Wednesday, January 28, 2015

Projects & Snow globes

Project teams are like snow globes; they function best after a good shake-up.

Tuesday, December 09, 2014

Eagle PCB to Autodesk Inventor - how to do it

This is mostly a note to myself, but I thought I'd share it in case it helps somebody.

To get an Eagle PCB board outline & drills into Inventor, you use the DXF export utility in Eagle.

Before exporting, make sure Eagle is only displaying the following layers, assuming you're using the default layer setup:
17 - Pads
20 - Dimension
44 - Drills
45 - Holes
46 - Milling

(Note, you might want to select additional layers, but I'd start with these first, because Inventor chokes on more.)

Next, click File/Export/DXF and save your file someplace.  I stick them in a sub-folder of my Eagle project named "Export".

Now go to Inventor and open the DXF file.  An import routine will be triggered, use these values:

Selective Import, layers 20 and 44.  Look at the drawing to confirm you're getting what you want.

Check - Wires
Specify units - mm (if that's what you used in Eagle)
Check - Constrain End Points and Apply Geometric Constraints
Select "New Part - Project wires to 2D sketch"
Mapping options - Check "Map all layers ... single sketch"

Click Finish.

Tada!  There is your board as an Eagle sketch, properly sized, ready for extrusion.

Now, you might ask, "Why are you displaying those layers in Eagle for the export, but then ignoring them in Inventor?"  The answer - it looks like Eagle has a bug.  Without enabling all those layers, the drills don't come across.  At all.  Frustrating, but surmountable.

Also... if you're getting your boards made by, then you can go ahead and extrude the board at 1.8mm in thickness.  This is the same value for both 2 and 4 layer boards.

Monday, September 02, 2013

Meshbot 2 chassis design released

I published "Meshbot 2" my second 3D printed robot chassis design on Thingiverse, you can check it out here.

Tuesday, August 06, 2013

So many grindstones, so little nose

I'm so thankful that I get to do the kind of work I do.  Writing software is a blast!

Saturday, July 06, 2013

Human evolution - Selfishness vs. Altruism

Just read a great article:

In it, there is a nice quote from Darwin.  This side of Darwin's thinking was ignored by his robber-baron lauding "social Darwinist" contemporaries:

An advancement in the standard of morality will certainly give an immense advantage to one tribe over another. A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection.

This perspective was not ignored by Kropotkin:

Kropotkin was misunderstood and belittled by his western contemporaries, as Gould describes in this great article:

Friday, June 07, 2013

Please make the Patriot Act go away

U.S. intel chief blasts leaks on web, phone use tracking - CBS News: "I'm angry, and I was the one that wrote the law. And I think that the Justice Department and the NSA have abused this by going to far," said Rep. Jim Sensenbrenner, R-Wisc., who helped craft the Patriot Act.

I would just like to say to Rep. Sensenbrenner, what exactly did you think was going to happen?  Have you not read enough history to know where these things inevitably go?  The Patriot Act was, at best, naive.  At worst, it's an unfettered invasion of privacy reminiscent of Hitler's "Enabling Act" or the actions taken by Joseph McCarthy (Sen. R-Wisc) during the Second Red Scare.

Tuesday, April 09, 2013