Information and Help for Students

Hello Architecture Students.

Thanks for researching LGM for your project needs. We appreciate you contacting us.  
We have been doing a large number of student projects and thought we should put up some bloggy style info to help the process.  


There are a number of things to think about when you are getting your model ready to 3dprint.

Keep in mind you are creating a scaled model of a (planned) real world object.  The model has to be able to exist in the real world where gravity and fingers both have great effect.  

Geometry Issues :

Scale: 
We see a broad range of work come in and sometimes it is difficult to get the scale/size correct.  Please always tell us how big you think (?? Please correct - InMaya press Control + t??) the bounding dimensions are.  Scaling becomes very easy if you could  please put a cube in the corner of your drawing that will be 1"x1"x1" at the printed size. (we won't print the cube or include it in our estimate) 

Wall Thickness 
The thickness a part needs to be is dependent on how big is it and how much stress it is under.  The Z plaster is like concrete, it is weak in shear with very little ductility.   If you have a long moment arm or long cantilever it will likely cause a  thin attachment point to break.  

I general wall small areas of wall can be as thin as .04" but this is very fragile   but the structural elements (those that we or you need to pick the model up) need to be .08 to .1 on small models and .1 to .18 on larger models.

Thin tapered surfaces and sharp points. 
We very commonly see areas that taper to sharp points and feather edges.  We take tremendous care with your work and have received very good feedback from the students we have worked with.  However we can guarantee that thin tapered surfaces  WILL break and chip... Somewhere the 

Powder evacuation:
All enclosed volumes need to have reasonable powder evacuation holes.  We have to be get the loose, unprinted powder out of any enclosed volumes or we have to charge you for it.  A single 1/16" hole will not suffice.  The larger the hole and/or, the higher the number of them, the better.   We can put holes in for you but we have to charge for that service. 

Mesh Resolution 
Sometimes we see HUGE file sizes which makes things run a lot slower and make it harder for us to help you get things done quickly.   Remember that the printers are effectively running as something like 150 dpi.   The tiny triangles that make up a lot of the surfaces wont show.      Please reduce your part's triangle count before sending it to us.   (Please post if you can help provide direction on how to do this in Maya)      It is very rare that any model needs more than  2 million polygons or something like 40 meg as a VRML. 

Texture Maps  
Please be aware that color models are MUCH more difficult to process than monochrome ones.  You need to give extra time!  Also we only have one machine out of 5 that we run in high quality color so it is very likely that we cannot print next day on this machine.  Plan a WEEK!  
We cannot remap or otherwise adjust textures on student projects.  Please make sure that when you send a wrl or obj that the texture that is referenced by the object is the one you send.  Maya is not easy with this and wants to reference .rgb files but we seem to get jpgs.  The object attributes under the texture map should be the name and file type that you send.  Look for places in the export dialog to include textures in the transmittal  (If anyone can document how to to this correctly you win a $50 off coupon!)



Business Issues : 


Pricing
Our student pricing is 40% or more off our retail pricing for color printing. We price by the volume of material consumed and  we try hard to optimize your geometry and get you the best pricing possible.  

Unless your geometry is perfect it is not possible to give an exact estimate until your model is nearly ready to run.  We can get pretty close but it takes us time to do so.  A single part with good geometry is fairly easy to quote.  Many small parts are tough.     

It takes a baseline of labor to print and handle a part.  For many small, low volume parts, we may have to charge a base rate or a per part charge.    Typically many small parts don't look that good in a model anyway.  Better to make an assembly and save yourself some work unless you think it will break.  (see below).

Also  if you need to reduce costs, consider not printing the model base, terrain  or large flat surfaces that are  typically easier to build with a laser.

Lead Times 
A good lead time is 3 days from when you send us your file to when we ship.  Some times we can compress this to 48 or 24 hours but the risk goes up.  Sometimes machines fail to build or crash, or there maybe geometry issues.  We want to have time to fix things.  

Shipping Costs.   

Our first priority is to package your model so that it gets to you in one piece.  This typically means bubble wrap  plus  2 inches of foam peanuts around the models.  Typically this means that the shipping company will charge us for "dimensional weight"  which really means that they charge a minimum weight for a large light box based on the volume the box takes up in the truck/plane.  
Express Shipping is EXPENSIVE.     We are happy to do it, all we do is click a button and it gets there faster but it is your $.  We make no money on shipping your model.    Next day air early am can be 2x the cost of 2 day saver....    Saturday delivery costs more although not that much.  There is no reasonable way to get something to you on a Sunday or a holiday, nor do Shipping companies pick or move packages on Sundays or Holidays.  Shipping does go out on Saturday although we may have to charge overtime rates.  

