3D to 2D slices

[Jeff Wilkins]

I am trying to create 3D objects with my laser engraver. Since the engraver can cut a 2D shape with a uniform thickness I can stack these layers on top of one another to recreate the 3D part (not perfect, but for prototyping and proof of concept would work great). I am trying to take a 3D model and slice it into vertical layers. These layers would be uniform in thickness based on the material used. For example 3mm baltic birch plywood. Does anyone have any experience doing this sort of thing? I use Autodesk Inventor to make the 3D model, I can export to STL or other file.

[Gary Hair]

One of Vectric's programs does this - vcarve pro maybe?

Gary

Edit: I checked their website, it's Cut3D - $299

[Michael Hunter]

I thought STL files were describing stacked layers anyway - that is how the original STL machines worked, by building up layer on layer.

I have seen a few slicing utilities in the past, but they were always too expensive just for playing with, so I gave up. Too long ago to remember what they were.

[Rich Harman]

You can import the STL into SketchUp (using a free plugin) then slice the model into layers (using another free plugin) and then export the faces of each slice as an SVG (yup, another free plugin).

STL importer: jf_stl_importer.rb
Slice : SliceModeler.rb(for slicing in two planes) or Slice43.rb (for slicing in one plane)
SVG Export: FlightsOfIdeas

Also useful;

STL/DXF exporter: skp_to_dxf.rb
Gear creator: gear.3.rb
Unfolder: flattery

[Zsolt Paul]

I am trying to create 3D objects with my laser engraver. Since the engraver can cut a 2D shape with a uniform thickness I can stack these layers on top of one another to recreate the 3D part (not perfect, but for prototyping and proof of concept would work great). I am trying to take a 3D model and slice it into vertical layers. These layers would be uniform in thickness based on the material used. For example 3mm baltic birch plywood. Does anyone have any experience doing this sort of thing? I use Autodesk Inventor to make the 3D model, I can export to STL or other file.

...you mean I am not the only crazy one out there? LOL Not sure what you are trying to build, but this was a monster project!
214287214288214289

[Zsolt Paul]

I am still trying to improve my method and am playing around with Rhino 3D with the grass hopper plugin.

[Jeff Wilkins]

Okay, so it looks like there is really nothing that makes it easy :) I can actually do section views in a idw file from inventor, but this takes a lot of time as well. I think this might be easier than the proposed method though. Thanks for the thoughts.

[Paul Grothouse]

In Inventor (assuming it is a lot like solidworks) you can define reference planes and take slices of each plane, convert the solid enties to sketches and export the sketches as dxf or stl files.

Depending on the CAM software you use, for example with MasterCam or AlphaCam, you can just use dynamic planes and contour around the solid at the plane. This would be the fastest and easiest way to deal with this. With MasterCam or AlphaCam you can then nest all those contours onto sheets of plywood.

[Dee Gallo]

[QUOTE=Zsolt Paul;1818343]...you mean I am not the only crazy one out there? LOL Not sure what you are trying to build, but this was a monster project!

Paul, that's ambitious! Crazy, maybe, but impressive.

[Rich Harman]

Okay, so it looks like there is really nothing that makes it easy ...

That depends on what you consider easy.

The Slicer43.rb plugin works pretty well. You enter the thickness and offset and a couple of other parameters (if you wish) then it will slice it up for you. It even lays out all the sliced pieces in one plane. It really only takes a couple minutes.

[Bruce Boone]

I just sintered powdered bronze on my YAG for the fist time tonight. It worked great. I have some solid washers in metal where it was just powder before. I'll need to see where this leads.

[Zsolt Paul]

[QUOTE=Zsolt Paul;1818343]...you mean I am not the only crazy one out there? LOL Not sure what you are trying to build, but this was a monster project! Paul, that's ambitious! Crazy, maybe, but impressive. Thank you Dee. Its not for everyone, but that coffee table has been a big hit with customers who are looking for rustic, yet elegant pieces. The shape is actually based on a tree.

[Joe Hillmann]

I just sintered powdered bronze on my YAG for the fist time tonight. It worked great. I have some solid washers in metal where it was just powder before. I'll need to see where this leads.

