9 replies to this topic

[bluesilver]

Hi,  I am in the process of trying to work out what height i should be looking to make my pier height,  I am hoping i can please get some suggestions that may help me to determine what height i should be looking at.

 

I have managed to pick up a good length of 8" diameter Schedule 40 pipe,  so this has a wall thickness of 0.644"  or if you like and I.D. of 7.981" and O.D. of 8.625"

I have read the e-book on Telescope Piers by Jim McMcathren and the Schedule 40 pipe is a good decent pipe size to use.

 

I will be putting the setup in a roll of roof ,  but the main thing is to work out what is a good height to make the per.

The pier will be bolted onto a concrete slab,  this slab will be separated from the main slab in the observatory.

 

The mount is a iOptron CEM120

The imaging scope is a Skywater Esprit 150

I was hoping ( if i can ) to be able to swap out the Sykwatcher Esprit 150 and mount my Celestron C14 on it for visual observing the planets when the season comes around and possibly also image them as well with the C14

 

So this is kind of the issue in working out the pier height.

At the moment,  the tripod is set up at around 38" in height for imaging.

 

Would it make more sense to:

Setup the C14 on my current tripod,  find out what a good visual height is and make the pier to that height?

( I have yet to have the C14 out for visual use )

 

I will then make the observatory to suit the pier setup,  rather than making the pier suit the  observatory

Here is a link i found to calculating the wall height of an observatory if anyone is interested in that:

http://astronomy.mdo...Wall_Height.pdf

Any advise on tis would be very much appreciated.

 

Thanks.

Edited by bluesilver, 05 August 2022 - 08:47 PM.

[RSJ]

Other things to consider would be whether any current or future automation of the roof closing could collide with the telescope (for example, a failed park attempt by automation, then the roof close command is issued), and if having the telescope visible (above the side walls) to passers-by would invite curiosity and potentially crime -if unattended/automated overnight or controlled from the house. 

[charlesgeiger]

One of the many things you will need to consider is comfort in viewing.  Do you want to stand or sit while viewing.  If you are just imaging, you may need to reconsider.  I think one should set up the instrument on the mount provided and with the tripod it comes with.  This will give you a benchmark.  You might want to increase or decrease the height depending how this all relates to a benchmark wall height and distance to walls.  You will also get a feel for the horizon you will be able to achieve.  25 degrees may be too high for you even if the sky is poor quality.

I too am building an observatory and will probably just try out with the instruments I have before deciding on a pier height.  The formulas are again benchmarks as one needs to consider your height, flexibility, agility, age and health conditions.  I will prefer to sit at my scopes rather than stand as I have done all my young years.

Let us know what you decide.

Charlie  

[bluesilver]

Appreciate the comments and advice.

The good thing is that i am on a remote sort of property with nice dark skies,  usually around bortle 2-3 

The C14 being the largest / tallest of the scopes would only be used occasionally at this point in time as most of the time i am imaging which i use the Skywatcher Esprit 150 for,  may eventually look at going a Rassa.

 

At the moment the tripod is set at around 38" in height,  so for the C14,  this means that at the default polar aligned position, it is a good height for eye piece use standing,  when the planets get up nice and high it works out to be a good position for sitting.

So kind of a win win there.

 

I am thinking that imaging,  it may not really matter too much about the height,  I have just to hit a tripod leg.

So maybe then the height of 38" may be what i am looking for.

[macdonjh]

Bluesilver, your idea of setting up your C14 and determining the most comfortable height and matching it in your pier design is what I would have recommended. It's exactly what I did when I built my observatory. Practical experience and experiments are hard to beat.

If you were setting up for photography, pier height really comes down to being high enough your camera doesn't hit the floor and being able to see over your walls when you are photographing the lowest object you planned to shoot. Your camera doesn't care high high or low it is. :-)

Oh, your pipe is much thicker than sch 40. 8" sch 40 pipe is 0.322" thick. 8" sch 80 is 0.500", I think (going from memory...), so I think you have sch 120...

[archer1960]

Hi,  I am in the process of trying to work out what height i should be looking to make my pier height,  I am hoping i can please get some suggestions that may help me to determine what height i should be looking at.

