collimation frustration

[johnny diamond]

as im a newbie,thought it best to get to the bottom of this sanety testing procedure (little did i know)

after much hunting i finaly found a baader mk111 colli and was ready when it arrived to start the procedure,having thoroughly read many collimating instructions i followed astro babe's using the card & cap to set up the secondary to perfection all seamed well so continued with the laser for final alignment's....again all went well and was quite pleased with my efforts!! then as per astro babe's instructions i went thru it all again (to be sure/to be sure ) everything checked out until i placed the lase in again

laser dot way off!! removed laser and reinserted....way off but in differant spot,presume to be slack in skywatcher focus tube,now i know its not the most precise focuser available but how do i know if its right???...what's the point in buying the laser??i presume a chesire would do the same,do i need to buy a more precise focuser or accept it wont be right without a star test??

[NGC 1502]

There is lots of differing advice, but if you are certain the secondary is sorted, then I'd adjust the primary using an out of focus star.

Hope you sort it, Ed.

[Damo636]

I had the Baader mk lll but didn't get on with it. Like you i couldn't get consistant results with it. Its important to place the laser in the same place in the focuser each time but even then couldn't get repeat results with it. I replaced it with one of these..Antares Laser Collimator. New & Improved Version | Telescope Accessories | Rother Valley Optics and find it much better. Its also fully adjustable if it ever goes out of collimation itself. I always double check the primary with a cheshire to finish though.

[johnny diamond]

cheers ED,

think im just a little dissapointed....i was hoping for a more acurate base setting

i wouldnt have waisted £55 on a laser if id known...probably sell it and get a cheshire instead!

[up2nogood]

Im not pro mate, but iv'e been there i was going to get a laser one, but from lot of reading i have done, it's not as spot on as a chesire!

I use a chesire and a 1.25" cap like she sayes, and drill a hole in it.

Dont have to really do the first part ever again, unless you remove it etc.

but now and then i still check, cos i just like to make sure!

The 2nd part i have only done 2 times (like last night)

Bit more tedious the chesire way! but have to just say it's done when it done

as last night on the primary, i spent 30 minutes, where before it was like 1hour and 15 ish llol.

Next time it be 10 minutes, i towards the end i tried my own way with the screw to adjust the primary!

but make sure (which i found) to have the scope on a nice lit wall if u can, helps me see the black circle better when allining.

And if u brought the lazer not to long ago, send it back (as long as your with in the 7 days 14 days etc, depending where you brought it from!

[johnny diamond]

cheers damo,

i just put a strip of brass shim sheet in focuser and thats improved it so defo focuser sloppy i had marked it for constant accuracy but even in same spot i got differant readings,hey ho suppose thats how things are with this hobby!

[johnny diamond]

uptonogood,cheers i agree with what you say but due to the stupid closing flaps on the box i cut them off so cannot return,but according to hinds,they are a bit rare at moment as low stocks so may place it on ebay.

[LeeB]

Hi when using a laser the inconsistancy of insertion can be removed by using the barlowed laser method ( you will need a centre spot on the primary) but by diffusing the laser a reflection of the centre circle is seen in low light on the laser screen. Centre this an roberts your mothers brother.

[Rob Severn]

Perhaps....

►*7:22►*7:22

19 May 2011 - 7 min - Uploaded by astronomyshed

So many people give up with these laser collimators not realising that they too have to be ...

If it's collimatable.