Date   

Re: Mach1 and checking PASILL4 results

Dean S
 

Yes Pierre, mine is indeed the latest version.

Good luck with finding the issue with yours as this a sweet mount! I have
never experienced guiding this nice and smooth. It is better than my 1200
right now.

----- Original Message -----
From: "phenrotay" <Pierre.Henrotay@skynet.be>
To: <ap-gto@yahoogroups.com>
Sent: Saturday, May 03, 2008 1:48 AM
Subject: [ap-gto] Re: Mach1 and checking PASILL4 results


Hi Dean,

could you confirm that your model is effectively a PASILL4 (ie the
latest one, with engravings till 2030 and rotating housing) ?

Thanks !
Pierre
--- In ap-gto@yahoogroups.com, "Dean S" <dean@...> wrote:

Hi Pierre,

I managed to check the polar alignment scope tonight. After my
drift
alignment with Pempro, the polar scope is perfectly aligned with
all 3
stars.

What was unusual is, that when I looked thru the polar scope, it was
perfectly aligned without me even touching it. I doubt that would
happen
very often.

Dean


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Re: Backlash Adjustment in Mach1

hewholooks
 

Thanks. To update all interested parties - I was out last night and
the mount performed like new, no problems.

Hunter

--- In ap-gto@yahoogroups.com, chris1011@... wrote:

In a message dated 5/3/2008 4:03:32 PM Central Daylight Time,
hewholooks@... writes:


After I did this proceedure, it suddenly hit me that I did the
adjustment with the mount fully loaded with about 40 pounds of
equipment.

Should I have done it with the mount empty, or is it OK to have
done
this fully loaded?
Doesn't matter. Either way is correct.

Rolando




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[Non-text portions of this message have been removed]


Re: Belated thanks to bguerin1234

javier laina
 

Brian,

Could you explain how to balance a servo-controlled mount by using
and amp-meter?

Cheers
Javier
http://personales.ya.com/javier_laina/



--- In ap-gto@yahoogroups.com, "bguerin1234" <zapkgbg@...> wrote:

Tom,

I'm glad it helped!!

Brian




--- In ap-gto@yahoogroups.com, "tucstargzr" <tucstargzr@> wrote:

I'm almost ashamed it took this long to complete this, but...

bguerin1234 posted a hand drawn schematic in the Files section
that
illustrates how to use an amp-meter to balance the mount. I
finally
installed Amperage and voltage meters just under the rope lights
in
the Observatory. Since I'm using an 11.5 Amp power supply, I got
a
10
Amp meter.

With both the AP 600 and 1200 humming along, it barely measures
an
amp! Slewing, of course bumps it up another ~1/2 amp, but on a
10
amp
meter, that isn't quite the resolution for the fine balance task.

At the same time, for an all thumbs "electrician", it was
interesting
to see how much of a load various 12V items I have draw.

Tom
Sings with the Stars


Re: El Capitan Question

Larry Phillips
 

Roland,
Will the software you mention below be usable only on El Capitan or
also on the other mounts?

Larry


"In addition to the hardware possibilities, Ray Gralack is working on a
software program which will be the control center for any PC based
operation of this mount. All commands will go thru this program and get
sorted out before being sent to the servo. This means no more problems
with inappropriate Sync/Rcal commands which can get the mount "lost".
The program will also allow you to see the position of the scope
relative to the mount at any given time, so you will see whether or not
you can safely aquire or track an object beyond the meridian. The
program will also allow you to set software limits of telescope motion
for all parts of the sky. Together with the hardware limits, the system
should be pretty much bombproof."


Re: PulseGuide and script

Pierre Henrotay
 

Thank you, Ray.
Seems that I still need to have a closer look at the "Rate inversion"
theme: I cannot figure out a rule of thumb yet, sometimes the results
are excellent and sometimes I need to invert the rates. Hit and miss.

BTW, I noticed that you added check boxes for doing this; they are
presented when the measured rates results are presnted. I would
suggest to move them to the Pulse Guider page itself. But I remember
that no further version of PG in its present form is to be expected,
or ? If you change your mind, have a think of this one...