 

I have managed to pick up a good length of 8" diameter Schedule 40 pipe,  so this has a wall thickness of 0.644"  or if you like and I.D. of 7.981" and O.D. of 8.625"

I have read the e-book on Telescope Piers by Jim McMcathren and the Schedule 40 pipe is a good decent pipe size to use.

 

I will be putting the setup in a roll of roof ,  but the main thing is to work out what is a good height to make the per.

The pier will be bolted onto a concrete slab,  this slab will be separated from the main slab in the observatory.

 

The mount is a iOptron CEM120

The imaging scope is a Skywater Esprit 150

I was hoping ( if i can ) to be able to swap out the Sykwatcher Esprit 150 and mount my Celestron C14 on it for visual observing the planets when the season comes around and possibly also image them as well with the C14

 

So this is kind of the issue in working out the pier height.

At the moment,  the tripod is set up at around 38" in height for imaging.

 

Would it make more sense to:

Setup the C14 on my current tripod,  find out what a good visual height is and make the pier to that height?

( I have yet to have the C14 out for visual use )

 

I will then make the observatory to suit the pier setup,  rather than making the pier suit the  observatory

Here is a link i found to calculating the wall height of an observatory if anyone is interested in that:

http://astronomy.mdo...Wall_Height.pdf

Any advise on tis would be very much appreciated.

 

Thanks.

Hmm, the math on your pipe doesn't add up. An ID of 7.98 and an OD of 8.625 gives a wall thickness of about 0.32, not 0.64. Which would be Schedule 40. If the thickness is really 0.64, then either your ID or your OD are off.

[lovejaca]

Hmm, the math on your pipe doesn't add up. An ID of 7.98 and an OD of 8.625 gives a wall thickness of about 0.32, not 0.64. Which would be Schedule 40. If the thickness is really 0.64, then either your ID or your OD are off.

My guess is that he measured and subtracted the diameters and forgot to divide by 2 to get the thickness.

[bluesilver]

My guess is that he measured and subtracted the diameters and forgot to divide by 2 to get the thickness.

Yes,  error there.

I am use to working in metric and converted it to inches as that is generally how pipes are measured.

So the pipe is definitely Schedule 40 and 8 inches in diameter.

[lovejaca]

Yes,  error there.

I am use to working in metric and converted it to inches as that is generally how pipes are measured.

So the pipe is definitely Schedule 40 and 8 inches in diameter.

I know this mistake very well 

[cavedweller]

Hi,  I am in the process of trying to work out what height i should be looking to make my pier height,  I am hoping i can please get some suggestions that may help me to determine what height i should be looking at.

 

I have managed to pick up a good length of 8" diameter Schedule 40 pipe,  so this has a wall thickness of 0.644"  or if you like and I.D. of 7.981" and O.D. of 8.625"

I have read the e-book on Telescope Piers by Jim McMcathren and the Schedule 40 pipe is a good decent pipe size to use.

 

I will be putting the setup in a roll of roof ,  but the main thing is to work out what is a good height to make the per.

The pier will be bolted onto a concrete slab,  this slab will be separated from the main slab in the observatory.

 

The mount is a iOptron CEM120

The imaging scope is a Skywater Esprit 150

I was hoping ( if i can ) to be able to swap out the Sykwatcher Esprit 150 and mount my Celestron C14 on it for visual observing the planets when the season comes around and possibly also image them as well with the C14

 

So this is kind of the issue in working out the pier height.

At the moment,  the tripod is set up at around 38" in height for imaging.

 

Would it make more sense to:

Setup the C14 on my current tripod,  find out what a good visual height is and make the pier to that height?

( I have yet to have the C14 out for visual use )

 

I will then make the observatory to suit the pier setup,  rather than making the pier suit the  observatory

Here is a link i found to calculating the wall height of an observatory if anyone is interested in that:

http://astronomy.mdo...Wall_Height.pdf

Any advise on tis would be very much appreciated.

 

Thanks.

 

Nice diagram explaining the pier height tool. Would we want to add half of the aperture to get the full view over the wall?

 

Edit: Add to pier height or subtract from wall height.

Edited by cavedweller, 08 August 2022 - 04:38 PM.