Date   

Astro-Physics Email

Christine Schmidt
 

Hello everyone,

I wanted to let you know that we are aware of our email issue. We made
a change to our service last night and it did not go as smoothly as one
hoped.

If you are getting a bounce back or you did not get a reply, we should
be up and running again soon.

Christine
Astro-Physics


Re: Exceptional Night for imaging M106

Paul Gustafson
 

Very nice! I also appreciate the no-music option.

Paul Gustafson


Re: Exceptional Night for imaging M106

Stuart Heggie <stuart.j.heggie@...>
 

Beautiful shot Ruben! Great colour and detail!

Stuart

----- Original Message -----
From: stardoctor5
To: ap-gto@yahoogroups.com
Sent: Thursday, April 26, 2007 11:00 PM
Subject: [ap-gto] Exceptional Night for imaging M106


Dear group,

Last Friday night, both seeing and transparency co-operated for almost
6 hours.

http://www.stardoctor.org/M106-hush without music

http://www.stardoctor.org/M106 with music (may activate ActiveX
control, don't panic)

Feedback welcome!

Ruben

ST10XME
Meade 12" LX200R
AP 0.67x reducer
AP900GTO mount
Hidden Lake Observatory


Exceptional Night for imaging M106

Robin Kerr
 

Dear group,

Last Friday night, both seeing and transparency co-operated for almost
6 hours.

http://www.stardoctor.org/M106-hush without music

http://www.stardoctor.org/M106 with music (may activate ActiveX
control, don't panic)

Feedback welcome!

Ruben

ST10XME
Meade 12" LX200R
AP 0.67x reducer
AP900GTO mount
Hidden Lake Observatory


Re: Takahashi TOA-150 on AP 900GTO ?

flyrcairplanes
 

Hello,
I posted this question a while ago so you might want to check for
those suggestions as well. I ended up getting the Parallax rings
specifically for the TOA 150 and attaching them directly to Losmandy
DAP5. I then have a TV60is riding on top. This all sits on the AP
Dove08. This works really well for me and I am imaging at the TOA
150's native focal length. FWIW.

Jeff

--- In ap-gto@yahoogroups.com, "jjbadal2003" <jbadal21169@...> wrote:

-Neils. I think the TOA150 is 179mm diamter, so 155 rings wont fit.
Parallax makes rings for TOA150. You could use those with the
terrific and well priced AP 15inch ribbed plate. I think Socalastro
makes a TOA150 ring also (or at least used to). Joe





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

I want to attach my Takahashi TOA-150 refractor to my 900GTO.

I could purchase an appropriate dovetail and a Losmandy saddle.

However, the quick release is not important as this will be a
permanent setup.

Should I make a heavy aluminum base plate for the TAK rings and
scrue
it directly on the 900GTO?

Can such a plate be purchased? (I cannot CNC machine it myself)

I imagine that such a plate will be even more rugged than a
dovetail-
saddle system, but may be wrong. What do you think? Any
experiences?

Any suggestion or comment is highly appreciated.

Best regards,

Niels Foldager


Re: Takahashi TOA-150 on AP 900GTO ?

jjbadal2003
 

-Neils. I think the TOA150 is 179mm diamter, so 155 rings wont fit.
Parallax makes rings for TOA150. You could use those with the
terrific and well priced AP 15inch ribbed plate. I think Socalastro
makes a TOA150 ring also (or at least used to). Joe





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

I want to attach my Takahashi TOA-150 refractor to my 900GTO.

I could purchase an appropriate dovetail and a Losmandy saddle.

However, the quick release is not important as this will be a
permanent setup.

Should I make a heavy aluminum base plate for the TAK rings and
scrue
it directly on the 900GTO?

Can such a plate be purchased? (I cannot CNC machine it myself)

I imagine that such a plate will be even more rugged than a
dovetail-
saddle system, but may be wrong. What do you think? Any
experiences?

Any suggestion or comment is highly appreciated.

Best regards,

Niels Foldager


Re: Takahashi TOA-150 on AP 900GTO ?

Joe Mize
 

Niels, if you do have a plate made one of the most critical aspects you'll have to remember is the "exact" alignment of the holes
for the attachment of both the mount and the OTA. You want to maintian orthanoglity. Choose a 'good' machinest...joe :)

------- Original Message -------
From : nfoldager[mailto:nf@dadlnet.dk]
Sent : 4/26/2007 5:48:11 AM
To : ap-gto@yahoogroups.com
Cc :
Subject : RE: [ap-gto] Takahashi TOA-150 on AP 900GTO ?

