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Ambrose Burnside
Aug 29, 2007

pensive


welcome designers, modellers, engineers, artists and draftsmen, all! welcome to CADthread, the long-awaited catch-all computer-aided design discussion hub. No longer must CAD shop-talk be scattered across a half-dozen special-interest megathreads, each with its own fiercely-independent CADfolk clans operating with little awareness of one another. Today we begin building CAD nation.
Wanna know which CAD program you need for a particular application? You better believe we can point you in the right direction. Or maybe you have an incredibly esoteric question about a legacy program written in FORTRAN that has no documentation and whose developers are all dead or in hiding? We can help with that too. *help not guaranteed, merely hoped-for

~contents~

  1. CAD? What's that? by: Sagebrush
  2. Hobbyist's CAD Overview Cheatsheet by: NewFatMike
  3. In Depth: Mechanical CAD
  4. In Depth: other CAD (extremely w.i.p.)
  5. Hands-On: Being Poly in a NURB world [a guide to modifying STL + other poly meshes in mechanical CAD environments]
  6. ~ UNDER CONSTRUCTION ~

1. 'just what is this 'cad' thing anyways?', you may be asking? comrade-poster Sagebrush puts it well:

Sagebrush posted:

I think you should start out by defining CAD (computer-aided design) in contrast to other styles of 3D modeling.

When most laypeople think of 3D modeling, if they're aware of what it is at all, they will think about polygonal models like you'd see in video games or movies like The Last Starfighter. Polygon modeling, where the model is formed entirely from square or triangular facets stitched together, is well-suited to making models for video games or movies. It's quick, freeform and lightweight, so you can kind of squish your model around until it has the right shape while also optimizing it for render performance. Programs like 3DS Max, Cinema 4D, Maya, and Blender are built for polygon modeling.

However, polygon modeling is not suited for engineering and design work, because a polygon model can never represent a truly smooth curved surface. You can approximate a curve with many small polygons, and that might look fine rendered in a game or movie, but a polygonal cylinder must always be built out of facets. An axle made from a polygon cylinder will never fit exactly properly inside a bearing, and a car body made from polygons will never look smooth (without cheating in the render engine). You need a different kind of model for that.

Engineering CAD applications (for the most part -- there are some ancient/grognard holdouts like AutoCAD and OpenSCAD) represent geometry totally differently, using what are called NURBS surfaces. These are three-dimensional mathematical surfaces defined by complex equations. For a trivial example, you could replace your polygonal cylinder with a surface equation that takes the center point, the radius, and the height. This equation can be evaluated at any point to any level of accuracy, so no matter how close you look at it, the NURBS curve or surface will always be infinitely smooth, and your cylinder will be perfect. It's comparable to the difference between a rasterized pixel image and a vector drawing. This is great for engineering use! Everything is perfect and precise.


polygon mesh spheres vs. NURBS sphere

NURBS surfacing techniques are very different from polygon modeling techniques. Basic shapes aren't significantly more difficult to build, but complex ones can be. However, if you want precision, that's where you need to be. NURBS applications can be divided according to their modeling strategy: solid modeling or surface modeling (with a third strategy, subdivision modeling, sometimes tacked in there somewhere).

In solid modeling the concept is: you are working with a solid object. You can add chunks of material to the outside or you can cut holes into it. It's like carving a block of wood. Most engineering-focused CAD applications are solid modelers.

In surface modeling the concept is: you are working with a hollow shell. You can draw wire curves and stretch surface skins along them to create a volume. It's like making a papier-mache model over chicken wire. Pure surface modelers are intended for industrial design and other fields that are concerned with making highly precise compound curved surfaces.

Solid modeling is required for physical output, like 3D printing or CNC machining. Surface modeling is enough if you are only going to made 3D renderings, or if you plan to take your surface model and convert it to a solid for manufacturing later. I do the latter thing a lot professionally, because it's easier to refine the form as a surface and then come back and add all the mechanical parts later.

Solid modeling is generally considered to be easier to learn, perhaps because the logic of adding chunks/cutting holes makes sense to the primitive toddler-playing-with-play-doh brain, while skinning fabric over chicken wire is not quite as intuitive. It's also quicker for some types of work (basic mechanical shapes, primarily), but is slower for others (precision sculpting). Certainly there are not that many people in the world who really know what they're doing with a surface modeler, while I have taught basic SolidWorks to 10 year olds no problem.

Both solid and surface modeling are interchangeable within a model, because both are ways of making NURBS surfaces. And all solid models are surface models, but only some surface models are solid models. Most solid modelers have limited surface modeling tools and all surface modelers are capable of building solids. Make sense?

2. Hobbyist's CAD Cheatsheet. poster-in-arms NewFatMike offers a quick run-down of CAD programs, specifically as applicable to hobbyists looking to design their own parts for home 3D printing/CNC machining, architectural design, electrical/PCB design, etc- if you don't know what program to pick for your application, here's a good place to start.

NewFatMike posted:

It may be worth noting in the OP or organizing the different programs by what you can do with them (relatively easily) in the hobbyist space.

SOLIDWORKS being easily gotten from the EAA for $40/year was is probably the best Windows-based CAD deal for...anyone. You can also check in with local libraries and makerspaces (like mine) to see if they include SWX access with membership dues. Strictly noncommercial licenses.

3DX for Makers is dropping in H2 of this year (May for students), and that's $10/mo or $99/year. That includes SWX Professional, and Dassault's cloud-based CAD applications xDesign (parametric) and xShape (subdivision surface modeling). Those last two run great on my Pixel Slate Chromebook, so it'll be a good deal even just for those. Not sure where it'll land on CAM (Standard vs Pro), but you can pull projects from those last two into SWX for assemblies or mold work or CAM very easily.

SOLIDWORKS is great for 3D printing, CAM/milling/turning (turning on CAM Pro, which is included with SWX for Makerspaces, not sure about the EAA deal), hell you can even plot directly from SOLDIWORKS Drawings to Universal laser engravers instead of loving around with a DXF. The nice thing is that if you don't like the built-in CAM engine, you can pick up MasterCAM add-ins and all sorts of other things (I believe even Espirit have an add-in? Other CAM companies do for sure).

xDesign is great for 3D printing - I pull down .3mf files straight from Tha Cloud to PrusaSlicer's Linux appimage on my Chromebook, and just plop the USB drive into my 3D printer.

Fusion 360 was independent but got bought out by Autodesk and is having Autodesk things happen. I used it professionally for design and fabrication work for a few years and it's so sad that they've really shrekt their hobbyist version. 10 open documents at a time is just garbage. The nice thing, though, is that for hobbyists their CAM is still pretty good with 1 tool at a time. That'll cover most routers like ShopBots and Sainsmarts and what-have-yous. Unfortunately if you have a makerspace with something with an ATC, you'll have to shell out like $40/mo.

Blender, Maya, 3DS, etc. are really most suitable for resin 3D printing, and FDM 3D printing is a close second depending on geometry.

Illustrator, Inkscape, AutoCAD, DraftSight are great for laser cutting and contour milling (pick up some Vectric product if you're going to be milling from these programs). Vectric programs will let you do pockets and other 2.5D milling things from these programs. I have made and will be making even more outdoor signs on a ShopBot using VCarve and these 2D art applications.

Re: architectural stuff, I've done some factory layout and flythroughs on discovery calls in SOLIDWORKS. I don't know how popular it is for it, but it does have some functionality there.

