Precision Modeling in Blender? | You Decide, Blender vs CAD | Precision Modeling | Blender | Fusion 

youre welcome!

In Fusion you can also show the sketches and dimensions so you don't have to edit them to make changes which is super nice when laying out part.

construction lines addon for blender is slowly getting there.. i'm at the point now im able to use it for making useful tools and things to 3d print. Making screws, and threads even seem to be pretty accurate now.

​@@miked5487great to know this. Any tips on who to watch? Maker tales seems to have moved on too far.

on the far right of the toolbar you should see a selection drop down. By default the selections should be set to "Through" but yours may be turned off. so go to "Select > Selection Filters > Select Through" not that the selection filters change so if you are in a sketch and set it, that is different than in a design.

for parts like this I 100% agree with you.

Nah, doesn't need to be paid, not for all of it. CAD Sketcher is a free adon for instance.

Very True, I did start the video by saying I don't do hard modeling in Blender :) Several people had asked me how to do it so I took the time to model it as you would in cad. "sketch" the shape" Extrude(Solidify) to a solid, Bevel the edges. I did speed through the Fusion part because in large my audience is more advanced Fusion users who are venturing into Blender. It wasn't meant to skew the results so oops. This could be done with modifiers like Boolean but honestly in both methods I don't really like the downstream effect of modifiers. There are the add ons like CAD Sketcher that sort of fills in the gaps between the process for you. At the end of the day for me it just doesn't make sense to do precision modeling in a poly program. I need precision that means the part is getting machined or has some down stream use. Shared mesh is a neat workflow to sync up the holes! I can't think of a way you could easily change the distance between the holes. Sure you could stretch but if you wanted to move them to say 400mm you would have to edit the mesh, select all the verts or edges on one side and move them by 100mm in the Y direction(or whatever it was). I appreciate the comment and I am curious if you would choose to use Blender for something like this? If this was an artifact for a game or render and it was a simple part like this maybe. But if there was more of a lattice structure or more dimensions to it would it make more sense in CAD? Also have you used CAD Sketcher? Several people want me to make a video on it but i just haven't had the time yet.

@@LearnEverythingAboutDesign Shared mesh is usually used in a way in which you make a shape (in Edit mode) and then manipulate it (Translation, Rotation, Scaling) in Object mode. So that way you would have 2 copies of one shared mesh, which you could move around (as separate objects) freely. What AFAIK is not possible is to tell Blender to keep them at specific spacing. You would have to move them manually - but in Object mode, no mesh editing neccessary. I do modeling for 3D printing. Not at a pro level, but far from amateur. And yes... up until now I did it in Blender. I was deciding between Fusion and Blender and I was pulled to Blender size for the following reasons: 1) I like "open source" community stuff. Blender is full featured and for free. 2) I like ergonomy - Blender is fully customizable. In Fusion 360 I couldn't even take advantage of my 14 button mouse. I had to Pan and Rotate by using CTRL(+SHIFT)+MidMouse... I am sorry, but that is lame. In Blender, I can fully navigate the world (and more) just by using my mouse. 3) When I first opened a few projects in Fusion and Blender - Blender was just faster. It was a bit unfortunate, that the project I opened in Fusion was quite bit, so Fusion was at a disadvantage, but still... Blender is snapier. So yes... I did a lot of designing in Blender and it can be done. I hear a lot of people say, you cannot do precision modeling in Blender. I think that is incorrect wording. You can do precision in Blender just fine. What you cannot do is parametric and non-destructive. You can... up to some point... but for more complex engineering it is not enough. It can easily be demonstrated on: 1) the egde beveling, where you can tweak it retrospectively in Fusion or when you ask Fusion to keep certain distance between objects. 2) Fusion also can "recognize" 2D drawings... what do I mean by that... if you draw 2 separate 2D shapes that intersect, Fusion will offer you to extrude the intersection. Blender does not recognize that. You would be able to extrude the original shapes, but if you would like to extrude the intersection, you would have to do more work first. 3) Making a slot for a pin. In Blender, you have to have one object for a pin and second object for the slot (you can use a shared mesh for the shape and scale the slot to 1.05 of the pin object to make it easier). But if I understood correctly, in Fusion you just have the screw "object" and set the tolerance as a parameter. I would call it creature comforts. It is possible to achieve it in Blender, but it is more convenient and flexible in Fusion. For my next project I will be trying Fusion, since it will be a bit more complex from the engineering side and I am quite sure it will be easier than in Blender. I have to setup AutoHotKey scripts to work around the lack of control customizations though (Pan and Rotate using mouse etc.)

