At 18:29 30-04-18, sdsiedentop@... [ESPMC-Eight] wrote:
>Questions for Jerry (or anyone else that may be able to answer):
>
>What function do the RA Direction and DEC Direction controls perform?

They are instead of steering the mount by hand;
as long as the clutches are engaged, PMC will
continue to know where the mount is pointed.

>Also, would a .33 difference in the tracking
>rate present itself visibly in the eyepiece in a
>very short period of time, or is it something
>that would present itself in a long exposure (5 minutes +)?

(0.33/53.33) x 100 = 0.62%

Since the stars move 15°/hour, or 1.25° per 5
minutes, even if your mount doesnt move for five
minutes, a star will only have moved 1.25° from
the centre of view. If the field of view of your
scope/eyepiece is greater than 2.5°, the star
will not have reached the edge of the field of
view in 5 minutes! Thus, if your mount is
tracking 0.62% slower than it should be, the star
should still be well in view after longer than 5 minutes.

David

At 16:47 01-05-18, Steve Siedentop sdsiedentop@... [ESPMC-Eight] wrote:

>As Jerry stated, the RA Direction and DEC
>Direction switches in the preferences pane
>change the direction of each axis to accommodate

>the mount pointing south. I had these turned

>on, which may very well have been what was causing the drift.

Unless you are doing photography, or are using a
large magnification, it should be fairly easy to
keep objects in the field of view even if the motors stop running.

>My next outing will include fresh batteries and
>a standard configuration in the app.

Fresh batteries sound like an expensive long term
proposition. I am using a YUASA NP7-12 7.0 Ah
rechargable lead acid battery. I am also making
up a 12-19 volt convertor to keep my laptop
running from the same source. Time will tell
whether this has enough capacity for the job. Watch this space... :)

Best,

David

Hi David -

By fresh batteries, I mean a fully charged deep cycle.  Mine was about 6 years old, so I replaced it with an AGM deep cycle today.  It’s a 60 amp hour battery, which should be enough capacity for a 5 hour imaging session.

My original power box with a group 24 lead acid battery powered a cooled DSLR, an NEQ6, an Intel Compute Stick, Moonlite focuser, a powered USB hub, and a Surface Pro for about 5 hours.

I’m going to put an ammeter in-line on the power supply to the PMC-8 to see what the real time consumption is while slewing and tracking.

I’ll post my findings as well.

-Steve

On Wed, May 2, 2018 at 4:48 AM David Pickett yahoo@... [ESPMC-Eight] <ESPMC-Eight@...> wrote:

At 16:47 01-05-18, Steve Siedentop sdsiedentop@... [ESPMC-Eight] wrote:

>As Jerry stated, the RA Direction and DEC
>Direction switches in the preferences pane
>change the direction of each axis to accommodate

>the mount pointing south. I had these turned

>on, which may very well have been what was causing the drift.

Unless you are doing photography, or are using a
large magnification, it should be fairly easy to
keep objects in the field of view even if the motors stop running.

>My next outing will include fresh batteries and
>a standard configuration in the app.

Fresh batteries sound like an expensive long term
proposition. I am using a YUASA NP7-12 7.0 Ah
rechargable lead acid battery. I am also making
up a 12-19 volt convertor to keep my laptop
running from the same source. Time will tell
whether this has enough capacity for the job. Watch this space... :)

Best,

David