开云体育

Hi,

Just joined this group and would like to solicit your opinions on
encoder resolutions for the GM8. I have picked up a set of used
encoders from a GM9 and retrofitted them on to my GM8. The encoders that
came with the GM9 are labeled 2160 and will only work with my Losmandy
DSC when programed as 4096. Has anyone out there used higher resolution
encoders on their GM mount? Is there an advantage?

Also I am still struggling with the two star alignment procedure. Does
every one have to go through the 90 degree alignment setup before
getting accurate DSC read out?


Thanks...

-Mark Simmons-

Mark,

Here is what I did to determine exact encoder res.

Remove your weights and the bar that holds them. Remove the OTA as well.

Balance the mount with the bubble levels, then use a small bubble level
like the line levels used by carpenters which are hexagonal in shape,
available at most hardware stores. Level the mount head so the RA axis
and the DEC axis are level in both vertical and horizontal positions.

Now, turn on your DSC's and ensure the encoder resolution function is
set to zero. Turn either the RA or DEC axis one complete 360 deg
revolution with the encoder resolutions set to first 2160 and then again
at 4096 and your cables connected. Watch for cable binding.

Both your axis encoder readouts should return to zero on the resolution
setting that is right for the encoders you are using. That will be your
encoder res. to use always. You gain pointing accuracy the higher the
encoder resolution. They are inexpensive, so upgrading is no problem.

Check out;

<>

On star alignment. I am not sure what DSC's your are using, but I will
tell you how I get great alignment with my NGC Sky Vector.

I first polar align the system, taking my time to ensure as accurate an
alignment as possible. Here, you should try to be directly behind the
ep, not off to one side which is usually more comfortable. I find the
star is more accurately align this way.

Upon power up, the DSC's ask me to set my DEC to equal 0 degs. I first
balance the RA shaft to have it pointing east/west, again using the
small line level. I then balance my OTA/DEC axis to have pointing
directly at my zenith. I now have a T-configuaration with my two axis as
it the T is laying on it's side. Do this with the DSC's off.

I turn on my DSC's so the encoders readout function is set to zero. I
then move my OTA/DEC axis until the encoders read +90 degs. I then turn
off and back on my DSC's to reset the encoders to zero. Again, I slew
the OTA/DEC axis back toward its original position until the encoders
read the product of 90 degs minus my longitude of 47.17.48 N or -42. I
then turn off the DSC's and back on, and when the DEC = 0 comes on, I
hit enter. This works every time and provides me with an excellent
initialization.

I then use two stars that are at least 60 degrees apart, such as Deneb
and Arcturus. The first star's warp factor is always way off. The second
star is within the limits suggested by Lumicon for their particular
DSC's. I then ask the DSC's to guide me to M13, an easy target in the
finder scope. I center that in my 12.5mm Ultima, and hit align. I get a
very good warp factor and off I go.

This seems like a lot a work to do before ever looking at anything, but
it becomes second nature after awhile and takes very little time.

Depending on the resolution of the encoders being used, you should
occasionally re-align on what ever target you may be looking at, a
couple of times through out your observing session to ensure accuracy
based on what ever slop may be in the system.

Sorry for the long post everyone.

Take care,
Gregory david Stempel
FIREFRAME

Mark,

If you are using the Losmandy gear set you need to set the encoder resolution at 4320 because
Losmandy uses a 2:1 gear ratio. Try that number and see what happens.

Don

4320? When I received my Losmandy DSCs, my dealer advised that they should be
set to 4096.

Greg Crawford

--- In Losmandy_users@..., Mark Simmons <msimmons@d...> wrote:

Hi,

Just joined this group and would like to solicit your opinions on
encoder resolutions for the GM8.

Also I am still struggling with the two star alignment procedure.

Does

every one have to go through the 90 degree alignment setup before
getting accurate DSC read out?


Thanks...

-Mark Simmons-

Mark:
Polar align the mount, then use the one-star alignment method.
The two-star and 90 degree are for innaccurate or poorly aligned
mount. After choosing one-star alignment, merely choose your star
from the list and center it using high power EP, preferably with a
reticle. If your star is on the western side of the mount, after
choosing one-star alignment, press it again and the display will read
something like "sight second star", then choose your star from the
list, etc. I think this information can be found at www.losmandy.com
under support.

Bruce Inscoe

Greg,

Mark specifically said he had 2160 encoders. The Losmandy supplied encoders are normally 2048 which
when doubled by the gear ratio will require a 4096 setting. Mark is using used encoders and did
notice that the label said 2160, so doubling that means his setting should be 4320.

Don

Don,

Thanks for enlightening me. I was not aware of this difference.

Greg

Donald,

You're the man. I am running with excellent targeting as a result of
YOUR help.

Thanks for input Don, take care.
Gregory david Stempel
FIREFRAME

Greg,

Glad to have been of help.

Don