@@radeklukas Thanks for the detailed reply. Years ago I used to use 3d mouse and customize my UI but now i leave most programs default. Easier to teach. I have heard the complaint about Fusions lack of customizations for navigation. I don't mind it again because i don't customize but I totally understand. I think the term Precision can be misleading. For me 3d printing is usually a midstep to a design. You won't be cutting a mold for plastic parts from a mesh so modeling in Blender just isn't an option. I mean yes you could make toolpaths off an STL mesh but having a true surface is much better. When i think of precision modeling I do equate that with parametric modeling. Designing parts to fit together with specific tolerances. certain draft on walls etc. In Fusion for example with the Pin/Slot example you can create a parameter that is the diameter of the pin, then another that is the pinDia + .05 or something like that. Or Draft = 3 so when you make a design in the dimension dialog you simply enter Draft and you can change every feature in one place. There are features like Hole that let you make counter bore, sunk, tapped holes easily. If Fusion isn't your jam there are others. FreeCad i think is open source. You might like to try Plasticity which is setup very much like blender but you are working with NURBS/BREP rather than mesh. It lacks the dimension input like a CAD program has but a lot or artists like it. I think the big thing here is that poly modeling and cad modeling are just different approaches. Poly modelers HATE the CAD workflow of making sketches for some reason. Programs like Solid Edge have a direct modeling approach that is sort of a hybrid(but i don't like it), Fusions direct modeling when you turn off history doesn't really change the workflow. Plasticity is really the closest Ive come across that sits in the middle. If it had precision inputs(which it might before its for sale) I think it would go a long way. There is also Shapr3d, Moi, Rhino and so on. Vary in price between those 3 with different license structures. But yeah at the end of the day if Blender does what you need it to that is great! I love Blender and wish i could play with it more. It just doesn't work for what I do since I need precision and flexibility on complex designs, the ability to do fea, make drawings and create physical parts for machining, molding, create toolpaths etc. Starting with a poly model is a death sentence there :)

@@LearnEverythingAboutDesign Yup... agreed. I am looking forward to trying Fusion with proper controls finally. And I guess I will make a move towards that. I am gonna go watch more from you CAD vs Blender series though 🙂. Happy designing!

@@radeklukas Keep in mind i still think of myself as very much a blender Newbie, so it probably isn't worth your time :) but don't hesitate to ask questions. And I would suggest you take a look at Plasticity if Fusion doesn't fit with you. I think its a few months out from release so you can still get in and give it a shot for free. It has surfaces now. I haven't covered it in a while as I have been too busy.

I agree with everything you said. I had a lot of requests to make this video even though I linked users to other videos where people use CAD sketcher. This is also why I started to cover plasticity. I did a video that never released on low vs high poly assets into Unity but I am in the CAD side of the spectrum so left that one out :)

I also agree completely. I can see the advantages of a parametric modeler such as Fusion or FreeCAD for certain types of models especially machine parts type models, and Blender being advantageous with other types of models. I tend to go to Blender just because I'm very used to modeling with it from years of making game & flight simulation content.

Yeah, this specific video was to answer a user question about modeling it with blender tools. The video is a bit old. CAD sketcher is a step forward but its still not a BREP model like you get from Fusion, Plasticity etc. Honestly the best workflow is Plasticity with the Blender Bridge. Live updates but modeling with CAD tools on BREP geometry and you have control over how it gets converted to a mesh rather than having to worry about edge loops or a mod stack full of booleans. At least for me. I know a lot of people love CAD sketcher. I avoid hard surface modeling in Blender :)

I think the core of it for me is that in CAD you have a bit more control over the geometry. You work with BREP or NURBS bodies until you convert it to a mesh for 3d printing (or now a days most slicers will take in a STEP file and let you do things like G2/G3 true arc movements for holes). While in blender, even with CAD sketcher, you are still working directly on the mesh. For me being able to tweak some dimensions to control say tolerance or gap between parts rather than scaling faces if 2 printed parts don't fit is much better. BUT, if you prefer the blender workflow and especially if you say need to sub-divide your model and do some sculpting, then do it all in Blender. For me if i need to control dimensions/parameters, its easier in CAD. If i want to deal with mechanical motion, easier in cad than rigging in blender, If i want to do any simulation or CNC machining, It has to stay in CAD. Most simulation software packages won't let you bring in a mesh file, it has to create its own mesh of the solid and they are not the same thing.

