Why you should NEVER use SketchUp, which is a steaming pile of crap.

[626Pilot]

SKETCHUP IS COMPLETELY AWFUL FOR DESIGNING PARTS FOR 3D PRINTING.

Do yourself a favor and learn Autodesk or something else. ANYTHING else. It looks easy to use, in the same way that spiderwebs look transparent to many insects. Indeed, you may use it for several hours and never have a problem - until you do, and then you find yourself taking twice as much time to fix your part.

SketchUp is usually okay if you're designing large things, like houses. However, its internal resolution limits, and tendency to move vertices 0.0004 mm in some random direction, or rotate something 0.03 degrees out-of-plane, mean that you will spend MANY hours repairing geometry that your "easy-to-use" modeler needlessly screwed up. You'll find that you extrude something next to something else, and one of the extrusions is inexplicably leaning off to the side by a fraction of a degree, so that nothing lines up. Or, you'll draw some lines on a flat plane, and find that those lines cannot create a polygon on that plane no matter what you do. It will simply refuse to recognize lines you drew directly on a plane, as being on that plane. Even if you extrude the polygon through the plane and ask it to find the intersection, it will claim that there is no intersection, even though the polygon is literally passing through the plane, and by the rules of mathematics and geometry, obviously IS intersecting the plane.

The Boolean tools, which they charge hundreds of dollars for - tools that let you intersect, do unions, cut, trim, etc., in 3D - do not work. Using these tools will eat holes in your geometry that you will NEVER be able to fix. You will find yourself having to scale things up 10x, perform whatever operation, and then scale them back down 10x, to work around this.

Also, there is no sphere tool. You have to draw an ellipse and use the Follow Me tool, and half the time, the resultant "sphere" will be full of holes.

The STL export plugin works, but usually introduces small errors that you have to fix with NetFabb. Sometimes the errors are bigger, and you have to re-create faces and hope it doesn't chew everything up.

I don't know who designed this festering barrel of sewage, but I'm beginning to see why Google spun this terrible waste of time and money off to Trimble. I'm guessing that they didn't want to have this sadistic, root-canal-like crap associated with their company.

[Andre B]

And just in case I missed your meaning.
You don't like SketchUp.

[DeltaCon]

In my minor experience with SketchUp I found the simple stuff really easy to make. But the limits of an easy part are reached rather quickly indeed. Lot's of functions have different outcomes each time. And I didn't even dare trying to draw accurate measurements. I love the intuitive way of drawing though. Since I come out of the graphical design corner, and not from a technical design corner, I find myself lost pretty quickly while trying anything else that is on the market. Can you recommend a 3d drawing tool that has a not too steep learning curve?

[Windshadow]

OnShape is great if you can't afford the expensive per seat costs of the old standards.
but like any of them you have to invest the the time in learning it

i love being able to tweak stuff in the iOS version as well as reworking stuff on the old 2009 vintage macbook pro i use for the printer.

[626Pilot]

Autodesk Fusion 360 is $25/month if you buy it annually ($300/year). I'm looking at that, and also DesignSpark Mechanical, which is free.

[Holy1]

Fusion 360 is free for hobbyists.

[626Pilot]

I'm debating whether to build a Windows machine to run either Fusion 360 or DesignSpark Mechanical. DSM definitely doesn't work in a Windows VM (not even slowly), and I'm betting Fusion 360 won't either. SketchUp does work in a VM, at least the version I have. No idea whether SU2016 can do that.

I'd love to use Fusion 360 for free, but I'm doing paid work, and I need to keep everything above-board. It might be better to use it than anything else, as it is one of the industry standards, and possibly the most important one. I don't know any architects who use software from anyone other than AutoCAD. Some of them use SketchUp for rendering, but the don't take it seriously for any real design work.

[teoman]

As far as i can remember if you make less than 100k usd a year it is still free.

[wkarraker]

Excellent observation about SketchUp. I was approached by one of our 3D designers about a project his wife was working on. Seems they were using SketchUp Pro for a building proposal to a foreign client. When the client wanted a 3D print of the new design they attempted to upload it to Shapeways and it promptly failed every test for printability. I imported the file into my 3D application of choice and easily found over 200,000 unconnected polygons and isolated planes that made the STL unusable with any 3D printer I could think of. The application may make pretty pictures but it is a terrible choice for 3D printing.

I use Cinema 4D R17 and love it for modeling. It recently received a mesh check feature for locating non planar polygons, mesh errors, complex points, non-manifold objects and more, it highlights each problem with different colors and provides a count of each type of error. While it's not a free application I'm certainly glad our company uses it.

[ramai]

You have some valid points Pilot. I use sketchup almost exclusively, and your criticisms are valid. Things like having to scale because it can't handle small geometry are dumb things they should have fixed ages ago. Other things too like only being able to punch in the radius of a circle instead of the diameter. It's really limited when it comes to organic shapes, and unless you are SUPER careful, you pretty much are guaranteed a trip through netfabb.
The only thing I can say in defense of it, is once you understand it, and figured out work around for its quarks, it is useful for pumping something out pretty quick.

[bvandiepenbos]

Fusion360 is awesome!
It IS free if you make less than 100k per year with it. Maybe it's 300k? can't remember

Oh, and it does excellent 3D CAM tool paths for your CNC machines

[joe]

Fusion360 is awesome!
It IS free if you make less than 100k per year with it. Maybe it's 300k? can't remember

Oh, and it does excellent 3D CAM tool paths for your CNC machines

/\ /\ Fully agree, Awesome program. Constant updates and improvements.