Re: electrical, KiCAD and Eagle are the ones I have heard of the most. Eagle is now included in Fusion 360 somehow, I've never used it, though. SOLDIWORKS, again, has a massive Electrical tool that I have not touched but have had my eyes glaze over a lot when people talk to me about it.

Everyone should have a Rhino license because it is great. It'll pretty much eat any file and yeet any other file. I've used it for conversions, surface modeling repair, and all kinds of other garbage. There is a RhinoCAM that I have not yet used, but am v. interested in.

My own additions to this:
-Mastercam Art is an unexpectedly-great CAD suite laser-focused on turning raster/vector images into artistically-useful 3d designs- the kind of work where you want lots of natural-feeling, organic contours but donít particularly care about the actual dimensions as long as the pockets are suited to the endmill youíll be using/ as long as it fits on your 3d printer bed/etc. It seems specifically intended as a complement to the slow-and-precise surface workflows of typical mechanical CAD programs like Solidworks/Rhino/Mastercamís own thinly-implemented CAD suite, which are awful for ďjust make this detailed vector design embossed as if it were handmadeĒ -type design tasks.
Seems like a competitor to Vectric's programs; definitely worth considering if you already have Mastercam and wanna expand its native capabilities into art.
- Illustrator (or Inkscape if on a budget) are absolutely critical for doing artistic designs, or anything where you're transferring a complex 2D design to a 3D composition. I'd say they're at least as important as the CAD suite itself for a lot of the work I've done- turning a raster into a vector is easy, but turning a raster into a vector that serves as a suitable toolpath for an end mill or for laser cutting can actually be very labour-intensive and tricky, and it's often the biggest single timesink in pure art projects. The built-in CAD tools for this work tend to be pretty lousy compared to a purpose-built vector-editing beast like Illustrator so if you work with art designs often it's absolutely worth learning both and using them in your workflows.


3. In-Depth: Industrial & Mechanical CAD

The very first CAD application, and perhaps still the most prominent, this group of CAD software is for developing and refining the everyday mass-produced goods that permeate modern industrial society. Modern CAD suites allow CAD developers to straddle, to varying degrees, the once-disparate career roles of designer, draftsman, sometimes even adding a little machinist and engineer to the mix. This sort of CAD work tends to be simple and functional, guided primarily by manufacturing and end-use considerations; part relationships + parameters are critical in mechanical CAD, which tends to produce resilient and flexible 'rules-based' designs that can be quickly modified or iterated without 'breaking'.
Role: Designing real-world physical parts/objects, often with an eye to manufacturing. Producing annotated sketches so other designers/manufacturers can replicate your design. Conducting mechanical studies of designs to predict their real-world properties.
Software: Lots of options here, all with their own particular specialization or appeal.
Solidworks- The king of professional CAD, extensive and fully-featured and polished, SW tries to do it all (CAD/CAM, electrical design, FEA analysis and fluid/physical modelling, etc) and actually kinda-sorta succeeds. Naturally the full software package costs as much as a new car. Extremely important to be comfortable with if you wanna do this professionally, overkill-but-nice-if-you-can-get-it-cheap for hobbyists.
Fusion 360- A cloud- & subscription-based one-stop-shop CAD/CAM program geared towards hobbyists, Autodesk's Solidworks-killer is notable as the only fully-featured CAD program that's more or less free for personal use. People tend to have strong feelings one way or another here, Autodesk's recent decision to strip a bevy of features from F360's nonpaying userbase in an attempt to push them into monthly plans has (anecdotally) soured a lot of people against them. I'm particularly salty about them forcing you into cloud-only file storage and then restricting access to your own design work unless you pay up.
Rhino 3d- a lightweight, nimble and focused modelling program, Rhino shines at sophisticated surface modelling and has an old-school look to it that you may or may not dig. I've only been using rhino for a month or so so someone else can speak to it better than I.

Here's Sagebrush's very thorough overview of the CAD programs you'll run into here:

Sagebrush posted:


SOLID MODELERS

SolidWorks (or officially SOLIDWORKS) is, as noted, the 600-pound gorilla, the Photoshop of the 3D CAD world. It is a solid modeler (duh) with limited surfacing tools. It has extremely powerful tools for building engineering models, but is limited in freeform surface work. Great for engines and bearings and robot parts; not as great for car bodies; bad for orks and pokemon and whatnot. It is extremely expensive, costing $3000-$10000 for a single license, though there are educational options and supposedly there will be a free hobbyist/maker tier soon.


yeah that's pretty much what you'd use solidworks for. lots of mechanical junk with accurate dimensions. boooooooring but it pays the bills

I use SolidWorks extensively for mechanical parts. Anything where you have a lot of dimensions that all stack up against each other, parts where you're reverse-engineering something to fit something else, things with moving components that need to be connected with hinges or sliding joints or whatnot. It's the best program there is for that.


Fusion 360 is Autodesk's attempt to eat SolidWorks' lunch, sort of. Their actual attempt to eat SolidWorks' lunch (Inventor) was kind of a dud because it failed to provide any benefits over SolidWorks while also not being SolidWorks and therefore not having any industry inertia. Fusion 360 is their next move. It's competitive with SolidWorks for basic modeling, and includes a whole pile of other stuff crammed in that varies from dumb (one-click ordering of 3D prints) to amazing (the CAM package). Most notably for hobbyists, it is free for non-commercial use. You have to jump through some hoops with licensing but it's not bad and then you can't beat the cost.


technically you could model something like this in fusion, yeah. lol though the only people who ever have are the autodesk artists who slave away to make the marketing images. note similarity to solidworks, but with hot new ambient occlusion shading!

If I didn't have SolidWorks I would probably use Fusion instead. The modeling is good, the CAM (CNC machining software) is excellent, the assembly tools are okay, and the cloud rendering seems pretty good. They crammed in a half-baked subdivision modeler that is kind of neat. The most annoying thing about Fusion is that all of the files have to be saved to AutoDesk's cloud because it's one of those programs. Still the best free option, no question.

Inventor is, as noted, Autodesk's other SolidWorks competitor. It's more directly comparable but also costs a lot of money and doesn't have the market that SolidWorks does so it's just not there. Like Photoshop vs. Paint Shop Pro or whatever.


lol it's even more of a solidworks ripoff than fusion is

CATIA, Solid Edge, Pro-E/Creo, NX/Unigraphics, and others are all SolidWorks-likes designed for huge industries like General Electric or Mitsubishi or Siemens. People posting here probably will never encounter them. Their distinction from SolidWorks is in the ability to handle like 50 terabyte models of an entire nuclear power plant with 500 people working on different parts simultaneously.


CATIA is owned by dassault, who make all the french fighter jets, so of course they like to show off turbines and poo poo. oh and look it's another solidworks ripoff but everything is upside down because it's french

SURFACE MODELERS

Rhinoceros (Rhino) is the best surface modeler there is. I love it. It's built for industrial design specifically and has tons of tools for perfectly massaging and refining the shape of a surface. It can also do solid modeling, because every surface modeler can, but for purely mechanical work SolidWorks is better. Rhino also has a large audience of people who use it for its jack-of-all-trades nature. Rhino can open and save pretty much any 3D format, NURBS or polygon, and has tools for editing both. (It's not a polygon modeler but it can do basic modifications to scanned meshes and STL files and stuff, which SolidWorks etc cannot). It also has a crap-ton of plugins for doing everything from procedural architecture to shoe design. Its Grasshopper plugin is extensively used in architecture.


