3D Software

[nonsuch]

I currently attending a short Local Authority evening course aimed at 'Absolute Beginners to 3D Printing'. Which describes me exactly. The tutor is using Blender to produce the mesh and Cura for the slicing. Blender does not seem to be particularly suitable for the kind of stuff a railway modeller might want to do. Can any of you with more experience suggest anything better (and preferably free!).

Thanks

Neil B aka Nonsuch

[EvadingGrid]

3D is hard.
People want easy answers.

The best advice is to keep an open mind, because you need to change how you think about objects. Artists are taught to see the world as composed out of a few basic primitive shapes. We humans look at a coffee mug and don't as a rule think Torus and cylinder.

The other thing is CAD is pretty limited and time consuming. By that I mean, say I want to model a chain. Obviously, its composed of links, so I make a link as like a master copy... But to make the chain, do I copy paste that chain link OR do I write a quick loop in code ? Erm.... How long is the chain, because if its short its best to copy paste, but if its a 100 links I'd be there all day doing copy paste.

The examples I've given are not perfect, just to try and express ideas.

In short, magic bullets only exist in the warren commission report

[tebee]

I'd look at https://www.onshape.com/open-source

It's online so a bit slow, but does everything you want.

One caveat - you can only create open source models without paying for it, so it's no good for commercial projects, but for hobby use it's fine and we can all share models on there.

If I ever get any time I'm intending to do a few tutorials on there about the processes and techniques I use.

Tom

[rue_d_etropal]

Tom recommended me to try a 3D CAD package Alibre, now called Geomagic Design, it works well for me, being more engineering based. You can try it out for free for a short period, so make sure you have the time to work through their tutororial, and it is then it costs a single fee of £400 , no yearly license fees, no commercial limitation. In fact I am on my second version as I had to get a new laptop. Only problem now is Windows 10 getting in the way.
Worth trying, as it is free to have a quick play.

[csundstr]

I have used OnShape for a few models. When I was using it you could only have five parts active without open-sourcing them, so you either had to create a monolithic model or open-source the parts. It is also missing many advanced functions, so composite shapes (curves and so on) are difficult to model. The interface was a little counter-intuitive but that may have improved in the last year or so. Worth trying.

I have seen Sketchup used successfully, but it is not as engineering-based. Similarly I have known people to use Rhino.

I used to use Alibre CAD and tried GeoMagic design. Decent products, but not particularly powerful. Think of them as Microsoft Paint compared to Adobe Photoshop. Adequate for simple design work.

I currently use a licenced version of Solidworks, but the $10,000 CDN price tag once you invest in the computer required may be beyond what you want to spend. The benefit (other than using it for work projects) is that I can create models 3-4 times faster than all other products I have tried with more resultant detail, accuracy and flexibility. For example, I have a wheelbarrow model available on Shapeways in 1:32, 1:24 and larger scales; a user here recently requested a 1:43 version and modifying the model took me about 10 minutes in Solidworks. I estimate the modifications would have taken me an hour or more in OnShape.

Although you cannot use them for commercial production (you don't own the copyright) or on some of the 3D printing services where your models become publicly available, there are many sites where you can download 3D models of people, steam engines and so on. The models are usually licenced for personal use. These are usually in .x3d format, but you can easily use MeshLabs to convert them to .STL files and scale them appropriately. I found an incredibly detailed and accurate set of vertical steam engines on GrabCAD and have printed one of them in FUD at Shapeways...I now have a super-detailed single-cylinder vertical steam engine suitable for driving a belt system. All for about 5 minutes of work doing the download, conversion and upload to Shapeways.

No matter which solution you invest in, I do recommend MeshLabs as a tool to manipulate your .STL files. I generate a single .STL file of a 1:1 model in Solidworks and then do all my scaling through MeshLabs. Fast, accurate and easy to use once you find the commands (their menu choices are highly technical and often a little obscure).

One other note: several members of this board (including myself) are producing models commercially or semi-commercially on Shapeways or other 3D printing services. If you get stuck or decide that doing the drawings yourself isn't for you, you could try contacting one of us through the Trade section of the Gnatterbox; one of us should be able to help you out.

Happy modelling!

Cheers,

Chris

[nonsuch]

Thanks for your replies.

Evadingrid - I am not looking for an easy option, although software that turns a 2D third angle three view into an stl document would be nice(!)
Blender however seems to be heavy on animation tools which I don't need. However I will persevere.

Chris and Teebee's replies show that there are a lot of options, and it is not easy to evaluate them, but I don't think that my wife will sanction an investment of 10 000 in almost any currency.

Next, is it worth buying a cheap printer?

Cheers

Neil

[csundstr]

Teebee should probably chime in on this, as I believe he has tried printing at home.

In general, though, the more expensive a printer you buy, the higher quality the print, although there are other issues and exceptions to any rule.

