Good laser collimation tool?

[Starkler (Geoff)]

Originally Posted by White Rabbit

Can someone tell me what a V-block is and where I can get one?

Thanks

I used a large block of wood and four large nails. It doesn't have to look pretty.

I pretty much ruined a cheap laser collimator in my attempts to collimate it.

Like just about every <$100 model it consists of a 1.25" barrel with a $2 keychain type laser pointer inside. The aiming is adjusted with 3 grub screws. I spent a good hour or more trying to get it spot it and failed. In the process of making minute tweaks I have compressed the barrel of the internal pointer to the point where the batteries wont come out without some hard whacking, and that throws the collimation out again

[Babalyon 5]

I have a Howie Glatter laser collimator. It is 1.25 in machined aluminium body and has a changeable end piece for a beam or a grid. The grid is used to assist in the collimation of SCT's where needed. They are very dear but when I use it for a quick set up/check, the viewing results speak for themselves.

[PhilW]

There seem to be two classes of collimators in the marketplace: the cheap ones that are built the way Geoff (Starkler) describes, & the high end of the marketplace (Glatter, Catseye, Astrosystems, Kendrick). In my view, it's worth getting a high end one because you will use it every time you observe. You can get good results with the cheap ones, but you have to spend a lot of time messing around with them, as per this thread.

One other nice thing about the Astrosystems one: the batteries are separate from the laser, so changing them does not disturb the factory preset collimation. I use the Astrosystems one & love it, but my hunch is that all the premium ones work well.

[erick (Eric)]

I'm ordering the Hotech tomorrow:-

http://www.hotechusa.com/collimator.html

Found a supplier for USD113.95

It's still deficient because while the laser may be accurately centred in the focusser for collimation, the first eyepiece you put in may not be - but I have an idea......... I'll let you know how it goes.

[Quark (Trevor)]

Hi All,
Interesting thread.

I had one of the original nylon bodied Ezy Collimator's that suffered from collimation problems itself. Bintel kindly replaced it with the second generation aluminum bodied Ezy Collimator. This is a double pass laser and does a great job.

There really are some critical considerations with regards to laser collimator's. The clearance of it in your focuser is critical to it's performance.
I have machined my own adapters for my focuser to keep this clearance minimal.

I think the locking screw on the focuser should be orientated on top in the vertical plane to minimize any wobble of the laser body in the focuser.
This orientation should be used each time the scope is collimated.

Very few lasers are actually collimated accurately enough for the job expected of them, their intrinsic alignment can change over time. Every six months I put my laser in the 3 jaw self centreing chuck of my lathe and collimate it on a target 12ft away.

I have tested three different double pass lasers, all when brand new, none were collimated correctly. I have been to 5 SPSP's and met many people that thought their scopes were collimated because they used a laser. After looking through their scopes it was apparent that they were not collimated very well at all.

It is amazing how many times the quality of the seeing is blamed when poor collimation is more likely the problem.

My point here is that the alignment of the laser really needs to set very accurately and it really requires specialized equipment to do that.

Regards
Trevor

[erick (Eric)]

My Hotech arrived yesterday. Nice looking. I dropped it on a rough "V-block" and was surprised to see the dot trace out a big (18mm dia) circle on the wall 3.68m away. I contacted Hotech who replied overnight saying:-

"From your description, you place the laser on two v-blocks and rotate
about to see if the laser is centered. It is a very common mistake
using this method to check for laser alignment which someone ever
suggested in the internet. This method is referencing the two center
points at which one of them is irrelevant because one is on the
none-adapting section, namely the body section of the device.

The front 1.25? or 2? collimator adapting section should be the only
place to be rotated about on the v-blocks for a rough test. Therefore
the two referencing points should be within the distance of the
adapting section.

We adjust the laser pointing error within 0.05 degree full angle,
which yiels maximum 8.7mm diameter circle at 5M. It is a new adapting
method. Please see the following video links we made which helps you
to install the SCA Laser Collimator more successfully."

Interesting. OK, I'm off to design a better V-block for testing in the way they propose. I also now have their specification. Of course, one test is to leave it just loose enough to rotate snuggly in the focusser and watch the spot on the primary mirror. I'll do that as well.