Look at that subtle blended curvature. The tasteful patch structure. Oh my God, it even has G2 continuity

Rhino is also relatively cheap, as far as CAD programs go. $995 for a regular license, or $150-200 for an educational license if you're associated with any sort of education. The Rhino educational license is notable for being a full commercial license, no restrictions on use or expiry date -- it's just cheaper because they're nice people who want to help out students and teachers. Great. I love Rhino.

Alias is the other big surface modeling name. It's older than Rhino, going back to the 80s at least, and has the most complicated interface ever invented. You tried to move an object by dragging it? You moron! You're supposed to hold ctrl and shift, press the middle mouse button, swipe up to select the marking menu select tool, click the object, hold ctrl and shift and the left mouse button and swipe left to invoke the move tool, then use left/middle/right buttons to translate in x, y and z. Duh!!


what's that you're modeling, Alias? another car? ok, cool, keep it up

Alias arguably has a slightly more powerful surface modeling set than Rhino, but that's all it does and the interface is so obscure you'll never see it anywhere outside of an automotive industrial design studio. Not something people in here are likely to encounter.

PRACTICAL JOKES

AutoCAD is the original 3D modeling program, and in some situations people will say "CAD" to mean AutoCAD, or "AutoCAD" to mean "3D modeling" in the same way that we say photoshopped to mean "edited with Adobeģ Photoshopģ brand image-editing software." This is all wrong. AutoCAD is ancient garbage that people used in the olden days because there was nothing better available. It is backwards and kludgy and just generally awful. Today there is a better program for any given task than AutoCAD (if you're doing mechanical work use SolidWorks, if you're drafting use Revit, etc). The only time AutoCAD should be used today is by an old company that has a ton of old plans still in AutoCAD format, and then only by a summer intern whose job is to convert them all to Revit. AutoCAD also does not generate NURBS surfaces, only polygon approximations. Don't use AutoCAD.


see??? this is what comes up when you look for pictures of autocad. grandma's country kitchen floor plan. it's not a 3D modeler!! it's a two d drafting application from 1983 with a bunch of other poo poo glued on for old farts who refuse to learn anything new!! don't even try to do 3D in it!! give me a loving break!!

OpenSCAD is a programming language for 3D models. If you've used LaTeX, the word processor invented by programmers who wished they could program their essays instead of writing them, you are familiar with the OpenSCAD mindset. Maybe the idea of writing a program to create a list of operations that end up producing the model you want appeals to you. If you like the idea of, say, making a design with a bunch of global variables that you can change to quickly generate a new version of the whole model without remodeling it -- well, OpenSCAD can do that, but so can SolidWorks, and SolidWorks does it better. Rhino with Grasshopper can do it too, and far more. OpenSCAD also does not generate NURBS surfaces, only polygon approximations. I personally don't like it because it doesn't do NURBS and because I think that procedural/parametric modeling works better in SolidWorks. Use OpenSCAD if you feel like it I guess, though. It's not as actively toxic as AutoCAD.


1. clearly running on linux
2. documented hacks for broken functionality in the comments
3. look at those loving polygons on the "cylindrical" parts
4. look at those loving """airfoils"""
5. nuff said



4. Other CAD [extremely wip]
Architectural CAD: Like mechanical cad but, like, bigger. Represented by venerable old AutoCAD, among others. Can you tell this is not my area?

Electrical/PCB CAD: circuits and printed circuit boards have their own dedicated tools, both for laying out the PCB traces required for manufacturing custom circuit boards, but also for designing and testing the circuit itself.
KiCAD and Eagle are popular, with Eagle being packaged with Fusion360, plus Solidworks has its own thorough electrical design plugin (thanks newfatmike)

Media/Graphic CAD: these guys don't seem to care about dimensions at all, extremely untrustworthy imo.



5. Hands-on: A practical guide to rebuilding polygon models (i.e. STLs for 3D printing) as easily-editable NURBS models, by Sagebrush

Sagebrush posted:

Here is a very general overview of how you remodel from polygon meshes (3D scans, downloaded STLs, whatever) in Rhino.

Generate a clean mesh using the ReduceMesh and/or QuadRemesh tools (you don't need to do this, but it helps).


Use the Section tool to pull curves off the mesh. Place them at appropriate locations on either side of areas with curvature. You need to have at least a basic understanding of surface modeling to grasp where to put the curves. In this case it's pretty clearly a couple of simple profiles with a blend/loft between them so that's not hard.



These curves will be segmented, because they're extracted directly from the mesh. Use the drafting tools to redraw them accurately. The 3-point circle tool is extremely valuable for finding radii, because you can click 3 vertices along the edge and place a circle there. You can then measure the circle and guess what the intent was -- in this case 5.091mm (in the command line at the top) probably means it was a 5mm fillet. If you have any critical dimensions, you can measure them with calipers and draw that part from scratch.


You can also use the Rebuild tool to recreate curves with complex shapes. Adjust the number of control points to get reasonable accuracy without going overboard. Or just carefully draw a new curve that looks right, using the old one as a reference.


Get all your curves placed where you need them


Build the object (specific techniques are left as an exercise for the reader)


