secondary mirror?

[+seven_legs]

hi all

 

wonder if anyone can help.

the problem is that I collimate my scope with a HoTech laser collimator and a Cheshire collimator. everything is fine and aligned, I go back to it 10 minutes later and the secondary mirror is way out by anything up to a few inches. the main screw is tight and so is the other smaller screws.

this is really doing my head in lol.

 

any idea's or help from anyone out there, please.

 

my scope is 350 flextube goto dob.

 

anyone who live near new basford are more than welcome to come and help lol

 

thanks all tony

[+Graham]

can you give a brief run through on the procedure you are using.

It is very unusual for the secondary to move. 

Edited March 19, 2015 by Graham

[+seven_legs]

Hi graham,

I insert the hotech laser collimator( which is self centring), I loosen one aligning screw and tighten the others one bit by bit if you know what I mean. I start with the secondary mirror and move to primary. At end the process I check with my Cheshire collimator as well. Yet as I said the secondary seems to get out of alignment even with touching again.

However since the last time I checked it seems not to have moved. But will not hold my breath.

Thanks a lot

Tony

[+Graham]

Sounds like you might be over tightening the secondary's screws and twisting the Spider. 

[+seven_legs]

They look and feel fine to me. But will keep that in mind thanks.