Need collimator for my telescope

[Abhishek Pawse]

Hello everyone. I need a little help.

I have got a skywatcher 10" goto Dobsonian telescope. And now I need an collimator tool for it. Which laser collimator should I get. It a f4.5 scope. Plz suggest 

[JOC]

FWIW I tried a laser collimator and in the finish discovered it was quicker and easier and to do the actual collimation with a standard visual collimator.  I just use the laser for the satsifaction of seeing it come back central, but a manual one is far easier to use and you gain an insight into what you are actually looking at and moving.

[Abhishek Pawse]

I tried doing it manually but it made it worse. Thus need a laser one.

 

[Stargazer McCabe]

I started with a standard Cheshire but moving to a laser made single handed collimation so much easier, particularly in the dusk / dark.

I began with a HoTech one like this  https://www.firstlightoptics.com/hotech-collimation-tools/hotech-sca-laser-collimator-with-cross-hair.html It worked really well, but needed collimation itself once in a while (which was easy to do by the way). I still have it and use it when we travel with our Heritage 130P.

But with our larger Dob, I eventually bought a Howie Glatter and found it to be more accurate and it holds its own collimation so much better. But to be fair, if well collimated, the HoTech used to do a splendid job...

Edited December 14, 2020 by Stargazer McCabe

[tripleped]

I know many don’t like laser collimators but I’ve had success with the Svbony collimator. It’s quick and I’m always able to verify good collimation afterwards by star testing. Works for me. U do have to make sure the collimation itself is well collimated. There are u tube videos on how to do that. 

[PeterW]

On 14/12/2020 at 09:32, Stargazer McCabe said:

 

I began with a HoTech one like this  https://www.firstlightoptics.com/hotech-collimation-tools/hotech-sca-laser-collimator-with-cross-hair.html It worked really well, but needed collimation itself once in a while (which was easy to do by the way). I still have it and use it when we travel with our Heritage 130P.

.

?surprised, the Hotech comes collimated and any adjustment screws and well buried and not easily adjusted, worked out the box just fine on my f4.

Peter

[johninderby]

Have had two Hotech and both were perfectly collimated and never lost collimation. Have never heard of a Hotech losing collimation. 🤔

[Stargazer McCabe]

9 hours ago, johninderby said:

Have had two Hotech and both were perfectly collimated and never lost collimation. Have never heard of a Hotech losing collimation. 🤔

Every day can be a school day... 

Used to take the HoTech with us as we took the Heritage to Namibia, La Palma and New Zealand. Maybe those trips caused the slight shift. or maybe we were just unlucky...
But fortunately some very helpful chaps on CN who had experienced similar showed a very simple way to adjust...

[SMF]

I’d go with the Hotech. I’ve ended up with two of them. Make collimating the 12” a breeze.

Both purchased second hand but far far better than the cheaper types.

The second one I got very definitely needed collimating but as StargazerMcCabe says they are really easy to do. I believe they are one of the few that have readily accessible adjusting screws.

Just unscrew the tapered collar to reveal three setting screws.

I found this useful on another site:

You can collimate the collimator in the focuser with a 0.005" hex key yourself to shorten the shipping time.  To access the alignment setscrews, you back out the cover between the target face plate tube and the battery tube.  Just unthread the cover with a jar-opener or a rubber grip.

 

Compress the SCA mechanism until the collimator has a snug fit without a lot of movement and yet you can slightly rotate the collimator in the focuser (with pressure registration on the opening).  You will do a quick rotation to get some idea of the center of the laser spot rotation (does not need to be center of the doughnut on the primary).

 

Adjust the corresponding setscrews to move the laser dot to the center of the rotation.  Do not over crank the setscrews which may damage the laser circuit.  Use the same adjustment technique on the secondary where you drive on down and let other two up.

[Spile]

On 14/12/2020 at 06:38, Abhishek Pawse said:

Hello everyone. I need a little help.

I have got a skywatcher 10" goto Dobsonian telescope. And now I need an collimator tool for it. Which laser collimator should I get. It a f4.5 scope. Plz suggest 

I have the 8” Skywatcher and follow Gary Seronik’s no-tools collimation advice

https://garyseronik.com/a-beginners-guide-to-collimation

and can recommend the Small Optics guide at

https://www.youtube.com/channel/UCVi6UI5BvXm9lyZg5AG0X1g/videos