54 replies to this topic

[FancyMichael]

I made the mistake of buying an SvBony collimator on amazon- it is, of course, worthless; if I spin it around in the mount, the laser makes a big circle on the primary-mirror. I have a celestron Omni XLT 150 reflector ota. I am trying to be, for lack of better terms, a "baller on a budget," and so I am not really in a position to spend too big of bucks for a HoTech collimator. But, if there is one out there that isn't too expensive, but reliably precise, I would really like to know.

 

Regards,

Michael S.

[BJS]

Look up the Farpoint 1.25" laser collimator.  I have a friend who bought one and was very pleased with it.  It compares very well to my Glatter; at a better price.

[Starman47]

There is a very favorable review of the Farpoint laser on CN. I personally have a more expensive collimator.

[shohin]

Before you completely give up on the Svbony, is there any chance you could collimate it?  See this thread on collimating a laser collimator:

 

https://www.cloudyni...ieve-it-or-not/

[vdog]

Have you tried collimating the laser?

 

I'm not going to tell you it's easy (it's a pain), but it wouldn't cost you any more money:

 

https://www.cloudyni...collimator-r509

[vtornado]

Don't worry Michael, all is not lost.

 

The big spinning circle on your primary mirror may be either a collimation issue of the laser, or it could be a registration error

of the entire collimator.

 

First check the collimator.  If you can get the unit to lay flat on a table edge, simply spin the laser and look at the spot it

generates on a far away wall.  When you spin the laser, if the spot stays still your device is collimated.

If you can't get the unit to lay flat, you can make a v block.  This is simple a pice of wood with a vee shaped notch in it

where you can put the collimator in it and spin it.   Another way to make the vee block is to pound two sets of long nails

into a scrap piece of wood.   Put each pair of nails in so they criss cross, and form a vee.

 

If you find your laser is not collimated,  sometimes there are three micro hex screws in the body of your colimator.

By loosening and tighening these hex screws you can adust the angle of the laser in the body of your collimator.

Sometimes the screws are underneath a label, and you have to remove the label.   The picture of your collimator

on amazon, I cannot see these tiny screws, but ... sometimes these are stock photos, and don't represent the actual unit.

 

If you find your collimator is out of alignment, and you can't align it, I would send it back to amazon.

 

========

Next,  If your collimator is collimated,  and you still see the dot spin on the primary the most likely cause is that the collimator is

not square in the focuser.  This can happen for many reasons, one is that you have tightend the locking screw too tight.

Try playing around with the collimator in the focusing tube. 

 

========

Did your scope come with a collimation cap.  These work pretty good.  I can use one to get my scope close, but not perfect due to my

bad eyes.   Use your cap to align your optics, then try the laser again.   That will eliminate gross errors in the secondary alignment.

 

If you do get the laser dot to not make a cirlce on the primary after all of this, you should use a barlow with your laser to adjust the

primary mirror.   Even small errors in registration of the laser will throw off the primary adjustment.  See barlowed laser tecchnique

on this site.

 

VT

Edited by vtornado, 22 January 2019 - 04:36 PM.

[photoracer18]

I made the mistake of buying an SvBony collimator on amazon- it is, of course, worthless; if I spin it around in the mount, the laser makes a big circle on the primary-mirror. I have a celestron Omni XLT 150 reflector ota. I am trying to be, for lack of better terms, a "baller on a budget," and so I am not really in a position to spend too big of bucks for a HoTech collimator. But, if there is one out there that isn't too expensive, but reliably precise, I would really like to know.
 
Regards,
Michael S.

You can adjust those types of lasers so that they will rotate and stay in a single spot. They usually have small hex head screws in the barrel that allow you to readjust the laser position in the barrel. When I was with Hands On Optics I pretty much had to readjust most of the laser collimators we got from our Asian supplier. Not real tricky if you can setup a little place to do them.