I want to attach my Takahashi TOA-150 refractor to my 900GTO.

I could purchase an appropriate dovetail and a Losmandy saddle.

However, the quick release is not important as this will be a
permanent setup.

Should I make a heavy aluminum base plate for the TAK rings and scrue
it directly on the 900GTO?

Can such a plate be purchased? (I cannot CNC machine it myself)

I imagine that such a plate will be even more rugged than a dovetail-
saddle system, but may be wrong. What do you think? Any experiences?

Any suggestion or comment is highly appreciated.

Best regards,

Niels Foldager





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Re: Takahashi TOA-150 on AP 900GTO ?

Edd Weninger
 

AP makes several plates for the 900 with a variety of bolt patterns.
See their website. The AP rings for my AP155 bolt directly to the
plate. If you're lucky, the Tak rings might also. If they don't you
might only have to drill a few holes for the Tak bolt pattern.

Or see if AP rings will fit your Tak.

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

I want to attach my Takahashi TOA-150 refractor to my 900GTO.

I could purchase an appropriate dovetail and a Losmandy saddle.

However, the quick release is not important as this will be a
permanent setup.

Should I make a heavy aluminum base plate for the TAK rings and
scrue
it directly on the 900GTO?

Can such a plate be purchased? (I cannot CNC machine it myself)

I imagine that such a plate will be even more rugged than a
dovetail-
saddle system, but may be wrong. What do you think? Any experiences?

Any suggestion or comment is highly appreciated.

Best regards,

Niels Foldager


Takahashi TOA-150 on AP 900GTO ?

N. Foldager
 

I want to attach my Takahashi TOA-150 refractor to my 900GTO.

I could purchase an appropriate dovetail and a Losmandy saddle.

However, the quick release is not important as this will be a
permanent setup.

Should I make a heavy aluminum base plate for the TAK rings and scrue
it directly on the 900GTO?

Can such a plate be purchased? (I cannot CNC machine it myself)

I imagine that such a plate will be even more rugged than a dovetail-
saddle system, but may be wrong. What do you think? Any experiences?

Any suggestion or comment is highly appreciated.

Best regards,

Niels Foldager


Re: Pulsed LED on Polar Scope

Joe Zeglinski
 

Hi Rick,

I guess I'm spoiled in wanting to use the LED to see the alignment reticle
a bit more easily. Besides, it is difficult to spot Polaris most times, and
nearly impossible in late dusk, around here.
Actually, at that point, without the LED lighting the reticle, it is almost as
easy to just bore-sight Polaris through the opening in the axles, like through
a tank canon (in the olden days).

However, the point I was trying to make is that with just a very few more
lines of firmware code, the LED blink rate could be added, thus improving the
way the PASILL scope works, as well as the user's LED reticle in his "guiding
eyepiece" plugged into the GTOCP3 reticle port.

There is no hardware or other costs involved, for AP to add this standard
capability. The firmware already allows the user to set the LED brightness -
so the added code could easily tap into that section of program to "dim the
Reticle port power to OFF", at regularly spaced intervals, set by the user.

I'm sure this was just a simple oversight at AP, since if they had thought
of it, they would have quickly included it in the latest firmware release.
Distribution and installation isn't an issue, because this could be easily
done in the next GTOCP3 Keypad firmware download. Certainly, there is ample
program space to add this.

Alignment (or guiding) using an LED illuminated reticle that is not
constantly distracting the eye, is much easier to use. Turning the LED off at
regular intervals makes seeing the target much easier. Surely, this would be a
good feature, easily implemented, and a considerable improvement in the way
the Reticle port operates.

Joe

----- Original Message -----
From: "Rick Wiggins" <rickwiggins@earthlink.net>
To: <ap-gto@yahoogroups.com>
Sent: Wednesday, April 25, 2007 3:52 PM
Subject: [ap-gto] Re: Pulsed LED on Polar Scope


Hi Joe,
Here is a point of reference. I use Pasill2,3,&4 models. I can
easily line up the two stars from my home. I am right next to LAX
airport and do the alignment looking right over LAX and into
downtown Los Angeles with streetlights very close, so I am in a near
worst case light pollution situation. I can do it without
illumination at dusk or with any source of red light after full
darkness. I have even used a red flashlight with a cupped hand to
direct light into the polar scope.
Thanks, Rick


Re: Is the GTOCP3 North-South switch really needed?

