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

Hi Dominik,

Your electronic friend was absolutely right about the "potential" keyboard
corrosion problem!

I just happened to be thumbing through the: "Astro-Physics GTO KEYPAD
Version v4.12" user manual, and discovered that it confirms this to be perhaps
somewhat common.

See page # 63 Troubleshooting:
Problem:
"The keypad locks up on the Astro-Physics screen and will not advance to the
next screen".

Now: look at the final "bulleted" possibility, at the top of the next page #
64:
"Corroded circuit board in the keypad"

I suppose, when I first read that, I just assumed this happens from salt
air, for observers near the ocean. Maybe it is more common than we thought.
Strange though: I figured that the entire hand controller is completely
sealed. Would it help to apply a thin bead of Vaseline to the edge of he case,
sealing it before reassembling, so no corrosive air gets inside, or is the
corrosion a natural occurrence caused by solder flux? Perhaps the new ROHS
mandated by Europe will help newer versions.

I would hope that the circuit board has a "conformal coating" applied to
it on both sides, to prevent such corrosion. As for connectors, they should
have gold plated pins and circuit board contacts. Maybe that is the reason for
the limited warranty period.

Joe

Thanks for clarifying that - this is a circa 2003 mount, purchased
used as you say.

Are there any instructions/pictures as to how to remove the motor box
cover, just to make sure I get the correct screws?
If it's obvious, that's OK, but I'm at work right now and can't see
the mount to check.

John


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

In a message dated 4/23/2007 1:13:34 PM Central Daylight Time,
winfij@... writes:

The AP900 instructions from the AP support section I was following
definitely say to remove the worm shaft endcap and turn it by hand.
See step 8 in the Dec section of this doc:

http://www.astro-physics.com/tech_support/mounts/900gto/900backlash.htm

I did this over the weekend and could indeed turn the worm shaft

by hand.

Thanks for pointing this out - I have not visited that page in a

while. Those

are very old instructions and will need to be revised because the

newest

mounts do not have the worm shaft protruding out to where you can

easily turn

them. You have an older mount (purchased used?) which did have the

worm shaft

accessable. In any case, it is easier to remove the motor box cover

and turn the

large spur gear. It is much easier to turn. You can then also check

that the

worm spur gear is tight on the worm shaft. What can happen is that

this gear's

set screw can loosen over time, so that the motor turns and turns,

but the

worm itself will not turn for many seconds. To fix that, you will

need to tighten

the set screw (center it on the flat!!) which holds the gear onto

the worm.

If this is not done, then all the mesh adjustment in the world will

not fix the

reversal delay in Dec.

Rolando


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


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

John --

If you _can_ turn then worm shaft by hand, and the backlash has been
eliminated, then you're good to go. I think Roland was just saying that
it can be quite hard to _grip_ the worm shaft hard enough to turn it.
(I usually use the worm shaft as well -- as it's easier to get to than
the spur gear.)

-- Jeff.



________________________________

From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On
Behalf Of John Winfield
Sent: Monday, April 23, 2007 7:10 PM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: AP900 Dec backlash



Hi Roland,

The AP900 instructions from the AP support section I was
following
definitely say to remove the worm shaft endcap and turn it by
hand.
See step 8 in the Dec section of this doc:


http://www.astro-physics.com/tech_support/mounts/900gto/900backlash.htm
<http://www.astro-physics.com/tech_support/mounts/900gto/900backlash.htm

I did this over the weekend and could indeed turn the worm shaft
by hand.

Are you saying that means I've disengaged the worm gear from the
spur
gear?
I haven't tried driving the scope with the motor since the
adjustment
- should be clear tonight.

Is there a different procedure I should be following?

