Q for the 3D design folks

[bbussey]

As Jason indicated, the educational version of SolidWorks is in the $100 range for a one-year license and it has the full functionality of the standard version.  Find a student or faculty member in your family to purchase the educational version for you from any number of online education software websites.  Rhino 3D also has a fully-functional educational version that doesn't expire after a year and, I believe, allows you to upgrade to the standard version at minimal cost.

[DKS]

If you have reached the size limitation in SketchUp, then you've quite likely reached the rendering limitation of Shapeways. Kind of doubt the result is going to be acceptable. But then, I ain't no expurt.

[peteski]

I'm pretty sure that HuskerN mentioned that all of his wonderful creating are done in ..... drum roll ..... SketchUp!

I will also add my vote that in SketchUp desiging in 1:1 scale (or anything much larger than N), then reducing the design to N scale as a final step works the best. While SketchUp is capable of working with small dimensions, many of the features do not work as expected with such small objects. Don't know why, but I experienced that myself. Maybe because it's original purpose was for modeling shapes of 1:1 scale buildings (which are rather large). 

[PiperguyUMD]

I did my WM 2-8-0 in sketchup!  The program is kinda quirky, but if you tinker with it, you can get it to do most of the things you want.  That being said, it struggles with complex curved surfaces.   Something like the nose of an F unit is very difficult in sketchup.

[randgust]

You did ALL that stuff in SketchUp?   Or just the 2-8-0, which would be enough even if you didn't. That's amazing.   [Applause icon] Makes me feel better, as I learn the program, that its capable of that kind of work if you get into it deep enough.

[GimpLizard]

I've have over 20 years professional CAD experience. And have been using Solidworks since 2003. Frankly... I hate it. I find parametrics terribly constraining. The goal is (or should be) to create the model using the fewest number of features possible. The fewer features you have, the more robust the model is. The more feature 9and parent/child relationships) you have, the more fragil the model. You really have to think about what you want to do, and in what order, to get the results you want. http://www.solidworks.com/

I much prefer the freedom of "direct" modelers, such as KeyCreator (formerly called Cadkey). There is no history tree. There are no constriants. There are no parent/child relationships. Just pure geometry. Light-years faster than Solidworks. And, I believe, easier to learn. http://kubotek3d.com/home.aspx

However... both Solidworks and KeyCreator are "mid-level" CAD systems. Costing $3000 or more. So, if you're looking for something more affordable, I would suggest TurboCAD Deluxe. (http://www.turbocad.com/TurboCAD/TurboCAD-Windows/TurboCAD-Deluxe-v20) It is also a parametric modeler, like SWX, but it's very affordable. Around $130. And while the Deluxe version doesn't support neutral file formates, such as IGES or STEP, it will export STL files, for use in rapid prototyping. And based on what happened to me, a number of years ago... Once you have the Delux edition, they might (no guarantee) let you upgrade to the pro edition ($1700 MSRP) for a discount, down the road, later on. It has more features, and handles more file types.

[wcfn100]

I've have over 20 years professional CAD experience. And have been using Solidworks since 2003. Frankly... I hate it. I find parametrics terribly constraining.

But Parametric Modeling has some very distinct advantages.  Being able to change a dimension and have it update all my parts is very handy.  Also, being able to define variables such as 'scale', 'minimum thickness' or 'rivet diameter' creates a model that can be easily sized or adjusted for different machines (with different resolutions) can save a lot of time in the end and allow you to refine a model on the fly as the technology gets better.  I do agree that is can be more cumbersome, but it's not for nothing.

There's no one-size-fits-all 3D modeler.  I started 3D modeling before there were even Surfaces as part of the main package.  It was all meshes (triangles).  I've used and taught a lot of the big name animation software and each one had it's strengths.  For me, Inventor was the best choice because it felt just like 3D Studio Max.  It works well for 'man made' type objects, but if I'm looking at something more organic, I turn to Rhino.

Jason

[kalbert]

Wow I feel like a dummy.  Full size is the trick! I don't know why I couldn't arrive at that. Why you cannot draw a circle that small I don't know either, but I drew full size and scaled it down no problem! Finding another CAD program is a bridge I'll have to cross some day, but today is not it.

[peteski]

Wow I feel like a dummy.  Full size is the trick! I don't know why I couldn't arrive at that. Why you cannot draw a circle that small I don't know either, but I drew full size and scaled it down no problem! Finding another CAD program is a bridge I'll have to cross some day, but today is not it.

Don't feel like a dummy. It is very counter-intuitive.  To be honest, I don't recall whether I figured this out myself or heard about it from others (probably the later).

[robert3985]

Wow I feel like a dummy.  Full size is the trick! I don't know why I couldn't arrive at that. Why you cannot draw a circle that small I don't know either, but I drew full size and scaled it down no problem! Finding another CAD program is a bridge I'll have to cross some day, but today is not it.