Joe Zeglinski
 

Hi Dave,

I'm glad you corrected my thinking. I had completely forgot the
possibility of using it manually, without GOTO. In such case, definitely, a
N-S switch would make good sense; it would be essential in an uncomputerized
controller.

Then again, I don't think a non-GOTO version of the AP900/1200 (maybe
others) has been made since the "AP900 SMD Servo" back in 1998 - and that was
discontinued due to lack of a market for it. Besides, if you were able to
order something like an AP900 QMD or SMD today, there is no longer a "quartz
digital drive"(similar to the non-GOTO Losmandy G11 digital drive) available
for it . The only way you could adjust the position of the scope is to push
and pull it by hand, unless you attach one of those "springy rods" directly to
each worm, somehow. Shades of the 60's!

I think I am right in saying that there are no "non-GOTO" AP mount
versions available. So the hemisphere switch isn't required, unless you can
dig up an old quartz drive. Besides, the ancient digital drive is the one
requiring the switch - not the computer controlled GOTO controller, which can
do the same thing based on the firmware being given your latitude (north or
south).

Thus, the N-S switch on a GOTO controller these days, is an anachronism,
better replaced as a power switch. It is akin to leaving a place for the buggy
whip, in a new automobile :-)

Then again, I don't work at AP, so I don't know the "real purpose" of the
N-S switch, and why it wasn't removed from the GTOCP0, in 1998. Maybe it's
like that switch on the lamp post at the crosswalk, that a pedestrian pushes
to change the traffic lights - its a "feel good switch" that really isn't
wired to anything; the lights still change in their own sweet time, by some
computer controller downtown.

I'm joking, of course. Its just that it suddenly, one day, it struck me as
odd to have a manual motor direction reversing switch, when the firmware is
smart enough to do it, based on available information.

Joe

----- Original Message -----
From: "mogulskier_groups" <mogulskier_groups@yahoo.com>
To: <ap-gto@yahoogroups.com>
Sent: Wednesday, April 25, 2007 8:41 PM
Subject: [ap-gto] Re: Is the GTOCP3 North-South switch really needed?


I personally would rather have a power switch. That aside, I believe
that the AP mounts were designed with many target requirements, one
of those being someone doing visual observing with or without the
goto (my guess). In that case, one could align and use the scope
manually, but the RA would need to rotate in the opposite direction,
depending on the hemisphere.

Why not both?

A switch somewhere would be welcome.

Dave

--- In ap-gto@yahoogroups.com, "Joseph Zeglinski" <J.Zeglinski@...>
wrote:

I wonder if someone at AP might consider eliminating the N-S
switch, in
future versions of the GTO Control Panel. Indeed, use it as a
lighted POWER
Switch, which many of us have asked for.

Seems to me that if you enter your location coordinates, you
are already
specifying whether your AP Mount is being used in the north or
south
hemisphere. That makes the N-S switch redundant.

If there is more than one circuit board contact that needs to
be switched,
couldn't this be done by the firmware setting flip flops, or
activating a
multi-pole reed relay, based on that observer's Latitude setting?

By comparison, the Losmandy G11 Digital Drive controller - the
stepper
motor version, not being a GOTO, and thus having no processor -
does require
an internal N-S switch, which the user needs to set after removing
the control
panel. However, the Losmandy GEMINI GOTO controller, servo motor
version, does
NOT have a N-S switch on that processor board. I suppose it relies
on the
observer's North or South latitude setting, instead of wasting
panel space for
a mechanical switch, which perhaps for most of us, is rarely
toggled anyway.

Just wondering,
Joe






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Re: Is the GTOCP3 North-South switch really needed?

mogulskier_groups
 

I personally would rather have a power switch. That aside, I believe
that the AP mounts were designed with many target requirements, one
of those being someone doing visual observing with or without the
goto (my guess). In that case, one could align and use the scope
manually, but the RA would need to rotate in the opposite direction,
depending on the hemisphere.

Why not both?

A switch somewhere would be welcome.