John

--- In ap-gto@yahoogroups.com <mailto:ap-gto%40yahoogroups.com>
, chris1011@... wrote:
>
> In a message dated 4/21/2007 4:53:43 PM Central Daylight Time,

> winfij@... writes:
>
>
> > Secondly, once I had loosened the bolt and retightened with
finger
> > pressure pushing on the motor housing, the instructions said
to remove
> > the shaft cover and ensure the shaft could be rotated by
hand without
> > binding. However, I couldn't remove the shaft cover.
> >
>
> The instructions for the 900/1200 GTO mounts say to remove the
motor
box
> cover, not the shaft cover. The motor box cover has a number
of
small Allen head
> screws that need to be removed, then just pop off the cover.
You
need to turn
> the spur gear by hand, NOT the worm. You will never be able to
turn
the worm
> gear itself unless you attach some kind of knob.
>
> Roland Christen
>
>
> **************************************
> See what's free at
> http://www.aol.com. <http://www.aol.com.>
>
>
>
>

Hi Roland,

The AP900 instructions from the AP support section I was following
definitely say to remove the worm shaft endcap and turn it by hand.
See step 8 in the Dec section of this doc:

http://www.astro-physics.com/tech_support/mounts/900gto/900backlash.htm

I did this over the weekend and could indeed turn the worm shaft by hand.

Are you saying that means I've disengaged the worm gear from the spur
gear?
I haven't tried driving the scope with the motor since the adjustment
- should be clear tonight.

Is there a different procedure I should be following?

John


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

In a message dated 4/21/2007 4:53:43 PM Central Daylight Time,
winfij@... writes:

Secondly, once I had loosened the bolt and retightened with finger
pressure pushing on the motor housing, the instructions said to remove
the shaft cover and ensure the shaft could be rotated by hand without
binding. However, I couldn't remove the shaft cover.

The instructions for the 900/1200 GTO mounts say to remove the motor

box

cover, not the shaft cover. The motor box cover has a number of

small Allen head

screws that need to be removed, then just pop off the cover. You

need to turn

the spur gear by hand, NOT the worm. You will never be able to turn

the worm

gear itself unless you attach some kind of knob.

Roland Christen


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

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

In a message dated 4/20/2007 7:39:30 PM Central Daylight Time,
g-heath@... writes:

Well .... I'm fed up with Yahoo, and am leaving this (and all other
Yahoo) forums.

Sorry to see you go. I'll stick around for now.

I moderate another group and he tried the same lengthy anti-Yahoo
posting. Since all new posters are moderated, his posting never saw
the day of light.

I suspected his posting was all trolling and nothing else.

Anthony.

Rolando


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


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

In a message dated 4/23/2007 2:08:04 PM Central Daylight Time,
winfij@gmail.com writes:

Thanks for clarifying that - this is a circa 2003 mount, purchased
used as you say.

In a lot of cases, when a mount has been purchased used, the person who ships
it will not package it correctly, and the result is that stress is put on the
motor box/worm gear. This then results in poor worm mesh, so the first thing
a new user must do when he/she recaives a used mount is to do a re-mesh on
both axes. Probably the biggest mistake is to take such a mount out of the box,
set it up outside and expect it to work perfectly. It probably will not work
quite right until the gear mesh has been checked. Also, many times a mount can
have other minor things out of adjustment which the previous owner never
realized, but which the new owner will see right away. Therefore do not hesitate to
check all things in the daylight before trying it out in the dark.

Are there any instructions/pictures as to how to remove the motor box
cover, just to make sure I get the correct screws?

The motor box cover is located on the opposite end of the worm shaft cover.
Remove the 6 small Allen head screws and the cover will slip off. You will then
see the spur reduction gears. Once you see them, you will understand how it
all works.

Rolando


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

In a message dated 4/23/2007 1:13:34 PM Central Daylight Time,
winfij@gmail.com writes:

The AP900 instructions from the AP support section I was following
definitely say to remove the worm shaft endcap and turn it by hand.
See step 8 in the Dec section of this doc:

http://www.astro-physics.com/tech_support/mounts/900gto/900backlash.htm

I did this over the weekend and could indeed turn the worm shaft by hand.