Eric

[erick (Eric)]

If you are interested, some videos:-

Installing SCA Laser Collimator:
http://www.youtube.com/watch?v=FBd54XrFQhU

Uninstalling SCA Laser Collimator:
http://www.youtube.com/watch?v=0EL54zzMXuw

Newtonian Collimation using SCA Laser Collimator:
http://www.youtube.com/watch?v=ME-CBtemo7Q

OMG! Look at the flex in that Meade spider!

[redsquash]

Originally Posted by erick

My Hotech arrived yesterday. Nice looking. I dropped it on a rough "V-block" and was surprised to see the dot trace out a big (18mm dia) circle on the wall 3.68m away. I contacted Hotech who replied overnight saying:-

"From your description, you place the laser on two v-blocks and rotate
about to see if the laser is centered. It is a very common mistake
using this method to check for laser alignment which someone ever
suggested in the internet. This method is referencing the two center
points at which one of them is irrelevant because one is on the
none-adapting section, namely the body section of the device.

The front 1.25? or 2? collimator adapting section should be the only
place to be rotated about on the v-blocks for a rough test. Therefore
the two referencing points should be within the distance of the
adapting section.

We adjust the laser pointing error within 0.05 degree full angle,
which yiels maximum 8.7mm diameter circle at 5M. It is a new adapting
method. Please see the following video links we made which helps you
to install the SCA Laser Collimator more successfully."

Interesting. OK, I'm off to design a better V-block for testing in the way they propose. I also now have their specification. Of course, one test is to leave it just loose enough to rotate snuggly in the focusser and watch the spot on the primary mirror. I'll do that as well.

Eric

8.7mm different at 5metres doesn't seem very precise.
ie they are accurate only up to3minutes
Is this an acceptable measurement.

I am sure a Geodetic surveyor would say not..........but i am not precisly sure

[HOTECH (David)]

You can definitely barlow HOTECH SCA Laser Collimator for your primary mirror collimation by placing it in a barlow lens OTA and align the combination accordingly. In addition, the SCA technology improves the accuracy of the barlowed laser system by center positioning the laser in the barlowed lens OTA and making the assembly even more accurate.

[redsquash]

Agianst my better judgement i proceed with the laser purchase.
The Hotech Laser isn't adjustable without taking apart the unit . It is a big job. It is suggested that you return it to the supplier in the instruction sheet,if it gets out of wack., ie you wont be able to collimate your collimation tool.
I collimated against a cheshire catseye and the collimation tool was way off. It not cost effective to send back registered mail and then post agin to japan .

I had a faulty problem with a green laser.

I mentioned this to David as soon as it arrived.After a few emails to David on this problem I now find the after sales service is non existent. All email contact has stopped. So several emails have been ignored and I am stuck with something that doesn't work as advertised.

If you don't need after sales support , even though it is supposed to come with a guarantee and want an inaccurate collimation tool then proceed at your own risk. I think it prudent that members and the public be forewarned . The finish of the product is very good but its functioning is very questionable.
In the end its up to you to decide but unless I get some sort of positive sales service I wont be buying from Hotech any Laser Collimation tools or Green point lasers.
Its regretable that such a negative respose has been given.
Perhaps mine is an isolated case . It wil be interesting to see if David replies publicly. In my last email of 2 or 3 days ago I hinted to him that something like this might happen.

It always too easy for the little guy to be squeezed , particularly on the Internet where companies seem to think they can get away with things they may not try when face to face with the customer.

[HOTECH (David)]

In response to redsquash:

Are you Graham Paull from island of Kyushu Japan!? Are you currently teaching in Australia? I remember clearly about you because you inquired to become our dealer in Japan. I called you and talked about regulation issues in selling products in Japan. I have also been waiting from your reply since your 8/25/2008 email. We have moved recently, and we had to change our contact email to info@hotechusa.com because we had so much spam emails at which crashes the server several times. But if you try our “contact us” page, you should be able to reach me, and I check it daily.

I believe I have been patiently supporting you with more than 17 supportive emails since 8/7/08 in helping you to distinguish our product uniqueness from others. In which you mentioned that you are a beginner astronomer and like to know all before you can sell any products. And in you 8/25/08 email, you also mentioned that you forwarded my dealer support information to my competitor.

