Newbie questions


Howard Ritter
 

Greetings from a new member of the group. I’m a longtime AP user, having owned a 155EDF on a 600E GEM since new probably 25 years ago. I apologize for the length of the post, but I need a couple of questions answered before I go further.

I decided to take the plunge into a permanent pier, now that I live on a lot with some room and good sky exposure. I was fortunate enough to bag a 1600GOTO this run, expecting delivery in February. I plan to put my Meade 16” SCT OTA on this, with the possibility of alternating with other OTAs. I can’t get equipment in to auger a hole wider than 12”, but I can make it up to 4’ deep. My thought is to manually dig a circular hole 24” in diameter and 8-12” deep (well below the frost line), then to auger a 12” shaft down from the center of that. I’d then fill everything up to grade with concrete. The L-bolts for the pier would go in at pour time.

Does this sound adequate? Sonotube for the pillar to buffer it from the collar? Rebar? Sakrete OK? Which version?


The second question is about absolute encoders. I’m getting more active in imaging and may be doing some pro-am research, but I don’t see a reason to add $5500 to the cost of the mount. I need some clarification about the capabilities of the standard 1600GOTO mount and what the encoders add.

My impression is that the standard mount has motor encoders that tell the mount’s computer how much motor rotation has taken place since, say, the last time the mount was star-aligned. The computer uses the number of motor rotations/fractions to determine the angular position of the shafts relative to where they were at alignment. As long as the computer has power and the shafts aren’t de-clutched from the motors, the computer will know just where the scope is pointed. Is this all correct?

Absolute encoders, as I understand, report the absolute point on the axis shaft that an optical sensor is looking at, so the computer can tell at all times where the shaft is positioned. Continuous power and re-alignment are not necessary, and the precision (least count) of the absolute encoders may be greater than that of the motor encoders. Do I have this right?

If this is correct, then the absolute encoders would be beneficial to me if I have to remove power from the installation between uses, so I don’t have to star-align, or if I have critical tracking needs. I don’t think I’ll have to remove power often, and I don’t think I can use the increased tracking precision. I don’t see a reason to get them, at their price.


Any comments/corrections/clarifications greatly appreciated!

Howard Ritter
Perrysburg, OH


fernandorivera3
 

Leaving the mount powered on 24/7 or almost continuously means you need to consider surge protection such as in case of nearby lightning strikes. 

Fernando


Howard Ritter
 

I’ll do that, thanks.

Howard

On Oct 25, 2021, at 5:47 AM, fernandorivera3 via groups.io <fernandorivera3@...> wrote:

Leaving the mount powered on 24/7 or almost continuously means you need to consider surge protection such as in case of nearby lightning strikes. 

Fernando



M Hambrick
 

Hi Howard

My two cents worth on your concrete pillar: I would go 2 ft deep with the 24-inch diameter hole. Try to get as much rebar in the pillar as possible, and I would not isolate the 24-inch diameter section from the 12-inch diameter section. Try to taper the bottom of the 12-inch diameter hole outwards to create an elephant's foot type of effect. Get the highest strength Sakrete they sell, and check to make sure that there are no temperature limitations (e.g. below freezing) on when you can pour it. Use as little water as possible when mixing it to minimize the chance that it will develop cracks. Soupy concrete due to too much water will crack when it cures. If you follow the mixing directions on the bag you should be OK. If you are mixing it by hand it may take a little more water than the instructions say, but go sparingly with additional water. As little as a cupful can make a big difference.

Hopefully, you will never have to remove the pillar.

As for leaving the mount powered up, I do not think that is necessary. As long as you park the mount at the end of your observing session you can power it all down and the mount will remember where it was the next time you start it up. This is true whether you have a permanent or portable setup as long as the mount is polar aligned.

Are you using a Keypad ? If so, you will use the Resume from last position option when you start it back up. If you are only using a computer (with APCC ??) it will be something very similar.

