Stereolithography

[beegee]

As there's been mention in a couple of threads about STL file types, I wondered if anyone has come across, or is using sterolithography to produce 3D models.

Dedicated "plotters" will actually build a model from your CAD file. The models are made from a starch substance, which can be drilled, sanded and painted to create the final product.

Sterolithography has been used for some time in manufacturing to create protypes, often with liquid polymers which solidify upon contact with a laser. The models are built in layers from bottom to top.

Current tecnology for architectural models uses a powder binder which is spread in a thin layer, followed by an ink jet printer head which lays down a binder layer on the cross section of the part being created. The finished model is produced in a similar manner to a plot.

Apparently some model builders will work with VRML as well as STL files.

The most affordable 3D printer produces a models of maximum dimensions of 8" x 10" x 8" high and costs $32,000 (US). It will take anywhere from 3 1/2 to 10 hours to build a model. ( Still much faster than I would do it ! ) Larger machines can build up to 20" x 24" x 15' and cost around $ 175,000 (US).

Like most electronic technology, we can expect those prices to come down dramatically over the next few years, as the technolgy takes hold.

If you want to see more check out this web site (www.zcorp.com/products/printersdetail.asp?ID=1)

[mlgatzke]

Beegee,

I teach at a Community College in Iowa (Midwestern U.S.) and we have a rapid-prototyper. I've been offered unlimited use of the system - provided that I pay for my own "material." This has 2 bad points: 1. The machine we have will only produce a model about 14" cubed and 2. The material is extremely expensive. Our machine uses the "plastic" pellets to "feed" the machine. We produced a chess piece as an experiment (approximately 5 or 6" high) and it cost almost $200 for the material.

I've been told that we are currently finding funding for one of the newer "powder" machines, but I'm afraid it's just too expensive until then.

[tatlin]

Beegee,

We like Zcorp - they are right up the street from us in Burlington, Ma. Apparently one of the founders literally hacked together the first prototype from a few ink jet printers down at MIT.

The manufacturers and service providers are usually pretty happy to talk to architects (and sometimes even let you run a test model for free. Of course, the first one is always free... 8) )

One thing to note is the size constraint and the resolution possible on these machines. If you are printing out a model at 1/16"= 1'0" or 1/32", even 4" curtain wall mullions will not come out very well (at least they did not a few years ago). I know Zcorp came out with a new machine last year that was supposed to have better resolution.

The time to plot is not that bad. I remember we had an old pen plotter that took almost that long for a 30"x42" sheet!

Anyway, I can't wait for the day when you can sketch up a new study model in the morning in Revit, print it out over lunch and then take it to a design meeting in the afternoon. It would be pretty interesting to plot out the site model for as well (no more cutting chipboard for every topo line!).

matt jezyk
autodesk revit

[J-G]

This is a very intersting topic. Are there any other makers are are in the same price range and quality range as zcorp. It would be intersting to here from anyone actually using such machines. What is the client reaction? How are you justifying the price of such a machine...or are you taking it to someone else.

Also if an office was to buy a machine and then offer it to other firms, what do you think a model would go for. The size seems quite small, but for the types of houses we do (large and spread out) I think you might be able to create a few smaller models and then assemble them for the larger total effect. The zcorp color printer looks really interesting. What if you could create a rendered model and print it? That would be pretty neat.

[beegee]

Jon,

Refer this thread (www.zoogdesign.com/forums/phpBB2/viewtopic.php?t=1147) also.

[PeterJ]

I was away when this thread came up and missed it, but its a field that I am also interested in. There is a company in belgium who offer larger machines and I have lost there details but will dig them out if anyone is interested.

Where I have seen this type of technology put to good use is not in modelling but in making things such as complex one off or two off light fittings and what have you. As has been noted the time can be a bugbear but the people who are making best use of the technology are looking at how to produce nested products as it is primarily the layering that takes time and the number of solid points in a layer has a lesser impact. So if you want a cup then a nest of cups like a childs toy will take the same length of time to create. Moving on from this idea you can make folding meshes and hinges in one piece so people have been able to produce semi rigid materials that fold out to form a screen and provided this has a module size no larger than 10" or whatever the limiting dimension is the screen can be as large as the module thickness divided into the depth of the printing area.

[cwentworth]

I work a service bureau that uses ZCorp machines to make models for architects. We also sell the printers. The new printers Z510 have four times the print resolution than the old ones. The color is much better also. If you want more info please let me know. Attached are some pictures of models that we have made.

Chris
3DRP

[truevis]

I work a service bureau that uses ZCorp machines to make models for architects. We also sell the printers. The new printers Z510 have four times the print resolution than the old ones. The color is much better also. If you want more info please let me know. Attached are some pictures of models that we have made.
Can you share your process from Revit to 3D print?

RVT>DWG>VRML or RVT>DWG>STL? STL appears to be monochrome but VRML has colors.

What programs for the conversion? Easiest way to set colors?

I tried my 1st ZCorp print with DWG to VRML from Viz. Came out, but some parts were too thin and they broke.

[cwentworth]

Right. Revit outputs the model 1:1. when you scale it down to the scale you want the walls will be too thin. Thicken the walls and windows before you output it from Revit. You could make it even more simple by deleting the interior walls and stairs, it's very easy in Revit. Scott recommends saving a "Model" version of your project. I think that's wise!