Dave

--- In ap-gto@yahoogroups.com, "Joseph Zeglinski" <J.Zeglinski@...>
wrote:

I wonder if someone at AP might consider eliminating the N-S
switch, in
future versions of the GTO Control Panel. Indeed, use it as a
lighted POWER
Switch, which many of us have asked for.

Seems to me that if you enter your location coordinates, you
are already
specifying whether your AP Mount is being used in the north or
south
hemisphere. That makes the N-S switch redundant.

If there is more than one circuit board contact that needs to
be switched,
couldn't this be done by the firmware setting flip flops, or
activating a
multi-pole reed relay, based on that observer's Latitude setting?

By comparison, the Losmandy G11 Digital Drive controller - the
stepper
motor version, not being a GOTO, and thus having no processor -
does require
an internal N-S switch, which the user needs to set after removing
the control
panel. However, the Losmandy GEMINI GOTO controller, servo motor
version, does
NOT have a N-S switch on that processor board. I suppose it relies
on the
observer's North or South latitude setting, instead of wasting
panel space for
a mechanical switch, which perhaps for most of us, is rarely
toggled anyway.

Just wondering,
Joe


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


Re: Balance Procedure

drgert1
 

Hi Joe,

It's best to have a slight imbalance so that any (small) gear backlash
is always pushed out. I prefer the mount always to 'pull' a bit.

Clear Skies,

Gert

--- In ap-gto@yahoogroups.com, "Joseph Zeglinski" <J.Zeglinski@...> wrote:
...

Of course, the safest bet is to minimize any imbalance, as best
as one
can.

Joe


Re: Pulsed LED on Polar Scope

Wiggins, Rick
 

Hi Joe,
Here is a point of reference. I use Pasill2,3,&4 models. I can
easily line up the two stars from my home. I am right next to LAX
airport and do the alignment looking right over LAX and into
downtown Los Angeles with streetlights very close, so I am in a near
worst case light pollution situation. I can do it without
illumination at dusk or with any source of red light after full
darkness. I have even used a red flashlight with a cupped hand to
direct light into the polar scope.
Thanks, Rick

--- In ap-gto@yahoogroups.com, "Joseph Zeglinski" <J.Zeglinski@...>
wrote:

Hi,

I was wondering if there has ever been a consideration of
adding "pulsed
power" control for the PASILL3/4 polar scope. This could be either
an argument
to the keypad command to change not only the brightness, but also
the on/off
rate for the GTOCP3 reticle socket, or an attached box with a
small circuit in
the scope illuminator cable, with which you could adjust the pulse
rate and
brightness. This is similar to the way the "Pulse Guide" product
operates for
illuminated crosshair eyepieces.

The reason I bring this up, is that I took my PASILL4 outdoors
for a dry
run test, in the light polluted skies of suburbia of a large
metropolitan
city. It was somewhat difficult to spot Polaris, and did not
expect any
success in aligning the second, let alone the third, star onto the
reticle.
However, I was amazed to actually see the faint "glimmer" of the
second star,
if I quickly rotated the scope eyepiece back and forth. Of course,
this was
just a test of the scope itself, not yet mounted in my new AP900.
It makes no
sense to oscillate the eyepiece, as in my test, when you are
attempting to
precisely align the reference stars on the hash marks - that
defeats the
purpose. But I realized that if the red LED illuminator were to
be "pulsed",
instead of being steady, it would be easier to align two, or maybe
even all
three stars on the reticle.

Since the battery powered setup has neither a dimmer nor a
pulse width
adjust, the reticle is far too bright, making it difficult to
align on
Polaris. An attached control module, and/or a similar control in
the keypad
miscellaneous command set for the reticle port on the GTOCP3
control box,
would be useful. The latter, of course, would be used for not only
the polar
alignment with the PASILL4, but also perhaps with an illuminated
eyepiece on
the main OTA.

Thanks,
Joe




Re: Balance Procedure

Joe Zeglinski
 

Thanks Jeff,

I had forgotten about the large initial worm stress, with no OTA. I
suppose if it can (and must) survive that, then the normal imbalance is no
issue at all, in comparison. I had some concerns about operating the mount,
and not rebalancing on meridian changes, if something of the size of say a
large SBIG camera were hanging out there. Shifting weights so often, to
protect the worm drive, would be a hassle. I'm also relieved, that the servo
motors have a safety trip point protection circuit against this as well.