I want you to understand that customers (dealers included) are my boss! We improve our product with customers’ feedback. So I am the little guy work my way to design and built good products for you to enjoy. You can call up any of my dealers to verify this. I am not hiding from anyone. I am sorry that I have to write this in the forum because we are running off the subject in this thread. Please write or call me, I will be happy to resolve your frustration you encountered.

To clarify a few things before we go back to the subject, I like everyone to know this.
1. “The collimator isn’t adjustable without taking apart the unit.” You only have to remove a small cover to expose the alignment screw to adjust. You are over exaggerating the task. And we don’t recommend you to align the collimator because you might not have the correct jig, and will end up even worse alignment.
2. The SCA technology is a new technology. It requires some simple instructions to master the repeatable installation and we have a video to show you at http://www.youtube.com/HoTechUSA.
3. The “faulty problem with a green laser” you mentioned is not accurate. The Astro Aimer is a great product, and the laser timer is designed to turn off in approximately one minute to save power and extra work to turn off the laser if you use it as a finder aimer on a telescope. You described it “faulty” because the timer is not exactly 60 seconds.

My deepest apology to everyone that I have to write so much to clear things up.

[erick (Eric)]

I'm happy to share my experience of the Hotech laser I bought. Unfortunately that experience has been limited for a lot of reasons which have meant I have had little observing time over several months. David was very helpful, responding prompting to the few email queries I had.

I haven't got to my "better V-block" which has turned into the concept of using my spare GSO Crayford focusser as a suitable jig to test the laser's internal collimation, however I have used it 3-4 times, as supplied, collimating my 12". Haven't barlowed it as yet - just used it directly. A little more effort to mount snugly in the focusser, compared to just plonking my previous GSO laser in and tightening the screw, but I'm happy I am getting it mounted correctly now - the videos on the Hotech site are very useful for this. Then it was easy to adjust secondary and primary for centring and accurate laser return. Then I immediately dropped in my farvourite Cheshire collimating eyepiece and it showed the collimation to be as good as I would want it to be. So I'm very happy with the Hotech collimator.

I will still look to test the collimator on the bench with the spare focusser and also need a good and quiet night to carefully check the results against a couple of cheshires and then star test.

And, no, I haven't tried it on my C8. I probably won't.

Eric

[bobson (Bob)]

Many here are saying how Cheshire is better than laser.

How can you be sure that Cheshire is collimated properly?
I mean if hole and cross are aligned.

With laser, at least you can put it in, turn it around and see if the dott moves in circles or not. And then adjust it if needs adjusting. There is a lot written about Barlowed laser collimation too.

I don't have laser tool yet, but I am ordering one from Andrews Comms. soon.

At present I am using film canister, and it works fine on my 12" Bintel. Star test showing concentric circles. But it would be much easier to do it with either cheshire or laser tool.

[h0ughy (David)]

how did the Hotech laser collimator end up Eric?

[Starkler (Geoff)]

Originally Posted by redsquash

8.7mm different at 5metres doesn't seem very precise.

No it doesn't. I would expect half that before trusting one to collimate my scope.

[erick (Eric)]

Originally Posted by h0ughy

how did the Hotech laser collimator end up Eric?

See

http://www.iceinspace.com.au/forum/s...ad.php?t=39137

and

http://www.iceinspace.com.au/forum/s...ad.php?t=39108

I am very happy with it. I might fiddle with its internal collimation at some stage to get it more precise. All I can say is that if, after I use it, I put in a cheshire tool, it is spot on.

If I was imaging, I would want to use an autocollimator as well - the better suites of tools.

[peter_4059 (Peter)]

I have a Baader one that works quite well except there is still a bit of play in the focuser locking ring so getting a repeatable position each time you insert the laser can be a bit tricky and I now use star colimation if I want to be really accurate. I recently heard of these self-centering colimators - sounds like a really good idea but I haven't tried one yet.

http://www.myastroshop.com.au/produc...sp?id=MAS-280C

[h0ughy (David)]

Originally Posted by erick

See

http://www.iceinspace.com.au/forum/s...ad.php?t=39137

and

http://www.iceinspace.com.au/forum/s...ad.php?t=39108

I am very happy with it. I might fiddle with it's internal collimation at some stage to get it more precise. All I can say is that if, after I use it, I put in a cheshire tool, it is spot on.

If I was imaging, I would want to use an autocollimator as well - the better suites of tools.

thanks Eric