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Help PLEASE.

LukeSkywatcher

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LukeSkywatcher

LukeSkywatcher

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I just got my new scope today. It is a Sky-Watcher 130P Heritage. The collimation way way off so i attempted to fix it. I did what it said in the manual to do "loosen the large bolts on the back". I did this but one of them i loosened too much and it fell off. Now i cant seem to be able to put it back on. It doesnt seem to be biting the screw that is inside.

Have i completely messed up the scope?

Help really needed. You can see from the image what i have done.

post-18019-133877415575_thumb.jpg

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LukeSkywatcher

LukeSkywatcher

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OK problem solved. I had to reach down inside the tube and gently push the mirror casing backwards a bit til the knob that fell off connected with the screw inside. The scope is seriously out of alignment though. I THINK the secondary mirror is the one that needs aligning.

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LukeSkywatcher

LukeSkywatcher

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None. I do have a set of allen keys and screwdrivers. They didnt come with the scope. When i look into the focuser (no EP attached) i can see that not nothing is aligned in the centre (primary is off a bit,seconday is off and the little circle in the centre of the primary is off), HOWEVER...............when i attach an EP and look through it i can clearly see a house way down the road in perfect sharpness (albeit upside down). I've read that scopes below 6" dont really need collimating BUT should be for max performance. Is it something i should really worry about if it is not done?

What are the drawbacks of not having it done?.

*edit*

ok i see the drawback. I am not getting the full light bouncing back from the primary to the seconday. That could be a rather big issue.

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pvaz

pvaz

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You'll see things less sharp without collimation.

Take the cap off a photographic film case, make a small hole exactly in the center and attach it to the focuser. Then peek through the hole to see if everything aligns. That's a home made collimation cap, you'll need at least that to check the alignment.

Then read the manual of your scope on collimation. Take a look at astro baby's guide if you have some doubts, or ask questions here.

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LukeSkywatcher

LukeSkywatcher

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I've read Astro baby's tutorial and also watched the video of the other. The principles of collimation are fine to me and i have a good idea of what to do (make sure full primary is visible,secondary is centred in primary and donut on primary is centred in seconday). To my naked eye when looking down the focuser, its plain to see that they are all out with each other. I'll give it a test drive on the next clear night and see how it performs. IF i can live with it as it is i might just leave it the way it is. If not then i will adjust it accordingly. Might invest in a laser collminator. I have a green laser pen and a spare lens cap that i could cut a hole into and sit the laser pen into the focuser. Would that work?

Thanks for all your input guys. Its much appreciated. I'm sure i will have a few questions, but hopefully i wont need to ask them.

Hahaha i never thought i'd be sat here having a discussion about collimation as the only scope i have owned up til now is a small refractor and i didnt really have plans to upgrade it.

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LukeSkywatcher

LukeSkywatcher

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I just made the collimation cap and had a look into it. I can only see 2 of the primary mirror clasps. The third one is gone off to the NE. The donut on the primary is also gone off in a NE direction. I'm not too sure which mirror is out of alignment. I'm gonna guess the primary. Bet i'm wrong though. The whole system doesnt seem to be out by very much but i guess in astronomical terms it could be out by lightyears.

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brantuk

brantuk

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Sounds like the secondary is off if you can't see all three primary clasps in your viewing hole. Do the secondary first and ensure all clasps are in view and you're looking cemtrally down the tube - then when you do the primary it'll be easier to get the donut in the middle.

You will have to repeat this all when you're set up outside using a bright star - then defocus slightly to check all the rings are concentric.

I know this cos I did exactly the same with my first dob 2 wks ago - loosened a primary screw too much and it fell out lol

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Ptolemaeus

Ptolemaeus

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Eureka !!!!!!

The manual says that if i cant see the 3 clips holding the primary mirror that i need to adjust the 3 screws on the secondary mirror. Done that. It's looking GOOD.

:D I hope you are retaining all this information so you can help me when i get mine! :)

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LukeSkywatcher

LukeSkywatcher

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Brant are you serious?.

I'll have to collimate outside in the cold and dark?. Sounds like FUN. Yeah when that screw fell off i was about to pop my clogs. Then to add insult to injury a second one came off as i was trying to figure out how to put the 1st one back on. I thought the whole primary was gonna fall out of the scope.

Ptolemaeus (can i just call you Derek?),

Dont worry. Stick with me kid and this time next year we will be collimating blindfolded with our hands tied behind our backs while reading War and Peace (just for fun of course).

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Ptolemaeus

Ptolemaeus

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Dont worry. Stick with me kid and this time next year we will be collimating blindfolded with our hands tied behind our backs while reading War and Peace (just for fun of course).

:D Just call me Chris, thats slightly easier to type and has the added benefit of being my name :)

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LukeSkywatcher

LukeSkywatcher

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Grrrrrrrrrrrrr..............

I knew it would be too much to expect to get to play with my new toy on the day i got it. Its starting to rain and the weather people say that snow IS on the way. Guess i'll just sit here and admire it. Least i seem to have the collimation sorted for the most part. Not bad for day 1. My "old" scope is sitting there giving me the evils.

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brantuk

brantuk

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Well Luke - it's a final adjustment to ensure eveythings lined up in the tube right - but the good news is that it's just tweaking rather than full collimation and should hopefuly only apply to the primary.

Focus on a star, undo the draw tube sligtly till you see a bunch of rings, if they're all concentric then pat yourself on the back cos you did a great job indoors and you're very close to (if not actually on) the sweet spot.

If you go the photography root and want micron accuracy, then a laser collimator is the way to go - just don't use a laser pointer or you'll have your eye out with it.

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LukeSkywatcher

LukeSkywatcher

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I can honestly say now with my hand on my heart that collimation is nothing to be afraid of. Once you know that the aim of collimation is to have everything (primary,seconday and donut) centered in your FOV when you look into the focuser (without an EP attached) you really cant go too wrong.

Brant as good as it seems indoors to me, i dont think i will ever hit that sweet spot. My eyes are not as good as they were 6 months ago (Thank you very much Type II Diabetes), but they are not BAD. I just dont think i'll get pinpoint accuracy with them.

I have to say that the colli cap is/was a great idea. When i used it, the alignment wasnt out as much as it appeared to be with the naked eye.

Good to know that when outside i will only have to tweak the mirror(s). Full collimation is not something i would like to do in the dark with only a head torch to illuminate my view.

I have to say i am pretty proud of myself with what i have done today. I owe it all to Astro Baby and the guy on the collimation video.

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pvaz

pvaz

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Congratz on your first collimation! :D

I know the feeling, it sounds scary at first. The name itself is kind of strange, they could have just called it "mirrors alignment" or something. Anyway it's pretty easy and the only thing you should do outside is some minor tweaking on the primary screws. I usually do it all inside and just leave it be. I don't like to mess with the screws in the dark.

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LukeSkywatcher

LukeSkywatcher

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I agree. "Collimation" does sound VERY technical and frightening AND scarey. You feel that if you unscrew the wrong screw at the wrong time that your scope will be ruined.

It really is nothing like that.................once you have done it once, you will wonder what all the fuss was about.

It really should be called "mirror alignment".

It is only slightly more technical then adjusting the rear and sideview mirrors in your car so that you can see what is around you.

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