 

As for the best laser collimators there are only 2, the Hotech and the Glatter  holographic lasers which are designed primarily for catadioptric scopes but work OK for Newts also. They are also the most expensive ones (Glatter passed away if I remember so only the Hotech is still being made maybe).

Edited by photoracer18, 22 January 2019 - 04:46 PM.

[spaceoddity]

Since you already have the laser, try to collimate it with a v-block as already suggested. When you have done that you can use the laser to adjust secondary tilt(which a laser is great at) and get a close primary alignment. Then I would use a collimation cap(or a cheshire) to make the final check and adjustment  of the primary. 

 

https://agenaastro.c...t-eyepiece.html

[tphili1959]

I have a hotech it works great..they have it for 1.25 or 2 inch focusers.. it's about 98.00 on Amazon for the 1.25 model..there is a large turn ring,as you tighten it to rubber rings expand simultaneously to insure that the laser remains centered when using.

[MellonLake]

If the laser is well collimated, get a Parallizer. It will square the laser in focuser and ensure it does not go off angle on tightening the set scree. It will keep the eyepieces square too. The Parallizer and collimating my cheap laser have led to perfect star collimation tests in my scope.

I really like the Parallizer! It is a great tool with cheap lasers for collimating.

[emflocater]

Like all others have said try to collimate it first. I have collimated several lasers and its not all that hard. Takes a bit of patience. V Blocks work for this or you can do a DIY as there are posts or maybe Youtube videos that can help. Heck I had a harder time aligning my Polar Scope. Once you get the laser collimated, then do the Barlow/Laser style collimation of your reflector.

Cheers

Don

[Biggen]

I’m surprised no one mentioned a simple and cheap Cheshire. No batteries, lasers, and pretty cheap. 

[SloMoe]

Best collimation tool for the money,,,,,,,,,,,,,

 

Vic Menard's "New Perspectives on Newtonian Collimation", 5th Edition

[39.1N84.5W]

I bought a budget collimator from Agena and it was collimated.

As far as collimating your current laser, you can also spin it slowly in the focuser on your scope. Adjust the laser until the dot no longer makes a circle. Easy.

[SloMoe]

For 1.25" lasers in 2" focusers I recommend dedicating a 1.25" to 2" adapter to the laser, in other words, remove the thumb screw in the adapter and replace it with an allen recessed set screw, then as mentioned above, slowly rotate and adjust the laser until the dot no longer walks in a circle, takes time,to help center the laser rotate the laser in the adapter until it makes the smallest circle, then secure the set screw and rotate the adapter in the focuser.

 

It's best to back one of the laser screws out a bit befor trying to tighten either of the other two, you can over tighten the adjustment screws too much and damage the laser.

 

Once you have it that way leave the to components together as one unit, occasionally recheck with a spin or two to recheck.

Edited by Mike W., 23 January 2019 - 08:42 AM.

[SloMoe]

For my laser I took about two weekends and a few different adapters until I found a good one that worked.

I had that set up for a while and confirmed it's alignment with an Astrosystems 2" laser and a Farpoint 2" laser that were both perfectly collimated.

 

Then a month or two later an HG Parallizer popped up in the classifieds and so I did it all over again using the parallizer, and I did replace the thumb screw in it too.

 

Most of the adapters are metric thread thumb screws, the Parallizer is SAE.

 

btw, the laser I used is a Hotech Cross hair and no the self centering system isn't consistent enough for me.so mine is completely relaxed in the adapter, only the set screw holds it in place., and I recheck it every once in a while.

 

Once you advance in collimation a few levels, the laser is only used with a Barlow to get the primary close enough to use the Autocollimator.

Edited by Mike W., 23 January 2019 - 08:54 AM.

[Feidb]

My $3 plastic cap I got years ago at an Okie-Text in Oklahoma at a swap meet.

 

Does the job every time.

 

The only caveat is it has to be light enough to see the mirror reflection.

 

If it's dark, I have to resort to my $89 laser collimator which ALWAYS is way off, due to focuser slop.

