I am originally a Fusion 360 user but would like to do some animations in Blender. When I design in Fusion, I assign dimensions to everything, and then when I overwrite a dimension, it all gets recalculated. How do you design something more complex in Blender? It seems to me that it is all terribly far-fetched. For example, what if I’m designing a spaceship that has a lot of screws and I suddenly realize that they all have to look different? Or how do you design some technical things exactly according to the blueprint? And what if you decide to change something? How is it done and what if it would be too complicated because I did it a long time ago? I know that all these things have to be dealt with somehow, because people do incredible things in it, but how is it dealt with?
Yes Blender is a bit different in this sense.
The best way to tackle this is to use instances. This will also run faster. Instances share the geometry data so editing one will change all but you can change the location, rotation and scale of instances separately.
There are different ways to make instances, the most simple is to copy the object with Alt D. Shift D makes a unique new object Alt D makes a linked copy that shares the geometry data.
You can also instance on vertices or faces of an object by parenting the “skrew” to the surface object and using the instance options in the surface object. (Properties panel - object properties - instancing)
The most powerful way to instance is with geometry nodes, there is a learning curve but the possibilities become endless.
If you have already made all the skrews and want to link their geometry data (turn them into instances) in object mode select all the skrews, make sure one of them is active (bright orange, shift left click on one of them should make it active) in the object menu-Link/TransfereData-Link object data.
Instancing is a pretty long subject so I suggest you search a tutorial about it.
As for using Measurements and blue prints there are many tuts that explain that, search Blender using measurements. You can add blueprints as reference images in the add menu- add Image- reference, you then have to scale the reference image accordingly.
There are also some free addons that will help you, for example Measureit.
Again it can be a long subject so it is difficult to give you a short answer.
Each tool has it’s own strength and weaknesses, and flexible, parametric design is one of blender’s weaknesses, compared to fusion360.
as @DNorman said, instancing can help with a lot of it, but it’s going to be a different workflow than you would have with fusion.
Start with blocking out the overall shape, then start iteratively adding in details. if you find repeated modules in your design, make sure those are instances, so any changes you make to the model propagate between all the instances.
You can build instanced objects into collections that can be instanced for bigger assemblies. for example, you could have fastener hardware as an instanced object used 100x in a bulkhead module, then instance that bulkhead collection 100x as needed. now if you change your mind about the hardware, you can change it once, instead of 10,000 times.
Also, it might be worth looking into geometry nodes for more procedural modeling. if you have a rivet seam on a panel and you want rivets every 4 inches instead of every 6 inches, that’s fairly easy to setup and change in geonodes. of course this can also be integrated into your instanced collections.
If you instanced mesh datablock, you just have to refer to another mesh datablock.
Images can be displayed in Viewport as 3D objects to be used as references.
Or you can import curves as basis of model.
Whatever it is, you can change it.
That depends of what is changed.
That is not time that determines complexity of a change.
That is the way used to create something.
- If you do things in Edit mode, history of operations will be lost. To make a change later, you will have to correct actual state of mesh with operators available. Operators can do some operations. But often, they can also undo them. The issue is that after complicating geometry, you may need to make more complex selections or repetitive steps to undo an old action. That is why incremental saving can allow you to restart from a previous step, if that is easier.
- If you do things with modifiers or geometry nodes, you keep all states of process.
You can make one change at early state of process, at any time. But your mind has to be able to understand the whole process of modeling, instead of just model displayed in 3D Viewport. That is parametric. But that may be unintuitive.
And if you are interested in Blender for its animation abilities, that does not mean that you have to abandon Fusion 360.
You can import your Fusion 360 models in Blender and rig and animate them, with its tools dedicated to animation.
Modeling tools is a set of tools, mostly, not involved in animation.
Their use to animate depends of what is expected to be animated.
I think zeauro has made an important point. You can definitely use 360 and Blender together. I use Inventor and Blender all the time and it works great.
I use Inventor because for complex mechanical systems there is no comparison, that’s what it’s for. Blender modeling is not specifically geared toward mechanical systems. It can be done but it’s not nearly as efficient in that area. Polygon vs solid parametric modeling are two very different things.
When finished modeling I use the .step converter addon to import to Blender. If you don’t have that you can easily use .stl format. The .step import is just a bit more efficient.
This is not without drawbacks of course as if you need to make significant changes to the model at a later stage, it can be time consuming to re-export and re-do work done in Blender.
Overall this system works very well for me.
My dream is that Blender will someday take on the CAD market too and integrate solid parametric modeling 
Thanks for all the replies, this might work somehow. But I have one more question. I was under the impression that designing things in Blender was much faster than in Fusion 360. Is that true?
Maybe this can help
I’ve used both extensively for a long time so I’ll try to answer.
Depends entirely on what those “things” are. If it’s mechanical systems (unless they are highly stylized instead of realistic) then absolutely no. If it’s characters, environments, vegetation, organic things of any sort, then absolutely yes.
In short, Blender (polygon modeling in general) is far less structured and thus far more flexible. This is both good and bad depending on the situation. For example, you can bend and stretch and otherwise deform things in Blender to extreme with ease. But just try placing a few hundred holes where they belong and a few hundred bolts, washers, nuts and keep things to real dimensions then constrain everything properly. Not easy in comparison. On the other hand, try making a character with hair in a solid modeler. Not really possible or at least practical.
A couple areas that may be subjective are architectural and smooth curved surfaces such as automotive and various products where they may be somewhat comparable (both having strengths and weaknesses) using different methods.
Definitely use whatever tool is strongest for the output. I’m working on a large project using thousands of blueprints. Asset library for hardware/fasteners, Curve objects where possible for flexibility, CAD where it makes sense (then import into Blender).
This was done in CAD because it was needed for manufacturing (3D printed). I also need it in my Blender scene. Imported STEP file, reduced poly count, and removed polys which wouldn’t be needed for rendering.