CS,
Pierre

--- In ap-gto@yahoogroups.com, "Ray Gralak" <rgr@...> wrote:

Hi Pierre,
So, if your plate solves returns RA/Dec then you can just subtract
the RA
values divide by time and multiply by 15. So, you should not need
to adjust
for declination (Cosine of Dec) in this case.


About Mach1GTO

siqingtan
 

I've noticed from the A-P website that notification for the latest
batch of Mach1's has begun. I am curious as to the "lag time" for this
mount, so if anyone here has ordered one and has been contacted
recently I would be quite interested as to when you placed yourself on
the wait list.I have ordered it in April this year,How long will I get
it.
Thanks!


Re: El Capitan Question

Roland Christen
 

In a message dated 5/5/2008 11:40:21 AM Central Daylight Time,
llp41astro@cox.net writes:


Roland,
Will the software you mention below be usable only on El Capitan or
also on the other mounts?

Larry
Whatever applies the the large mount will also be useable on the others,
especially this new software. The servo is the same. A few options such as the
precision encoder, are not available for the small mounts, but most everything
else will be.

Roland


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Re: El Capitan Question

Roland Christen
 

Hello Steve,

We are adressing all the concerns which you have elaborated below. This new
mount will be configurable for any number of applictaions from the most simple
to the most constrained. The reasonig is so that each individual will be able
to set the system up according to his/her needs and pocketbook.

You saw the limit switches which were attached to the RA axis, but you did
not notice that this mount also had an optional precision lab encoder mounted
inside the RA axis, which not only allows for elimination of periodic error, but
also has a precise marker for precision homing. The external switch for
homing is accurate enough to allow startup from a known point and subsequent
imaging with a medium focal length scope, which will then allow plate solve for
precise pointing. We made this a simple switch in this example, but there is no
reason that a more accurate complex software switch cannot be mounted in its
place (magnetic homing switch or other type).

Please note that homing per se is not necessary with this mount, except in
cases of extreme messup by the operator. The servo actually never gets lost
because it always keeps track of the angle of the gearwheel position. What happens
when the mount "seems" to get lost is that wrong RA and Dec numbers get
attached to the gearwheel angles due to wrong data being sent to the mount. If the
operator does a SYNC operation on Vega and calls this star Sirius, then the
internal star map gets contorted, all subsequent objects will be shifted
accordingly, and no object will then be found. However, the limits of allowable
motion are still going to be in place to prevent the mount from going past the
actual meridian, or wherever the user decides to place them. They are not decided
by RA and DEC numbers, rather by gear angles. In addition, the servo always
knows which gear tooth is being engaged and where we are on the 0-360 degree
angles on the two worm gears regardless of how the internal sky map is skewed.
That never changes and the information of the actual gear angle can be used to
provide information to external programs to determine the position of the
gearwheel.

The meridian limit switches which we have attached to this first mount can be
used in a simple or in a complex way - this is all up to the user. For
instance, the simplest way is for the switch to be wired in series with the power
supply line. When the limit is reached, the servo will simply stop powering the
motors. The user can then bypass this switch with a switch or relay of his
own, which then sends power back to the servo and allows the system to start up
again. You can then enter the same object again and the mount will do a
meridian flip to aquire it on the other side. Conversely, there are many complex ways
to use this switch signal, depending on what you want to do. The signal can
be sensed by the auxiliary control center and acted upon in a number of ways
(automatic meridian flip, or stop until user input, or whatever).

In addition to the hardware possibilities, Ray Gralack is working on a
software program which will be the control center for any PC based operation of this
mount. All commands will go thru this program and get sorted out before being
sent to the servo. This means no more problems with inappropriate Sync/Rcal
commands which can get the mount "lost". The program will also allow you to see
the position of the scope relative to the mount at any given time, so you
will see whether or not you can safely aquire or track an object beyond the
meridian. The program will also allow you to set software limits of telescope
motion for all parts of the sky. Together with the hardware limits, the system
should be pretty much bombproof.

