Tuesday, August 18, 2015

3D Printing

I recently read a blog post by Shaun Hurley titled "3D Printing is Not a Fad". This post came at a perfect time because I had just attended a 3D Printing Road Show in Wichita, KS hosted by Stratasys and Depco. While I have always known several of the ways 3D printed parts were being used, I had no idea the scope. From prototype parts, to castings, to actual production parts it is amazing the way this technology is being adapted and utilized.

Here at Hutchinson Community College we were fortunate to be early adopters of 3D printing, specifically the Stratasys Dimension SST 768. We have had this printer for approximately ten years. While it is still a great printer, I decided it was time to upgrade to newer technology. Fortunately, we were able to secure a grant to purchase an Objet30 Prime printer. We will be making the purchase some time this fall. I am very excited for this new technology for a few reasons:

  • Rubbery material. Printing in ABS plastic is great, but I can't wait to create more flexible models (literally!)
How cool is this rubber tire?!
  • Clear material. The SST 768 was somewhat limited on material choices. I cannot wait to print some working assemblies with a clear outside so that students can see the inner workings!
  • Resolution. The SST 768 had a minimum layer thickness of .013 in.; the Objet30 Prime has a minimum layer thickness of .0006 in. (!) 
    • Take a look at the difference in these two parts:

Yep, that's why I am excited.

Incidentally, the part on the left was my first attempt to "glue" two parts together. I used acetone to essentially melt the parts into one. It worked like a charm, that thing is solid! Next I applied some body filler (Bondo) and sanded. Since this was a test part I didn't spend a lot of time to get it perfectly smooth, but it was a good indicator on how finishing a part would turn out. Here is the result:

Here is what I ultimately printed and finished. A Sabine helmet from Star Wars Rebels:

Yeah, I am a Star Wars geek.

Perhaps someday I will post the pictures of the process from beginning to end.

May the Force be with you in all your 3D printing endeavors!

Sunday, July 5, 2015

Joining Lines and Polylines

I hope everyone had a happy and safe fourth of July. The fourth of July is synonymous with explosions. If you got a little carried away yesterday and exploded some polylines and want to put them back together, you are in the right place!

First, I want to mention something (rant) about the explode command.

A few years ago Autodesk changed the toolbar button icon from to

As a user, no big deal. I type the alias x to explode anyway. As an instructor I miss the old button! I could set someone down who has never seen AutoCAD before and say "Find the explode button" and they could easily find it. Now I have to explain that it looks like a box that is being exploded apart. The button looks more like a 3D command than a 2D command. I miss my stick of dynamite!

Back to joining objects.

In the following video I demonstrate two different methods for joining lines and arcs to create polylines.

One more comment on the Polyline Edit command. If you prefer to use this method for joining lines and arcs, here is a tip to shorten the process. It always bugged me that AutoCAD asks "Object selected is not a polyline, do you want to turn it into one?" Of course I want to turn it into one! I have literally never said no to that question. Okay, once to see what would happen; it just ends the command having done nothing. To bypass this question type in the variable PEDITACCEPT and set the value to 1. Essentially you are saying that you accept turning the object into a polyline. You will never be asked that silly question again!

Thursday, July 2, 2015

The First Post!

Between CAD Classes - The First Post!

Welcome to my new blog! My name is Tracy Chadwick. I am the coordinator and lead instructor of the Computer Drafting Technology program at Hutchinson Community College. I have been teaching CAD classes at HCC for 14 years. Prior to that I did some drafting and design work in the grain industry.

I am a big reader of blogs related to CAD and design and decided to jump in and create one myself. I have a busy schedule, so I plan to blog between preparing for class, teaching, and grading; hence the name of the blog. (It could probably also be called "Between CAD classes and late at night after I put my daughters to bed" but that url was taken). I plan to discuss topics dealing with my classroom experience as well as software tips and tricks.

I hold professional certifications for AutoCAD, Autodesk Inventor, and Autodesk Revit. I update those annually (for free!) at Autodesk University. I am also a big user of Creo 2.0. I hope to delve into AutoCAD Civil 3D, SolidWorks, and 3DS Max as time permits.

If you are interested in all things CAD, I hope you will follow my blog as it grows!

Thanks for looking!
-Tracy Chadwick