Magazine dates make about as much sense as buying 2008 model cars in 2007???

Your December issue is the one that should have just arrived. The
November issue has been out for a month.

Larry

Gavin --

I have a Losmandy dovetail attached to the top of my Parallax rings
holding a Meade 16" LX200GPS OTA. On the rail rides a Tak FC-100.

The FC-100 is a doublet, and considerably smaller than 140mm, so it
probably weighs about 1/2 what the TEC does. Then agian, the 16" OTA is
about twice the weight of the 14", and leaves the Tak's weight on a
slightly longer moment arm.

Seems to work fine. The mirror flop is enough in the SCT that you can't
get both scopes to point to the same spot all over the sky, but the
refractors have a big enough field to mostly make up for that.

-- Jeff.


________________________________

From: ap-gto@... [mailto:ap-gto@...] On
Behalf Of Gavin Bray
Sent: Thursday, November 01, 2007 12:28 PM
To: ap-gto@...
Subject: [ap-gto] TEC 140 + 14" LX200R on an AP1200



Hello

I have a 14" LX200R attached to an AP1200 using a set of
Parallax
Instruments rings. The setup is housed in my observatory and I'm
very
happy with it.

I was wondering whether I could attach a dovetail plate to the
top of
the parallax rings (above the 14") and attach something like a
TEC 140
to that.

Is it feasible to mount something like a TEC 140 on top of the
14"?

Is there a better option I should be considering?

Thanks
Gavin

Gavin Bray wrote:

Hello

I have a 14" LX200R attached to an AP1200 using a set of Parallax Instruments rings. The setup is housed in my observatory and I'm very happy with it.

I was wondering whether I could attach a dovetail plate to the top of the parallax rings (above the 14") and attach something like a TEC 140 to that.

Is it feasible to mount something like a TEC 140 on top of the 14"?

It is certainly feasible. Many others have done exactly that and it's doubtful that you'd be getting anywhere near the capacity of your AP1200.


Just don't be too surprised if you cannot guide the LX200R with the TEC140.

Is there a better option I should be considering?

I'm sure somebody will suggest a side by side mounting which is also feasible. But IMO it's harder to deal with.

Regards

Bill

--

William R. Mattil : http://www.celestial-images.com

In a message dated 11/1/2007 11:44:35 AM Central Daylight Time,
J.Zeglinski@... writes:

Back to topic - I am surprised that S&T didn't scoop the astro publishing
world with such a major announcement review (prepared in advanced) of the
AP3600 - somebody there, in the new management, asleep at the wheel - (they
probably aren't astro literate) ?
They could have sent Dennis DiCicco to Antarctica to test it, and he would
have been back ... by morning :-)



Dennis was at AIC2006 in San Jose last weekend, taking photographs of all
the new gear, including the AP3600GTO.

Kent Kirkley



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

At 02:52 AM 11/1/2007, Gerald Sargent wrote:

The Nov issue of S&T has just arrived and the "next month's contents"
does not mention it. Likewise the contents list for the Dec issue of
Sky &Telescope, vol 114, No 6 on the "www.skypub.com" website
does not mention the Mach 1.
What have I got wrong please ? Gerald

The Mach 1 is reviewed in New Products in the Dec. issue, page 37, entitled "Staying on Track" ...
A good read ....

Dave

Hello

I have a 14" LX200R attached to an AP1200 using a set of Parallax
Instruments rings. The setup is housed in my observatory and I'm very
happy with it.

I was wondering whether I could attach a dovetail plate to the top of
the parallax rings (above the 14") and attach something like a TEC 140
to that.

Is it feasible to mount something like a TEC 140 on top of the 14"?

Is there a better option I should be considering?

Thanks
Gavin

In a message dated 11/1/2007 9:59:36 AM Central Daylight Time,
J.Zeglinski@... writes:

Does any other monthly magazine publish months in advance?
For me, it's more annoying than supposedly well intentioned.

Joe



More annoying to me is that the magazines begin sending out resubscription
notices a few months after your subscription begins or at least 6-10 months
before it expires.
By not sending out these early notices they could save a lot of money, not c
log landfill and, perhaps lower the subscription rate.

Remember when magazines cost 50 cents, a dollar, two dollars?
(I know that can be said just about anything)

Kent Kirkley



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

The Nov issue of S&T has just arrived and the "next month's contents"
does not mention it. Likewise the contents list for the Dec issue of
Sky &Telescope, vol 114, No 6 on the "www.skypub.com" website
does not mention the Mach 1.
What have I got wrong please ? Gerald

--- In ap-gto@..., "Dean S" <dean@...> wrote:

Hi Dean,

I have the 48" port. pier that I use when I go to my ranch. My
imaging scope is either my TOA 130 or the FSQ. Check out my web
site.

www.astrodave.com/oharra

Tom O'Harra

Hi All,

While waiting for my new mount to get finished, I am thinking

about the portable pier height. Currently mine is about 38" and the
1200 mount is 2" taller, so if I had a 36" tall AP pier it would be
what I am comfortable with. My observatory pier is this height also.