Thanks for pointing this out - I have not visited that page in a while. Those
are very old instructions and will need to be revised because the newest
mounts do not have the worm shaft protruding out to where you can easily turn
them. You have an older mount (purchased used?) which did have the worm shaft
accessable. In any case, it is easier to remove the motor box cover and turn the
large spur gear. It is much easier to turn. You can then also check that the
worm spur gear is tight on the worm shaft. What can happen is that this gear's
set screw can loosen over time, so that the motor turns and turns, but the
worm itself will not turn for many seconds. To fix that, you will need to tighten
the set screw (center it on the flat!!) which holds the gear onto the worm.
If this is not done, then all the mesh adjustment in the world will not fix the
reversal delay in Dec.

Rolando


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

In a message dated 4/21/2007 4:53:43 PM Central Daylight Time,
winfij@gmail.com writes:

Secondly, once I had loosened the bolt and retightened with finger
pressure pushing on the motor housing, the instructions said to remove
the shaft cover and ensure the shaft could be rotated by hand without
binding. However, I couldn't remove the shaft cover.

The instructions for the 900/1200 GTO mounts say to remove the motor box
cover, not the shaft cover. The motor box cover has a number of small Allen head
screws that need to be removed, then just pop off the cover. You need to turn
the spur gear by hand, NOT the worm. You will never be able to turn the worm
gear itself unless you attach some kind of knob.

Roland Christen


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

In a message dated 4/21/2007 4:53:43 PM Central Daylight Time,
winfij@gmail.com writes:

The first thing I noticed was that the grub screw locking the hex bolt
in place was still present, so presumably the adjustment had never
been done before since the instructions say to remove and discard this
screw.
However, although I could loosen the grub screw, I couldn't remove it
completely - it unscrewed to the point of contacting the Dec motor
housing but I couldn't get it out completely. Is there a trick to
removing it?

It can be removed if you remove the entire motor assembly, but it is not
necessary. Just loosen it, and that will be fine.

Roland Christen


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

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.

In a message dated 4/21/2007 8:42:51 AM Central Daylight Time,
drichey@sandia.net writes:

My AP900 is in a fiberglass observatory and in the summer it can get quite
hot, well over
100ºF. Is this a problem for the equipment?

Not a problem for the mechanics or the electronics.

Roland Christen


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

In a message dated 4/20/2007 7:39:30 PM Central Daylight Time,
g-heath@comcast.net writes:

Well .... I'm fed up with Yahoo, and am leaving this (and all other
Yahoo) forums.

Sorry to see you go. I'll stick around for now.

Rolando


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

Czesc Dominik,

Nice to see what the inside of the hand controller looks like. It would
seem that there was a poorly wave soldered pad under pin 10 in the 28 pin
"keycode decoder IC" - I assume that the keypad "flexible printed circuit
ribbon" itself, was not the "corrosion" which you had described in earlier
emails.

Hopefully this was a remote case of some poor quality soldering of the
copper etch trace, at that pin, and that this situation is uncommon, based on
AP's quality control of it's suppliers, such as this keypad manufacturer. I
was told that this unit is NOT made by AP themselves.

As for a spare, AP does sell that entire hand controller, but I wouldn't
buy a spare because this is constantly changing. You might not need a
replacement for several years, if (hopefully) ever again. By then, AP might
improve it, such as adding a lot more RAM, to handle even more programmed
features. The standard AP hand controller (keypad) is warranteed for at least
3 years, at present, according to the manual, so unless there is a rash of
problems, you shouldn't waste money on a backup. If you are taking about
"just" the keypad itself, nobody makes an identical part - this is a very
specialized application, as most such keypad products are.

If these photos don't completely answer Marj Christen's earlier concerns,
she might want to offer a refurbished replacement, to get yours back for a
"quality analysis", and so you don't suffer any down time either - but I think
since you have already fixed it, there shouldn't be any further problems.

