Re: MiniPCB2 bunches of weirdness

Dave Schwartz

Your SHC may be working for now (ignoring the connection to the controller for now as that may be a software issue) but it looks like issues will be likely to develop down the road due to soldering problems.

I see a lot of pads that do not have sufficient solder (e.g. voids) and that probably means cold solder joints which could let go at any time. I would touch up all the joints with a 300 degree C iron and a bit more solder. Hold the iron on the joint for at least a second and a half after you remove the solder wire to make sure you get good flow. The SHC in particular has some tricky spots to get right because the ground plane is a complete copper layer (the top layer) and as such acts as a prodigious heat sink... it requires more time to reach proper temperature than the non-ground pads. All the PCBs actually have the same issue, they all use a copper pour for the ground plane. There are lots of examples of what good (and bad) solder joints look like on the web.

If the soldering on the controller looks the same, I would go over that as well.

On 2020-03-26 12:29 p.m., Dennis Hurlbut wrote:
On Thu, Mar 26, 2020 at 06:08 AM, Dave Schwartz wrote:

A chattering motor with no torque could mean a motor wiring
problem to do with the phase connections. Steppers don't work well
if only one coil gets energized - they just sit there and jiggle.
They might move oddly/noisily if the coil pulse is great enough to
move the rotor from one magnetic detent to another but it would
not do anything near what would be intended.

This makes sense. I was re-building my connectors because the motor came with 3 ft of wire. One went well, the other has not even after two attempts. I'm going to move to breakout boards for the RJ45s.

If you get the SHC logo coming up it means your power and ground
are coming in on the right wires and thus your cable stands a good
chance of being correct. It probably says 'Establishing
connection' and 'Connection failed' before it goes blank (which is
normal after connection failure. This would mean the controller
and SHC aren't properly handshaking over some of the signal lines
and the most probable cause of that is a missing or
installed-backwards resistor network.

I believe I have both connected correctly (pic attached). I checked the cable, and each wire has between 5 and 7 tenths of an ohm resistance end to end. I'm also checking whether the RJ12 jacks are soldered on well.

Join to automatically receive all group messages.