Thursday, June 14, 2007

Yard Art

My folks have about 1000 bird feeders in their yard. They also have a mariachi band, which even though the house next door is for sale for an unGODly amount of money, must be pushing down property values.

Still, they say the apple does not fall far from the tree and I guess I am no exception. Today I completed the project that was featured in a couple of previous posts.

Here it is:

It is a wonder to me what some time off, nice computer hardware, wildly over powered CAD software, and a fairly expensive CNC machine can add up to. This is one of the two projects I have really wanted to do since we first got the table last year.

If you haven't been following, I ordered a toy skeleton kit online and then I scanned the pieces into the computer. After I did that I wondered for a little bit why I just didn't scan the instructions, which would have been much easier to trace. But who knows, maybe that image doesn't match the pieces exactly. I ported the image into AutoCAD and blew up a kit that was roughly 21 inches to 96 inches (96/21 makes for about 4.5 times the original size). I picked 96 because that would fit on a single sheet of plywood. In hind site I think maybe this budget restriction was an unfortunate stipulation on my part.

So then we have several hours of tracing in the computer. The CNC program wants to see closed polylines for each tool path. I think there was about six hours in this stage total. It might have been a little less, and had I been doing it for work it would have gone even faster.

It's at this point that I start to notice some things about the kit. There are some features of the pieces that appear to sort of depend on the scale of the piece. While drafting I notice that a few of the notches don't appear to be right on the centerline of the piece and things like that. In the small size it probably doesn't show much of an error when assembled. Blown up? Well at this point I am committed, so all I can do is cross my fingers. It does lead me to wonder if there are other things that depend on the scale or the material to work properly. A small annoying voice in my head begins to ask me if I think it will drop under it's own weight.

With everything drafted I go shopping for material. In another somewhat ill researched decision I decide to go with pressure treated ply so I don't have to paint. Season and weather and the like mean the 23/32 pressure treated ply is actually more like 0.8" More for your money you say? I say my slots are 0.750" Press fit is nice though.

The router BLAZES through the stuff. 66 minutes to cut the whole sheet in two passes and I imagine I probably could have doubled the feed rate. But when you only have one bit you tend to be a little more conservative.

Assembly went fairly well. Here again we discover a few economies of scale we lose when doing a larger version. A couple of things that really don't want to be square, one or two things that probably don't want to be flat, but overall a very smooth process. I barely used any glue, only stapled two joints, and only broke one piece which was easily mended.

Assembly complete, I load up the truck and try to make the drive home without wrecking my creation. On the way I have thoughts in my head of selling the piece to someone that sees it in the bed of the truck and never even getting it home. Briefly I contemplate what a good price point would be and what URL would be good for a sales website. One woman does shout at me while we're stopped at a red light: "Did you make that? Neat!"

Home with no disasters, I unload and try to find the best spot compositionwise. I think it looks pretty good.
So, spread the word. I think I am taking orders. I have the trike drafting and debugged. I know I can also do a Tyrannosaurus, Stegosaurus, and a Spinosaurus. Those will just mean more drafting. I've also seen a pterodactyl, which might look cool hanging from a tree - but I don't have that kit. I've also thought about how it might be possible to work a child's desk into one of these, which I think might more justify the required price tag. Also I wouldn't mind trying to do one out of clear acrylic, but that would require some kind of commission and there are some flexi/bendy advantages from the plywood I would lose.

Anyway, seems to be a success, and not at all a bad way to spend a day.



8 comments:

elj said...

I've got three or four of those things (original scale) lying around my parents' house... including a pterodactyl! If I thought I was going to be in Pittsburgh anytime soon, via Cincinnati, I would offer it to you.

andrea said...

how much? seriously. i would very much like my new house populated with giant dinosaurs.

oh, and hi again :)

bk said...

this is a great idea and it looks fantastic, but I wonder whether you can really take someone else's design and sell an enlarged, but otherwise exactly identical version of it.

David said...

Definitely I think if it were to grow to the point of a business I would have to license the design or come up with one on my own.

For that matter, the shop would likely want a cut too.

For a couple pieces I don't think it would be worth anyone's time to pursue.

Anonymous said...

Right on David. You have a gorgeous yard. If mine didn't look like a strip mine I'd consider buying a file from you and cutting it here.
-deano

TC Schwindling said...

That's really really cool! My grandmother bought me this huge wooden model of St. Paul's Cathedral that's supposed to have a 4'x6' foot print when it's finished. Maybe we can blow it up and build a life sized St. Paul's where that Gates Building is supposed to go.

Anonymous said...

That’s amazing, he looks like he will attack at command.

Julie

Doug Morency said...

search for cnczone 3d puzzles, there is a dino ttf font that has the plans for a few dinos, and there is a ton of other models that can be scaled to any size.

Have fun
Doug