Happy to be of assistance!  I arrived at the solution quite by chance.  I had the scale drawings which I'd made from actual measurements of the real object I was drawing, so, being lazy, I just drew it full-sized, then scaled it down.

Only after searching the web for answers to other Sketchup mysteries did I discover that the program has a minimum size limitation and that reducing your model is the way to go.

[bbussey]

I love SolidWorks.  Been using it since the 2001 version.  And I don't see how the number of features is a factor on how robust or fragile a railroad rolling stock model is.  The number of features used determines how detailed the model is.  The greater the number of free-standing parts, the more "fragile" the model.  But the number of features used to design it has no relation to that.

I also design in 1:1 scale for the main details, and then shrink it down to 1:160 to finish.  The first reason is, if you are working from engineering drawings (blueprints) of the prototype, it is MUCH easier to use the drawing dimensions as-is instead of risking a conversion error while building in a smaller scale.  If you already know the N scale sized adjusted dimensions of common detail features (such as rivet heads), you can multiply that by 160, or wait to add such details after the model is scaled down.  The second reason is, if you work in multiple scales, it's better to build in 1:1 and then scale-down to the various scales as it saves double-work.  I don't add "scale specific" details such as coupler pocket placement and bolster height until after I've scaled-down the model.  But I do use the X plane (top plane) as the rail height and build the digital 1:1 model accordingly.  Then, when it is scaled-down in relation to the origin, that's one less thing to worry about.

[6axlepwr]

I use a program called Alibre or now at least it is called Cubify. I originally purchased the student version for $75.00. That license ran out a long time ago, but did not know it until I went back to use it recently. I purchased the basic program for $200.00. It was easy to learn and I still have to learn a lot, but for what I want to use it for I know enough. Eventually I would like to know more. There is a good user forum for it as well (alibre user forum).

When preparing a file and writing out an stl file for printing I set the facets very low which creates smoother rounded surface. I also set the angles low basically set everything very fine. The trade off is you will create a rather large file.

Download a free program called netfab. It is an stl viewer and will allow you to view your file to see how sharp or rough it is.

I cannot tell you the printing shop I use. I was told about this shop by a friend who is also a manufacturer and promised not to give it up. If you use Shapeways, you are at the very low end of printing. Use the internet and search for 3D printing shops. Look for perfactory printing. It is at a very low resolution and gives a better finish than stereolythography. The one I used to use is in Wisconsin and they used stereolythography.  I can't even remember the name of it though. I have not used them in a long time. I found them with an internet search. I found about three shops with high resolution machines with an internet search. I received free samples from one of them. I will tell you though, good shops are not cheap. You will pay dearly for even the smallest part. The two coupler pockets I had made cost more than the locomotive they went on. But the quality is worlds better than Shapeways. I feel it is worth the price to get a high quality master. When you do your search, look for resolution down to the 0.0006" to 0.0004" per layer range. Again, be prepared to pay for it. A cab will run you a pretty penny.

That is my experience so far with 3D programs and printing.

[HuskerN]

Brian, why are the better ships so pricey?  Is it the cost of the machine or the limited supply of services that demands the high rates?  The reason I ask is that I would like better quality than Shapeways, but obviously don't have other options for what they offer, at the price they offer it.  How long before we see other services competing? 

HuskerN

[6axlepwr]

Brian, why are the better ships so pricey?  Is it the cost of the machine or the limited supply of services that demands the high rates?  The reason I ask is that I would like better quality than Shapeways, but obviously don't have other options for what they offer, at the price they offer it.  How long before we see other services competing? 

HuskerN

I have no idea what factors in the cost. I think it is probably the cost of the machine doing the printing.

I found the shop I used to use in Wisconsin.

http://adcinc1.com/

This is a good shop. Very fine printing. Lots better than shapeways. This shop uses a stereolythography machine. I had some GE speed recorders done and they turned out great. You will still get print lines, but MUCH finer than what shapeways has.

With perfactory, I still get lines also. But, again much finer. I had a 3200 gallon fuel tank done. The curvature of the tank had fine lines along it. They were VERY easy to clean up though.  A little scraping with a knife and some sanding and they are gone.

[wcfn100]

why are the better ships so pricey?  Is it the cost of the machine or the limited supply of services that demands the high rates?

Part of the reason is the "Rapid" portion of rapid prototyping.  You have to remember you're competing for machine time with companies who are spending 1000's of dollars on their prototype and these shops are promising overnight turnaround.   So far the best trick (from BBussey) is to try and talk with a shop about your situation in that you can wait until there's an opening in the machine to run the parts.

I just found out the shop I work with is no longer an option.  I'm not sure what this mean for me yet.


Jason