[kwlug-disc] OT: Below freezing cables ...

[Khalid Baheyeldin]

On Wed, Jan 9, 2019 at 8:00 PM Andrew Kohlsmith (mailing lists account) <
aklists at mixdown.ca> wrote:

>
> Unless you’ve got a real reason to suspect poor or intermittent
> connectivity I would look more at the steppers and mechanicals needing more
> current due to stiffening and low temperature.
>

The reason I suspect bad connections is that I changed the controller to a
backup
board that I have. Same result. Then other RJ45 cables. Same result.

The following day, I wrote a program to stress test the telescope and move
it from
extreme position to the other extreme position repeatedly, for more than
hour,
and this was indoors: things worked well.

What is the current carrying capacity of the power supply?


It is rated for 2A, and seems to work fine indoors.

Can you swap out a more powerful (higher current) power supply easily?


I have one that is 5A, but it is very bulky (looks like a PC power supply,
with
long cables going in and out, with a car 12V plug). Will try that one.


> What about the stepper drivers, are they marginally sized and higher
> current required for stepping in cold temperatures is causing them to fault?
>

They are tiny. NEMA 11 instead of the usual NEMA 17. But they have an 18:1
gearhead which gives them enough torque, and there are others who are using
the same model of motors without issues (not in sub zero temperatures
though).

I have a number of RJ45 connections in outdoor settings and unless the
> connectors themselves are poorly made or of poor quality, I would not
> suspect them contracting and breaking contact.
>

I did buy the flat RJ45 cables and the sockets, from eBay, so they may not
be the best
out there.  But they are the flat ones, which are the most flexible.

-- 
Khalid M. Baheyeldin
2bits.com, Inc.
Fast Reliable Drupal
Drupal optimization, development, customization and consulting.
Simplicity is prerequisite for reliability. -- Edsger W.Dijkstra
Simplicity is the ultimate sophistication. -- anonymous
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://kwlug.org/pipermail/kwlug-disc_kwlug.org/attachments/20190109/db7b197d/attachment.htm>