Roland Christen

In a message dated 5/3/2008 11:58:27 AM Central Daylight Time,
astropix@ptd.net writes:

Hi Roland,

I've seen El Capitan at AIC last November and again last weekend at
NEAF. It's a very impressive hunk of "iron". I see that you now have
added external limit switches and am wondering about them.

If I understood you correctly at NEAF, you said that these switches
are intended for both limiting travel and for homing the mount to a
known position. Also I think you said they would not be integrated
into the mount's control box but would be used by external software.

So a couple of questions for respectful discussion:

1. While these switches would clearly work fine for limiting travel,
I am doubtful that they would provide sufficient accuracy for a
homing function. Do you intend them to be used for homing? Do you
believe they will have sufficient accuracy (ie. repeatability) for
that purpose? If they are just for limiting travel, how will homing
be accomplished?

2. The mount at NEAF only had these on the RA axis but I presume a
second set could be placed on the DEC axis. Is it your intent to put
them on both axes? I am not sure how limit switches would work for
homing (or even limiting travel) of the declination since the full
range of rotation is needed. How would they serve to home the
declination axis?

3. By not integrating these into the mount's control system, I think
there will be some issues for homing (if that's an intended function
for the switches). If the mount has been improperly synced, the
external computer will have no way to know which way to slew to reach
a particular switch. It will have to simply choose a direction and
slew until the limit is reached. Then it will know which side the
mount is on. The same will be true for the declination axis. So I
think there could be some situations where the slews of both axis can
cause the scope to hit the pier even though both RA and DEC are
within their limits. Am I mistaken in this?

To be honest, I was a bit surprised to see something other than a
protected (ie. inside the mount) optoelectronic device used for this
function. Also I was disappointed to see that there is no integration
with the control system (ie. no "GOTO Home" function).

Anyway, I'd appreciate your remarks on this. I am considering El
Capitan for a new observatory but I really feel I need a homing
function. Maybe I missed the point on these switches.

Thanks!



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Re: Backlash Adjustment in Mach1

Roland Christen
 

In a message dated 5/3/2008 4:03:32 PM Central Daylight Time,
hewholooks@yahoo.com writes:


After I did this proceedure, it suddenly hit me that I did the
adjustment with the mount fully loaded with about 40 pounds of
equipment.

Should I have done it with the mount empty, or is it OK to have done
this fully loaded?
Doesn't matter. Either way is correct.

Rolando




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Re: Meade tripod - wedge bolt hole pattern

pm57uk
 

Thanks Eric,
Cheers Paul
--- In ap-gto@yahoogroups.com, "eric98112" <eric98112@...> wrote:

I believe this might be what you are looking for:

http://www.pierplates.com/AP%20900%20to%20PierTopPlate.pdf

I had my 900 pier adapter modified in this way. I'm not sure
whether you have a permanent pier installation, but note that the
countersunk holes for attaching the 900 pier adapter to your pier
top plate will interfere with the tapped holes for mounting the RA
axis to the 900 pier adapter unless you can rotate your pier top
plate away from north by at least 7 degrees.

-Eric

--- In ap-gto@yahoogroups.com, "pm57uk" <ast57@> wrote:

Hi,

This is a long shot but I thought I'd try anyway.

I'm going to be putting the 900 standard pier adapter onto the
top
of
my flat-topped pier.

My pier top has some tapped holes to match the pattern of the
bolt
holes of the meade wedge (centre hole plus 3 holes 120 deg apart
a
few inches out from the centre) which used to sit on my pier.

I was hoping to have the AP pier adapter pre-drilled so I could
fasten it directly to my pier for minimum hassle and was
wondering
if
anyone might know the specifications of the bolt hold pattern for
the
meade wedge that I could supply in advance to have holes drilled.

(I guess I could paper trace the bolt pattern on my pier top, but
I
don't want to disasemble the mount that is currently riding on it
if
at all possible for the moment.)

Cheers
Paul McGale


Re: Belated thanks to bguerin1234

Brian Guerin
 

Tom,

I'm glad it helped!!