I see from your comparison of the 600GTO and 1200GTO mounts, that I made a
very good decision in purchasing the AP900, in this regard.

Thanks for the added reassurance. The AP900/1200 are one heck of a nearly
bullet-proof mount.
Joe

----- Original Message -----
From: "Jeff Young" <jey@adobe.com>
To: <ap-gto@yahoogroups.com>
Sent: Wednesday, April 25, 2007 11:10 AM
Subject: RE: [ap-gto] Balance Procedure


Joe --

I accidentally balanced my 600E GTO once without diagonal or eyepiece.
When a 2" diagonal, 2" Barlow and T4 Nagler was added, it produced
intermittent stalls when slewing (but not when tracking). I'd guess it
was about 40 in-lbs out of balance.

I never re-balance my 1200 GTO with equipment changes. I might go from
no eyepieces in either SCT or refractor to a heavy T5 Nagler in each
with a Barlow in one. These weights are much farther out on the moment
arm, so I'd guess we'd be looking at more than 100 in-lbs of inbalance.
I've never had this mount stall.

Lastly, when I load up my scopes on the 1200, I load the c-weights
first. This leaves the mount temporarily some 2,500 in-lbs out of
balance.

Cheers,
-- Jeff




________________________________

From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On
Behalf Of Joseph Zeglinski
Sent: Wednesday, April 25, 2007 3:22 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Balance Procedure



Hi Roland,

This is good news - I was becoming concerned about
"meticulously"
rebalancing the counterweights, every time I crossed the
meridian. Indeed, the
AP900 is a superb design, and even more so, from what you say
about the
rebalance issue.

One question:
You use the phrase "8 lbs out of balance", do you mean 8
inch-lbs?
Being "out of balance" with an 8 lb camera overhand at 6 inches
is different
from the same weight overhanging 2 feet away. Could you be more
specific about
the "moment arm" on the OTA imbalance you are describing?

Actually, it would be interesting, if someone there could do a
bit of
testing in this regard, on various "moment-arm measurements",
before you would
consider the AP900 or AP1200 seriously out of balance, for the
expected
performance. For that matter, before you would consider possible
damage to the
worm gear. That might provide a good rule of thumb which could
be applied to
any OTA overload situation, to specific AP mounts.

I suppose one might say that the imbalance on any mount has
reached a
maximum, if the clutches won't hold, but some might torque down
the clutches
too tightly, even with a wrench, in order to avoid having to
shift the
weights.

Thanks for any further info,
Joe

----- Original Message -----
From: <chris1011@aol.com <mailto:chris1011%40aol.com> >
To: <ap-gto@yahoogroups.com <mailto:ap-gto%40yahoogroups.com> >
Sent: Monday, April 23, 2007 1:04 PM
Subject: Re: [ap-gto] Balance Procedure

In a message dated 4/21/2007 8:52:34 AM Central Daylight Time,
drichey@sandia.net <mailto:drichey%40sandia.net> writes:


What's the procedure for rebalancing. If I have very good
polar alignment
and a good
pointing accuracy, but need to loosen the clutces and
reblance the load due
to adding
equipment, how do I maintain my pointing model.
Your pointing model is not affected if you loosen the clutches
to rebalance.
On the other hand, why do you need to do this? I image all the
time without
ever rebalancing. It is not really necessary. I have been as
much as 8lb out
of
balance on both 900/1200 mounts, and recently ran 6lb out of
balance on my
little bitty Mach1 mount. The tracking/guiding was spot on
perfect.

Roland Christen


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Re: Help with orthogonality

Auchter Tom-W11806
 

We are mixing pointing at the pole and pointing at Polaris. If the
mount is polar aligned and the telescope is orthogonal then you can do
the following. When you point the telescope at the pole ie 90 degrees
Polaris will not be centered. If you tell the mount to goto Polaris
then Polaris will be centered. I have done it many times.

Tom


Re: Balance Procedure

Joe Zeglinski
 

Hi Roland,

Not knowing the centre of gravity of your (160/F7.5) OTA, but assuming it
is at mid point (23.6 inches), that would be approximately a moment of 189
inch-lbs.
O.K. that is a useful working example to know, to judge our own OTA
conditions.