Maybe someone else can comment about whether you should leave the CP4, laptop, and / or keypad out in the observatory. If it were me I would  not, especially in the Ohio winters.

Hope this helps

Mike


Howard Ritter
 

Thanks for your suggestions, Mike. 

As for leaving electronics out in the observatory in all weather, I wasn’t planning to do that. However, what I didn’t mention is that my “observatory” is going to be a heavy-duty, waterproof, aluminized shroud that will be snugged tightly around the pier. My HOA won’t allow me to put up a building, but it occurred to me that an unheated, non-air conditioned observatory building is in effect just a loose shroud, and that the scope and mount are tolerant of environmental temperatures; what’s important is protecting the scope from water, condensation, dust, and insect intrusion. Leaving a piece of fine electro-opto-mechanical gear outside under a tarp 24/7/365 is to say the least an unconventional idea, but I believe it stands up to close scrutiny. I put the question to my local club, and got positive replies. In fact, one of the members has had several scope installations outdoors and shrouded for years with no ill effects. We live in a quiet residential development outside the city, and the scope would be in a sheltered side yard that’s largely obscured from view from the street.

Howard

On Oct 25, 2021, at 9:10 AM, M Hambrick <mhambrick563@...> wrote:

Hi Howard

My two cents worth on your concrete pillar: I would go 2 ft deep with the 24-inch diameter hole. Try to get as much rebar in the pillar as possible, and I would not isolate the 24-inch diameter section from the 12-inch diameter section. Try to taper the bottom of the 12-inch diameter hole outwards to create an elephant's foot type of effect. Get the highest strength Sakrete they sell, and check to make sure that there are no temperature limitations (e.g. below freezing) on when you can pour it. Use as little water as possible when mixing it to minimize the chance that it will develop cracks. Soupy concrete due to too much water will crack when it cures. If you follow the mixing directions on the bag you should be OK. If you are mixing it by hand it may take a little more water than the instructions say, but go sparingly with additional water. As little as a cupful can make a big difference.

Hopefully, you will never have to remove the pillar.

As for leaving the mount powered up, I do not think that is necessary. As long as you park the mount at the end of your observing session you can power it all down and the mount will remember where it was the next time you start it up. This is true whether you have a permanent or portable setup as long as the mount is polar aligned.

Are you using a Keypad ? If so, you will use the Resume from last position option when you start it back up. If you are only using a computer (with APCC ??) it will be something very similar.

Maybe someone else can comment about whether you should leave the CP4, laptop, and / or keypad out in the observatory. If it were me I would  not, especially in the Ohio winters.

Hope this helps

Mike


Jack Huerkamp
 

Howard,

 

If you a cover similar to a ScopeStuff 24/7 cover with reflectix on the inside, just hang a 25 to 40 whatt bulb below the scope, let it run and the heat it generates will keep the mount and electronics dry.  I did that for years with good results.

 

Yours truly,

 

Jack

 

Jack Huerkamp

Jack's Astro Accessories, LLC

38388 Pine Street

Pearl River, LA 70452-5192

985-445-5063

mallincamusa@...

www.mallincamusa.com

30.37N  89.76W

 

All of us get lost in the darkness.
Dreamers learn to steer by the stars.

………………………………….Neil Peart

 

 

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Howard Ritter via groups.io
Sent: Monday, October 25, 2021 8:34 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Newbie questions

 

Thanks for your suggestions, Mike. 

 

As for leaving electronics out in the observatory in all weather, I wasn’t planning to do that. However, what I didn’t mention is that my “observatory” is going to be a heavy-duty, waterproof, aluminized shroud that will be snugged tightly around the pier. My HOA won’t allow me to put up a building, but it occurred to me that an unheated, non-air conditioned observatory building is in effect just a loose shroud, and that the scope and mount are tolerant of environmental temperatures; what’s important is protecting the scope from water, condensation, dust, and insect intrusion. Leaving a piece of fine electro-opto-mechanical gear outside under a tarp 24/7/365 is to say the least an unconventional idea, but I believe it stands up to close scrutiny. I put the question to my local club, and got positive replies. In fact, one of the members has had several scope installations outdoors and shrouded for years with no ill effects. We live in a quiet residential development outside the city, and the scope would be in a sheltered side yard that’s largely obscured from view from the street.

