SketchUp for 3D milling, printing, etc.

Led by Bertier Luyt


This was a very unstructured session, mostly centered around viewing some videos on YouTube and folks discussing their experiences with 3D milling, routing and printing.  It wasn’t very SketchUp-centric, but seemed to be enjoyed by all of the participants.

For the unfamiliar, the basic gist is that a wide range of machines are available out in the world that can be put to use in creating large mass-produced furniture, performing detail work and finishing of various pieces, carving intricate details, and even "printing" 3D parts.  A variety of means exist for these endeavors, basically all involve one of two things:
  • additive methods of construction, in which the work begins with a blank slate and successive layers of material are placed on top of one another until the final product is achieved
  • subtractive methods of construction, in which the work begins with an object of some sort which is drilled, sawed, routed, ablated or otherwise manipulated in order to remove material until the final product is achieved


Lots of machines exist out there for people to purchase that can perform 3D printing, milling, or routing.  Some are even straightforward to build on one's own, without great expense, like Cupcake CNC or RepRap.  Various machines may have their own data file requirements, but almost always, the required file format is STL.  An STL exporter plugin is available for SketchUp, which makes it a useful tool for DIY folks who want to give it a shot.

Even if a person doesn't have money to buy a fancy machine, it can be possible to play with the technology.  Machines are so expensive that many independent owners are willing to run jobs on their machines to generate a little extra cash flow when the machine would otherwise be idle.  You can find such services all over the internet, where you consult with them about what material to use, how fancy the machine work can be, and then send an STL file for them to execute.  Some time later, your work item appears at your doorstep.  DPT Technologies (http://www.dpt-fast.com/) is an example of a company that allows you to upload an STL file and then provides an instant quote.

One of the biggest problems with trying to export to a 3D device is that the object being constructed must be "solid".  An awful lot of the modeling programs out there let you perform operations that break solids in fantastic ways that are not obvious until a person tries to export to a 3D printing format.  In the past, determining if something was “solid” was quite a difficult thing to judge in SketchUp.  With the introduction of solid tools in SketchUp 8, this workflow will be improved substantially in the base product.

We talked about the possibilities for improving workflow with SketchUp in other ways.  For instance, what if SketchUp can be scripted to know the density of various materials and then upon using the trim tool, could show not just volume, but also weight?  A lot of possibilities exist for enterprising plugin writers.

Obvious methods of 3D construction include simple routing, cutting and milling, but there are some other exciting ones as well.

One method of 3D construction is via inkjet.  Within that field there exist a number of materials that can be used, but the basic concept is the same.  Essentially, a powdered material is placed on the surface where an item is to be constructed.  Then, the inkjet head is run over the powder, where it deposits an activator.  When the combination of powder and activator hardens, the part has been "printed" in 3D.  Successive layers of this method allow the construction of a wide array of items.

Laser cutting is another possibility that is pretty cool.  Certainly there are others.

HOMAG is a company that makes some massive machines for things like furniture construction. Check out YouTube for examples of some incredibly fast milling and routing operations that even include gluing laminated edge strips on exposed cut edges of office furniture.   Being able to perform these incredibly complex operations is basically a matter of how many axes a machine supports.  A simple 2-axis machine can only move around in the X and Y axes, carving what are basically 2D shapes from a small object.  A 3-axis machine adds a Z height to allow much more variability.  A 4-axis machine is even more nimble because it allows the cutting tool to be tilted, which can basically poke it more nimbly into tight areas without necessarily disturbing the material above it as would happen with a 3-axis machine.  The complexity goes up tremendously from there.

The remainder of the session involved a lot of side conversations between folks who either had no familiarity with the topic whatsoever, were familiar but somewhat new, or were total experts.  Unfortunately it was not possible to capture all of these conversations, but luckily, the information age allows us to easily get such information--from where else?--Google.  :)

One bit of information I caught from a side conversation is how the speaker is an advanced woodworker and really enjoys using the mortice and tenon plugins for SketchUp.  He had not yet had the opportunity to try the new SketchUp 8 solid tools, but he was looking forward to trying them.

Here are a few interesting items that were mentioned or demonstrated in the session.

Contour Crafting - extrusion machine for printing houses!: http://www.contourcrafting.com/

Cupcake CNC - a CNC machine for your home, that's super-easy to build: http://store.makerbot.com/cupcake-cnc.html

reprap - a somewhat self-replicating open-source deposition machine: http://www.reprap.org

linuxcnc - control software for DIY CNC: http://www.linuxcnc.org/

heekscad - http://code.google.com/p/heekscad/

facit - http://www.facit-uk.com/

Open Cascade - http://www.opencascade.org/

At the end of the session, an argument broke out about Linux.  It didn't last long, but one person mentioned the existence of a Linux distribution that he thought was incredibly awesome and with which no one else at the session was familiar: MEPIS.

Please note that a number of brand names or services were mentioned during this talk.  Making mention of them here is in no way an endorsement by Google or by the folks who participated in the talk.  Sometimes it's just convenient to cite examples, even when someone has no experience with the company in the example.
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