I will use this at star parties, and don't want to get too low as

passer bys inevitably get too close and seem to want to look down
the scopes, or worse yet shine a light on it while I am imaging:)
My OTA's are currently a C9.25, guide scope, and Epsilon 160, not
sure if I ever will get a big refractor.

So this is why I am a bit concerned with the 32" pier. I do think

the 42" is way too tall for my vertically challenged stature. Ap
said they would consider making me a custom pier tube during their
next run, but of course this also means changing the turn buckles
too or else I would just cut one down myself.

Anyways, I like to hear some opinions and experiences with similar

setups and your pier height considerations.

Thanks,
Dean


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

Hi Joe,

I come from the school of thought in astrophotography that there is
no substitude for stiffness, like in auto racing there's no
substitute for cubic inches. A lot of ideas for astro mounts,
cameras, etc can work, but some of them take special care. We are
fortunate now that DSLR's don't need the long term precision guiding
that film required in order to get nice astro photos. I used to
guide film with a piggy back scope that I thought was a very stiff
mount, yet the change in gravity direction in 45 minutes of tracking
caused elongated stars due to the deflection of the structure. Any
imbalance of the scope/mount, or change in the direction of hanging
cables can cause elongated stars over longer exposure times.

Good luck if you decide to try the PVC pier. It's certainly cheaper
and much easier to handle and install than a steel pier. I know, my
steel pier weighed over 450 lbs and took a lot of planning and
manpower to get it into position. It's never going to move now. Let
us know what you try, and how well it works.

Regards,
Don

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

Hi Don,

My engineering background reminds me of these pitfalls as well,

and it is

a concern at the back of my mind, but I still wonder how much

stiffness in

this application, is really enough. If I were building

an "observatory pier",

fully committed to location, I would go for maximum strength of

materials, but

this pier is a test system, if I can call it that. If it works

sufficiently

well, (and I don't kick it, intentionally out of frustration, or
unintentionally), then I will consider it a viable success. Since

this is my

backyard, I don't expect blustery winds (certainly not if I have to

be

outside - in which case the seeing will be a deciding factor, not

the pier).

There are enough buildings, shrubs, fences, and low trees, etc. to

provide

some wind break. Heaving of the ground from year to year, might

eventually

require a reset, or redesign with heftier materials, but a 4 foot

depth and

packed with yard soil (not necessarily sand). I don't expect much

long term

motion, especially since there is no "footing" to push up - it's

just a

relatively thin 1/2" cylinder wall rather than a flat bottom. As

for short

term stability, I am trusting that the wall thickness will suffice

for the

load being carried. But by then I will know if this is the best

spot -

certainly can't be worse than using my 6" diameter Losmandy G11

aluminum

tripod supporting my AP900 and Questar-7. If there is any shift

caused by

seasonal heaving, I can realign the mount, but hopefully it won't

be required,

or at least not often. I like the clean lines of green PVC, no

painting

required, no pitting or rusting below ground, and it won't ring

like a bell.

As for pulling cables, or unbalance - if cables are pulled, I

have some

serious soldering repairs ahead of me. The mount should be

perfectly

balanced - after all it's one of the best, and if anything, we like

our setups

perfectly balanced.

I'm still investigating the feasibility, but appreciate any

heads up and

warnings I can get from you and others. For now, I am considering

it a

"temporary pier" - with no early plans to require dismantling it

(once

planted). I had hoped someone had already tried this approach, but

I might

have to be the first to do so.

What I really would like is to turn it into a Greek Column

during the day,

as I described - that WOULD be the topper!

Thanks,
Joe



----- Original Message -----
From: "dmwmpd" <westergren@...>
To: <ap-gto@...>
Sent: Wednesday, October 31, 2007 8:51 PM
Subject: [ap-gto] Re: Pier design and sand

Hi Joe,

I really don't think PVC pipe buried in the soil is going to be a
very good pier. The ringing that you mention is a high frequency
tone, that the PVC pipe wouldn't have compared to a metal (steel)
pipe. But the real concern for pier design is how stiff it is
against bumping (not hitting), wind, weight shift (as the mount
moves with any unbalance), pulling cables, etc. These are all

long

time effects, like many seconds to hours. The stiffness of the

pier

pipe is a function of E (modulus of elasticity of the material)

and

the Section Moment of Inertia (depends on diameter and wall
thickness. The stiffness is E*I. It then determines how much
delction of a canteleverd pier has at the top, when one or more of
the steady forces or moments I mentioneed above are applied.