 

Howard



On Oct 25, 2021, at 9:10 AM, M Hambrick <mhambrick563@...> wrote:

 

Hi Howard

My two cents worth on your concrete pillar: I would go 2 ft deep with the 24-inch diameter hole. Try to get as much rebar in the pillar as possible, and I would not isolate the 24-inch diameter section from the 12-inch diameter section. Try to taper the bottom of the 12-inch diameter hole outwards to create an elephant's foot type of effect. Get the highest strength Sakrete they sell, and check to make sure that there are no temperature limitations (e.g. below freezing) on when you can pour it. Use as little water as possible when mixing it to minimize the chance that it will develop cracks. Soupy concrete due to too much water will crack when it cures. If you follow the mixing directions on the bag you should be OK. If you are mixing it by hand it may take a little more water than the instructions say, but go sparingly with additional water. As little as a cupful can make a big difference.

Hopefully, you will never have to remove the pillar.

As for leaving the mount powered up, I do not think that is necessary. As long as you park the mount at the end of your observing session you can power it all down and the mount will remember where it was the next time you start it up. This is true whether you have a permanent or portable setup as long as the mount is polar aligned.

Are you using a Keypad ? If so, you will use the Resume from last position option when you start it back up. If you are only using a computer (with APCC ??) it will be something very similar.

Maybe someone else can comment about whether you should leave the CP4, laptop, and / or keypad out in the observatory. If it were me I would  not, especially in the Ohio winters.

Hope this helps

Mike

 


Virus-free. www.avg.com


Howard Ritter
 

Clever idea, Jack, thanks!

Howard

On Oct 25, 2021, at 9:37 AM, Jack Huerkamp <Mallincamusa@...> wrote:

Howard,
 
If you a cover similar to a ScopeStuff 24/7 cover with reflectix on the inside, just hang a 25 to 40 whatt bulb below the scope, let it run and the heat it generates will keep the mount and electronics dry.  I did that for years with good results.
 
Yours truly,
 
Jack
 
Jack Huerkamp
Jack's Astro Accessories, LLC
38388 Pine Street
Pearl River, LA 70452-5192
985-445-5063
30.37N  89.76W
 
All of us get lost in the darkness.
Dreamers learn to steer by the stars.
………………………………….Neil Peart


 

Along these lines, I use an inexpensive gun safe dehumidifier

It emits low level heat and has very little risk of things catching fire






On Mon, Oct 25, 2021 at 6:50 AM Howard Ritter via groups.io <howard.ritter=mac.com@groups.io> wrote:
Clever idea, Jack, thanks!

Howard

On Oct 25, 2021, at 9:37 AM, Jack Huerkamp <Mallincamusa@...> wrote:

Howard,
 
If you a cover similar to a ScopeStuff 24/7 cover with reflectix on the inside, just hang a 25 to 40 whatt bulb below the scope, let it run and the heat it generates will keep the mount and electronics dry.  I did that for years with good results.
 
Yours truly,
 
Jack
 
Jack Huerkamp
Jack's Astro Accessories, LLC
38388 Pine Street
Pearl River, LA 70452-5192
985-445-5063
30.37N  89.76W
 
All of us get lost in the darkness.
Dreamers learn to steer by the stars.
………………………………….Neil Peart



--
Brian 



Brian Valente


Howard Ritter
 

Looks like an excellent idea, too, Brian. Thanks!

Howard

On Oct 25, 2021, at 9:53 AM, Brian Valente <bvalente@...> wrote:

Along these lines, I use an inexpensive gun safe dehumidifier

It emits low level heat and has very little risk of things catching fire






On Mon, Oct 25, 2021 at 6:50 AM Howard Ritter via groups.io <howard.ritter=mac.com@groups.io> wrote:
Clever idea, Jack, thanks!