I am a bit surprised that AP uses "weight" instead of "moment (torque)"
when talking about imbalance. I found the same terminology used on page 23 of
the AP900 user manual: Troubleshooting - (additional explanation) - "It
typically takes about 4 lb. of unbalance to trip the overload circuit ...
etc."
This is a "weight", not a "moment arm" reference, which really depends on
which OTA you are using on the mount. A long OTA with 4 lbs is different from
a short SCT with the same 4 lbs. of unbalance.

As for not being concerned about "damaging the worm gear teeth", once
again, the user manual page 15 - RA & DEC Clutch Knobs: "3: How tight can they
be...etc." warns:
"You should not attempt to push your scope by hand against this locked up
resistance, or undue stress will be placed on the worm wheel/worm an
bearings".

My concern arose from reading that section in the mount set-up manual. In
using the mount for astrophotography, it is "recommended" to tighten the
clutches a bit more (1/8 turn by wrench). An overly "unbalanced OTA" may
introduce the same stress situation as "pushing the mount by hand", as
described in the manual. No "guideline" is given about how many "inch-lbs of
torque", potentially from OTA imbalance, are considered crossing the line on
too much stress on the worm gear.

Of course, the safest bet is to minimize any imbalance, as best as one
can.

Joe

----- Original Message -----
From: <chris1011@aol.com>
To: <ap-gto@yahoogroups.com>
Sent: Wednesday, April 25, 2007 10:47 AM
Subject: Re: [ap-gto] Balance Procedure


In a message dated 4/25/2007 9:21:36 AM Central Daylight Time,
J.Zeglinski@rogers.com writes:


You use the phrase "8 lbs out of balance", do you mean 8 inch-lbs?
Being "out of balance" with an 8 lb camera overhand at 6 inches is
different

from the same weight overhanging 2 feet away.
I have had an imbalance of 8 lb at the end of a 160F7.5 refractor. You will
know when the imbalance is too large because the motors will have a problem
slewing in one direction, but it will take more than 8 lb except maybe when
it is
bitterly cold outside. Also, if the clutches won't hold, it is probably too
much imbalance. I doubt very much that you could ever damage the worm gear
teeth. These are quite large and rugged.

Rolando


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Re: Help with orthogonality

primeclash
 

--- In ap-gto@yahoogroups.com, chris1011@... wrote:
There is always some confusion as to what this 2 Star thing is
supposed to
do. It is not a calibration routine. It does not calibrate anything
in the
mount. It is simply one more of dozens of polar alignment routine
options. This one
in particular can be hard to converge, especially if you happen to
choose the
wrong two stars. As such, this polar alignment option is probably
the weakest
of all. You should never conclude from this alignment routine that
something
is amiss with your orthogonality. In fact, I am tempted to eliminate
this
routine because of the confusion it seems to cause everyone who
first uses this
mount after using other commercial Alt-Az mountings.
Noted. I should have followed your preferred methodology you outlined
in message 17688. I would have sworn it included the '2-star
calibration' but it does not. I started using the 'carpenter's level'
technique but then referred to the manual. I'm ripping that page out
tonight after I get home from work ;-)

Thanks for the help,
Louis Marchesi
New London Twp, PA


Re: Balance Procedure

Jeff Young <jey@...>
 

Joe --

I accidentally balanced my 600E GTO once without diagonal or eyepiece.
When a 2" diagonal, 2" Barlow and T4 Nagler was added, it produced
intermittent stalls when slewing (but not when tracking). I'd guess it
was about 40 in-lbs out of balance.

I never re-balance my 1200 GTO with equipment changes. I might go from
no eyepieces in either SCT or refractor to a heavy T5 Nagler in each
with a Barlow in one. These weights are much farther out on the moment
arm, so I'd guess we'd be looking at more than 100 in-lbs of inbalance.
I've never had this mount stall.

Lastly, when I load up my scopes on the 1200, I load the c-weights
first. This leaves the mount temporarily some 2,500 in-lbs out of
balance.

Cheers,
-- Jeff




________________________________

From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On
Behalf Of Joseph Zeglinski
Sent: Wednesday, April 25, 2007 3:22 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Balance Procedure



Hi Roland,

This is good news - I was becoming concerned about
"meticulously"
rebalancing the counterweights, every time I crossed the
meridian. Indeed, the
AP900 is a superb design, and even more so, from what you say
about the
rebalance issue.