Finish the object.



~~~ADDITIONAL HOT N FRESH CONTENT TO FOLLOW~~~

Ambrose Burnside fucked around with this message at 17:56 on Mar 23, 2021

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Sagebrush
Feb 26, 2012


"Why does that Subaru break down every time you look at it, Travis", Punchy said. I nearly fell out of the jump seat in my Brat, aghast. "That thing a princess?" I coughed and gulped. "Hahahaha, nice one, Punchy", I said

Sure, I can add some stuff about the programs I use.

I think you should start out by defining CAD (computer-aided design) in contrast to other styles of 3D modeling.

When most laypeople think of 3D modeling, if they're aware of what it is at all, they will think about polygonal models like you'd see in video games or movies like The Last Starfighter. Polygon modeling, where the model is formed entirely from square or triangular facets stitched together, is well-suited to making models for video games or movies. It's quick, freeform and lightweight, so you can kind of squish your model around until it has the right shape while also optimizing it for render performance. Programs like 3DS Max, Cinema 4D, Maya, and Blender are built for polygon modeling.

However, polygon modeling is not suited for engineering and design work, because a polygon model can never represent a truly smooth curved surface. You can approximate a curve with many small polygons, and that might look fine rendered in a game or movie, but a polygonal cylinder must always be built out of facets. An axle made from a polygon cylinder will never fit exactly properly inside a bearing, and a car body made from polygons will never look smooth (without cheating in the render engine). You need a different kind of model for that.

Engineering CAD applications (for the most part -- there are some ancient/grognard holdouts like AutoCAD and OpenSCAD) represent geometry totally differently, using what are called NURBS surfaces. These are three-dimensional mathematical surfaces defined by complex equations. For a trivial example, you could replace your polygonal cylinder with a surface equation that takes the center point, the radius, and the height. This equation can be evaluated at any point to any level of accuracy, so no matter how close you look at it, the NURBS curve or surface will always be infinitely smooth, and your cylinder will be perfect. It's comparable to the difference between a rasterized pixel image and a vector drawing. This is great for engineering use! Everything is perfect and precise.


polygon mesh spheres vs. NURBS sphere

NURBS surfacing techniques are very different from polygon modeling techniques. Basic shapes aren't significantly more difficult to build, but complex ones can be. However, if you want precision, that's where you need to be. NURBS applications can be divided according to their modeling strategy: solid modeling or surface modeling (with a third strategy, subdivision modeling, sometimes tacked in there somewhere).

In solid modeling the concept is: you are working with a solid object. You can add chunks of material to the outside or you can cut holes into it. It's like carving a block of wood. Most engineering-focused CAD applications are solid modelers.

In surface modeling the concept is: you are working with a hollow shell. You can draw wire curves and stretch surface skins along them to create a volume. It's like making a papier-mache model over chicken wire. Pure surface modelers are intended for industrial design and other fields that are concerned with making highly precise compound curved surfaces.

Solid modeling is required for physical output, like 3D printing or CNC machining. Surface modeling is enough if you are only going to made 3D renderings, or if you plan to take your surface model and convert it to a solid for manufacturing later. I do the latter thing a lot professionally, because it's easier to refine the form as a surface and then come back and add all the mechanical parts later.

Solid modeling is generally considered to be easier to learn, perhaps because the logic of adding chunks/cutting holes makes sense to the primitive toddler-playing-with-play-doh brain, while skinning fabric over chicken wire is not quite as intuitive. It's also quicker for some types of work (basic mechanical shapes, primarily), but is slower for others (precision sculpting). Certainly there are not that many people in the world who really know what they're doing with a surface modeler, while I have taught basic SolidWorks to 10 year olds no problem.

Both solid and surface modeling are interchangeable within a model, because both are ways of making NURBS surfaces. And all solid models are surface models, but only some surface models are solid models. Most solid modelers have limited surface modeling tools and all surface modelers are capable of building solids. Make sense?

Okay on to the programs.

SOLID MODELERS

SolidWorks (or officially SOLIDWORKS) is, as noted, the 600-pound gorilla, the Photoshop of the 3D CAD world. It is a solid modeler (duh) with limited surfacing tools. It has extremely powerful tools for building engineering models, but is limited in freeform surface work. Great for engines and bearings and robot parts; not as great for car bodies; bad for orks and pokemon and whatnot. It is extremely expensive, costing $3000-$10000 for a single license, though there are educational options and supposedly there will be a free hobbyist/maker tier soon.


yeah that's pretty much what you'd use solidworks for. lots of mechanical junk with accurate dimensions. boooooooring but it pays the bills

I use SolidWorks extensively for mechanical parts. Anything where you have a lot of dimensions that all stack up against each other, parts where you're reverse-engineering something to fit something else, things with moving components that need to be connected with hinges or sliding joints or whatnot. It's the best program there is for that.


Fusion 360 is Autodesk's attempt to eat SolidWorks' lunch, sort of. Their actual attempt to eat SolidWorks' lunch (Inventor) was kind of a dud because it failed to provide any benefits over SolidWorks while also not being SolidWorks and therefore not having any industry inertia. Fusion 360 is their next move. It's competitive with SolidWorks for basic modeling, and includes a whole pile of other stuff crammed in that varies from dumb (one-click ordering of 3D prints) to amazing (the CAM package). Most notably for hobbyists, it is free for non-commercial use. You have to jump through some hoops with licensing but it's not bad and then you can't beat the cost.


technically you could model something like this in fusion, yeah. lol though the only people who ever have are the autodesk artists who slave away to make the marketing images. note similarity to solidworks, but with hot new ambient occlusion shading!

If I didn't have SolidWorks I would probably use Fusion instead. The modeling is good, the CAM (CNC machining software) is excellent, the assembly tools are okay, and the cloud rendering seems pretty good. They crammed in a half-baked subdivision modeler that is kind of neat. The most annoying thing about Fusion is that all of the files have to be saved to AutoDesk's cloud because it's one of those programs. Still the best free option, no question.

Inventor is, as noted, Autodesk's other SolidWorks competitor. It's more directly comparable but also costs a lot of money and doesn't have the market that SolidWorks does so it's just not there. Like Photoshop vs. Paint Shop Pro or whatever.


lol it's even more of a solidworks ripoff than fusion is

CATIA, Solid Edge, Pro-E/Creo, NX/Unigraphics, and others are all SolidWorks-likes designed for huge industries like General Electric or Mitsubishi or Siemens. People posting here probably will never encounter them. Their distinction from SolidWorks is in the ability to handle like 50 terabyte models of an entire nuclear power plant with 500 people working on different parts simultaneously.


CATIA is owned by dassault, who make all the french fighter jets, so of course they like to show off turbines and poo poo. oh and look it's another solidworks ripoff but everything is upside down because it's french

SURFACE MODELERS

Rhinoceros (Rhino) is the best surface modeler there is. I love it. It's built for industrial design specifically and has tons of tools for perfectly massaging and refining the shape of a surface. It can also do solid modeling, because every surface modeler can, but for purely mechanical work SolidWorks is better. Rhino also has a large audience of people who use it for its jack-of-all-trades nature. Rhino can open and save pretty much any 3D format, NURBS or polygon, and has tools for editing both. (It's not a polygon modeler but it can do basic modifications to scanned meshes and STL files and stuff, which SolidWorks etc cannot). It also has a crap-ton of plugins for doing everything from procedural architecture to shoe design. Its Grasshopper plugin is extensively used in architecture.


Look at that subtle blended curvature. The tasteful patch structure. Oh my God, it even has G2 continuity

