First time collimating newtonian advice?

[RussellH]

Hi All,

So my Skywatcher F5 6" Newt arrived yesterday, and I'm going through the setup process and need a little advice please.

I spent some time making a jig to collimate my laser collimator, and have just finished that process. Putting the laser in the scope, it shows out of alignment. Looking through the front of the cope, the laser point is on the ring around the centre spot on the primary.

So, I'm trying to loosen the phillips head screw in the centre of the secondary mirror, but it won't budge. I don't want to break anything by forcing it. It's a standard RHS system I assume, so I should be turning the screw counter clockwise to undo it? Should they be this tight out of the box?

Thanks.
Russell.

[Rainmaker]

You should collimate using the three screws surrounding the centre screw, loosen one tighten another to tilt the secondary and thus move the laser beam...

[RussellH]

Well they aren't moving either, which is why I was trying to loosen off the centre screw. I'll try them again. Even so, if it ends up the secondary is not centred in the eyepiece properly, I'll still need to undo it.

I might also try using a cheshire, in case there is an issue with the laser.

[Startrek]

Russell

Go to the following sites for Collimating a Newtonian

Astrobaby

Starizona

Both are excellent and details full of pictures and details

Centre screw of the secondary mirror only holds the mirror mount in place whilst the 3 outside screws do the adjusting of the secondary
Always align your secondary 1st with Cheshire eye piece and Primary mirror last with laser
Tweet secondary if needed with laser

Martin

[RussellH]

I did try to read the Astrobaby article, but it's more confusing than other articles I've read. I tried the cheshire, but couldn't do the step of putting the paper blocking the primary as my hand won't fit past the vanes.

I did manage to get the alignment screws to move, so after much fiddling I did centre spot the laser. Spent a lot of time with the laser circling the centre spot. It seemed very hard to get it to go inside the spot, but I got thee eventually. Once it was there though, even just putting the allen key into the screws bumped the laser out again. Also there are lots of spots in the focuser that can move around too, so whether it's truly aligned remains to be seen when I can get outside and spot an actual star, but I still have more setup routines to go through yet before I get that far.

[Ukastronomer]

THIS is one of the best films

https://youtu.be/8G98RTP6jbY


I enjoy doing my scopes, only takes a few minutes but most enjoyable

As for cheshire, hate using them never could

Finally is your laser collimator collimated ?????

https://youtu.be/A6R2InWjFbQ


.

[mynameiscd]

Hi Russell,
I have exactly the same scope as you and yes its a bit tight getting past the vanes but my hands just get through.
I was having trounle centering the mirror and the collimating until i did the whole astrobabys directions with the paper etc.
I had to take my secondary off to fit the dew heater properly and while it was off i gave it a well needed clean.
When i put it back on i couldnt quite get it right.
The laser would say its right but the there was plenty of coma towards one side.
With help from other members I've finally got it !!!!.
http://www.iceinspace.com.au/forum/showthread.php?t=176181

I also did the plastic milk carton washers at the same time.
Try chopsticks and blue tak to get the white card in the tube just to hold it in place.
I've got two lasers and film canisters but until i got my Cheshire type tube I was still having trouble. https://www.bintel.com.au/product/orion-telescope-collimating-eyepiece-mkii/?v=6cc98ba2045f
Hope you have a less frustrating time than i had.

Cheers
Andy