Brian




--- In ap-gto@yahoogroups.com, "tucstargzr" <tucstargzr@...> wrote:

I'm almost ashamed it took this long to complete this, but...

bguerin1234 posted a hand drawn schematic in the Files section
that
illustrates how to use an amp-meter to balance the mount. I finally
installed Amperage and voltage meters just under the rope lights in
the Observatory. Since I'm using an 11.5 Amp power supply, I got a
10
Amp meter.

With both the AP 600 and 1200 humming along, it barely measures an
amp! Slewing, of course bumps it up another ~1/2 amp, but on a 10
amp
meter, that isn't quite the resolution for the fine balance task.

At the same time, for an all thumbs "electrician", it was
interesting
to see how much of a load various 12V items I have draw.

Tom
Sings with the Stars


Belated thanks to bguerin1234

tucstargzr
 

I'm almost ashamed it took this long to complete this, but...

bguerin1234 posted a hand drawn schematic in the Files section that
illustrates how to use an amp-meter to balance the mount. I finally
installed Amperage and voltage meters just under the rope lights in
the Observatory. Since I'm using an 11.5 Amp power supply, I got a 10
Amp meter.

With both the AP 600 and 1200 humming along, it barely measures an
amp! Slewing, of course bumps it up another ~1/2 amp, but on a 10 amp
meter, that isn't quite the resolution for the fine balance task.

At the same time, for an all thumbs "electrician", it was interesting
to see how much of a load various 12V items I have draw.

Tom
Sings with the Stars


Re: 1200GTO balance point

John Murphy
 

The spreadsheet looks very useful. Unfortunately, despite there being
lots of dimensions in the spreadsheet, I cannot find the ones I
need... I guess that the dimensions I am after are not dependant on
the latitude setting (the affect of any angle will cancel out).

Thanks
John Murphy

--- In ap-gto@yahoogroups.com, "tucstargzr" <tucstargzr@...> wrote:


There's a spreadsheet in the files section that has all the
dimentions you need. IIRC it's called Lat Calc.

Robin Casady also has a great article on CWs.


--- In ap-gto@yahoogroups.com, "John Murphy" <john_and_hong@>
wrote:

Hi all

I am on the waiting list for a 1200GTO mount. I am trying to
calculate approximately how much counter weight I will need and
at
what distance.
To do this I need to know:

(1) Distance from RA axis to where the counterweight shaft screws
in
(2) The distance from the RA axis to the telescope mounting plate

I assume that how far out of balance the mount is without the
counterweight shaft is too small to be significant.

The length and weight of the counter weight shaft are available
on
the web site.

If my memory of high school maths is valid, I can then calculate
with:
(M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

Does anyone know if the 1200GTO is the next stand to go into
production? :-)

Thanks
John Murphy


Re: 1200GTO balance point

tucstargzr
 

There's a spreadsheet in the files section that has all the
dimentions you need. IIRC it's called Lat Calc.

Robin Casady also has a great article on CWs.


--- In ap-gto@yahoogroups.com, "John Murphy" <john_and_hong@...>
wrote:

Hi all

I am on the waiting list for a 1200GTO mount. I am trying to
calculate approximately how much counter weight I will need and at
what distance.
To do this I need to know:

(1) Distance from RA axis to where the counterweight shaft screws
in
(2) The distance from the RA axis to the telescope mounting plate

I assume that how far out of balance the mount is without the
counterweight shaft is too small to be significant.

The length and weight of the counter weight shaft are available on
the web site.

If my memory of high school maths is valid, I can then calculate
with:
(M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

Does anyone know if the 1200GTO is the next stand to go into
production? :-)

Thanks
John Murphy


1200GTO balance point

John Murphy
 

Hi all

I am on the waiting list for a 1200GTO mount. I am trying to
calculate approximately how much counter weight I will need and at
what distance.
To do this I need to know:

(1) Distance from RA axis to where the counterweight shaft screws in
(2) The distance from the RA axis to the telescope mounting plate

I assume that how far out of balance the mount is without the
counterweight shaft is too small to be significant.

The length and weight of the counter weight shaft are available on
the web site.