Howard

On Oct 25, 2021, at 9:37 AM, Jack Huerkamp <Mallincamusa@...> wrote:

Howard,
 
If you a cover similar to a ScopeStuff 24/7 cover with reflectix on the inside, just hang a 25 to 40 whatt bulb below the scope, let it run and the heat it generates will keep the mount and electronics dry.  I did that for years with good results.
 
Yours truly,
 
Jack
 
Jack Huerkamp
Jack's Astro Accessories, LLC
38388 Pine Street
Pearl River, LA 70452-5192
985-445-5063
30.37N  89.76W
 
All of us get lost in the darkness.
Dreamers learn to steer by the stars.
………………………………….Neil Peart




--
Brian 



Brian Valente


Mike Dodd
 

On 10/25/2021 9:53 AM, Brian Valente wrote:
Along these lines, I use an inexpensive gun safe dehumidifier
<https://www.amazon.com/gp/product/B06XQ7PSYH>
I think that's a good idea; no chance of breaking a glass bulb. But it produces only 10 watts -- is that enough for outdoors?

--- Mike


DFisch
 

I use the gun safe dehumidifier rods too, mostly in my safes.    They are designed to create an airflow in the tube, not wanted in a telescope but welcomed when you are drying out air and changing the ambient temp. 

 

TJF ThinkPad1

 

From: Brian Valente
Sent: Monday, October 25, 2021 9:56 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Newbie questions

 

Along these lines, I use an inexpensive gun safe dehumidifier

 

It emits low level heat and has very little risk of things catching fire

 

 

 

 

 

 

On Mon, Oct 25, 2021 at 6:50 AM Howard Ritter via groups.io <howard.ritter=mac.com@groups.io> wrote:

Clever idea, Jack, thanks!

 

Howard



On Oct 25, 2021, at 9:37 AM, Jack Huerkamp <Mallincamusa@...> wrote:

 

Howard,

 

If you a cover similar to a ScopeStuff 24/7 cover with reflectix on the inside, just hang a 25 to 40 whatt bulb below the scope, let it run and the heat it generates will keep the mount and electronics dry.  I did that for years with good results.

 

Yours truly,

 

Jack

 

Jack Huerkamp

Jack's Astro Accessories, LLC

38388 Pine Street

Pearl River, LA 70452-5192

985-445-5063

30.37N  89.76W

 

All of us get lost in the darkness.
Dreamers learn to steer by the stars.

………………………………….Neil Peart


 

--

Brian 

 

 

 

Brian Valente

 


weems@...
 

My 12” concrete pier goes 4’ down, and extends above ground level to just a few inches below the mount. 12” concrete is extremely stiff and very cheap. It’s also very weather resistant. I have a Dan’s Pier Plate with an AP adapter plate, sitting on 4 3/4” SS bolts, about 2.5” off the top of the concrete. I can kick the pier hard enough to hurt, or slap the base of the mount hard, and there’s no visible motion even at high power. Something to consider if you want maximum stability and are sure of the height you will use. 

I rented an electric mixer from the local hardware store, and it made the job much easier. Sakrete is fine, as long as it is the mix for foundation work. Yes on the rebar, with wire between the vertical bars to hold them stable. Be sure they don’t interfere with the J-bolts, but do overlap with them. Make a wooden template to hold the J-bolts in position and test fit with the rebar before mixing. Be prepared for the mix to make it challenging to push them in. Gravel always seems to block them. I ended up filling the top foot with the template just above the top of the sonotube, through the gap under the template, then wiggling them down the last few inches. I wished I had cut a center hole in the template to make it easier to fill, but it still worked out. 

Chip


Howard Ritter
 

That’s very helpful, Chip, thanks. Certainly, casting the pier as an extension of the foundation pillar would be a heck of a lot cheaper than buying the ATS aluminum pier. I appreciate the reference to Dan’s pier products. I think I’ve just changed my plans!

