Saturday, November 10, 2012

3d printing notes and links

Every task that we humans do can be broken out into a series of steps, a chart of the work flow that we have to take from beginning to end.  Most of learning a job comes from discovering the most efficient path to most rapidly and cheaply complete what needs to be done.   3d printing is no different.  Was I have been exploring http://www.thingiverse.com/ the past couple of weeks, in anticipation of getting my own printer, in 4 to 6 weeks, I have noticed that nearly every post contains some little hint, or pearl of wisdom that was probably very hard fought to figure out.  This page is an attempt to condense all this information into a single place for my own use, and for yours as well.

There is also a culture on the website, where giving proper attribution is important.  It is built into the website.  Although I believe there is one weakness, when you make a derivative of one work you click a button to create a new page.  But what if you combined two peoples work equally?  I see many people trying to give credit as well as possible, but then having to cut and paste links to the other people's links

Overall the process of 3D printing goes like this:

For the new user:
  1. Find a pre-made model
  2. Load model into printing software that came with the printer
  3. Press print
  4. It prints or it does not.
  5. Randomly adjust settings, repeat 3

This is pretty much where I am now.


I have started trying to learn more than this, so that when my printer arrives, I can start printing my own designs.  The workflow for designing a 3d shape for printing goes like this:

  1. Use software to create a shape.  
  2. Export this into a format that can be imported by printer software.

This seems easy enough.  Just two steps.  Except that you might need to create simple shapes, or start with an existing model or two and then move the files from one application to another in order to get access to features that one has, and the other does not.

You can take one shape and subtract it from another shape to create a unique mashup.  Maybe you add a slot to the back of a sculture so that it will fit the head of a nail in your wall.  Or you could fit a vesa mount onto one or more cases so you can screw a computer to the back of your LCD monitor.

But how do we do that?  One person on the site had this to say:

How to get a model from Sketchup into Blender: export as a Google Earth object, change the extension of the saved file to .zip, open the archive, retrieve the .dae file in the 'models' subdir and import that into Blender using the 'import Collada 1.4' option. 

That would take forever to figure out on your own.  Even with the directions someone could look at that and just see Greek.  So there are tricks to converting between each of the more popular applications that other people have figured out over time.  

Another person says: 

ddurant
    https://groups.google.com/forum/#!topic/makerbot/RpaXwt0x4v8
I spent several months like that when I started printing. NOTHING %$#!ing worked and I was ready to throw the damned thing (a Cupcake) out the window.
Start with an easy goal and just focus on learning how to do that well. Take notes, change one thing at a time, get a feel for what the different settings do. Don't go for layers at 2 microns or printing at 7000mm/s. Pick a simple target, stick with it until you make progress, figure out how you made progress. Don't be afraid to ask questions.
Unless you have broken hardware, you have enough hardware for now - throwing more at the machine (usually) just adds complexity. The hard part is understanding what the software is doing and developing a routine.
The biggest and most common mistake I see is that people start with the assumption that they understand what's going on. I did it, too - I'm a senior software developer so I should be good at this right out of the gate, right? Wrong. Months of frustration worth of wrong. Once I got that out of the way, I started making progress pretty quickly.
 

What are these major 3d modeling software for 3D printing? Ways to design your initial 3d shape:

3D animation software:
Blender
Poser
DAZStudio

One problem you are going to have is that the traditional 3d model is just an outline filled with empty space.  It has to be converted into a solid model  so that the printer software can handle it using the following software:

3D solid modelling software:
Google Sketchup
openscad 
qcad
other 3d modellers
Some people have been using the processing language to generate the models.



What you see mostly on the site are files that end in .stl extensions.  These files are the shapes, ready to be put into the printer software and printedBefore you try to print something as a newbie, read the comments, and check to see if anyone else has posted a print that they made.


Applications to do this for my Makerbot Replicator 2 include:


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Once you have finished the print, how do you make it more durable for real world use?  Screws will not hold well in plastic without some helpA screw can pull out, or crack the plastic.  This page reminded me about metal inserts:

http://www.makersite.com/blog/2012/8/24/threads-in-a-3d-printed-part

You can get a variety of Heat set inserts for plastic pieces from a variety of sources such as McMaster:

"During installation, heated plastic flows into the insert's knurls and ridges. When the plastic solidifies, the insert resists torque and pull-out. Install or remove using a soldering iron with an installation or extraction tip (sold separately). Inserts are made from brass, which is nonmagnetic, corrosion resistant, and electrically conductive. Thread class is 2B for inch sizes and 6H for metric sizes.  Use the soldering iron with installation and extraction tips (sold separately). Operates on 120 volts AC, 60 Hz, 40 watts."

I have used these before with a plastic case, you just push them in with solder tip that fits them, for smaller ones the solder tip on a normal soldering iron works fine. 

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