Results with my New Baader Laser Collimator

[Doc]

Received my new Baader laser Collimator today from Flo's.

Extremely well packed and arrived super quick.

Now according to my old collicap my collimation was bang on.

Put the laser in and the laser light was about 20mm from the centre donut on the primary.

Adjusted the secondry so the laser light fell inside the dount.

Then looking at the etched grid pane the laser was hitting just at the edge of this.

So went round the back and undone the locking nuts and moved the primary until the red laser beam went into the centre and through the middle hole.

Tightened all nuts and replaced the collimation cap to just see.

Collimation in the cap still looked good but the secondry mirrors reflection had definetly shifted more offset then what it was.

The Baader laser Colli is Very easy to use and very well made.

Well fingers crossed for the first night out.

Maybe splitting doubles will become easier.

[kniclander]

I have a baader laser coli too and it is very easy to use. There are threads suggetsing that the laser colli can need collimating :shock: (or at least checking that it is accurate) but I haven't gone down that road.

My query is, when aligning the secondary, is it best done by loosening or tightening (ie if you loosen all the hex bolts or tighten them all you can get the same effect) - is there a point at which you will cause a problem by making things too tight or (worse) cause the secondary to become too loose and potentially fall off :shock:

Dan

[Doc]

Dan thats a great question and I don't know the answer.

I done a bit of both.

Same with the primary. Two of the three locking bolts are definetly locking but the third winds it self right in and doesn't seem to do alot.

Also if you overtighten the locking bolts this also moves the primary mirror slightly.

[steppenwolf]

Against the grain a bit, I love my laser collimator and use this as my only check for collimation on my 8" and 10" Newtonians but you DO need to ensure that the collimator is itself collimated or you are wasting your time and I am sure that this is why in some camps, the laser has a bad reputation! To check the laser's collimation, you need a 'wedge' to revolve it in and a nice white wall about 20 feet away to check for rotation of the laser dot as you revolve the laser. This is the 'wedge' I use:-

[MikeP]

When I first collimated my 300P, it was (deliberately) totally uncollimated. This is what I incorrectly did.

The three locking bolts were unscrewed so they were well clear of the mirror cell. Then the three spring loaded collimating bolts were loosened to make sure there was plenty of room for adjustment.

The laser collimator was inserted. The secondary was a bit off because beam missed the marker in the centre of the primary - after fiddling with just the adjusters (Bob's Knobs thank goodness) I found the easiest way to centre the secondary was to twist and hold the stem whilst tweaking the adjusters. After carefully tightening, the red dot was centred on the primary. So far so good.

The return beam didn't go into the focuser tube, so it took a bit of fiddling with the primary's collimating bolts to get it there and then some gentle tweaking to get it centred on the Baaders little screen. The three locking bolts were tightened and that was that ....... or so I thought.

The scope was new to me, so the views looked great but not quite as sharp as I expected, so I assumed moving it around the garden may have affected it. I'd also noticed there was a bit of a rattle when I carried it, so I looked for what was rattling ... it was the primary mirror cell.

The locking screws were screwed in to their full extent but because I'd collimated with the collimating bolts too loose, the locking bolts did not reach the mirror cell to lock it in place. To fix it, the locking bolts were loosened again and the collimating bolts tightened quite a lot to pull the mirror cell down against the springs, to a lower level. Collimation was repeated and when the locking bolts were tightened, now they pressed against the mirror cell holding it in place.

Since then the scope has been round the garden a few times and had a night out at Lightbucket's and only needed a tiny tweak.

Hope there is something in the above that helps.

Mike

[Astronut]

Good point in the above post. Don't allow the primary cell to be too loose. Make sure the springs are compressed or it won't hold collimation. If you're not sure the springs are doing their job then completely loosen the lock screws and tighten the adjusters fully until the springs are fully compressed. Loosen each adjuster by one turn and then start collimatiing. Use a colli-cap to centre the secondary in the outline of the bottom of the focuser tube first.

I wouldn't even think about adjusting the laser - it's factory set using equipment far more sophisticated than any DIY method.

Follow the Baader instructions carefully, especially the bit about locking the laser in the focuser with the focuser lockscrew in line with the on/off knob. You may not be able to see the return beam on the etched window while you're adjusting the primary but this is the recommended method for attaching the laser.

[kniclander]

Agreed MikeP.

Steppenwolf, presumably, you could also test a laser colli by rolling it along a flat surface and watching the beam on a wall? if it's a straight line (subject to a few bumps cos your surface isn't flat) it's ok but if there's a regular pattern of the line going up and going down (ie like v shallow waves) then it's not ok.... :scratch:

Dan

[steppenwolf]

I wouldn't even think about adjusting the laser - it's factory set using equipment far more sophisticated than any DIY method.

My laser collimator came with a full set of self collimating instructions and quite rightly too - if a telescope can go out of calibration in transit, so too can a laser collimator! You CANNOT assume that it is correct 'out of the box'.

Steppenwolf, presumably, you could also test a laser colli by rolling it along a flat surface and watching the beam on a wall? if it's a straight line (subject to a few bumps cos your surface isn't flat) it's ok but if there's a regular pattern of the line going up and going down (ie like v shallow waves) then it's not ok....

You could but far better to revolve it in some kind of 'V' wedge or even hold it in the chuck of a lathe and turn the lathe by hand whilst watching the dot on a distant wall - the key is to have a decent distance between the laser and the wall and a smoth fixed surface to roll the tube of the collimator in.