@@LearnEverythingAboutDesign wow, I see. They both have different purposes. I agree with you, there is difference between mathematical mesh and mesh made of vertex and edges. But in my case I'm a programer more than a designer. Learning so much softwares will take a lot of time. So I thought to go on with Blender (since I used it a lot). btw, Thank-you for your quick reply, I didn't expected it. You explained it very well All the best for your clannel.

I made this video at the request of users to see how to model a part in Blender. I wouldn't use blender for this sort of thing. I would use Fusion 360 or Plasticity where an Arc is an Arc. No matter how many times you subDiv a model it still is a bunch of tiny lines to get close. If the goal is render/animate or possibly even 3d print, that is fine as the object turns into a mesh anyways. But in Fusion 360 for example I could take that part and create Gcode to 3d print it with true arc movements off the CAD geometry vs a mesh out of Blender which will always be tesselated.

@@LearnEverythingAboutDesign No. You're referring to the old recursive subsurf algorithms. Modern OpenSubdiv uses the mathematical limit surface that is just as infinitely smooth as your CAD meshes. What you are teaching is outdated by many years. Just make sure your 3d printing or CNC software uses the same library.

@@MadMinstrel Do you have any papers or references I can read? If I am sharing bad info I want to correct it and learn in the process. How I understand it is that OpenSubDiv is just an improvement on Catmull-clark for performance. Nothing to do with surface accuracy of the underlying geometry. Its about using gpu/cpu to process the display faster to make use or more current tech. Pixar developed this so they could avoid characters touching other objects from going through them. Like hand through a glass. To the best of my knowledge the difference in open subDiv is that is uses precomputed tables for the subDiv locations of each face, edge and vert. These are all computed on the backend. If the subdiv is uniform, it uses catmull-clark directly. If you do an adaptive subdiv it still uses CC for the CVs for each cubic patch but then is tessellated differently, probably based on facet angle or something. At the core NURBS surfaces are more precise and better for "hard edge" modeling. SubD is great for complex freeform shapes. NURBS - points connected by curves. Polygon - thousands of small triangles or quads. Blender does have curves and surfaces, but that isn't the poly workflow we are talking about here and as I understand it they need to be converted to mesh to work with them, unlike Forms in Fusion which is a subD workflow that gets converted to a NURBS. Blender is the other way around with a curves/surface workflow that is converted to a mesh. For display purposes I don't see any difference between a smooth shaded subDiv mesh, but I am specifically talking about things like getting a true arc for a 3d printer or cnc machines G2/G3 movements. You can't get that off a model that comes out of Blender, but you can off of something modeled in a CAD program. Is that not correct?

Yeah there are a few of them to make the workflow more like CAD. Cad sketcher for one. The best option is actually (in my opinion) Plasticity. It has a blender bridge live connection. The geometry you create is true BREP solid and the live link lets you convert it while maintaining a link so model changes in Plasticity update in Blender.

Yeah the model is simple but to highlight some of the basic differences when trying that approach in Blender and Fusion. A more complex model just means more time to show the concept. Fusion does have a weird quirk of not retaining the Move/Copy distances BUT if all your bodies are in their own component then capturing the position will allow you to revert it. I don't typically model by transforming things. I generally use the Align tool when moving things to be planar if needed or use move/copy temporarily if i am working with bodies.

@@LearnEverythingAboutDesign I think that might be the difference between the two use cases. If you're fortunate enough to only model designs which have already been tested and validated, then use the legacy tools that are designed to fit into that space in the production pipeline. If, on the other hand, you have to make rapid ad hoc corrections to assembly positions after testing, and you want a record of those changes or to parameterize them, then Fusion doesn't quite satisfy.