Rhino is also relatively cheap, as far as CAD programs go. $995 for a regular license, or $150-200 for an educational license if you're associated with any sort of education. The Rhino educational license is notable for being a full commercial license, no restrictions on use or expiry date -- it's just cheaper because they're nice people who want to help out students and teachers. Great. I love Rhino.

Alias is the other big surface modeling name. It's older than Rhino, going back to the 80s at least, and has the most complicated interface ever invented. You tried to move an object by dragging it? You moron! You're supposed to hold ctrl and shift, press the middle mouse button, swipe up to select the marking menu select tool, click the object, hold ctrl and shift and the left mouse button and swipe left to invoke the move tool, then use left/middle/right buttons to translate in x, y and z. Duh!!


what's that you're modeling, Alias? another car? ok, cool, keep it up

Alias arguably has a slightly more powerful surface modeling set than Rhino, but that's all it does and the interface is so obscure you'll never see it anywhere outside of an automotive industrial design studio. Not something people in here are likely to encounter.

PRACTICAL JOKES

AutoCAD is the original 3D modeling program, and in some situations people will say "CAD" to mean AutoCAD, or "AutoCAD" to mean "3D modeling" in the same way that we say photoshopped to mean "edited with Adobe® Photoshop® brand image-editing software." This is all wrong. AutoCAD is ancient garbage that people used in the olden days because there was nothing better available. It is backwards and kludgy and just generally awful. Today there is a better program for any given task than AutoCAD (if you're doing mechanical work use SolidWorks, if you're drafting use Revit, etc). The only time AutoCAD should be used today is by an old company that has a ton of old plans still in AutoCAD format, and then only by a summer intern whose job is to convert them all to Revit. AutoCAD also does not generate NURBS surfaces, only polygon approximations. Don't use AutoCAD.


see??? this is what comes up when you look for pictures of autocad. grandma's country kitchen floor plan. it's not a 3D modeler!! it's a two d drafting application from 1983 with a bunch of other poo poo glued on for old farts who refuse to learn anything new!! don't even try to do 3D in it!! give me a loving break!!

OpenSCAD is a programming language for 3D models. If you've used LaTeX, the word processor invented by programmers who wished they could program their essays instead of writing them, you are familiar with the OpenSCAD mindset. Maybe the idea of writing a program to create a list of operations that end up producing the model you want appeals to you. If you like the idea of, say, making a design with a bunch of global variables that you can change to quickly generate a new version of the whole model without remodeling it -- well, OpenSCAD can do that, but so can SolidWorks, and SolidWorks does it better. Rhino with Grasshopper can do it too, and far more. OpenSCAD also does not generate NURBS surfaces, only polygon approximations. I personally don't like it because it doesn't do NURBS and because I think that procedural/parametric modeling works better in SolidWorks. Use OpenSCAD if you feel like it I guess, though. It's not as actively toxic as AutoCAD.


1. clearly running on linux
2. documented hacks for broken functionality in the comments
3. look at those loving polygons on the "cylindrical" parts
4. look at those loving """airfoils"""
5. nuff said


Maybe I will put some more stuff or more pictures in here but right now it is late. Something about use of these for 3D printing specifically.

Oh, and I've been using SolidWorks for close to twenty years now and 3D modeling programs in general for even longer so feel free to ask any questions.

Sagebrush fucked around with this message at 08:25 on Mar 18, 2021

ImplicitAssembler
Jan 24, 2013



Sagebrush posted:

Alias is the other big surface modeling name. It's older than Rhino, going back to the 80s at least, and has the most complicated interface ever invented. You tried to select an object by clicking on it? You moron! You're supposed to hold ctrl and shift, press the middle mouse button, and swipe up to select the marking menu select tool. Duh.


what's that you're modeling, Alias? another car? ok, cool, keep it up

Alias arguably has a slightly more powerful surface modeling set than Rhino, but that's all it does and the interface is so obscure you'll never see it anywhere outside of an automotive industrial design studio. Not something people in here are likely to encounter.


Man, the interface hasn't changed much in the last 20 years. Anyways, pretty sure The Mill still uses it...for car commercials.

biracial bear for uncut
Jun 9, 2009

ask me about being the most obnoxious person of all time

For 2D CAD applications, you can also gently caress around with DraftSight (3DS's AutoCAD killer). For a long time that program was free but now I think they have $99/year subscriptions for it if you want to do any quick-and-dirty 2d drawings of things (and they may still have a free version, but I stopped loving with that when they made you register it every 30 days).

Maybe not so useful for 3d modelling and printing of things, but most hobbyist CAM packages like the dxf output you can get from Draftsight and if you have a K40 laser or inherited the rare waterjet that isn't a bitch to maintain and run, the machine will usually have native support for the 2d DXF output as well.

Also for 100% organic/artistic 3d modelling programs, you can't go wrong with Zbrush/Sculptris. poo poo is cool, but as noted in the OP there is no real dimensional accuracy (though you can take a model and "scale to fit" if you're importing the file into a 3d printer's slicer software, etc.).

Comedy 3d modelling option - BRL-CAD; it's the US Army's open source 3d modelling software. Like a bastard baby of OPENSCAD and other circa 1980s 3d solid modelling software, but supposedly very powerful when it comes to simulations. The US Army uses it to run simulations on how much damage tanks and planes can take before system failures/destruction, so if you're super loving bored you can do similar things like "How much can a Ford Escort stand up to?" (assuming you have an accurate 3d model of one).

mattfl
Aug 27, 2004

Super Benintendo!


Man, I took AutoCAD classes in high school(when autocad still launched in DOS lol I'm old) and I was certain it was what I wanted to do when I got older. I even worked for a while for a company that installed nurse call systems and intercom systems in schools as their "autocad" guy that did the layout of everything. I was fresh outta high school and it was my first real job. I liked it but I had a long commute and the money wasn't that great so I got a new job and haven't touched a CAD program since.

I really should get back into it since I now have some 3d printers and while just printing off other peoples designs is fun I'd like to learn to make my own and be able to manipulate those designs to better suit my needs.

biracial bear for uncut
Jun 9, 2009

ask me about being the most obnoxious person of all time

mattfl posted:

Man, I took AutoCAD classes in high school(when autocad still launched in DOS lol I'm old) and I was certain it was what I wanted to do when I got older. I even worked for a while for a company that installed nurse call systems and intercom systems in schools as their "autocad" guy that did the layout of everything. I was fresh outta high school and it was my first real job. I liked it but I had a long commute and the money wasn't that great so I got a new job and haven't touched a CAD program since.

I really should get back into it since I now have some 3d printers and while just printing off other peoples designs is fun I'd like to learn to make my own and be able to manipulate those designs to better suit my needs.

There is a rumor that Solidworks is going to experiment with offering a $99/year subscription license for hobbyists/makers sometime this year, so I'd look into the tutorial videos for it on Youtube or LinkedIn to get familiar with the workflow (because it is a wildly different perspective from old-school CAD).

I work for a place that still uses old 2D CAD for some product lines because the shop workflow doesn't "benefit" from having multiple Solidworks licenses to do all of the 2D CAD drawings for those simpler products, and some of the younger guys they hired out of college in our Engineering department had no loving clue how to correctly draft things in AutoCAD for the couple weeks it took to teach them how things work.

Going from a software that accurately applies dimensions to sketch lines to one where you have to accurately draw the 2d lines and then apply dimensions was a serious mind-gently caress for them.

Kaiser Schnitzel
Mar 28, 2006

Schnitzel mit uns




Thanks for making this thread it is much needed! I occasionally mess around in Fusion and it's relatively easy, but I definitely still draft faster by hand. Is Revit pretty much just architecture or would it be useful for someone drawing furniture/cabinets?

Korwen
Feb 26, 2003

don't mind me, I'm just out hunting.