The modulus for steel is 30 million. The modulus for PVC is

between

380,000 and 540,000. In other words, the PVC pipe would flex more
than 55 times as far compared to the the same size steel pipe.

The paper on pier design by Dennis Persyk mentioned a few days ago
on this forum is a very good guide to best pier design, although

it

doesn't address the dynamics that I mentioned in my posts.

Regards,
Don

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

Hi,

I have been thinking about putting a temporary pier in the

ground, to see

how the back yard observing spot works out. I don't want to

commit

to heavy

steel posts and concrete bunker footing.

I was thinking of using one of those very thick walled, 10"

diameter,

street water main/sanitation pipes, and simply bury it 3 or 4

feet

deep (3

feet above ground), and fill the inside back in with earth

(perhaps only to

ground level). I am hoping that the perhaps 1/2", (or thicker),

PVC walls

won't ring as much as steel, and will be solid enough for an

AP900

system. I

think these street pipes should be temperature stable and should

not warp or

vibrate, in normal city street use, so it might have advantages

as

pier

material. Advantages include being easier to construct, (even

remove to adjust

for height), and can eventually be moved to a better spot, or

removed

entirely.

Opinions please.

Joe

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

Hi Don,

My engineering background reminds me of these pitfalls as well, and it is
a concern at the back of my mind, but I still wonder how much stiffness in
this application, is really enough. If I were building an "observatory pier",
fully committed to location, I would go for maximum strength of materials, but
this pier is a test system, if I can call it that. If it works sufficiently
well, (and I don't kick it, intentionally out of frustration, or
unintentionally), then I will consider it a viable success. Since this is my
backyard, I don't expect blustery winds (certainly not if I have to be
outside - in which case the seeing will be a deciding factor, not the pier).
There are enough buildings, shrubs, fences, and low trees, etc. to provide
some wind break. Heaving of the ground from year to year, might eventually
require a reset, or redesign with heftier materials, but a 4 foot depth and
packed with yard soil (not necessarily sand). I don't expect much long term
motion, especially since there is no "footing" to push up - it's just a
relatively thin 1/2" cylinder wall rather than a flat bottom. As for short
term stability, I am trusting that the wall thickness will suffice for the
load being carried. But by then I will know if this is the best spot -
certainly can't be worse than using my 6" diameter Losmandy G11 aluminum
tripod supporting my AP900 and Questar-7. If there is any shift caused by
seasonal heaving, I can realign the mount, but hopefully it won't be required,
or at least not often. I like the clean lines of green PVC, no painting
required, no pitting or rusting below ground, and it won't ring like a bell.

As for pulling cables, or unbalance - if cables are pulled, I have some
serious soldering repairs ahead of me. The mount should be perfectly
balanced - after all it's one of the best, and if anything, we like our setups
perfectly balanced.

I'm still investigating the feasibility, but appreciate any heads up and
warnings I can get from you and others. For now, I am considering it a
"temporary pier" - with no early plans to require dismantling it (once
planted). I had hoped someone had already tried this approach, but I might
have to be the first to do so.

What I really would like is to turn it into a Greek Column during the day,
as I described - that WOULD be the topper!

Thanks,
Joe

Hi Joe,

I really don't think PVC pipe buried in the soil is going to be a
very good pier. The ringing that you mention is a high frequency
tone, that the PVC pipe wouldn't have compared to a metal (steel)
pipe. But the real concern for pier design is how stiff it is
against bumping (not hitting), wind, weight shift (as the mount
moves with any unbalance), pulling cables, etc. These are all long
time effects, like many seconds to hours. The stiffness of the pier
pipe is a function of E (modulus of elasticity of the material) and
the Section Moment of Inertia (depends on diameter and wall
thickness. The stiffness is E*I. It then determines how much
delction of a canteleverd pier has at the top, when one or more of
the steady forces or moments I mentioneed above are applied.

The modulus for steel is 30 million. The modulus for PVC is between
380,000 and 540,000. In other words, the PVC pipe would flex more
than 55 times as far compared to the the same size steel pipe.

The paper on pier design by Dennis Persyk mentioned a few days ago
on this forum is a very good guide to best pier design, although it
doesn't address the dynamics that I mentioned in my posts.

Regards,
Don

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

Hi,

I have been thinking about putting a temporary pier in the

ground, to see

how the back yard observing spot works out. I don't want to commit

to heavy

steel posts and concrete bunker footing.