If my memory of high school maths is valid, I can then calculate with:
(M1 * D1) + (Mn * Dn) = (Telescope mass * Telescope distance)

Does anyone know if the 1200GTO is the next stand to go into
production? :-)

Thanks
John Murphy


Re: PulseGuide and script

Ray Gralak <rgr@...>
 

Hi Pierre,

I wrote a small (and primitive) script to derive the RA and DEC drift
rates for PG.
Basically, I take two images separated by an interval of a few
minutes, plate solve each and compute the difference in plate center,
then divide by the elapsed time. Then feed to PG.

For the RA rate, is this what PG expects or should I take into
account the DEC cosine ?
PulseGuide expects the RA/Dec rate to be in units of arc-sec/sec. e.g. A
value 1.00 would move Dec axis 1 arc-sec per second, and the RA axis 1/15
arc-sec seconds per second (since RA is measured in 24H format instead of
degrees).

So, if your plate solves returns RA/Dec then you can just subtract the RA
values divide by time and multiply by 15. So, you should not need to adjust
for declination (Cosine of Dec) in this case.

And second question: I understand that one possible usage of PG is
to compensate for (some amount of) polar misalignment
- such as the difference between true and refracted pole.

Am I pushing it too far if I also apply it for a misalignement of
several minutes (say 10). Of course, I understand that
there can be many factors (exposure time, declination, latitude...).
So there might be no simple answer.
The possible rate changes are rather complex to calculate and dependent on
which direction the polar misalignment is directed. As you expected there is
no easy formula to go by. You can measure the rate and null polar
misalignment for a good interval of time, maybe as much as 30-40 minutes
before re-measuring. The problem is possible field rotation, which is not
corrected for even by a rate change.

-Ray


PulseGuide and script

Pierre Henrotay
 

Hi all,

This one for Ray I think.

I wrote a small (and primitive) script to derive the RA and DEC drift
rates for PG.
Basically, I take two images separated by an interval of a few
minutes, plate solve each and compute the difference in plate center,
then divide by the elapsed time. Then feed to PG.

For the RA rate, is this what PG expects or should I take into
account the DEC cosine ?

And second question: I understand that one possible usage of PG is
to compensate for (some amount of) polar misalignment
- such as the difference between true and refracted pole.

Am I pushing it too far if I also apply it for a misalignement of
several minutes (say 10). Of course, I understand that
there can be many factors (exposure time, declination, latitude...).
So there might be no simple answer.

Regards,
Pierre


Re: Transitting exoplanet in Hercules

Bill Bradford
 

That is remarkable, Anthony. You are justifiably proud of your work. You should write an article for the astronomy magazines about it.

Bill

----- Original Message -----
From: ayiomamitis
To: ap-gto@yahoogroups.com
Sent: Saturday, May 03, 2008 10:11 AM
Subject: [ap-gto] Transitting exoplanet in Hercules


Dear group,

One of the latest exoplanet discoveries (2007) involves TrES-3 in Hercules. What is of
great interest surrounding this discovery is the exoplanet's proximity to its parent star and
its degenerative orbit. In other words, at some point this exoplanet will not be available for
study due to its orbit and impending collision into its sun.

What makes the photometry of this exoplanet most challenging is the fact that its host
star is very dim at magnitude 12.17 and the transit depth of 25 mmag translates to very
small changes in the overall dimness of the parent star during transit. I am delighted to
present you with a light curve for TrES-3 taken with a well-known 160 mm refractor
(LOL!) and which most beautifully illustrates the 105-minute transit.

I contacted a couple of individuals a priori surrounding this transit and I was told that it is
not possible in the slightest given the dim magnitude of the parent star, the transit depth
and my small aperture. Well, no pain, no gain.

For the light-curve in two-formats as well as a finder chart, I kindly direct you to
http://www.perseus.gr/Astro-Photometry-TrES-3-20080503.htm ...

There are additional exoplanet transits over the next few months and which I will certainly
be pursuing.

Clear skies!

Anthony.


Re: Backlash Adjustment in Mach1

Larry Phillips
 

Thanks Hunter.

Larry

--- In ap-gto@yahoogroups.com, "hewholooks" <hewholooks@...> wrote:

Larry,

I removed the two large allen screws - they just screw into the
cover
and nothing else.