We all here, notice, however, that both Roland and Marj were very
concerned about your problem, but seem to be having trouble reaching you by
direct personal email. Perhaps their emails are being "locked out" by that
nasty "free ISP spam guard utility" that your Polish ISP might be using. ( I
have had friends put auttomatically, on a "delete email list" by the ONET.PL
ISP, for no good reason - and the account owner wasn't even informed). Then
again, check your own spam guard for blocked senders. AP's emails might look
like spam to your filters.

Alternately, try contacting Marj at AP, via a different email ( a
friend's, etc.), so she can try THAT address to reach you successfully, using
a different route, or even "snail mail".

However, if your electronics friend does see "other corrosion" that will
potentially soon cause problems, then definitely, AP should get your unit for
a detailed analysis, in case that production run is only the start of a real
mess of issues with other similar units. Their supplier needs to be warned.

I will leave that topic between you and Marj, at AP.

Glad your friend has done a good repair.

(Do dalszego uslyszenia),
Joe

Joe,

Here you are two images. Sorry for their poor quality. On the first
one you will see the plastic (telephony ?) keypad with a wire
connected to one of its paths. On the second one the wire is
connected directly to the board.

http://www.astrophotography.pl/testy/ap1200/ap1200_keypad_p0.jpg

http://www.astrophotography.pl/testy/ap1200/ap1200_keypad_p1.jpg

Do you know where I could buy such a telephony keypad to have it just
in case of next problems with mine (to come - according to my
neighbour) ?

All the best from Poland,
Trzymaj sie Jozefie.

Dominik


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

Thanks Dominik,

Are there two PCB's inside - one is the keypad, and the other,

the

processor and display? I think Marj may be wondering if you had a

problem just

with the keypad PCB ( which is made by another supplier), or the

processor

PCB, if there is more than one board inside.

The picture will put everyone's mind at rest - or maybe something

to watch out

for, in future. Anyway, it will help all of us, with a potential

problem

someday.

Thanks, and dobra noc,
Joe


----- Original Message -----
From: "Dominik Wos" <dominik@...>
To: <ap-gto@yahoogroups.com>
Sent: Tuesday, April 17, 2007 7:08 PM
Subject: [ap-gto] Re: Keypad problem ?

Hi Joe,

OK, I will once again dismantle the keypad to take some pictures

and

will post them on the Group. You will see the repair and what is
inside the keypad.

All the best,
Dominik

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

Hi Dominik,

Glad to hear that all is well, after the fix.

For the rest of us, perhaps, you could clarify, just in case

we

run into a

similar problem. In anticipation of other's questions, (Marj was

not quite

clear on your post), perhaps we have a very slight

misunderstanding

in

translation - when you mention "silver" traces.

I have never seen "silver" used in PCB contacts or traces on

circuit

boards - they are either gold plated or beryllium plated

contacts,

and circuit

traces were, until recently perhaps, always lead/tin solder. I

wonder where

the "silver" comes in to play. Unless, silver is being used

somehow

to replace

solder, in order to meet Europe's ROHS pollution standard - an

expensive

solution, but this board likely predates that requirement.

Also, circuit traces, even if they are the "old solder

standard", are

almost always covered by a green layer of protective "conformal

coating", on

good quality circuit board products, which must be standard for

Astro Physics

products, surely.

So, I don't quite understand where your friend found

anything "silver". Is

it possible that he is using our Polish term "srebny", which

describes things

that are "silver coloured", in referring to the "colour" of

solder

(traces)?

Even so, I am surprised he could get to the solder trace without

some effort

to scrape away the green conformal coating, painted over it.