Does anyone have a preferred series of tutorial videos for Fusion 360? For someone totally new to CAD it's a bit daunting and video tutorials seem like the way to get started, just wanted to see if anyone had a preferred youtube channel/website/etc.

mattfl
Aug 27, 2004

Super Benintendo!


biracial bear for uncut posted:

There is a rumor that Solidworks is going to experiment with offering a $99/year subscription license for hobbyists/makers sometime this year, so I'd look into the tutorial videos for it on Youtube or LinkedIn to get familiar with the workflow (because it is a wildly different perspective from old-school CAD).

I work for a place that still uses old 2D CAD for some product lines because the shop workflow doesn't "benefit" from having multiple Solidworks licenses to do all of the 2D CAD drawings for those simpler products, and some of the younger guys they hired out of college in our Engineering department had no loving clue how to correctly draft things in AutoCAD for the couple weeks it took to teach them how things work.

Going from a software that accurately applies dimensions to sketch lines to one where you have to accurately draw the 2d lines and then apply dimensions was a serious mind-gently caress for them.

Hmm, through my work we have full access to LinkedIn Learning, so I'll def head over there and check out the courses they have.

Ambrose Burnside
Aug 29, 2007

pensive


Sagebrush posted:

Sure, I can add some stuff [...]

fuckiní A, thank you- mind if i add it to the OP?

e: Actually, I do have a question: can people still get Solidworks certifications for free, or am I misremembering?

Ambrose Burnside fucked around with this message at 14:20 on Mar 18, 2021

Ambrose Burnside
Aug 29, 2007

pensive


also

Sagebrush posted:



Look at that subtle blended curvature. The tasteful patch structure. Oh my God, it even has G2 continuity

this is some drat fine postcrafting

sharkytm
Oct 9, 2003

Gimme Gimme Swedish Fish...



Fallen Rib

In on the first page...

I'm self-taught, and use SolidWorks 2020 and AutoCAD 2010 (lol).
The best thing about SolidWorks is that there are tutorials for EVERYTHING, kinda like Photoshop or QuickBooks. Sure, they're expensive and cumbersome and lack a ton of features, but they're the industry standard.

I'd really like to learn Rhino/Blender or some other surface modeling program.

biracial bear for uncut
Jun 9, 2009

ask me about being the most obnoxious person of all time

Ambrose Burnside posted:

fuckiní A, thank you- mind if i add it to the OP?

e: Actually, I do have a question: can people still get Solidworks certifications for free, or am I misremembering?

No, there are fees to take the certification exams, access to Solidworks' online classes are free if you have a valid license (I think?).

If you had VIP access to this year's Solidworks World (or 3dExperience World) you have free access to exams until the end of July (reminds me I need to study up and take some exams to work towards my Expert certification; have a Professional certification but it'd be nice to get that last thing).

biracial bear for uncut
Jun 9, 2009

ask me about being the most obnoxious person of all time

mattfl posted:

Hmm, through my work we have full access to LinkedIn Learning, so I'll def head over there and check out the courses they have.

The ones by Gabriel Corbet (I think I spelled that right) are really detailed and well done, they're the ones I used to really get started waaaaaaaaay back in 2006 when I first started using Solidworks at work. He regularly publishes update courses with each Solidworks release, too.

Korwen posted:

Does anyone have a preferred series of tutorial videos for Fusion 360? For someone totally new to CAD it's a bit daunting and video tutorials seem like the way to get started, just wanted to see if anyone had a preferred youtube channel/website/etc.

Back in the day this was a good starting point webinar: https://www.youtube.com/watch?v=VbSkwvZyU_0 Skip to about 8:30 to get past the preamble stuff.

biracial bear for uncut fucked around with this message at 14:50 on Mar 18, 2021

NewFatMike
Jun 11, 2015




Worth noting that both CATIA and SOLIDWORKS are owned by Dassault

It may be worth noting in the OP or organizing the different programs by what you can do with them (relatively easily) in the hobbyist space.

SOLIDWORKS being easily gotten from the EAA for $40/year was is probably the best Windows-based CAD deal for...anyone. You can also check in with local libraries and makerspaces (like mine) to see if they include SWX access with membership dues. Strictly noncommercial licenses.

3DX for Makers is dropping in H2 of this year (May for students), and that's $10/mo or $99/year. That includes SWX Professional, and Dassault's cloud-based CAD applications xDesign (parametric) and xShape (subdivision surface modeling). Those last two run great on my Pixel Slate Chromebook, so it'll be a good deal even just for those. Not sure where it'll land on CAM (Standard vs Pro), but you can pull projects from those last two into SWX for assemblies or mold work or CAM very easily.

SOLIDWORKS is great for 3D printing, CAM/milling/turning (turning on CAM Pro, which is included with SWX for Makerspaces, not sure about the EAA deal), hell you can even plot directly from SOLDIWORKS Drawings to Universal laser engravers instead of loving around with a DXF. The nice thing is that if you don't like the built-in CAM engine, you can pick up MasterCAM add-ins and all sorts of other things (I believe even Espirit have an add-in? Other CAM companies do for sure).

xDesign is great for 3D printing - I pull down .3mf files straight from Tha Cloud to PrusaSlicer's Linux appimage on my Chromebook, and just plop the USB drive into my 3D printer.

Fusion 360 was independent but got bought out by Autodesk and is having Autodesk things happen. I used it professionally for design and fabrication work for a few years and it's so sad that they've really shrekt their hobbyist version. 10 open documents at a time is just garbage. The nice thing, though, is that for hobbyists their CAM is still pretty good with 1 tool at a time. That'll cover most routers like ShopBots and Sainsmarts and what-have-yous. Unfortunately if you have a makerspace with something with an ATC, you'll have to shell out like $40/mo.

Blender, Maya, 3DS, etc. are really most suitable for resin 3D printing, and FDM 3D printing is a close second depending on geometry.

Illustrator, Inkscape, AutoCAD, DraftSight are great for laser cutting and contour milling (pick up some Vectric product if you're going to be milling from these programs). Vectric programs will let you do pockets and other 2.5D milling things from these programs. I have made and will be making even more outdoor signs on a ShopBot using VCarve and these 2D art applications.

Re: architectural stuff, I've done some factory layout and flythroughs on discovery calls in SOLIDWORKS. I don't know how popular it is for it, but it does have some functionality there.

Re: electrical, KiCAD and Eagle are the ones I have heard of the most. Eagle is now included in Fusion 360 somehow, I've never used it, though. SOLDIWORKS, again, has a massive Electrical tool that I have not touched but have had my eyes glaze over a lot when people talk to me about it.

Everyone should have a Rhino license because it is great. It'll pretty much eat any file and yeet any other file. I've used it for conversions, surface modeling repair, and all kinds of other garbage. There is a RhinoCAM that I have not yet used, but am v. interested in.

I'm a SOLIDWORKS Application Engineer with a big ol' VAR, so I do a lot of training and tech support for it, so if you have questions hit me up. I'm also starting to learn how to write post processors ahead of the 3DX for Makers program launching so be prepared for CAMworks chat from me

Dr. Despair
Nov 4, 2009


39 perfect posts with each roll.



I'm a CAD novice (currently teaching myself Solidworks to make simple 3d printed bits and bobs, and I've used autocad in the past to update P&IDs), but I just want to chime in that the free 3dBuilder app that comes with windows can be pretty useful for a lot of stuff. I think the guy who designed and made a belt style 3d printer entirely in it was a bit crazy, but I do like making quick changes to things with it.

TerminalSaint
Apr 20, 2007


Where must we go...

we who wander this Wasteland in search of our better selves?


Korwen posted:

Does anyone have a preferred series of tutorial videos for Fusion 360? For someone totally new to CAD it's a bit daunting and video tutorials seem like the way to get started, just wanted to see if anyone had a preferred youtube channel/website/etc.

This guy took me from utterly clueless (my most relevant experience was making a half-life 2 map a decade before) to being able to CAD up pretty much any part I need for 3D printing. For example, I'm working on a custom controller for space games:

NewFatMike
Jun 11, 2015



Oh piss I forgot to mention OnShape. It's pretty good, started by former SOLIDWORKS guys and lives entirely in the browser. The CAM situation is not great, but it's fantastic for 3D printing and general CAD work.

Rexxed
May 1, 2010

Dis is amazing!
I gotta try dis!



