glend
18-01-2015, 05:31 PM
I have just assembled all of my pier adaptor components and mounted the NEQ6 on the pier for the first time, the idea being that I needed it all mounted so I can work out the wall height for the observatory.
The pier alone exhibits no vibration no matter how hard I slap it at the top of the pier. However, the higher the components get the more vibration enters the assembly. If I tap the dovetail mount point at the top of the NEQ6 I get a high frequency vibration but the amplitude seems very small. In comparison the same mount on the tripod when tapped with the same force, exhibits less vibration frequency but greater amplitude but damps quickly compared to the pier. The pier seems to resonate.
I had the tripod and pier side by side (tripod on the ground of course), and moved the mount head back and forth to try and work out why the pier seemed worse than the stock mount. Or perhaps its just different to what I am used to with the tripod, but I expected very little if any, certainly less.
The pier has three hold down bolts cast in the column, and the pier plates are 10mm aluminium plate sitting on 4 x 12mm bolts. The top pier plate is backed by a 100x100 x 10mm plate washer where the mount bolts to the adaptor.
As a mount pier adaptor I used the mount adaptor from the top of my Skywatcher Pier Extension as shown in this previous thread:
http://practicalastronomy.com/fitting-a-skywatcher-eq6-mount-to-a-telescope-pier/
I suspect that this Skywatcher tripod head adaptor might be part of the problem, simply because it has much less load bearing surface area than a flat machined puck would. I did sand flat the bottom of the Skywatcher adaptor and it sits flush on the top plate (and is backed by that big plate section as a washer underneath the top plate) but it concerns me. Is anyone else using this method?
So any advice from the pier experts? :question: Once I get up onto the mount section I start to get vibration (when slapped) and the higher up the worse it seems. No apparent vibration below the pier plates when the same force is used.
The pier alone exhibits no vibration no matter how hard I slap it at the top of the pier. However, the higher the components get the more vibration enters the assembly. If I tap the dovetail mount point at the top of the NEQ6 I get a high frequency vibration but the amplitude seems very small. In comparison the same mount on the tripod when tapped with the same force, exhibits less vibration frequency but greater amplitude but damps quickly compared to the pier. The pier seems to resonate.
I had the tripod and pier side by side (tripod on the ground of course), and moved the mount head back and forth to try and work out why the pier seemed worse than the stock mount. Or perhaps its just different to what I am used to with the tripod, but I expected very little if any, certainly less.
The pier has three hold down bolts cast in the column, and the pier plates are 10mm aluminium plate sitting on 4 x 12mm bolts. The top pier plate is backed by a 100x100 x 10mm plate washer where the mount bolts to the adaptor.
As a mount pier adaptor I used the mount adaptor from the top of my Skywatcher Pier Extension as shown in this previous thread:
http://practicalastronomy.com/fitting-a-skywatcher-eq6-mount-to-a-telescope-pier/
I suspect that this Skywatcher tripod head adaptor might be part of the problem, simply because it has much less load bearing surface area than a flat machined puck would. I did sand flat the bottom of the Skywatcher adaptor and it sits flush on the top plate (and is backed by that big plate section as a washer underneath the top plate) but it concerns me. Is anyone else using this method?
So any advice from the pier experts? :question: Once I get up onto the mount section I start to get vibration (when slapped) and the higher up the worse it seems. No apparent vibration below the pier plates when the same force is used.