I am not trying to hijack the thread here but could you put up more information on sintering? I have never heard of it before but it sounds like a very usefull process.

[Khalid Nazim]

This is incredible and really impressive. What a trip it is to see such a great use of technology to produce art.

[Bruce Boone]

Sintering is melting small beads of material together to create a solid. Many of the 3D rapid prototyping technologies use this to build solid metal or plastic parts. Check out bathsheba.com to see some of the more radical artistic uses for it. There are commercial places like shapeways.com where you can email a CAD solid model and get back a physical part, either in plastic or metal. It was just really fun to try it and have it work at home. It takes a lot of power density to actually melt the metal like that. I love any variations of the technology. Cardboard lamination is a great process available to anyone with a laser.

[Joe Hillmann]

Where do you get the powder from and how thick are the layers? I see you have bigger machines than I do. Do you think it could be done with a 40 watt yag if it is run slow enough? Or is that just not enough power no matter what the speed is?

[Dan Hintz]

Bruce,

You need to add the power of your YAG to your sig... I'm already envious of the ULS's power, might as well go all the way and make me outright hate you ;)

[Bruce Boone]

Don't hate. I got it to work with the CO2 laser also. I ran 100% power and about 2% speed, and that was too much power. On the YAG, I seemed to get better results by defocusing it by a couple of mm's. I could definitely get way too hot on the YAG, so it doesn't seem to need all that much power. There are powders of bronze, silver, copper, and steel out there, like Hadar's.

[Chuck Stone]

hmm... I'm sitting here with powdered metals.. never thought about using the laser for sintering.
Don't know that my lowly 30W would do it anyway, but I've got copper, nickel silver, bronze,
brass.. all -325 mesh. Think that might work?

[Bruce Boone]

It needs to be really small particles. There's no harm in trying. Full power at the slowest speed.

[Joe Hillmann]

As long as the thread has been thoroughly hijacked.... http://www.rm-platform.com/index2.php?option=com_docman&task=doc_view&gid=11&Itemid=5

I (http://www.rm-platform.com/index2.php?option=com_docman&task=doc_view&gid=11&Itemid=5) find it interesting that they can get the metal to bond with as low as 2 watts with a pulsed yag at 5kHz (with pulsed yag the output can be several hundred times what it would be if it were unplussed when pulsed slow, and 5 k is pretty slow)

[Eric Ucci]

Jeff,
Forget everything you've been told and check out "123dmake" from Autodesk. It will blow your mind.
I'm an Inventor user, so I can understand how much time is going into this process for you. 123d make does a couple things only, but it does them flawlessly. As long as you have a watertight stl 3D object, it will instantly generate the layers and the cut files for you.
One caveat...
It currently only runs on Mac OS. Autodesk is supposed to release a PC version soon. It's one of Adesk's acquisitions of a software company that was making a really cool product


Check it out!

[Bruce Boone]

I was looking at that today in a design engineering magazine. I'll have to wait for the PC version. It looks like it will be fun for kids to do as well. In that same magazine, I saw where you can lease the new 3D desktop printers for only about $250 per month! They make 3D plastic parts in an ABS material and have .010" resolution between layers. That would be fine for larger prototypes like mouse designs and similar things. I'm liking the direction of this kind of stuff. I had prototypes made by stereolithography back when it was first available, and the parts were very fragile and the material shrank a lot. The new stuff is almost as tough as real plastic parts.

[Rich Harman]

Thanks for pointing that out. The trial version expires in Feb. I wonder what it will cost...

[Kevin Groenke]

Rhino has a "contour" command that can slice as well. Its easy: select objects>contour>select axis>input thickness>input distance apart: Rhino generates the curves, surfaces or solids depending upon geometry selected. Then use RhinoNest to fit them onto a sheet and cut them out with your laser, cnc, plasma, waterjet, etc. If you've got 5 axis capability, this is an awesome way generate a physical object from a digital model using sheet material. If you've got only 3 axis, you better like either steps or sanding

Slicer.rb is another SketchUp plug in that works similarly.


http://vimeo.com/32402540

[Jeff Wilkins]

123d Make looks like the ticket. I have a few students with Mac's at home so they are going to give it a shot this weekend. I will post what we figure out hopefully next week! Thanks for the info.