Dr. Despair posted:

I'm a CAD novice (currently teaching myself Solidworks to make simple 3d printed bits and bobs, and I've used autocad in the past to update P&IDs), but I just want to chime in that the free 3dBuilder app that comes with windows can be pretty useful for a lot of stuff. I think the guy who designed and made a belt style 3d printer entirely in it was a bit crazy, but I do like making quick changes to things with it.

Yeah it may be worth mentioning that for simple stuff, there's programs like Windows 3D builder for Windows 10 or TinkerCAD (which is now web based) that are simple. They're definitely not serious CAD packages, they're pretty basic. However, if you're doing hobbyist things they may be worth a look. TinkerCAD is owned by AutoDesk and is often used in schools for the kids learning to use the school's 3D printer. If you're going to put some time into learning some CAD software it's definitely worth considering going with one of the big boys, though. They have way more tools and options than you'll need for basic stuff but doing a couple of tutorials will get you going with the basics and you can build on that knowledge later.

It may also be worth mentioning SketchUp which was a free program for doing stuff like houses and furniture and got bought by Google to become Google SketchUp. They spun that off into a paid version but the free one is still around on the internet. That said, it's bad at making solids, it's best for making 3d representations of things. It's fine if you want to sketch out where you're putting things in a room but bad for making a model to 3D print.

jammyozzy
Dec 7, 2006

Is that a challenge?

Sweet, finally somewhere I can come and vent about the garbage software I use without making GBS threads up YOSPOS.

I'm a mech eng and though I have some prior experience with SolidWorks and CATIA (gently caress I miss CATIA) I now spend my life using NX. NX is a massive CAD/CAM package now developed by Siemens that can trace its lineage back to the late 70's and was called Unigraphics until the mid 2000's, so you can immediately date someone by what name they've internalised.

As much as I like to whine about it, NX is actually pretty drat good at what it does. My role is primarily solid modelling, with a healthy mix of 2D layouts and also some surfacing thrown in from time to time designing castings. As a company we also use it for CNC programming, and the software has tons of other capabilities we don't touch like sheet metal design, electrical layouts and even fairly esoteric stuff like specific ship-building tools. I would say NX's primary strength is flexibility, because I can do a full day's work in two environments and NX will near-enough let me do whatever I want in there.

All CAD software has idiosyncracies, but I think NX's age makes it more prone to them than most. For example, almost everything in NX is a part file; A solid model? part file. An assembly? part file. Drawing? part file etc etc. I can open a solid model in the drafting environment, or a drawing in the modelling environment, and there's situations in our workflows where both of those are helpful. This is both a blessing and a curse, it lets us do some things that I don't think many other CAD packages would let us get away with but it can also be a nightmare to explain to people unfamiliar with it. "Open this assembly drawing, drop into the modelling environment, change the line weight of that part then go back into drafting" is a word salad, but also perfectly valid instructions in NX.

Tl;dr: NX, it's the Microsoft Excel of CAD software. Ancient, idiosyncratic, incredibly powerful and a disaster in the wrong hands.

(I still miss CATIA)

Rexxed
May 1, 2010

Dis is amazing!
I gotta try dis!



I'm not sure if its related beyond the company, but mentioning Siemens reminded me that they have their Solid Edge CAD available as a community edition for makers. I grabbed it when Fusion 360 started getting more restrictive but haven't tried it out yet:
https://www.plm.automation.siemens.com/plmapp/education/solid-edge/en_us/free-software/community

NewFatMike
Jun 11, 2015



I've seen it about but haven't touched it. Is there any included CAM or anything of note? Everyone I know who's used it moved on to SOLIDWORKS a decade ago or so.

His Divine Shadow
Aug 7, 2000

I'm not a fascist. I'm a priest. Fascists dress up in black and tell people what to do.


SolidWorks (student edition) can be had for $40 per year if you join the EAA.

Siemens Solid Edge can be had as a free community edition nowadays as well. Does not have a CAM package though.

I got really pissed off at Fusion after they did their latest round of changes and I have both of these apps on my PC, I've not used them a lot. Fusion really wins out with the large array of good tutorials, that Lars guy is solid.

fins
May 31, 2011



Floss Finder

Fusion 360: Ohh, look at me, I can change a dimension when you change a number.

Grasshopper: Hold my beer.

I can only imagine the hoops I would have to jump through with Fusion360 to talk in the archaic language my robot arms speak. With Rhino+Grasshopper and some python I'm 90% of the way to synced movement of two.

Liking the SubD stuff in Rhino 7.

mobby_6kl
Aug 9, 2009

"You are the best poster... do not let anyone say otherwise."


Is this also a stupid question thread for stupid newbies?



I was trying to sweep this donut profile along the straight path but even though it previews fine in some instances, it's never actually created when I confirm the dialog. I've tried several different paths but it never seems to work. The errors don't really make much sense for me.

For now I just extruded a section, rotated it and then cut it up with planes, which works for now even if it's not exactly the same.

NewFatMike
Jun 11, 2015



Sure is a good spot for it!

I believe in most packages, your path and profile need to intersect. I know in SOLIDWORKS that if they're just close, you need to make the profile of the sweep and the end point of the path nearest to it have a relation called "Make Pierce".

I'd try moving the path inside the profile. It may also help to just sweep a circular profile and use the "Shell" command to remove the closed faces. Sometimes multiple contour things can get wibbly

Ambrose Burnside
Aug 29, 2007

pensive


Iím gonna go ahead and add informative Effortposts to the OP; iíll PM and/or tag you if thatís the case, please feel free to let me know if youíd rather i didnít.

Unrelated: I should go ahead and endorse Mastercam Art as an unexpectedly-great CAD suite laser-focused on turning raster/vector images into artistically-useful 3d designs- the kind of work where you want lots of natural-feeling, organic contours but donít particularly care about the actual dimensions as long as the pockets are suited to the endmill youíll be using/ as long as it fits on your 3d printer bed/etc. It seems specifically intended as a complement to the slow-and-precise surface workflows of typical mechanical CAD programs like Solidworks/Rhino/Mastercamís own thinly-implemented CAD suite, which are awful for ďjust make this detailed vector design embossed as if it were handmadeĒ -type design tasks

Ambrose Burnside fucked around with this message at 18:24 on Mar 21, 2021

Ambrose Burnside
Aug 29, 2007

pensive


e: whoops doublepost

Iíve got a question: is there a CAD-based way to easily reverse-engineer a non-NURBS model like an STL? Alternately, a mechanical CAD suite that can easily work with STLs?
I often want to rework or customize 3D printer-intended models i find on Thingiverse or what-have-you for my own use, and the two mediocre avenues available are 1) attempting to directly-modify the poly-based model in Solidworks or Inventor or sth equally ill-suited to altering STLs, or 2) reproducing the design in a NURBS environment by manually pulling critical dims off the model, and then using my judgement to figure out if the designer was working in metric or imperial and what they were rounding to. As is stands, my workflows for both are pretty poo poo.

Iím fine editing STLs if thatís what makes sense- upthread someone said Rhino is good for this- how so?
And re: reverse-engineering, iím just spitballing here, but it seems within the realm of reason for some Design Wizard to be able to look at a poly-based model, maybe along with user-supplied units/tolerances/increments, and apply best-fit measurements & relationships. Is there anything like this out there?

NewFatMike
Jun 11, 2015



How much money do you have? Materialise makes stuff like that, but it's five figured a seat IIRC.

SOLIDWORKS does have a scan to 3D thing, but uhhh if you get it to work consistently, that would be an impressive feat. I'd say give it a go if it's included in your package.

Rhino is rad because it'll take an STL and if you tell it to save it as a STEP, by God it will. You can use layers and visibility to get a really snappy reverse engineering setup as well (e.g. an STL will spit out a cylinder as interpolated n-gons, but you can extrude a cylinder referencing specific edges, trim out the n-gon and boolean union it with the cylinder).

Or you'll still have a kludgy model, but you can pull it into SOLIDWORKS and do the same.

