Trick to draw circular PCB outlines in Eagle

December 26, 2017

If you haven’t used the Eagle PCB design tool lately, you will be surprised to learn that it has underwent a major update since it was acquired by Autodesk.

Eagle’s license model has been switched over to a subscription service and I am liking the experience so far. I am able to get the latest updates of the software (unlike earlier, the updates are quite frequent). I am currently using Eagle 8.5.x and it comes with the “Push and Shove” feature that automatically pushes signal traces while routing your PCB.

PCB Outlines

I was working on a circular PCB for building something like a fidget spinner. I assumed that I could draw circular PCB outlines by drawing a simple circle.


Circle feature in Eagle PCB

Being able to draw circular outlines can make your life easy. For example: You could draw a random circle and specify its radius, center etc (similar to Mechanical CAD tools).


It turns out that the software considers this an error. When I started to route the PCB, the automated DRC check ignored glaringly obvious errors.


Errors resulting from the Circular Outline

In the above snapshot, you will note that I am able to route traces over PCB pads and the cursor indicates bad news.

After wasting some time, I found out from this forum thread that I need to draw my outline using arcs.

In Eagle, drawing an arc is a three step process:

  • Specify the starting point
  • Move the cursor to specify the arc radius
  • Draw the arc

It is definitely confusing and imagine drawing a “closed circle” using arcs. It can be frustrating.

I eventually managed to find a simple solution that involves combining arcs to draw circular outlines. Check it out!

I am no video expert. I made this video using basic screen capture tools. I look forward to hearing your tips on improving the video.

I really hope Autodesk simplifies creation of non-standard outlines. Did you have a similar experience? Drop your thoughts in the comments section!

My design is off to OSH Park. What manufacturing house do you use for your designs? I will share my build in upcoming blog posts.




Pursuing a 3D printing hobby while living in the Rust Belt

September 4, 2017

I finally got around setting up my 3D printer over the Labor Day weekend. I needed the printer for my World Maker Faire preparations (Psst.. Stop by our booth if you are in the area).


Since my move to Buffalo, I haven’t unpacked all of my boxes and I cannot locate some accessories like 3D print removal tool, Kapton tape etc. I tried removing the first print using a pair of scissors and cut my fingers.

I decided to get a 3D print removal tool and I could find only one store in Buffalo that sold 3D printer accessories. You can visit the store only by appointment. 

The alternatives were Micro Center in Cleveland or Amazon. I chose the former and drove to Cleveland (I am a bit crazy). Micro center is an official distributor of the Raspberry Pi and they carry everything from Arduinos to 3D printers, filaments and other accessories.


Microcenter’s DIY stash

I got a spool of color changing filament, 3D print remover and a Raspberry Pi Zero W.


I think the options are limited when it comes to in-store purchases related to 3D printing in the Rust Belt. Fry’s electronics has stores in Chicago and Podunk, Indiana. Micro Center has stores sprinkled across Ohio.

It appears that Micro Center’s employees rely heavily on sales commission. Employees chase you around to help and stick a label on your selection. They keep hovering over you and I was not comfortable taking a picture of their 3D printing aisle.

I miss the SF Bay Area as I could have solved my problem by crawling through Craigslist or going to Fry’s Electronics (The Bay Area has about 3 or 4 Fry’s branches).

After a 6 hour trip, I got to put the remover to good use.


By the way, I forgot to buy some Kapton tape.