Lightbridge Collimation Problems

[hugobugo]

Hi,

Just joined as desperate for some help.

I have a 12" lightbridge dob.

Collimating not been a problem on any of my scopes before or on the lightrbidge previously.

My scope has been packed up for a while do to illness and got it out and up this evening. Went to collimate it and no problem puting dot in middle of primary.

Now the problem starts, nothing coming through on the laser collimator facia, turn nobs, loosen tighten nothing.

two months ago this was lining up perfectly with a wee tweak. Now nada!

It has not been bumped, banged or dropped.

Pulling my hair out.

So question is on primary mirror what is the starting point for collimation, all knobs turned half way for example?

Any help or advice most welcome.

Thanks

Hugo

[paul mc c]

Is the batteries strong enough in the laser,if not the beam may be too weak when reaching the facia.

And welcome.

[OneEyedSam]

Sounds like the return path is way off. Try waggling a small piece of paper in between the path of the laser, to see if that helps you visualise how far out the return path is off centre. Might help you suss out the necessary correction required in the main mirror

[Moonshane]

try tightening all the primary bolts as far as you can go and then back off a full turn. I presume you have checked the secondary position in the drawtube before doing anything else with the laser? you cannot check secondary position (in relation to the focuser drawtube) with the laser

[laser_jock99]

Is the laser passing the secondary completely on the return? Try waving some paper in front of the tube