Through these two holes are the screws that adjust the mesh. Use
the
same hex wrench. It's kindof strange, you just loosen the
adjustment
screws a turn or two, wiggle the axis, and re-tighten. Backlash
was
gone.

I tested with a couple high speed slews and it sounded good. I
hope
I didn't mess up my guiding, as I am always a little apprehensive
about things like this until I use the equipment again.

I thought adjusting it under load would be Ok, as I remember that
it
is actually suggested to adjust my old Atlas while under full load
to
correctly mesh the gears.

Hunter

--- In ap-gto@yahoogroups.com, "Larry Phillips" <llp41astro@>
wrote:

Hunter or anyone,
Roland' description of how to make the backlash adjustment for
the
Mach1 has left me confused. I can not find two cover screws on
the
top of the gearbox. I find three screws on the side which
exposes
the reduction gears. On the bottom where the electrical
connector
is
located there are two large allen screws. Are these the ones to
loosen? There are several other smaller screws that it looks
like
I
would have to remove along with the large ones to "remove" any
kind
of cover. I feel like I am looking at a different mount from the
one
Roland describes in the refenced message.

Larry

--- In ap-gto@yahoogroups.com, "hewholooks" <hewholooks@> wrote:

Have had my Mach1 for a couple months now and am very pleased.

Lately, due to break-in I assume, it has deleloped just a tiny
bit
of
backlash in both axes - not much, but it wasn't there to start
with.

I read message message 19854 ( http://tinyurl.com/5oktbn )
which
explains how to remove backlash in the Mach1. It worked
beautifully,
at least to my bare hand touch (haven't been out to test it at
night
yet, but I can feel no more clicking in the RA axis when I
manually
shimmy the axis).

After I did this proceedure, it suddenly hit me that I did the
adjustment with the mount fully loaded with about 40 pounds of
equipment.

Should I have done it with the mount empty, or is it OK to have
done
this fully loaded?

Thanks,

Hunter


Re: Backlash Adjustment in Mach1

hewholooks
 

Larry,

I removed the two large allen screws - they just screw into the cover
and nothing else.

Through these two holes are the screws that adjust the mesh. Use the
same hex wrench. It's kindof strange, you just loosen the adjustment
screws a turn or two, wiggle the axis, and re-tighten. Backlash was
gone.

I tested with a couple high speed slews and it sounded good. I hope
I didn't mess up my guiding, as I am always a little apprehensive
about things like this until I use the equipment again.

I thought adjusting it under load would be Ok, as I remember that it
is actually suggested to adjust my old Atlas while under full load to
correctly mesh the gears.

Hunter

--- In ap-gto@yahoogroups.com, "Larry Phillips" <llp41astro@...>
wrote:

Hunter or anyone,
Roland' description of how to make the backlash adjustment for the
Mach1 has left me confused. I can not find two cover screws on the
top of the gearbox. I find three screws on the side which exposes
the reduction gears. On the bottom where the electrical connector
is
located there are two large allen screws. Are these the ones to
loosen? There are several other smaller screws that it looks like
I
would have to remove along with the large ones to "remove" any kind
of cover. I feel like I am looking at a different mount from the
one
Roland describes in the refenced message.

Larry

--- In ap-gto@yahoogroups.com, "hewholooks" <hewholooks@> wrote:

Have had my Mach1 for a couple months now and am very pleased.

Lately, due to break-in I assume, it has deleloped just a tiny
bit
of
backlash in both axes - not much, but it wasn't there to start
with.

I read message message 19854 ( http://tinyurl.com/5oktbn ) which
explains how to remove backlash in the Mach1. It worked
beautifully,
at least to my bare hand touch (haven't been out to test it at
night
yet, but I can feel no more clicking in the RA axis when I
manually
shimmy the axis).

After I did this proceedure, it suddenly hit me that I did the
adjustment with the mount fully loaded with about 40 pounds of
equipment.

Should I have done it with the mount empty, or is it OK to have
done
this fully loaded?

Thanks,

Hunter