Collimating a laser collimator - is it worth it?

[moriniboy]

I got a second hand laser collimator (don't know the make) and decided to check its collimation.

Attched are photos of my rig (a piece of aluminium u section glued to a bit of MDF) which showed that over 5 metres my laser was approx 2" out!

Glad I checked, as what I thought were good views are now great views.

The black material is just some left over flocking which makes spinning the collimator on the rig easier and ultimately more accurate.

Its a bit rough but I was not entering a science competition!

You can just see one of the three allen adjustors toward the end of the collimator, which were sealed under black mastic.

Nigel

[steppenwolf]

A man after my own heart - if at all possible users should check the collimation of their laser collimators! My own jig is no more of an entry in a science competition than yours:-

[Merlin66]

definately always worth checking!

Very few commercial laser collimators are actual well collimated when received!

[ecosse]

I have the baader mkiii and it says in the instructions that came with it that the Collimation is set at the factory and is therefore "set" or something along those lines. Does this mean that mine isn't adjustable?

[Locko]

ecosse, probably means they've put a dab of glue or similar on the screws to stop movement after being set, should still be able to tinker with it if you can find them.

[JamesM]

As much as I am a fan of Blue Peter I would question the design of both the above suggestions in collimating the laser. Both examples have introduced two axes of reference when in fact you really only want one because that is all you use when you insert it into the focuser. What you are after is for the laser to be collimated against the front part only - the rest of the tube doesn't matter.

A possible alternative is to use the 1.25 element of the focuser and with the laser inserted, insert the whole lot in to a hole cut into very thick card/ply/hardboard accurately enough to allow the 1.25 focusing element to be turned 360 degrees without it immediately falling out. With the board clamped vertically, it should be easy to make any adjustments to keep the resulting laser dot/cross hair fixed on one point through 360 degrees. I use a target sheet at a distance of 6 feet to register the results.

James

[steppenwolf]

As the two tube diameters are identical according to my micrometer I don't believe it is an issue with my particular laser but your observation is a valid one for sure. I tend to test mine at 20 feet as this increases the resolution somewhat.

[umadog]

If it's not well collimated then it's not much use. You can also stick it into the focuser and rotate it. Does the beam move?