[626Pilot]

Late update:

In September of 2016, I bought a laptop with a 17" display, and installed Autodesk Fusion 360. I had thought to import all my SketchUp stuff into it, and go from there, as there is an importer. However, what gets imported is meshes, not F360's abstract breps.

If you create a cube in SketchUp, you get a solid object with eight vertices and six faces. If you then import that cube into F360, you don't get a solid object. Instead, you get twelve triangles that happen to look like they form six faces. Most of F360's tools are designed to work specifically with breps, not meshes, so what you import isn't very useful right off the bat.

F360 has what I guess is a curve-fitting algorithm for trying to convert that mesh into a cohesive object, but it isn't perfect, and is more likely to fail the more vertices are involved. There is also the question of the quality of what comes out of that algorithm. If the vertices are off even a tiny amount (because SketchUp stored them like that, or because F360's algorithm didn't quite figure them out right), your geometry will have errors. For anything complex, or that has to be dead accurate, I wouldn't bother.

When I decided to transition my magnetic arm effector and carriages from SketchUp to F360, I found it more useful to take measurements (something SketchUp is very good at, and arguably easier than F360), and translate those measurements directly into sketches in F360. The result was quite nice:

It took longer to design this effector in F360 than it had in SketchUp. However, in exchange for this, I got geometry that was guaranteed to be exactly perfect, with no vertices being moved around or any other funny business. Because F360 is a timeline-based modeler, if I wanted to change something, all I had to do was rewind the timeline to the right place, make a change, and watch that change propagate forward. Occasionally, a change would break some dependency further down the line, but these were easy to resolve.

The basic unit of construction is as 2D sketch. Lines and arcs can be drawn and subject to linear and angular constraints. If you constrain one line to another, and move the one line, the other will follow. Constraints can be literal numbers, or they can be set to variables. If you change the value of a variable, it gets updated in all sketches where it's referenced, and then any 3D objects extruded from the sketch are also updated. Variables can also be used with 3D objects and operations such as chamfers and fillets, so you can change many of them at the same time, in a single step. I did a custom object for a friend of someone who uses these forums, and that object had about 30 different variables tied to various constraints. If she wanted an angle or length changed, I'd type in a new value, and the entire object would change instantly. It was quite amazing to watch. SketchUp has nothing like this.

Because importing to F360 is problematic, I decided to use SketchUp to maintain old designs, and F360 for anything new or that requires serious modification.

Things that stand out for me in F360:

• Timeline-based editing
• Never tweaks my geometry
• STL output is flawless
• CAM simulation & G-code output available for various 3+ axis CNC mills, including the 5-axis Pocket NC
• You can loft (morph) smoothly between two arbitrary 2D shapes; so if you want a handle that starts as a chamfered square and ends as a circle, it'll do that
• More primitive types, including spheres
• Ability to easily do repeating linear or circular patterns, and mirroring, at the sketch and object level
• Many, many more tools, which always work exactly as advertised, and without ruining the geometry
• Ability to counterbore and thread holes, although threading doesn't work right on holes that pass through multiple objects (last I checked). You can also do this in SketchUp, but threading is about as fun as a root canal.
• Directly imports and exports STEP and IGES files, so you can edit stuff made in commercial modelers (including all SeeMeCNC open-source CAD files)
• Allows physical modeling of hinges, springs, etc. - you can actually move assemblies relative to each other about their joints, as they would in real life
• Finite element analysis and other fancy stuff for engineering
• Pretty good ray-traced rendering system built-in
• The community support is awesome. Autodesk has a downloadable screen recorder that can upload a video of you trying something in F360 directly to their support forums, where others can tell you what to do, or send you screen recordings of how to do it the right way. I asked a few questions, and they were all answered within a day or two, sometimes with videos.
• You get all this for free as long as you're making under a hundred thousand a year.

[Xenocrates]

A few things to mention on the threading:

Trapezoidal threads get broken occasionally, although more often DIN 103 than ACME (This is fixable by editing a few config files full of thread definitions, and you can add your own thread profiles to the tool).

For most files and applications, use the default cosmetic threads. Doesn't make a difference to almost anything. Stuff is modeled as the correct pitch diameter etc, so internals fit in externals (Although be careful to not use that to order stock, it won't work unless you're using a forming die or something else crazy). For those where you want a synchronized modeled thread (Larger printed threads for example), it's far easier to use a dummy body with the inverse of the thread, and use that as a subtraction tool. Alternatively, start it as a single piece.

For more exotic threads, you can define a shape, then make a spiraled curve to project it along.

Also, some simulations are behind a RAM gate last I checked. Not all of them will let you do local solving if you have less than 32GB of ram (This may have changed, or be for some of the beta sims I enabled). Additionally, make sure to not use the cloud renderer or similar if you have any plans to use the cloud solves on simulations, as they use the same credits, and those can be expensive. Some simulations also cannot be run locally.

And for those who have student accounts at a school, see if you can use Maya for converting STLs or other oddball geometry to quads, as Fusion tends to play nicer with those (Since Autodesk makes both maya and fusion, I'm not entirely surprised), and Maya has a really usefull quad-draw function to lay out a new mesh by hand over broken or badly done geometry, which means you can fix misaligned vertexes and similar issues.