 

I've borrowed a HO-TECH and even it was off, though less than mine.

 

Back to the plastic cap.

[Feidb]

My $3 plastic cap I got years ago at an Okie-Text in Oklahoma at a swap meet.

 

Does the job every time.

 

The only caveat is it has to be light enough to see the mirror reflection.

 

If it's dark, I have to resort to my $89 laser collimator which ALWAYS is way off, due to focuser slop.

 

I've borrowed a HO-TECH and even it was off.

 

Back to the plastic cap.

[Feidb]

My $3 plastic cap I got years ago at an Okie-Text in Oklahoma at a swap meet.

 

Does the job every time.

 

The only caveat is it has to be light enough to see the mirror reflection.

 

If it's dark, I have to resort to my $89 laser collimator which ALWAYS is way off, due to focuser slop.

 

I've borrowed a HO-TECH and even it was off.

 

Back to the plastic cap.

[Abhat]

Don't worry about collimating the laser. Use it with barlow as is. Search this forum for Barlowed laser collimation. It  works like a charm for collimation of primary. Cheshire also works fine but barlowed laser technique is far more accurate. Try this before spending big bucks on expensive collimators.

[spaceoddity]

My $3 plastic cap I got years ago at an Okie-Text in Oklahoma at a swap meet.

 

Does the job every time.

 

The only caveat is it has to be light enough to see the mirror reflection.

 

If it's dark, I have to resort to my $89 laser collimator which ALWAYS is way off, due to focuser slop.

 

I've borrowed a HO-TECH and even it was off, though less than mine.

 

Back to the plastic cap.

Yep, the cap is pretty simple and accurate if you can center a dot inside a donut. It's not the best for secondary alignment but works well for the primary which is the most important anyway. They are $7.50 nowadays. https://agenaastro.c...t-eyepiece.html

 

With my ho-tech, I could collimate and then take it out and re-insert it, turn it on again and it would be way off. Never matched the results with my other collimation tools so I didn't trust it. I think the problem was the 2-1.25 self centering adapter. It doesn't work. 

[Conaxian]

The Hotech 2" is a marvel of accuracy and ease of use. I verified it was collimated, then collimated the scope in about five minutes.  Pricey but it costs a lot less than many eyepieces touted on these very boards.

After setting everything I removed the Hotech, rotated it 180 and rechecked... spot on. did this test several times. My focuser is precise, that may be why it works so well.

If you get a bad one send it back.

[SloMoe]

It may be that the type of eyepiece holder in the focuser has something to do with the Hotech more consistent in some scopes than other's,like maybe the compression ring type eyepiece holder interferes with the self centering system of the Hotech.

[Starman1]

I made the mistake of buying an SvBony collimator on amazon- it is, of course, worthless; if I spin it around in the mount, the laser makes a big circle on the primary-mirror. I have a celestron Omni XLT 150 reflector ota. I am trying to be, for lack of better terms, a "baller on a budget," and so I am not really in a position to spend too big of bucks for a HoTech collimator. But, if there is one out there that isn't too expensive, but reliably precise, I would really like to know.

 

Regards,

Michael S.

Why not collimate your laser?  Cheapest of all, right?

Here are some links.  It's really not hard to do:

http://www.stark-lab.../llcc/llcc.html
http://www.astromart...p?article_id=96
http://www.cloudynig...collimator-r509
http://www.visualast...collimator.html

 

2nd choice: the Astrosystems LightPipe combination sight tube + Cheshire.

It works best in the daylight.

[REC]

I had a average laser collimator that came with my scope. It was just ok. When I saw a Hot Tech laser used, I jumped on it. It fits real tight in the 2" focus tube and no wobble at all. I'm alone and I find it very easy to use in both the front and back of the tube. Once I get the front set and locked down, Only minor adjustments to the rear mirror once in a while.

Edited by REC, 26 January 2019 - 02:13 PM.