Collimated my 250PX -- did I do it right?

[smolloy]

Hi all,

Since the snow is keeping me indoors tonight, I thought I'd have a stab at colimating my shiny new 250PX. Now that I've finished, I'm interested in knowing if you think I did it right.

Firstly, I don't own any proper collimation tools, so I used one of the dust caps that came with the scope as a collimation cap. I drilled a hole in the precise centre (based on some markings on the top) using the absolute smallest drill-bit I have. In order to allow me to see this hole when looking at its reflection, I glued a small metal washer to the underside of the dust cap so that the tiny eye-hole was right in the middle of it.

I then looked through this to see how many of the 6 primary mirror clips I could see, and played with the angle of the secondary until the view of the clips was as symmetric as possible.

Once this was complete, I noted that the little ring drawn on the primary wasn't in the centre of the image of the circular washer. I loosened the locking nuts on the primary, and, with my wife's help, adjusted the three bolts on the primary until the ring on the primary was perfectly aligned with my washer.

Now that that is done, I think I'm finished. I note that the image of the secondary is a little offset, but I think this is supposed to be the case for fast scopes like mine (f4.8). The important point is that the centre of the primary should be well aligned with the centre of the eyepiece.

How does that sound?

Steve

[Tinker1947]

You will only find out when you get it outside, get a Cheshire to do it properly and in the end a lot quicker, you will need the cross in the collimator to check the secondary is lined up with the paper circle, and the primary is showing in the collimator window correctly..

[smolloy]

Thanks Tinker. An outside test with stars would be the best, but can you see anything wrong with my procedure? Anything missing?