[CHP] Stepper boards update

For those of you who weren't following IRC last night, I built up the
first stepper driver board. The reflow soldering on the griddle worked
very well, but there were some difficulties in the temperature curve,
as the griddle doesn't tend to get hot enough quickly enough. Even so,
it worked, and with some minor reworking of the board, we ran a test.
Initial tests looked good, so we hooked it up to the Maker Bot, in
place of one of the driver boards already there. While it moved
slower, as it was configured for 1/16th steps, it worked perfectly,
allowing the Z axis to jog back and forth. With the knowledge that it
worked, we went ahead and started configuring a test with the Z axis
that we already have put together, to get it to move. We set up an
arduino, connected some wires, did some troubleshooting... and then
accidentally let a jumper wire brush the top of the allegro chip. It
blew up. One of the pins vaporized in a puff of smoke, and there's a
hole in the top of the chip. I should be able to salvage the rest of
the board once my hand reflow tools come in, but what this means is
that I need to build another board for testing, which I will do on
Tuesday. I will show off my technique, and people will be able to see
the solder reflow for themselves, and hopefully we can have our first
live test of the boards with the 2A steppers on Tuesday as well.

Sorry to hear about the magic smoke but really looking forward to
watching the reflow techniques used.


(Click images to go to the flickr page w/ larger images)

A nice new board:

A newly reflowed board:

A newly blown board (click image to see larger image)

That rocks! I am excited that the initial tests went well & look forward to seeing you build the next one at tomorrow’s meeting.


Thanks for the update James. I’m also sorry for the loss of the Allegro’s magic smoke, but it sounds like you were making great progress. Save the piece parts for the “Wall of Fame”. It isn’t our first and won’t be the last! Looking forward to tomorrow night!