Laser collimator issue

[gazza63]

Evening all

Having just read Alex's topic on collimators, brings me to my own question? I own a laser (new generation version) collimator. To be perfectly honest... I find them not to be very accurate.

Although my scope is classed as a slow focal length f8 and should rarely need adjusting, I thought i would test it out. Having firmly inserting the laser, adjusted mirrors as suggested ( I found it to be a little outside of the ring on the mirror beforehand ). Finally got it smack in centre. After replacing collimator it was showing out of position again. Tried this several times , had the same issue.

I'm thinking of purchasing a cheshire collimator to make sure they are properly aligned.

I've noticed there is a long and a short version. what is the difference between the two....if any?

Also, which one would my scope benefit from?

Regards

Gary

[OneEyedSam]

I found I had to collimate my laser. On the new generation lasers , the 3 adjustment screws are hidden behind dabs of black silicone. Once removed, you can use a small Allen key to adjust the laser and make sure it's centred.

[gazza63]

Cheers Sam, I didn't know that!

[OneEyedSam]

If you can place the laser horizontally in a v shaped groove of some kind, then rotate the laser in the groove. The laser will prescribe a circle on a wall/ piece of paper, a few meters away (4m away is what I use). If you turn the laser a bit and mark out where the dots end up after each turn it will assist you in working out which screw to tighten. Likelihood is you will see the dots prescribe an oval or circle. I mark each dot with the numbers on the brightness scale so I know which dot is which. Aim is to have the laser point at the same spot and stay there while you rotate the laser.

Hope that makes sense, if not, there are some you tube videos explaining the procedure.

[OneEyedSam]

One of the blocked up holes is behind a silver sticker. Christ only knows why they covered up the holes in the factory.

[OneEyedSam]

At 4m disance between the laser and the piece of paper i had stuck to the wall, the laser was making a circle about 3" in diameter. I got it down to about 3 to 4 mm....not perfect, but close enough

[gazza63]

Thanks again, i'll look it up tomorrow.

[skywatcher250]

just a quick note- im not sure which laser you have... buy Steve @ FLO said the laser was lined up with the actual nose / adaptor which goes in the scope tube itself and not the casing (im sure ive got my technical words mixed up there) anyway - the V block thing is not true of the Hotech (the one i have) again advice by Steve who so far has been very knowledgeable for years for me. anyway - im sure each laser is different - however try not to recollimate it if it doesnt need doing and just pushes it further out... (the laser that is)

[OneEyedSam]

In this case the laser can't be lined up with the 2" adapter as its removable and rotatable.

For a better result Perhaps the adapter should be glued in and then the laser collimated with the adapter in place.