The Gardner

[LLLGuapo]

I'm working at a bronze foundry where we recently got a CNC router. We have been messing with the software and hardware for a while and just made this puppy. He is about 4 feet tall and weighs over 150 lbs.

It was designed using a combonation of Silo and Zbrush.

We rigged it up with a garden sprinkler that pops out of the top of his head when it is on We call it The Gardener.

[Super Glitcher]

that's intense!!!!!
how cool

Any photos from the process?

[lemonnado]

Awesome! Are you using lost foam technique? I mill in foam and cast aluminum with good results.
Lemo

[LLLGuapo]

The process is pretty involved. We carve the sucker out of foam. This is a big one we made that required a steel armature. We didn't cast this one yet.



Then we take the carved piece and send it through the traditional lost wax process. It requires mold making all the way through to patina.

[Sebcesoir]

Geeeeeee!
Giant scale bronze casting...
Thats some serious job....

Now zbrush can be used for engeneering...!

I don't get all the process, but I guess you had a lot of molding work to do before beeing ready to cast the metal?

[lemonnado]

I cut the foam, then build the form around the foam and pour the AL right into the foam. The foam vanishes almost instantly without residue. I skip the entire wax step. The foam goes in the first seconds into a plume of black smoke. If I need a good surface finish, I prime the foam with investment slurry before building sand around it. However, the question remains is that method can withstand the high pressure (weight) and temperature of Brass or Bronze...
Definitely not Cast Iron... I tried that recently with a cupola furnace of a friend.
I don't have enough space around my house for a cupola ... otherwise... Iron is soooo cheap....
Lemo

[arbayne]

Lemonado, I have never tried to cast bronze directly into foam. I am sure it would work without a hitch except in regards to scale. A small solid object (under 1.5in.) would cast perfectly fine, but a large mass of bronze shrinks during cooling into inself, fouling the cast. For large scale bronze casting, the pattern needs to be hollow (about 1/8 to 1/4in wall thickness). In concept, I could carve out the interior by hand or machine, gate, invest and cast. This would probably work (read as "I should try this forethwith"). By throwing a rubber mold on the parts and doing a traditional lost wax casting, I can cast in series as many as I like, easily (repectively), at scale, and with predictable results. It is great to know that others are experimenting with metal casting of zbrush created sculpture!

[threetails]

this is great to hear and see, we have been working with ZB to create alot of pc's that go to our CNC router for large scale milling. we've started to mold and cast everything from fiberglass concrete and recently bronze, check out our update page.
[font='Arial','sans-serif']http://www.fdscenechanges.com/fd_news/fd_news_may08.htm[/font]
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[font='Arial','sans-serif']We are now playing with getting as much detail into our milled pc's as possible, as well testing new materials to topcoat them with. As far as burning out the foam it works great as long as you have good venting and a large pour spout were metal can be drawn from as it cools and shrinks, the foundry next door has done lots of work that way, and is working on the bears from the update email ablove, its nice to see ZB pushing the bubble upward and outword.[/font]
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[font='Arial','sans-serif']congrats on the Gardener, very good work.[/font]
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[arbayne]

Threetails, I would love to know what toolpathing software you are using. Our level of detail seems to be reliant on bit diameter and material carved. I have wanted to try a rough carve below surface in foam, spray it up with oil based clay, and carve at surface into the clay...I know the automotive industry uses this method...have you tried this? We tend to carve a bit below surface, coat with oil based clay and add the high freq. detail into the clay (fairly traditional aproach to digital enlarging in the art biz). It is great to correspond to someone doing a similiar process to ours. www.metalphysic.com

[womball]

How does zbrush play into this? And could you make a 10 foot tall sculpture of yourself with this process? ;-)

[threetails]

Womball the answer is yes, any model of any number of subtools of any character or form can be split and milled to what ever size you wish.

arbayne, we are getting into this more and more, using Zbrush and Rhino, carso, stl slicer, Tcpwin, right now, basicly using what we have from our flat cutting history, but are looking into others like Artcam, Tool path. Our cnc is still cutting things out in max. six inch thicknesses but we are looking into 5 axis and rotational milling machines, with tool changers that can handle larger blanks. right now we can stack as high as we want and cut any hole to slip over an armiture.
We have been coating with modeling clays and adding in the detail refferenced from the images exported from Zbrush, as per traditional aproaches.
We are now playing around with ZB's ability to take high frequency details and create stamps, to make sheets of texture that can be milled out and used as a texture stamp to apply back onto the model, so your getting more of what you originally sculpted. ( still testing this out, but it looks promising) but some where you have to establish the line between getting your primary and secondary forms off the table and use other methods to achive the high frequency detail elements, alot of ideas, which we pull from our staffs fx makeup experience.

It is for the most part about bit size and step over, and how much time you can leave the model on the table in terms of achieving any surface finish smooth or textured, in a production atmosphere its knowing when to move on to the next step and for every client its different, as well knowing what not to send to the table, and what to build by hand, and we are still learning. i'm not a huge fan of any additive process over the foam because it softens form too much, so hard coat which we use, is never my first choice of finish, if you can mold you should, its just a better way to transfer your surface to a perminent form, and its repeatable. When we do add we are offsetting the mesh a desired thickness and milling that, anticipating the clays or coatings thickness, but it has its limitation. we have also started to build our armitures inside the digital model and extracting them for engineering and fabrication by our welding department.

LLLGuapo, its great to see your work, and see it large, I love the process work that you've done, do you have a rotaional milling maching or a hot wire machine. what ever your doing keep it going, thats some nice work.

[LLLGuapo]

Here is a style Ive been working with, first i build a simple mesh in silo, then i bone it up in xsi, then off to zbrush to get the forms to look just right. Zbrush's ability to subtly define shape is second to none.

And guess what guys, sometimes billions of polygons are not what the doctor ordered. Oops... zcentral sacrelige

I havent taken this one to bronze yet. I do have other zbrush bronze sculptures in this style if you guys want to see them.





threetails, the carving is done with the same set up that arbayne uses, its a four axis CNC, its pretty awesome.

[Soletorcher]

wow great stuff,of course we want to see them!!

[Leshiy3d]

that's really cool
i wish i could cast sculptures in bronze directly from zbrush

[lemonnado]

I'm using rhinocam and some self made routines. I rough with rhinocam and then do an engraving path with a V-Bit. That leads to a reasonable amount of detail compared to ball end mills...
Lemo


PS:Cool thread! And yes.... I forgot the darn shrinkage 8). I have to try and rout inner/outer shell halves and then cast that. Right now I'm pretty much solid 8).

Here is a small cast I made recently. Simple sand cast. No post processing. A quickly made demo while a friend was over. A little AL cowboy who is the equivalent of two tall Kirin Ichiban can's 8))). I can cast up to a gallon of aluminium and that's it. Boy.... did metals become expensive recently.... Here it is 4$ per lbs of AL. Not to speak of Bronze or Brass...