"Review of 3D-printed Planets from Shapeways" Topic

Specifically, the Earth, Mars, and the Moon to scale, in full-color sandstone:

link

I'm all for pre-colored, but think the prices are such I could find a local painter to do up a couple of ping pong balls to look as good.

On the other hand, I'm still tempted… ;->=

Excellent coverage!

Doug

The other thing that 3D printing gets you is texture. I only mentioned this in passing in the review, but the Earth model does have some height to the mountain ranges.

I'm not sure if that makes a difference to you, but it is something you don't get from a ping-pong ball.

(And you're quite welcome.)

At that scale the earth should be perfectly smooth ….

At that scale the earth should be perfectly smooth ….

Each of us has our own threshold of suspension of disbelief. I held back a similar comment because of that.

Does make a difference, and on the downside, to me.

That said, I was also going to comment on the texture paint can leave. Some of our local boys can put it on pretty thick.

Even drybrushing can be a bit pebbly. ;->=

Doug

At that scale the earth should be perfectly smooth ….

A couple of thoughts:

Shapeways says that the minimum detail size for sandstone is 0.4 mm. If you're going to do any relief, that's the smallest you can get.

Based on my experience with printed minis, I'm pretty sure that I can feel details at least as small as 250 microns. An accurate scaling of Everest would be roughly 1/600 of an inch (so one-tenth what sandstone printing can accomplish). Could I notice details that fine? I have no idea.

Lastly, the relief might not be intentional — as I mentioned with the moon, different colored sections might shrink at different rates, and the "elevated" ares are different colors that immediately adjacent areas.

Before I throw my 2 cents in, let me give you some background. I have been an engineer since 1998, and having been making models with rapid prototyping for about eight years now. Note, these models re everything from industrial products to model railroad and gaming products.

All that said, be sure you know what you are buying when you buy a rapid prototype from Shapeways and elsewhere. Detail is limited, curves are not really round, but more like sheets arrayed to a curve, and the models are usually more delicate than typical plastic and metal figures. Whenever we used RP to make masters, we would make a second master from it, in pewter, and use that one for making production molds. While Shapeways uses industrial machines, a lot of modelers have gotten into the RepRap and MakerBot machines. Quality on those is worse than what industry had, 15 yrs ago!.

this sounds like a great project for my high school engineering students to do next fall as an intro to 3D printing. If they can do this, they will be able to rapid prototype parts for our FIRST Robotics Challenge robot.

Pilum,
Be sure to have them research the material properties before printing, as the materials can differ beyond what is desired. I suspect that the Shapeways materials may be borderline for your needs. We use Quickparts for engineering prototypes. I can get my contact info for you Monday if you are interested.