Meade LX200 Primary Mirror Tilt

[DimitriDouchin (Dimitri)]

Hi everyone,

First post here.

I have moved from Celestron to Meade, I'm a little confused.

I am experiencing the following issues:
- the image gets out of focus within seconds as the telescope is tracking (at correct rate)
- the field of view shifts a little when playing with the focus
- the response of the focus screw is asymmetric, if I go turn clockwise, going one turn anticlockwise will lead me to a different focus than the original
- stars are "collimated" on the center of the FoV but not on the edge.

All this makes me think that the primary is tilted out collimation. For the life of me I cannot find any doc on how to fix this. Not even sure what the purpose if a tiltable mirror is.

I have collimated the secondary mirror recently.

Any help greatly appreciated, thank you!

Dimitri

[Merlin66 (Ken)]

Which Meade SCT? I assume an 8"????
Over the years I've used all the different Meade SCT's.
The Meade focuser is completely different to the one used on the Celestron.
It's not as repeatable or as rigid.
Mirror slop/ flop can be reduced by running the mirror up and down the baffle tube - turn the focuser about 30 times in each direction. This re-spreads the grease on the baffle and reduces the gap and hence the slop.


It is possible to make and fit a mirror lock which can then be used to hold the mirror in the final position. Not 110% but can work well.
(Google Meade Classic LX200 mirror lock)
https://www.youtube.com/watch?v=6CIe0YsQbI8

[DimitriDouchin (Dimitri)]

Thank you Merlin 66. Ok it is called mirror slop and flop, Now I can work with that!

Yes the mirror is an 8in.

Will look into your link, thank you!