If you are looking to mass print relatively chunky parts where accuracy can be "thereabouts", buying a printer could be worth it, although like ink printers, it is the material that will cost you in the end. If you are doing a lot of parts (figures, for example) where supports are needed, you could be looking at as much as 50% wastage in material for supports. Similarly you can expect a percentage of failed prints, especially during the period where you are getting used to how the system operates. There are numerous articles online describing add-on features that cost a fair amount to try to alleviate the failed print issues (heated build plates, coated build plates, special nozzles, free-flowing materials, etc.). When you factor in the cost of the materials, you might find the 3D printing services are cheaper.

There are also serious issues with the environment. Depending on the material you are printing, there can be serious outgassing during production...I have read of at least one case of a 3D printer killing the operator due to inadequate ventilation in the work room.

Accuracy is the other main issue. In 1/24 or larger you can get away with home printers. In smaller scales the minimum dimensions and accuracies are pushing the boundaries of believability. Using FUD, which is capable of dimensions smaller than any home printer, I recently worked on a wheelbarrow model. In 1/24 and 1/32 the handles could be a scale 1.5" in diameter. In 1/48, the handles were a slightly chunky 2" in diameter. In 1/64 the handles would be 2-5/8" diameter and in 1/87 they would be 3.5" in diameter. As well as this, the nature of the design is such that it would require significant support structures to print at home and would likely have a high failure rate as well as a high material usage rate. FUD is printed by stereolithography in support wax, which is not available in home systems yet, but which allows this fine detail and doesn't require permanent supports (the wax supports the parts during production and is melted away and reused after printing).

As much as the Form 3D system looks like the ideal solution, I am leery about trying it. The Shapeways equivalent has serious issues with the breakoff of support structures. I have written on the Gnatterbox about these issues before. The liquid acrylic printing medium is very brittle once cured.

One alternative I have considered is master printing via Shapeways. You could either get a part printed in FUD or in casting wax through Shapeways and use that as a master for casting, either through investment casting with the wax part, or mold casting with the FUD parts. Most major craftsman model railroad magazines have published articles on casting your own parts in urethane, plaster, low-melt metals and so on. The only difference is that the masters can be made via 3D printing instead of by hand in Styrene or wax. You could even do "part multiplication"...3D print one part as a master and make a singleton mold, then cast 10 or so and use them to make a 10-piece mold. There is even the option, although I haven't tried it yet, of making a 3D printed rubber mold. Receive the mold from Shapeways and then start mass-producing bricks, ties, and other scenic parts in plaster.

Chris

[henrix72se]

I have just about 10 days (evenings) with the free Autocad 123d Designer program and it is great! I did know absolutely nothing to start with and yesterday I come to this level on my new Atlas wagons. It is not only easy to use, there is also loads of clips on youtube which describes all the functions.

Henrik

(more on my site)

[PeterH]

That looks great. What operating system does your 123d designer work in? I've tried the iPad version and was impressed.

The Autocad website says they aren't developing 123d designer, but it and some of their other software will be replaced by something new. I'm wondering if there will be a subscription then, since that's the way the world is going.

[tebee]

The slight problem is that 123d has just been discontinued .....

[henrix72se]

Well maybe, but it does what it should so not much need for updates ..

Henrik

[henrix72se]

That looks great. What operating system does your 123d designer work in? I've tried the iPad version and was impressed.

The Autocad website says they aren't developing 123d designer, but it and some of their other software will be replaced by something new. I'm wondering if there will be a subscription then, since that's the way the world is going.

I have windows 10 but it works on previous versions to.

Henrik

[adamc]

Try tinkercad as a very simple entry point. It's web based and so students can carry on at home. You can progress then to more advanced options later that require installing software etc. The stl's it produces can be used in slicers etc to make 3d models.

[rue_d_etropal]

Someone mentioned tinkercad to me at the weekend and said that it was OK for initial designs but could not then modify them.
Also when it comes to costings, then I am concerned some still don't appreciate many free packages are not for commercial use. Student versions of software are for educational use as well. Great to have a play with initially , but not for commercial use.
Companies are having to get their money from somewhere, which is why there has been a trend towards subscription software. one reason I have stayed with my original(although I did have to buy a new version for a new laptop) software. I don't pay a monthly fee, and it is licensed for commercial use, so my designs are mine. No money grabbing lawyer can say I not not allowed to do what I am doing, and therefore claim I don't own my designs.

I suggest trying out various free versions, including trial versions and see what works for you.

[adamc]

I think they might have meant that you cant directly modify a STL that you import into tinkercad perhaps, because you can certainly re-visit anything that you've done yourself from scratch in it. You can still chop up and add to imported STL's as well of course. Once you have the beginner basics down you'd want to move onto a fuller package.