Rocking

[Guest]

I've had this problem with imaging for a while. When I take a set of pictures, every now and again I get one where all the stars are streaked. I thought maybe there was a problem with the motor drive or perhaps there was a gust of wind. Tonight I worked out what it was. It was a rocking slab. I have to move my scope out every time I use it. I set up my laptop next to it on a little camp table with a stool. The tripod rests on a 3x3 pad of two foot square concrete slabs. They seem pretty firm but I discovered that one of them rocks ever so slightly. When I'm sitting there on the stool waiting for say a one minute exposure and I shift my weight slightly, the slab moves. Good grief!

[Adam1234]

Glad you discovered the cause

Edited April 11, 2020 by Adam1234

[MarkAR]

NOOOOOOOOOOOO. 

Daft little things can get so annoying, it'll give you something to do now during the day.

[Guest]

I can fix the slabs. I'm just glad it's not a fault in the mount.

 

[Waldemar]

That is why a remote set-up, even for a few meters, is ideal.
On top of that you could stay in the warmth of the house, and let the equipment have it's private thing going on...

[theropod]

I’ve considered pouring a concrete observational pad several times, and I have the space for it. I was thinking that such a slab could “float” on a thick layer of coarse sand. If the sand was drained well so that precipitation wouldn’t “stand” under the slab there should be little, if any, heaving with freezing temperatures. My thinking is that such a “floating” slab would absorb vibrations more fully than if the pad were in direct contact with the packed earth underneath. Am I overthinking the issue?

Sorry for the thread hijacking.