Dan’s Motel-O-Scope also looks intriguing as an alternative to a simple shroud, and can be added to an existing pier. Food for thought once the scope is in place and I can make some measurements. Incidentally, the concrete pier and collar installed through a brick deck that the web page uses to illustrate the Motel is precisely what I had in mind for my installation, with a concrete pier substituted for aluminum. 

Howard

On Oct 26, 2021, at 12:51 AM, weems@... wrote:

My 12” concrete pier goes 4’ down, and extends above ground level to just a few inches below the mount. 12” concrete is extremely stiff and very cheap. It’s also very weather resistant. I have a Dan’s Pier Plate with an AP adapter plate, sitting on 4 3/4” SS bolts, about 2.5” off the top of the concrete. I can kick the pier hard enough to hurt, or slap the base of the mount hard, and there’s no visible motion even at high power. Something to consider if you want maximum stability and are sure of the height you will use. 

I rented an electric mixer from the local hardware store, and it made the job much easier. Sakrete is fine, as long as it is the mix for foundation work. Yes on the rebar, with wire between the vertical bars to hold them stable. Be sure they don’t interfere with the J-bolts, but do overlap with them. Make a wooden template to hold the J-bolts in position and test fit with the rebar before mixing. Be prepared for the mix to make it challenging to push them in. Gravel always seems to block them. I ended up filling the top foot with the template just above the top of the sonotube, through the gap under the template, then wiggling them down the last few inches. I wished I had cut a center hole in the template to make it easier to fill, but it still worked out. 

Chip



Mike Dodd
 

On 10/26/2021 12:51 AM, weems@cs.umass.edu wrote:
My 12” concrete pier goes 4’ down, and extends above ground level to just a few inches below the mount.
Yes; my 12" pier is almost the same -- but only 28" in the ground, with a "club foot" base about 16" in diameter.

I reduced the pier diameter to 10" near the top, but didn't need to do that. Should have gone 12" all the way up.

with an AP adapter plate, sitting on 4 3/4” SS bolts, about 2.5” off the top of the concrete.
I use the AP SPA Standard Pier Adapter. I drilled and tapped a 1/4"-20 hole in one end of four 5/8"-diameter 2-foot threaded rods ("all-thread"), not J-bolts. Cap screws attach the SPA to the rods. Here's a photo: <http://astronomy.mdodd.com/observatory.html#Level>

BTW, the photo below this one shows how I cut long tapered wedges from 2x4s, and used them to plumb the Sonotube while the concrete cured.

I rented an electric mixer from the local hardware store, and it made the job much easier.
Same here. I clamped it into the bucket of my subcompact tractor, then raised it above the Sonotube to make it easier to shovel the concrete into the form. <http://house.mdodd.com/proj_obs_prep.html#PierPour2>

Make a wooden template to hold the J-bolts in position and test fit with the rebar before mixing.
I started to make a plywood template, but then asked myself why, since the SPA itself is the perfect template. I just bolted the threaded rods to the SPA, then worked them into the wet concrete. I had no problem with the rebar interfering with threaded rods.I leveled the SPA, and blocked it in place until the concrete cured.

This was the second pier I've made, and both turned out very well. My first pier was 8" (different mount), but after a couple of months, I decided that was too small. So I wired rebar around it, slid a 10" Sonotube down over it, and shoveled-in more concrete to make a 10" pier. That, too, worked well.

Bottom line: Casting a 12" concrete pier is not difficult.

--- Mike
http;//astronomy.mdodd.com


Howard Ritter
 

Thanks, Mike, that’s all very encouraging. But I had a look at the AP website and could not find a mount adapter for the 1600, although there was one for the 900. Could you have a look at the AP website and see if you can find what you used, and send me a link?