STLs specifically are tough because they're triangles, and every modern parametric CAD system is using quads, so now you have to either split or combine triangles into quads. That's just the topological issues

STLs also don't really have wireframe information the way, say, a STEP does. STLs also can't store any other metadata. It's almost like trying to put a 45 in a PS5 and hoping you can burn a new song on there.

So it's manual or shell out the bucks if you're starting at an STL, sadly.

biracial bear for uncut
Jun 9, 2009

ask me about being the most obnoxious person of all time

No, not easily.

An STL is like applesauce while NURBS style models are like apples.

Turning apples into applesauce is easy, turning applesauce into apples is not.

NewFatMike
Jun 11, 2015



Specific Rhino things also:

If your model is fairly simple, i.e. a mechanical design that is just only out there as an STL, you can really easily build a wireframe referencing vertices in the STL. Again, layers are your friend here.

You'd use line tools essentially to just click and drag from edge to edge, and use surface fills. If you can even get the "meat" of your design out of it, then saving the new work as a STEP and pulling it into SOLIDWORKS is great, and you'll be able to use a software you're familiar with to actually get your critical dimensions.

I wish Rhino hadn't terminated my license - apparently not until recently you couldn't have it on more than one computer, so be aware that you'll need to make sure the current EULA supports it. Hopefully I'll be able to grab another license in a year or two when I'm done paying down this credit card debt from freelancing.

Sagebrush
Feb 26, 2012


"Why does that Subaru break down every time you look at it, Travis", Punchy said. I nearly fell out of the jump seat in my Brat, aghast. "That thing a princess?" I coughed and gulped. "Hahahaha, nice one, Punchy", I said

NewFatMike posted:

STLs specifically are tough because they're triangles, and every modern parametric CAD system is using quads, so now you have to either split or combine triangles into quads. That's just the topological issues

Rhino 7 has a fantastic new QuadRemesh command. One click to go from the left STL mesh (generated from SolidWorks, in this case) to the right quad mesh.



From there it's far easier to:
- edit using the polygon editing tools
- take dimensions off and remodel in NURBS
- use MeshToNURBS and #yolo it

Sagebrush fucked around with this message at 00:51 on Mar 22, 2021

NewFatMike
Jun 11, 2015



Fuuuuuuuck that rules so hard! I will probably be able to afford it around Rhino 9. Thankfully my work laptop still has a functioning installation.

Sagebrush
Feb 26, 2012


"Why does that Subaru break down every time you look at it, Travis", Punchy said. I nearly fell out of the jump seat in my Brat, aghast. "That thing a princess?" I coughed and gulped. "Hahahaha, nice one, Punchy", I said

Here is a very general overview of how you remodel from polygon meshes (3D scans, downloaded STLs, whatever) in Rhino.

Generate a clean mesh using the ReduceMesh and/or QuadRemesh tools (you don't need to do this, but it helps).


Use the Section tool to pull curves off the mesh. Place them at appropriate locations on either side of areas with curvature. You need to have at least a basic understanding of surface modeling to grasp where to put the curves. In this case it's pretty clearly a couple of simple profiles with a blend/loft between them so that's not hard.



These curves will be segmented, because they're extracted directly from the mesh. Use the drafting tools to redraw them accurately. The 3-point circle tool is extremely valuable for finding radii, because you can click 3 vertices along the edge and place a circle there. You can then measure the circle and guess what the intent was -- in this case 5.091mm (in the command line at the top) probably means it was a 5mm fillet. If you have any critical dimensions, you can measure them with calipers and draw that part from scratch.


You can also use the Rebuild tool to recreate curves with complex shapes. Adjust the number of control points to get reasonable accuracy without going overboard. Or just carefully draw a new curve that looks right, using the old one as a reference.


Get all your curves placed where you need them


Build the object (specific techniques are left as an exercise for the reader)


Finish the object.

Sagebrush fucked around with this message at 03:16 on Mar 22, 2021

Sagebrush
Feb 26, 2012


"Why does that Subaru break down every time you look at it, Travis", Punchy said. I nearly fell out of the jump seat in my Brat, aghast. "That thing a princess?" I coughed and gulped. "Hahahaha, nice one, Punchy", I said

mobby_6kl posted:

Is this also a stupid question thread for stupid newbies?



I was trying to sweep this donut profile along the straight path but even though it previews fine in some instances, it's never actually created when I confirm the dialog. I've tried several different paths but it never seems to work. The errors don't really make much sense for me.

For now I just extruded a section, rotated it and then cut it up with planes, which works for now even if it's not exactly the same.

Have you tried putting the profile at the bottom of the curve and sweeping it in only one direction?

Like I would just draw two sketches, one with the two profiles and one for the path



And sweep away

NewFatMike
Jun 11, 2015



Ambrose Burnside posted:

I’m gonna go ahead and add informative Effortposts to the OP; i’ll PM and/or tag you if that’s the case, please feel free to let me know if you’d rather i didn’t.

Unrelated: I should go ahead and endorse Mastercam Art as an unexpectedly-great CAD suite laser-focused on turning raster/vector images into artistically-useful 3d designs- the kind of work where you want lots of natural-feeling, organic contours but don’t particularly care about the actual dimensions as long as the pockets are suited to the endmill you’ll be using/ as long as it fits on your 3d printer bed/etc. It seems specifically intended as a complement to the slow-and-precise surface workflows of typical mechanical CAD programs like Solidworks/Rhino/Mastercam’s own thinly-implemented CAD suite, which are awful for “just make this detailed vector design embossed as if it were handmade” -type design tasks

I got distracted by the other thing, but meant to ask about this. It seems like it occupies a similar niche to Vectric products - does that sound about right?

Ambrose Burnside
Aug 29, 2007

pensive


NewFatMike posted:

I got distracted by the other thing, but meant to ask about this. It seems like it occupies a similar niche to Vectric products - does that sound about right?

I haven't used any Vectric stuff, but from a quick look-see, it looks a lot like if Aspire were a less polished/cohesive plugin for a dedicated CAM program instead of a standalone product. It looks like Aspire has a superior design suite vs. Art leveraging Mastercam's superior CAM end of things
Definitely gonna muck around with an Aspire trial when I get a chance, I'm not designing anything for conventional CNC so I don't have any use for killer CAM on personal projects anyhow.

ImplicitAssembler
Jan 24, 2013



Sagebrush posted:

Here is a very general overview of how you remodel from polygon meshes (3D scans, downloaded STLs, whatever) in Rhino.

Or just use a caliper and rebuild it from scratch? I think that would have been quicker .

Fusion360 has a mesh to solid function and it can work for simple objects., ie if you just want to cut a hole at a bigger size, etc.
Most of the time, I find it much faster to pull in the object as a reference and model it from scratch instead.

NewFatMike
Jun 11, 2015



The primary advantage with Rhino is that if someone sends you a high resolution STL, your computer doesn't immediately turn into a glow in the dark space heater.

Rhino can just straight up and down work faster, and if you're billing, a license is worth it in a hurry.

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Sagebrush
Feb 26, 2012


"Why does that Subaru break down every time you look at it, Travis", Punchy said. I nearly fell out of the jump seat in my Brat, aghast. "That thing a princess?" I coughed and gulped. "Hahahaha, nice one, Punchy", I said

ImplicitAssembler posted:

Or just use a caliper and rebuild it from scratch? I think that would have been quicker .

For that part, sure. It was the first STL I found in my junk folder. Though I'd argue that it's still easier to get the correct blend between the profiles, if that matters for the purpose, using a reference model than by trying to measure and interpolate points.

For something with more complex geometry, like a motorcycle gas tank or whatever, working from a scan is absolutely faster and more accurate. Still use direct measurements for any critical dimensions, but for the freeform stuff? No question.

Also this method is suitable for the specific question of modifying a downloaded STL file, which cannot be measured with calipers. Measuring vertices and overlaying circles to find radii as shown is the digital equivalent.

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