Billing 
 We will bill you when your model is complete or nearly complete.   Payment is due upon receipt of the invoice and can be made online at https://www.lgmmodel.com/payments/   by credit card or bank transfer. 

Communication
 We have an upload point at:  http://www.lgmmodel.com/products/upload-a-file/ or you can email to plans@lgm3d.com.   For communication  please use plans@lgmmodel.com   We appreciate it if you communicate by email whenever possible.  It helps our small staff  to be more efficient.  Please don't call to see if your upload came in, it did...  Please DO let us know ahead of time if you have a class deadline.  We would VERY much like to put these dates into our production planning system.  


Services we offer.  

Machines 
We currently (02/13) run four powder/plaster based Z printers.  We run three of them in white only and one in color.  White is cheaper than color.
We plan to add two new technologies in the spring of 2013 and be happy to provide those services to you once we decide if they are suitable. 
The build volumes on the Z Printer are 10" x 14" x 8" so that is the largest single part we can make.  However it is easy to put multiple parts together.

File Fixing
We do a great deal of file prep and file fixing for our commercial clients.  We use a very expensive (about $10K a seat!)  but very worthwhile program for file prep called Magics If you are pulling your hair out trying to get a file completely ready to print, we can help but if we do more than about 10 minutes of prep we have to start to charge for it.  

Some things we can do really easily.  
-Hollowing.  We have a routine for hollowing out parts to a specific wall thickness.  Typically if you have one or two simple volumes that are well drawn, we won't charge to hollow them out.  It helps us both.   However, if you have many complex shapes and want us to spend a long time figuring out how to get every last cubic inch of powder out, we typically have to put more labor in than it is worth to get the powder out.  You have to decide if you have more time than money and crunch on that.  

-Global  offset 
Our friends at Yale School of Architecture used to have a design class where they typically made very complex organic shapes like bridges or other space structures.  Typically they were too thin all over.  We can perform a fairly robust GLOBAL offset that thickens the entire part.   This works well if the entire part is all of a similar level of detail.  It does not work so well if there are some areas of high detail that you want to preserve and some areas that are less detailed.   It is a GREAT trick for concept models.  

-Slice a plane through solids  or nearly solid 
We have noticed that sometimes slicing a complex object with a plane creates more problems in Maya or Rhino.  It works well in Magics.  If you need us to slice an OTHERWISE GOOD model in two along a plane, then just draw the plane and we will the geometry   However think through this first and visualize it.  Make sure the model is really ready to be cut and that is the only problem you have. 


Some things we do typically need to charge for.   

Geometry fixing.   Any good 3d printing service bureau should fix the basics, a small hole, a flipped face etc.  However as soon as someone has to start thinking  "What is this supposed to look like" then it gets expensive.   Yep, good decisions cost money, that is why you are going to school right?   If you have to think about it, we have to think longer.... 

Creating "drain" holes to get un- printed powder out. - See above... 

Shrinkwrapping  - One trick we have for geometry out of Sketchup and other program is to run a Shrinkwrap.  This is an idea we invented and it basically takes your geometry and "wraps" it with a virtual piece of saran wrap, creating a new printable, exterior mesh.  It is a good trick in some cases.  For more on Shrinkwrapping, how you can do it yourself and our FREE as well as paid software please see www.CADSpan.com

Color Map fixing are modification.   - This is typically really tough for us to do on a student project budget or deadline. 

Lots of section planes or many shells that need hollowing.



Colors, Images and Finish

Colors: There will be a variance in the final part color compared to what you have in the CAD model in a color 3D print.  This is an unfortunate by product of the color printing process.  We cannot match colors exactly!

White: On a color model, any parts that are white will not a be a bright, stark "copy paper" white.  The white areas will have a slight yellow hue to them.  This is primarily due to the epoxy infiltrant.  On smaller parts, we use a CA infiltrant that does not have the yellow hint.

Bitmap resolution - It has been our experience, that no matter how a color part is mapped, the process to get it print ready will decrease the overall image resolution.  For smaller parts, the bitmap images look fine.  On larger parts, the images tend to look more pixelated.  Please keep this in mind.

Clear coating:  If you have a color part, you can clear coat it with Krylon Crystal Clear Acrylic.  A few coats of the gloss are required to make your part have a glossy finish.  Even though the final parts have been infiltrated with an epoxy, they are still somewhat porous, so they will soak up the first few layers of clear coat.



Top 5 issues
1.  Not leaving enough time
2.  Assuming we understand your model and make subjective decisions
3.  Walls that are too thin 
4.  Surface planes that do not explicitly define a space.
5.  High price due to large enclosed volumes of material. 
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