[thing]

I've had a Baader for a while now and often wondered how you would know if it was aligned properly. Then Paxo did a test on one of my DSO pictures that measures the collimation of the primary (don't ask me how or what software it was) and it was so accurate that the crosshairs on the alignment were invisible because they were underneath the crosshairs of the 'perfect alignment'. Which I thought was pretty good.

It's at the bottom of this thread http://stargazerslounge.com/index.php/topic,32311.0.html

[Astronut]

I wouldn't even think about adjusting the laser - it's factory set using equipment far more sophisticated than any DIY method.

My laser collimator came with a full set of self collimating instructions and quite rightly too - if a telescope can go out of calibration in transit, so too can a laser collimator! You CANNOT assume that it is correct 'out of the box'.

But the trouble with the Baader is the shape doesn't lend itself to this type of DIY collimation. The barrel for the focuser is only around 1" long. It's been recommended by others not to attempt it. If it's out of line, send it back for replacement or ditch it and get a cheshire.

[NiteGawper]

I understand that many laser collimators come with calibration instructions and indeed do need "tweaking" before use.

But am I right in thinking that the Baader laser Collimator is a sealed unit. According to the instructions no adjustment should be made:

"Please understand that precise adjustment is about the most time consuming work during the production of the Laser Colli. Factory realignment is expensive and involves two times freight charges. So better not to tamper with the adjustment, it's at it's best already."

If you have any suspicions that your Baader laser Collimator is not right - surely it's a call to the supplier rather than a fiddle with the hex-keys...??!!??

IMHO...

Andy :-)

[Astronut]

Agreed

I gave mine away because the end result didn't quite agree with the cheshire and I wasn't keen on the slop in the focuser. It might have been better with the compression ring focuser I've got now but that barrel length is a bit on the short side IMHO. I guess that's why Baader recommend aligning the on/off switch with the focuser lockscrew but then the reticle is difficult to see when you're fiddling with the primary adjustments if the lockscrew's on the opposite side of the focuser.

[MartinB]

The Baader collimator isn't designed to be user collimated and should be sent back if it doesn't give accurate collimation.

Collimating my Skyliner with the collimator takes 2 minutes and star testing is spot on. Using CCD inspector I am typically within 8" of collimation but that will have been affectec by the weight of the camera in the focuser.

[Astronut]

Martin - either you got lucky or I got unlucky It's possible that the one I got was slightly out - comparison with a cheshire was close but no cigar. I've moved on since then and now have total faith in my Catseye collimation kit - collimation with these gadgets is so precise and fun.

[rusirius]

I had a similar issue with the secondary being shifter after adjustment. I also thought that my new Baader collimator was off. FLO kindly sent me a second one and a cheshire for comparison. It turned out that the collimator was Ok and the results agreed with the cheshire so I am, for now, prepared to trust the laser. I was advised, however, not to tamper with the Baader Laser Colli as this would void the warranty.

Since due to its design you can't easily place the Badder laser colli as per steppenwolf on a 'wedge', Klevtsov suggested that I remove the EP adaptor from the focusser and place it in a vice (being very carefull not to squash it) and then attach the laser colli to the EP adaptor as normal. This approach worked Ok and I was able to confirm that the laser was pretty much spot on centre.

The laser collimator does, of course, need to be itself collimated properly and it would appear that some manufacturers do allow you to do this. The (presumably deliberately) awkward design and the warranty limitation on the Baader do tend to suggest however that, despite the provision of adjustment screws, Badder prefers the hands off and return for replacement approach.

I'm guessing that in my case the process of first-time collimating the secondary has resulted in shifting the secondary up or down with respect to the centre of the focusser so that although primary to seconday collimation is Ok, the secondary to EP is slightly off which is why I am no longer seeing all three mirror clips. I've ordered some Bob's knobs for mine so I'll investigate this when I get around to fitting them.

Astronut, I'm curious about this Catseye thingy. I tried to Google but it came up with all sorts of rubbish. Do you have a link perchance?

[Astronut]

Astronut, I'm curious about this Catseye thingy. I tried to Google but it cam up with all sorts of rubbish. Do you have a link perchance?

Have a search for 'catseye' on the forum. There are a couple of threads knocking about.

Here's a link to the manufacturer and supplier:

http://www.catseyecollimation.com/

[rusirius]

Thanks Astronut. I'll have a look.

[Doc]

Thanks Mike for that great advice about loosening locking nuts etc.

On mine 2 locking nuts do tighten against the mirror, but one does not.

That might mean that the primary mirror is sitting on an angle and the secondry mirror is compensating for it.

But then according to the laser it's collimated.

I might do what you suggest Mike and start from scratch

[MikeP]

Doc,

Use a colli-cap or something to make sure you have the secondary centred THEN put the laser in adjust the primary. Astronut's suggestion to tighten the collimation bolts against the springs then back them off a turn then collimate is a good idea - it will guarantee that the locking bolts will all contact and keep the primary locked in place.

Mike

[todd8137]

thats put me off getting one now ,does any one live near Alfreton with one of these who could show me this i would pay the petrol money for the pleasure ,i jut do not want to buy one and find out they not as good as my blue cheshire from floi usally like to look at the gadget am about to buy and test first wehat to do ?

[John]

This is a 3 year old thread. I think the Baader laser collimator has been redesigned since then.

I use a cheap laser collimator but I did have to check and collimate that (using the V-block method) before it was accurate enough to be useful (rather than misleading).

[derekm]

I can understand the appeal of laser collimators in this hi-tech age, but is there not at least a bit of trying to re-invent the wheel?

[earth titan]

I've been using a barlowed laser collimator for over a year now. Theres a thread on the advice section. Seems to make no difference about the laser collimation.

Unless I'm missing something, this seems the best to me.