@@LearnEverythingAboutDesign Fusion also doesn't have assembly-wide parameters. Each sub-assembly has its own parameter sheet. I don't think you can even export the parameter sheet as a CSV or anything

@@TreeLuvBurdpu The parameters should be design wide. Do you mean if you insert an external design into a new design? If you have an externally linked design the only time those parameters are exposed is during edit in place. If you have assemblies/sub assemblies in a design that don't have Xrefs, all of the parameters are available all the time. They are broken down by User parameters/ Favorites and then organized by components just like the browser. These also will be moved up to the top level if you break the link of an Xref component. If you derive a body/component out of a design and it has associated parameters you can also bring them along with it. You can create parameters to drive rotations and movements of bodies/components. Unfortunately move/copy is captured for a body and if you edit it, the values are all empty. even if you link a parameter. Its a problem for sure. I don't model parts that are tested/validated. Everything is new designs. I have run into tolerance and clearance issues that require me to move/rotate designs and validate/edit. Recently I had an issue for clearance that was supposed to have a positive stop at 3.5deg rotation from a pivot point that was 1.2mm in space from a reference. To do the adjustments I made a copy of the body and rotated it based on the theoretical pivot. Then rolled the timeline back, edited the geometry and rolled forward. The move/copy with the copied body had all the updates and that is how i validated it through section views and intersection tools. Trust me i know it isn't ideal for sure. But surely blender can't be better for mechanical part design in that regard? Again I don't use Blender for this, i just had so many requests to cover it so I made the video. I stay in my CAD lane :)

​@@TreeLuvBurdpu isn't that the whole point of the parametric timeline? something far better than a read out - something you can actually use to go back and modify your outcome? let alone having a decent align tool to make corrections to positions after testing rather than relying on vertex positions for fine control or being stuck to grid snapping. I just don't get how blender - .a poly modelling tool focused around animation - is going to be better at generating parameters for fabrication.

hahaha

Hey Damian, FreeCAD looks very promising, but I haven't actually used it so I can't really say for sure. I know Fusion offers a lot in the Free version including PCB design and the commercial version is a manageable price for most that need it professionally. I will put FreeCAD on my list to check out/try and maybe I can give you a better answer than that.

@@LearnEverythingAboutDesign I started using FreeCAD as I'm a OpenSource fan and if possible I try to use the OpenSource software. Fusion360 isn't hard to use but I truly think that it's easier to use FreeCAD than Fusion360. It took me 30min to make a mounting plate for my 3D printer on FreeCAD while with Fusion360 in 30min I only knew how to create a document, while on FreeCAD all the lines and constrains are right there in the menu.

@@randomdamian That is great to know Damian, thanks for sharing! I have it on my list to check out when I can.

The AI stuff, you need to pay extra for. Fusion360 is getting more expensive and they are removing local simulation, you will have to use thier cloud services with tokens you buy.

@@sqwert654 Sort of and true. They are making the simulation studies that could be solved locally moving to cloud only, but have stated that it will still be free to solve Linear Static Stress, which is the most common/used one. The AI stuff being paid I don't mind since all the other solutions on the market are VERY expensive. I know the move to cloud solve only is an abrupt one, but FEA simulation is expensive in nearly all other software packages so it is an interesting move to have it but pay per solve(or buy unlimited solves if you use it a lot). Love/Hate for most people :)

I have downloaded CAD Sketcher for Blender but haven't played yet. At the end of the day they are just very different modeling programs as you pointed out.

@@LearnEverythingAboutDesign cad sketcher isnt bad - if you need this type of labor work. It would be nice if blender could implement or add drawing poly lines and poly curves arcs like sketchup does. And yes they are all very different apps - blender my fav subD modeler render animation and texture tool

fusion 360 tangent tools are incredible! I just started using it two days ago and would never use Blender for hard surface again after doing a few tutorials.

Really? Try to model a car. I use more than 5 years Fushion 360. I tried to model a car and it was a disaster. Always error and complaining. This year I installed the Blender and watched tutorials. I can tell you Blender is the way to go if want to model figures,cars just so much easier and faster. Fushion is good for cnc,,machines and simply shapes.

Try to model a organic body

@@laszloszell8753 for the sode panels you need to sweep or loft curves, project then so they all touch the loft.

wrong is costly and FREECAD WILL DO THE SAMETHING

@@daadood100 Installing now :)

It is. There are better ways with add-ins like CAD sketcher, but i go to a CAD program. Plasticity has a great blender bridge.

@@LearnEverythingAboutDesign Yeah, I've seen your phone holder tutorial and it seems the best of both worlds. Sadly the pricing for Plasticity is a bit steep for hobbyists in 3rd world countries. Great tutorials btw, specially from one year back to now, they keep getting better.