Be that as it may, it would appear that there was a possible

bad spot in

the "wave soldering" of the board, leaving a short segment of the

original

"copper trace" on the etched PCB exposed, which obviously has

corroded over

the last 5 years, or more. This break in the trace caused a loss

of

some

signal in the Keypad circuit, which your friend expertly cleaned

and

resoldered - he has a good eye to have spotted it. Now everything

is operating

normally.
If so, I wonder about the quality checks made by the original

keypad

manufacturer.

Have I got this right?

Anyway, I probably just made a short story ... long ;-)
Best regards,
Joe (a.k.a. Jozef)


----- Original Message -----
From: "Dominik Wos" <dominik@>
To: <ap-gto@yahoogroups.com>
Sent: Tuesday, April 17, 2007 5:27 PM
Subject: [ap-gto] Re: Keypad problem ?

Czesc Jozefie,

U mnie wszystko OK. Dzieki :-)

So where the problem was ? According to my neighbour the

plastic

keypad which is inside is very sensitive to corrosion (he
manyfactures electronics for agiculture machines and uses this

kind

of products). The paths are made from silver. Accourding to him

it is

a rather common problem esspecialy that I bought my mount

second

hand

and I belive it is 2002.

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gto
Yahoo! Groups Links

I have successfully used the following:

1. Slew the mount to the park 1 position (with locked clutches).
2. Precisely note the positions of the setting circles.
3. For each axis, loosen the clutches and balance without disturbing
the positions of the setting circles.
4. After each axis is balanced, use its setting circle to return it
manually to its prior position and lock the clutches.
5. Voila!

Regards,
Dick Steinberg











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

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.

My AP900 is very tolerant of imbalance, so I don't bother even when
changing from a 1 1/4" eyepiece to a binoviewer with 2 Radians on my
AP155.

Don't know what equipment you're changing, but try it without re-
balancing.

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

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.

Jeff,

PulseGuide, which is what John used, does not use the ASCOM driver. PulseGuide
talks directly to the mount.

-Ray

negligible. As to the cover, if it is the same as mine and is about
1/2" in diameter and domed, then it threads out / unscrews normally.

Excellent - just the info I was after, thanks Rick.



--- In ap-gto@yahoogroups.com, "Rick K" <JunkMailGoesHere@...> wrote:

I am assuming you managed to get the mesh correct and the backlash is
negligible. As to the cover, if it is the same as mine and is about
1/2" in diameter and domed, then it threads out / unscrews normally.
If it is really tight, it might need some firmer persuasion using a
pair of pliers with some strips of leather or rubber to protect the
finish of the cap.

Rick

--- In ap-gto@yahoogroups.com, "John Winfield" <winfij@> wrote:

Hi,

I've recently bought a used AP900 and just ran the backlash tests in
Ray's Pulseguide app.

I found a load of Dec backlash - so much that the tests didn't reverse
direction at all.
I needed a backlash setting of 87 in the driver to correct for the
backlash.

Today I went to follow the instructions on the AP website to adjust
the Dec worm adjustment (using the advice of finger pressure rather
than a hammer!).

The first thing I noticed was that the grub screw locking the hex bolt
in place was still present, so presumably the adjustment had never
been done before since the instructions say to remove and discard this
screw.
However, although I could loosen the grub screw, I couldn't remove it
completely - it unscrewed to the point of contacting the Dec motor
housing but I couldn't get it out completely. Is there a trick to
removing it?

Secondly, once I had loosened the bolt and retightened with finger
pressure pushing on the motor housing, the instructions said to remove
the shaft cover and ensure the shaft could be rotated by hand without
binding. However, I couldn't remove the shaft cover.
Does it screw on, or is it a push fit? Any tips for removing it
without marring?

Thanks,

John

I am assuming you managed to get the mesh correct and the backlash is
negligible. As to the cover, if it is the same as mine and is about
1/2" in diameter and domed, then it threads out / unscrews normally.
If it is really tight, it might need some firmer persuasion using a
pair of pliers with some strips of leather or rubber to protect the
finish of the cap.

Rick