One question:
You use the phrase "8 lbs out of balance", do you mean 8
inch-lbs?
Being "out of balance" with an 8 lb camera overhand at 6 inches
is different
from the same weight overhanging 2 feet away. Could you be more
specific about
the "moment arm" on the OTA imbalance you are describing?

Actually, it would be interesting, if someone there could do a
bit of
testing in this regard, on various "moment-arm measurements",
before you would
consider the AP900 or AP1200 seriously out of balance, for the
expected
performance. For that matter, before you would consider possible
damage to the
worm gear. That might provide a good rule of thumb which could
be applied to
any OTA overload situation, to specific AP mounts.

I suppose one might say that the imbalance on any mount has
reached a
maximum, if the clutches won't hold, but some might torque down
the clutches
too tightly, even with a wrench, in order to avoid having to
shift the
weights.

Thanks for any further info,
Joe

----- Original Message -----
From: <chris1011@aol.com <mailto:chris1011%40aol.com> >
To: <ap-gto@yahoogroups.com <mailto:ap-gto%40yahoogroups.com> >
Sent: Monday, April 23, 2007 1:04 PM
Subject: Re: [ap-gto] Balance Procedure

> In a message dated 4/21/2007 8:52:34 AM Central Daylight Time,
> drichey@sandia.net <mailto:drichey%40sandia.net> writes:
>
>
>> What's the procedure for rebalancing. If I have very good
polar alignment
>> and a good
>> pointing accuracy, but need to loosen the clutces and
reblance the load due
>> to adding
>> equipment, how do I maintain my pointing model.
>>
>
> Your pointing model is not affected if you loosen the clutches
to rebalance.
> On the other hand, why do you need to do this? I image all the
time without
> ever rebalancing. It is not really necessary. I have been as
much as 8lb out
> of
> balance on both 900/1200 mounts, and recently ran 6lb out of
balance on my
> little bitty Mach1 mount. The tracking/guiding was spot on
perfect.
>
> Roland Christen
>
>
> **************************************
> See what's free at
> http://www.aol.com. <http://www.aol.com.>
>
>
>
>
>
>
> To UNSUBSCRIBE, or for general information on the ap-gto list
> see http://groups.yahoo.com/group/ap-gto
<http://groups.yahoo.com/group/ap-gto>
> Yahoo! Groups Links
>
>
>
>


Re: Balance Procedure

Joe Zeglinski
 

Hi Roland,

This is good news - I was becoming concerned about "meticulously"
rebalancing the counterweights, every time I crossed the meridian. Indeed, the
AP900 is a superb design, and even more so, from what you say about the
rebalance issue.

One question:
You use the phrase "8 lbs out of balance", do you mean 8 inch-lbs?
Being "out of balance" with an 8 lb camera overhand at 6 inches is different
from the same weight overhanging 2 feet away. Could you be more specific about
the "moment arm" on the OTA imbalance you are describing?

Actually, it would be interesting, if someone there could do a bit of
testing in this regard, on various "moment-arm measurements", before you would
consider the AP900 or AP1200 seriously out of balance, for the expected
performance. For that matter, before you would consider possible damage to the
worm gear. That might provide a good rule of thumb which could be applied to
any OTA overload situation, to specific AP mounts.

I suppose one might say that the imbalance on any mount has reached a
maximum, if the clutches won't hold, but some might torque down the clutches
too tightly, even with a wrench, in order to avoid having to shift the
weights.

Thanks for any further info,
Joe

----- Original Message -----
From: <chris1011@aol.com>
To: <ap-gto@yahoogroups.com>
Sent: Monday, April 23, 2007 1:04 PM
Subject: Re: [ap-gto] Balance Procedure


In a message dated 4/21/2007 8:52:34 AM Central Daylight Time,
drichey@sandia.net writes:


What's the procedure for rebalancing. If I have very good polar alignment
and a good
pointing accuracy, but need to loosen the clutces and reblance the load due
to adding
equipment, how do I maintain my pointing model.
Your pointing model is not affected if you loosen the clutches to rebalance.
On the other hand, why do you need to do this? I image all the time without
ever rebalancing. It is not really necessary. I have been as much as 8lb out
of
balance on both 900/1200 mounts, and recently ran 6lb out of balance on my
little bitty Mach1 mount. The tracking/guiding was spot on perfect.

Roland Christen


**************************************
See what's free at
http://www.aol.com.






To UNSUBSCRIBE, or for general information on the ap-gto list
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