreeCAD just falls on its face and errors out, where other CAD packages have enough error handling or edge case awareness to do things like add fillets or chamfers in places without perfect geometry.

[macrumpton]

Listening to this brings to mind a quote from Martin LeBlanc: "A user interface is like a joke, if you need to explain it it's not that good".

[neclimdul]

As a regular freecad user this was really interesting.

First, for midpoint you probably wanted the symmetry constraint. I didn't know there was a midpoint constraint which is probably why I struggled finding the symmetry constraint in onshape.

Second, the multiple geometry in a sketch problem is easily solved with exports. Selection could be easier like what you showed but finding the feature was a game changer for me.

Third, using points as external geometries has saved me a lot of headaches. Lines are frustrating unless you want to make something coincident, perpendicular, or parallel. If you want to match, the points make more sense because the points are what's actually the constraint you want to match.

These hurdles are probably because they're a different approach to the problem which you wouldn't know to look for based on you experience and knowledge in other platforms.

Conversely for me looking back, I find the timeline feature in fusion and onshape infuriating. I often get so fed up I just delete everything and start from scratch. The topology approach definitely is frustrating for filets and drawing off existing faces(use datum planes, your life will be easier) but it's much easier for building parts in my opinion. Stacking Legos just makes more sense to me.

For what it's worth, if you read the topology thing you're probably aware, but the "topology problem" is actually tied to how edges and faces are defined internally. They get incremental numbered IDs. Drawing off faces will actually run into the same problem which is why datum planes are so important. If freecad used a timeline it would currently run into the same problem because the names would change as things changed earlier in the timeline.

There are several forks trying to address this and they definitely improve it but its still a big problem and you do have to make sure you have to do a couple things like using datum planes, external geometry, and applying filets at the very end, etc.

Anyways, looking forward to trying this new fork! Exciting to see an open source alternative gaining traction and getting some much needed improvements.

[BloodyMobile]

FreeCAD definitely has a rough time prepared for beginners. I probably only got into it at all because I eventually managed to get into Blender too.
Which back then was just as obscure and needed tons of tutorials for some of the most basic things.
But with Ondsel alongside to FreeCAD now, I'm fairly confident that just like with Blender, it'll get there 🎉

[hyperspeed]

4:28 FreeCAD has you import existing geometry into your sketch rather than it already being available to constrain to. The button with the cube and the line offset from it, about the middle of the screen in the bottom row of the toolbar, is the tool you use to import existing geometry into a sketch

Edit: looks like he figured this out by 9:19

[theshazman]

Because of you and your awesome videos I learned OnShape. Nowhere near a professional but I'm able to create most of what I envision. Looking forward to learning more about Ondsel as a free alternative! Thanks for making these videos.

[Lulzigi]

I've been learning the realthunder branch on FreeCAD for a few months now because it fixes the typologic naming problem, but it's still rough. That's my biggest barrier for entry, personally.

[amadensor]

Center constant is definitely a thing. I use it often, but it's called symmetry

[amadensor]

To make the other sketch able to be constrained to the previous face in FreeCAD, pull up the grometry into the current sketch using the plunger looking tool.

[DracoMhuuh]

Two sizable comments on your workflow. You can add a midpoint by adding a point and constraining it to the line as well as symmetry constraining it between the ends of the line. It might be nice to have a button that does that for you but it's possible. Furthermore the spreadsheet is a really powerful feature you can use to dimension different things using only one instance so that when it changes everything goes along. Also or alternatively the external geometry tool should've allowed you to select a feature from the object and then you can use coincidence constraints

[MarkFraserWeather]

As a Linux user, FreeCAD is my only real choice as I don't want to to use a website to create 3D models. I've been using it for over a year now and it has improved over that time. I'm currently using the 0.22 dev version and that also has the assembly WB.
Since October last year I've started a new job which requires me to use CATIA v5 and I think that having some knowledge of CAD via FreeCAD has really helped me learn some of the tools.

[m_IDEX]

Thanks for the video. I am rooting for FreeCAD and Ondsel. Hope they catch up to modern 3D CAD quickly.

[Mitchwich.]

Ondsel is really doing great things to improve FreeCAD. Glad they are getting the coverage they deserve!