Thursday, September 26, 2013

More Fun With Math, and a Joke

I did a little calculating on the printing cost.  Unfortunately, once you assume a hollow model, the final price is exquisitely sensitive to the wall thickness.  So the difference between a generous thickness and getting right down to the margins of what is printable is a range of 4:1 in cubic centimeters of plastic, hence cost.

And this is the point at which the project forks.  The original request was for a hex mat model; detailed enough to be representative, but no functioning hatches or interior detail and, indeed, few small details of the sort that might break off in transit to the game and back.

The laser-sintered nylon (PA 2200) Shapeways offers as "White Strong Flexible" is the best choice for this, and can print down to a wall size of .7 mm, but given the strength should probably be between 1 and 2 mm in wall thickness for this model.  At $1.40 a cm^3, the hull comes out under $25.  So as a guess, the entire model is around $40 in this material.  Sans wheels, which as solids add as much as $8 to the print.

Since I intend to add some of the surface details, including suspension and hubs, jerry cans, lifting eyes, etc., I figure the complete and total print cost will be a bit over $60.

Here's the current state of the thing:

I am ready now to close up the hatches and vision blocks, add thickness to the walls and make them "watertight" (necessary for printing), and then extrude some select surface details around the vision blocks and hatchs.  The Rh202 barrel is just a mock-up for me; the final print will omit the gun barrel as it is too thin to print.

Actually, I have one other step before that.  Right now the mesh is at arbitrary scale (it is scaled to how big the drawings were in the workspace).  I need to fiddle with the bounding boxes and so forth in order to get a true scale representation, so I can keep the printable mesh within the Shapeways design rules.  Of course Carrara is poor at dealing with changes to its workspace defaults (and what else is new?)

The second fork is a diorama version with posable hatches (although I shudder at the idea of interior detail).  The thinner walls are more than offset by the possible upgrade to SLS ("White Detail" on Shapeways); a full $2.99 per cm^3.  I've worked with the SLS more than I have with the nylon, so I am not a good judge yet whether this materials upgrade is strictly necessary.

There has always been a military modeling community in 1:56, although they tend to gravitate to World War II era.  There is a growing number of models available of later armor these days (by much better modelers than I am), but, as yet, obscure post-Vietnam armored cars are not among them.

So there are people who could make use of this.  Enough to justify the effort, I don't know.

The putative third fork would be Poser-izing it.  Which would be a pain, mostly as my current mesh has extremely poor flow, is not Poser-optimized, and isn't UV mapped either.  Wouldn't hurt to have another 3d model in my online store, though...

Someone landed on this blog with a search for theater tech jokes.  Given time I'd remember a few.  At the moment all I remember is traditions at certain theaters, like "Pumatic" tools at the Rep (due to a badly spelled drawer label on the road box).

And a few lightbulb jokes.  The kind of theater person who says each, you can probably fill in on your own...

"How many ___ does it take to screw in a lightbulb?"

"It's a LAMP, dammit!"
"It's not a prop or a set piece.  Get an electrician to do it."
"Ooh, I like it.  Keep it!"
"Five six seven eight!"

And related, there's the one a bass player told me; "One, five, one, five, one, five, one, five, one, five......"

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