Thanks,
Howard

On Oct 26, 2021, at 10:50, Mike Dodd <mike@mdodd.com> wrote:

On 10/26/2021 12:51 AM, weems@cs.umass.edu wrote:
My 12” concrete pier goes 4’ down, and extends above ground level to just a few inches below the mount.
Yes; my 12" pier is almost the same -- but only 28" in the ground, with a "club foot" base about 16" in diameter.

I reduced the pier diameter to 10" near the top, but didn't need to do that. Should have gone 12" all the way up.

with an AP adapter plate, sitting on 4 3/4” SS bolts, about 2.5” off the top of the concrete.
I use the AP SPA Standard Pier Adapter. I drilled and tapped a 1/4"-20 hole in one end of four 5/8"-diameter 2-foot threaded rods ("all-thread"), not J-bolts. Cap screws attach the SPA to the rods. Here's a photo: <http://astronomy.mdodd.com/observatory.html#Level>

BTW, the photo below this one shows how I cut long tapered wedges from 2x4s, and used them to plumb the Sonotube while the concrete cured.

I rented an electric mixer from the local hardware store, and it made the job much easier.
Same here. I clamped it into the bucket of my subcompact tractor, then raised it above the Sonotube to make it easier to shovel the concrete into the form. <http://house.mdodd.com/proj_obs_prep.html#PierPour2>

Make a wooden template to hold the J-bolts in position and test fit with the rebar before mixing.
I started to make a plywood template, but then asked myself why, since the SPA itself is the perfect template. I just bolted the threaded rods to the SPA, then worked them into the wet concrete. I had no problem with the rebar interfering with threaded rods.I leveled the SPA, and blocked it in place until the concrete cured.

This was the second pier I've made, and both turned out very well. My first pier was 8" (different mount), but after a couple of months, I decided that was too small. So I wired rebar around it, slid a 10" Sonotube down over it, and shoveled-in more concrete to make a 10" pier. That, too, worked well.

Bottom line: Casting a 12" concrete pier is not difficult.

--- Mike
http;//astronomy.mdodd.com





Mike Dodd
 

On 10/26/2021 12:17 PM, Howard Ritter via groups.io wrote:
Thanks, Mike, that’s all very encouraging. But I had a look at the AP website and could not find a mount adapter for the 1600, although there was one for the 900. Could you have a look at the AP website and see if you can find what you used, and send me a link?
I found this: <https://www.astro-physics.com/1612fp>

It says it works with the 1600 and all 1200 mounts.

--- Mike


Howard Ritter
 

OK, and it looks like that in turn takes a socket-type adapter for the 1600. They’re sold as a combination: https://www.astro-physics.com/1612fsa-fp

The 1612FP would bolt to threaded holes in the top of the allthread rods, as in your setup, and the 1600FSA bolts to that. But I’d think I could use the -FSA alone, bolted to the allthread rods directly, without the -FP component: https://www.astro-physics.com/1612fsa

—howard

On Oct 26, 2021, at 1:42 PM, Mike Dodd <mike@...> wrote:

On 10/26/2021 12:17 PM, Howard Ritter via groups.io wrote:
Thanks, Mike, that’s all very encouraging. But I had a look at the AP website and could not find a mount adapter for the 1600, although there was one for the 900. Could you have a look at the AP website and see if you can find what you used, and send me a link?

I found this: <https://www.astro-physics.com/1612fp>

It says it works with the 1600 and all 1200 mounts.

--- Mike








M Hambrick
 

Off topic, but I saw a post from Jack Heurkamp on this thread. I was wondering how you fared after Ida. It looks like Pearl River was right in the path.

Mike


M Hambrick
 

I like the Motel-O-Scope concept. I wonder if they make a version that would work with a long (e.g. 180 EDT) refractor.

Mike


Howard Ritter
 

That wouldn’t be a Motel-o’Scope, it’d be the Waldorf Astoria Hotel-o’Scope!

On Oct 27, 2021, at 8:34 AM, M Hambrick <mhambrick563@...> wrote:

I like the Motel-O-Scope concept. I wonder if they make a version that would work with a long (e.g. 180 EDT) refractor.

Mike