Collimation tip for larger newtonians

[Moonshane]

Hi all

I have been meaning to post this suggestion for a while. After just collimating my scope it reminded me to do so.

I have a 16" dob and move this into and out of the house each time I observe.

This inevitably creates some movement of such a large mirror and then when I take it out, the same issue.

I have found in the past that the collimation seemed out after a little observing time. The culprit is the slight movement of the mirror as it 'settles' back into position on the cell.

To combat this, I now routinely incline the tube to position and then gently drum with my fists for a couple of seconds on the tube wall near to the cell fixings to put the mirror into a solid position. This works very well and prevents movement during the observing session.

Might be useful and explain some poor viewing if others are not aware of this issue and assume that collimation remains good after the initial adjustment.

Cheers

Shane

[wrinkly]

Worked well on my eight inch but the neighbour threw cold water over me for waking him up.

[Bart]

Good idea Shane.

Wrinkly......nice neighbour! Were you tapping your scope with a hammer, or do you have hard hands?

Barry

[Starlight 1]

Worked well on my eight inch but the neighbour threw cold water over me for waking him up.

Did you ever play in a steel drum band.

[Gina]

Good one

[Moonshane]

ooops sorry if I got you a drenching! I did mean gentle drumming and I usually collimate when it's early in the night

[gooseholla]

Perhaps he employed the Animal technique of mirror adjustment?!!