As for the colors, Revit assigns goofy colors to the DWG file. Yellow and red and blue. It would be nice if it output the colors you assign in the program. Hopefully they will think about adding that functionality. In the mean time you could bring it into 3D Studio to map color and even map textures like roof tiles, or simple RGB color in the printer software.

Please let me know if you have any other questions! I love this stuff!!!

Chris
3DRP


Can you share your process from Revit to 3D print?

RVT>DWG>VRML or RVT>DWG>STL? STL appears to be monochrome but VRML has colors.

What programs for the conversion? Easiest way to set colors?

I tried my 1st ZCorp print with DWG to VRML from Viz. Came out, but some parts were too thin and they broke.

[zanzibarbob7]

I have a question on getting a Revit file into STL format. As stated above, I exported my Revit model as a DWG>then opened it in AutoCAD 2007. From there I am confused. I try to export is as a STL file but nothing appears in the location I have elected to save it to.

At one point I seemed to have it saved to my elected file but when I closed AutoCAD2007 it disappeared. Would someone post a more detail explaination or send me an email with appropriate screen shots? Actually, a tutorial on it would be better. I tried to get t his from Zcorp when we attended a demo but they seemed unclear concerning Revit.

We also heard that this was possible with Sketchup. True or not?

Thanks

[zanzibarbob7]

From the response I am assuming this is a little used process? Perhaps some one can direct me to an appropriate resource.

Thanks.

[Andre Baros]

We used LGM Manufacturing when we did ours they were very knowledgeable and have their own script for converting Revit files to STL files and adjusting the tolerances. It was a couple years back so they could only be better at it by now. Our contacts were Charles or Jason, LGM Manufacturing 970-827-5274. We would use them again, we just haven't needed models like that lately.

[zanzibarbob7]

Thanks for the reply Andre. I have contacted one of the vendors, requesting the conversion process and am awaiting a reply. At the seminar with ZCorp they said it could be done but I have never gotten a solid reply stating the proceedure.

It is also one of the things on my wish list. Direst SLT file creation along with the EPIX creation for Piranesi. One can hope.

[Andre Baros]

Simple conversion to STL isn't enough. You also need to be able to add an intelligent scaling factor for the tolerance of the output machine (and shipping method as we learned). If you're printing your model at 1/16 of an inch than any less than 1' won't print and anything less than 2' probably won't survive shipping.

Good luck with the process, for the models we used ZCorp for there was no other way to economically build all of the curved surfaces and details that we needed and the models looked pretty good.

[zanzibarbob7]

I just sent anohter email to ZCorp requesting the proceedure. Will post it here if it comes. I know ZCorp has it's own software for scaling and realize that you have to take structural size into account when scaling. It's easy to click down to 1/20th scale, then have a wall too thin for durability.

Thanks again for the input.

[Scott D Davis]

We've also found ith Zcorp printers that you need an STL file for monochrome "white" models, and VRML files for models with color.

There needs to be an easier way.

[zanzibarbob7]

Scott,

Yor are right about that. I prefer the white model as the color is not very true and can detract from the intention of the model. Like focusing on the drapes as opposed to your architecture.

If I don't hear from them Monday I will give them a call. They state that Revit models can be sent to their machines, but not how. I guess I could send the Revit model to Viz or Max for STL conversion, but it doesn't seem like you should have to.

Good article on detailing in the AUGI publication. Thanks.

When I attended the Visulization conference in Boston this summer, someone, I think it was the president of Occulus, stated that the prices were coming down so quickly on these machines that you could afford to have one at each office. Maybe in three or four years. Like printers. That would be nice.

[Andre Baros]

There was a similar thread to this on another forum and a product design pointed out that after having one around for a while they got rid of it for several reasons.
1: Mess, they said that the dry compound was quite messy and you would probably want to have a room dedicated to the machine... at which point the cost is much higher.
2: Infrequent use, unless you're a service bureau cranking these things out all the time, the machine tends to have problems if it just sits around. It works best if its running pretty regularly so you'd need to produce a lot of models to keep the machine in top form.
3: Training, it's not as easy as it sounds. They pointed out that by the time they learned how to use it they were probably more valuable as an operator than as a product designer because there was so much knowledge required to operate the machine effectively. Mostly on the prep and maintenance side.

Food for thought... it'll have to be as easy AND clean as a printer before you see them around most offices.

[cwentworth.135147]

I used to use ZCorp technology to make models and it worked good. But now I'm at
Spectrum3D.com where we use Stereo lithography to make models. Not a lot of architects are using it yet but the ones that do make some very impressive models. I have white plastic like resin and clear see through resin. So you can simulate glass and windows. My company also has an Eden polyjet for small very accurate models with .0005" thick layers!

I'm happy to explain the rapid prototype technology to anyone who is interested. I've given a few lectures on the subject as a mater of fact. I love the RP technology and architectural models are the most impressive I think. Whether you would be a customer or not makes no difference. I'm here to educate and broaden the understanding and use of RP technology in general.

The first RP machine was invented in 1987. It was a stereo lithography machine by 3D systems. Since then several technologies have come about. Like polyjet and 3d powder printing. If your interested in more information a man named Terry Wohlers has a very in depth book about RP technology and the current state of the industry. His web page is http://www.wohlersassociates.com/.

Thanks all!
Chris Wentworth
Spectrum3d.com