Laser Collimator not collimated

[andrewk_82 (Andrew)]

Hi,
My wife bought me an Orion deluxe laser collimator for christmas. I put it in the focuser and rotated the collimator in the focuser and the beam then rotates on the mirror in a circle about 1.5cm across.

I assume that if the laser collimator is correctly collimated then the dot should not move when the laser is rotated. Is this correct?

The laser collimator was tight in the focuser, so it was sitting in the focuser properly.

Because I thought that the collimation on the laser was out I rang the supplier and told them the problem (the book that came with the collimator said that if the collimation was out that it needed to be sent back to the factory).

The reply from the retailer was that they have NEVER had an orion laser collimator that was out of collimation. This got me thinking that maybe I'm being too fussy with how well the collimator should perform or maybe it is collimated properly and the I'm testing it incorrectly.

Any help with this problem would be greatly appreciated.

Thanks

[bmitchell82 (Brendan)]

your title is exactly right. they are not collminated unless your going to spend GOOD dollars. eg 150 or better. Eric has a Hotech laser collminator and by memory he picked it up for 130 + 20 shipping and it still has error in it. Why they cant collminate it before it comes to you is a total mystery to me as it doesn't take that long and if you have all the equipment there its even easier.!

If you want presice collmination there is a little bit of cost to start with but the equipment is A1 quality.

Look on the forum for collminating a laser collminator theres heaps of info on how to do it!

[Kevnool (Kev)]

Theres 3 little hex head screws in the side of the collimator these are what you loosen and tighten to colimate the laser ......some have six screws in the side but just look on the collimator up near where the batteries get put in.....cheers Kev.

[andrewk_82 (Andrew)]

Thanks for the reply guys,

I finally found the hex screws you were talking about. I had to pull off the sticker to get to them, and they were filled in with some sort of resin to prevent people from accessing them, which I used a pin to get out.

The book said that the warrenty was void if I did this, but I don't want to have to send the damn thing back to the factory every time the collimation goes out a little.

Why they tell you not to do this yourself is beyond me .

Thanks again

[Kevnool (Kev)]

Glad we could help ya out .....dont worry about the waranty.
If by some chance that when you adjust the scews and finally get it collimated and the laser wont come on it`s because the screw that turns the laser on is off to the side pull the on & off screw out and have a look inside.........Thats only if it dont come back on.
Cheers Kev.

[andrewk_82 (Andrew)]

Thanks for your help Kev, I even managed to get the thing collimated without much trouble at all.

All I did was put the laser collimator in the focuser and adjust the secondary mirror so that when I rotated the laser in the focuser, the circle it made was centred around the dot in the middle of the primary. All I did then was adjust the collimator till the dot was in the middle of the centre spot on the primary. Took all of about 2 minutes.

Now when I rotate the collimator the dot stays in the same spot. I don't know if this is the right way to do it, but it worked for me and it was quite easy.

Cheers

[PCH (Paul)]

Hi All,

don't want to hijack this thread, but the topic is the same. I'd always used my laser collimator to collimate my 12" LB - without regard to whether or not the collimator itself was accurate.

But this thread made me go to the trouble of checking it, - and it was woefully out. But as with Andrew, I decided to set about straightening it up, and it was really quite easy - given the pointers in this thread.

So advice to anyone and everyone, - check yours and have a go. It is not that difficult

[bmitchell82 (Brendan)]

happy days

[Spanrz (Brett)]

Guys, not sure where to post this....

Slight issue. Do I have a collimation problem. Using a laser and checking this and that.

All things align (red laser dots) but the reflected image is slightly to the left, even after laser collimating and checking twice.

Do I have an issue with collimation?? Do I have an issue with the laser not being straight, or am I pedantic?

Haven't checked the EP view yet. Just wanted ideas, if there was an issue with the reflected image bieng off centre.

Thanks.


http://farm4.static.flickr.com/3132/...c913034d3e.jpg

[bmitchell82 (Brendan)]

well not so much as a collmination problem though what seems to be the problem is that your secondary isn't pointing to the middle of the primary.. Now don't start freaking out just wait for the sun to dissapear and go and have a look see how it looks.

I use both ceshire and laser combination to get my collmination and i belive that i have outlined my proceedure earlier in the post.

Your collminator, put it inbetween something or a wedge so that you can spin it around, look at the shape the laser makes on a wall about 4 -5 meters away. if it stays still and doesn't do circle work then your laser is colminat ed @ 5 meters you should expect 1 - 1..5 cm diameter circle as acceptable.

other than that happy days

[Spanrz (Brett)]

Originally Posted by bmitchell82

I use both ceshire and laser combination to get my collmination and i belive that i have outlined my proceedure earlier in the post.

Brendan, thanks for that.
Ok, just to be sure, I've done so much research on collimation and which device to use (with "+'s" and "='s"), I've found what you have stated to be the most effective.
I've learned, not to just trust one instrument, as you would think a Laser on it's own would be suffice. I'm all studied out, hehehe.

I even tried the DIY job of a recticle (crosshairs, to see if I was in the ballpark). It did work, however, it was probably 70-80% effective. It gave me the "ballpark" but not anymore.

I did check the laser and it was fine (squared).
As with what was most helpful, is the "Barlowed Laser Collimation" procedure. Man, why didn't I think of that before.
That is by far the most easiest and successful procedure yet.
By doing that already made a difference and a half.
The problem though, I still had slightly unsharp images, all stars looked like saturn. And I was getting confused about "everything" being aligned to get near perfect collimation.

So today, coupling myself with brainwashing of trying to get the collimation step under my belt, I went and bought an Orion Cheshire Eyepiece. Man that was the jewel in the crown.

It is now about 98-99% collimated (still very tiny smudging, but it's way better than before).
The eye (middle point of focuser) is still slightly off kilter (reflected image on the secondary), but all the procedures to do with collimating are all 100% spot on. That's where the images are the most "clearest".
That's with the laser, with the barlow procedure and with the cheshire EP.
So now, I'm trying to deal with the eye slightly off, is "A OK"

Just wanted to say thanks for your input and most of the guys here for their inputs.

So lesson learned, don't trust just one piece of instrument for collimation (even laser on it's own).
I finally have not so much mastered "collimation", but in 2-3 days have certainly found to understand, the art of it.
I think the must have is, Cheshire EP, Laser, Barlow Lens and it's "laser" procedure and I think the last thing is "paitence".

As you say Brendan, very happy days

EDIT : 2am

Update ........Absolute perfecto... Been out for ages now. Dam cloud rolled in around 11PM, wispy stratus clouds, made it hazy. Jeez the only thing I hate about Melbourne...

But just went looking at M42, excellento. Even tried again for the Horsie one, no go, too much light pollution here.

But all good.