August 23, 2014

3D Printer Progress

Despite the lack of posts on the subject, progress is slowly being made on my 3D printer. A few months ago I got the structure pretty well flushed out in CAD. As sized in the model, this allows for something more than a 12 inch diameter build area. The height of the build is limited by how long I want to make the drive axes, in this version I targeted 12 inches tall.

August 18, 2014

Smart BLDC Commutator For Sale

The wait is over, the Smart BLDC Commutator is now available for purchase in the Makeatronics Store.

Unlike my other boards so far, I am not (yet) offering this one as a complete assembly. It's all surface mount and takes too long for me to assemble them myself. I am working on getting a stencil made so I can reflow them in my hacked toaster oven.

Thanks for checking in!

August 8, 2014

Smart BLDC Commutator - Hardware

Of all my circuits to date, the Smart BLDC Commutator is probably the one I'm most proud of. To those coming here for the first time, this board is for driving brushless DC (BLDC) motors. I spent a lot of time researching and prototyping to come up with this board. If you are trying to figure out how to drive a BLDC motor I think you will find the information below very helpful.

From a high level, I wanted an interface to a BLDC motor that behaved much like a H-bridge does for a brushed DC motor. The result is a board that handles the heavy work of commutating of a BLDC motor using hall effect feedback. After hooking up power, motor wires and hall sensors, the minimal inputs required to the board are direction (high/low) and PWM. Everything else is taken care of to properly spin the motor. Pretty nifty.

August 5, 2014

Scrap Yard

Check out the new Scrap Yard!

The process of making good designs often includes a few mistakes. Sometimes I'm lucky and get things working on the first try, but more often it takes two or three revisions to get it there. And since the PCB manufacturer I use has a minimum order quantity I end up with a fair amount of scrap.

Rather than throwing them away, I've decided to sell the extra boards at discount price. It's up to you to get them working. I will provide details of fixes I have made to get them functional, just click on the images to be taken to the details.

Obviously, I have a limited quantity of these boards. Once they are gone they will be deleted from the scrap yard never to return. Check back as often as you like, this page will be changing as I embark on new (and revisit old) projects. 

August 4, 2014

Smart BLDC Commutator Coming Soon

I recently received a small batch of Smart BLDC Commutator boards to verify V3 routing. I'm pleased to announce that it tested flawlessly. I made a few changes to the silkscreen, including some equations to the back side to help in using motors with voltages outside the current design limits, and placed an order for a larger batch.

I expect boards to be in by the end of August 2014. After a quick overview to make sure all is well I will put them up for sale in the Makeatronics Store.

Once I get some time I will write up a detailed post on the hardware changes and the firmware running on it. Until then, here's the schematic if anybody wants to benefit from my experimenting.

Design files are hosted on GitHub and licensed under CERN OHL v.1.2.
Firmware is hosted on GitHub and licensed under the BSD 3 clause license.