Pier Height - Comments?

[KenMiller]

My Parmaount is in and I am about to install a concrete pier on which it will be placed.

In considering the height of the pier I realize that I might make things a bit easier on myself by keeping the pier shorter than normal.

I do virtullay no visual work from this site - only astrophotography. Since I'll be mounting somewhat heavy scopes I'm inclined to substantially reduce the height of the pier to make mounting and dismounting a little easier.

Other than the counterweights and the end of the scope (plus focuser, camera, etc.) needing to clear the ground are there any other considerations?

All comments welcome before this decision is cast in stone... er concrete.

[szareh]

Originally Posted by KenMiller

My Parmaount is in and I am about to install a concrete pier on which it will be placed.

In considering the height of the pier I realize that I might make things a bit easier on myself by keeping the pier shorter than normal.

I do virtullay no visual work from this site - only astrophotography. Since I'll be mounting somewhat heavy scopes I'm inclined to substantially reduce the height of the pier to make mounting and dismounting a little easier.

Other than the counterweights and the end of the scope (plus focuser, camera, etc.) needing to clear the ground are there any other considerations?

All comments welcome before this decision is cast in stone... er concrete.

Ken,

If you do not have an enclosure around the pad, or do not plan to install some sort of enclosure/observatory in the future, then the shortest practical pier height would be best.

Depending on the type of telescope you will be using on Paramount, and depending on the camera and accessories attached to the telescope, a pier height of 30" +- 5" will do nicely. If using a longer refractor you may want to consider 36" - 42".

As you mentioned, it is easier to lift and place the mount and telescope on a shorter pier than a taller pier. This is very important if the equipment will not remain in place for extended periods. Also, all things being equal, a shorter pier is stiffer/more rigid than the same diameter taller pier.

For concrete pier, I suggest at least am 8" but preferably 10" diameter. Also rebar to add stiffness.

Shahin

[Rick Keppler]

Overall I would have to agree with Shahin. The only other item I would worry about is how close the optics or imager end gets to the ground. I have found that with a Newtonian telescope the tendency to dew up is higher when the mirror is closer to the ground. I have a 10 inch diameter pier 26 inches high on which I run my AP1200 mount from time to time. It has worked out well for the Newtonian since the focuser is high and cables all run to the top but not quite as well for the refractor. Cable management is a real problem with it. Since this is a remote site and there are normally weeds growing wildly, I have to take time to ensure everything is gathered up, bundled and tied off so that it cannot catch on the ground. This is even with a significant amount of weed whacking around the pier. In retrospect, I should have built the pier about a foot taller, in the 36" range.

[BT Technologies]

Hello Ken,

I would have to agree with both Shahin and Rick in reference to the "optimum" pier height for your Paramount.

When I had my permanent pier setup, with my NJP the height of the pier was at 34". Figure that you have to add the height of the mount and then mounting plates on top of that when calculating your measurements.

Since you have a variety of imaging instruments I personally feel that 32-36" would be ideal for your setup. Now all you need to do is to construct an enclosure around the pier/mount and you will be all set!!

[Murray]

This issue was raised (no pun intended) on another forum and I suggested that a higher pier would be good for a number of reasons and that a wooden platform could be used to make accessing the scope easier if needed.

I had not thought of the dew problem - but of course that makes sense and adds to the rational e for a higher pier to start with.

There are many ways to stiffen a pier - using an internal 4" steel tube in addition to rods would be one method.

However - has anyone noticed any discernible movement with a well found 8 or 10" pier ?

Murray