I was thinking of using one of those very thick walled, 10"

diameter,

street water main/sanitation pipes, and simply bury it 3 or 4 feet

deep (3

feet above ground), and fill the inside back in with earth

(perhaps only to

ground level). I am hoping that the perhaps 1/2", (or thicker),

PVC walls

won't ring as much as steel, and will be solid enough for an AP900

system. I

think these street pipes should be temperature stable and should

not warp or

vibrate, in normal city street use, so it might have advantages as

pier

material. Advantages include being easier to construct, (even

remove to adjust

for height), and can eventually be moved to a better spot, or

removed

entirely.

Opinions please.

Joe

Hi All,

While waiting for my new mount to get finished, I am thinking about the portable pier height. Currently mine is about 38" and the 1200 mount is 2" taller, so if I had a 36" tall AP pier it would be what I am comfortable with. My observatory pier is this height also.

I will use this at star parties, and don't want to get too low as passer bys inevitably get too close and seem to want to look down the scopes, or worse yet shine a light on it while I am imaging:) My OTA's are currently a C9.25, guide scope, and Epsilon 160, not sure if I ever will get a big refractor.

So this is why I am a bit concerned with the 32" pier. I do think the 42" is way too tall for my vertically challenged stature. Ap said they would consider making me a custom pier tube during their next run, but of course this also means changing the turn buckles too or else I would just cut one down myself.

Anyways, I like to hear some opinions and experiences with similar setups and your pier height considerations.

Thanks,
Dean

Hi,

The other benefit, I was considering, is that it can be sawn to length,
with some work. However, you can do a deal with a contractor doing road work,
and he will cut one evenly, to your requirements, using his machinery - you
might even get the pipe cheaper than from the dealer (who might not want to
sell you just one). I think they are standard 10 foot long, too much to bury.
You can also decide if you want the bell-swaged wider end up, for an inlaid
(wooden ?) plug/mounting-plate/pier vibration reducer - or swaged end down, to
have a slightly wider footing 4 feet down.

Joe

I went with a portable pier from Particle Wave Technologies for my Mach1GTO/TEC-140
combo, the Monolith LT with 12" extension. The LT heritage from the flagship Monolith pier
is unmistakable, as is the finish and quality. It is rock solid even with the extension.

http://www.pwtec.com/index.htm

Shahin, the engineer, (contact link on web site for info) will answer any questions you may
have regarding the configuration that will best meet your needs.

S

The bending can be captured using strain guages (gages for US speakers)

Would anyone be prepared to give all of this a go ?

I liked the idea of the 10" concrete drain pipe - I cannot see that bending very much. Its a quicker and possibly cheaper alternative to constructing a reinforced concrete pillar.

MPH

"N. Foldager" <nf@...> wrote: > If the Petrie dish has value, then it is far simpler to attach a mic to
> the side of a pier, and plug the mic output into your laptop audio port.

I question the "Petri method" as I don't think it for sure can
discriminate between the bell like oscillations (which we don't care
about) and the bending oscillations. (Or can it? The frequency of
latter should be much lower.) I believe that a microphone attached to
the pier will only record the "sound of the bell", not the bending of
the pier.

Best regards,

Niels Foldager

You are trying to measure the motion of the pier. Use an
accelerometer, not a microphone.

--- In ap-gto@..., "N. Foldager" <nf@...> wrote:

If the Petrie dish has value, then it is far simpler to attach

a mic to

the side of a pier, and plug the mic output into your laptop audio

port.

I question the "Petri method" as I don't think it for sure can
discriminate between the bell like oscillations (which we don't care
about) and the bending oscillations. (Or can it? The frequency of
latter should be much lower.) I believe that a microphone attached to
the pier will only record the "sound of the bell", not the bending of
the pier.

Best regards,

Niels Foldager

Can anyone tell me if version 4.12 of the GTO Keypad firmware is still
shipping with the current Mach1GTO mount or has there been an update
released?

I read somewhere that it is to be updated soon. If so, when will
Mach1GTO mounts have the updated firmware included when shipped?

Also, will the next update of the firmware require changes to the
manual?

Larry

Todd,
See my answer on the ap-ug site.

Larry

--- In ap-gto@..., "teche70" <teche70@...> wrote:

Larry,

What are you putting you mount on? What tripod?

Todd


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

I am new to owning an AP mount and expect to have one soon. In
preparation for that, are there any recommendations for a DC

power

supply that is appropriate for the Mach1? That is, 11.5 to 16

volts DC

filters and regulated with 110 V AC input? I have an 18 V power

supply

now that I have been using with a Gemini system but this appears

to

be

too high a voltage.

Larry