collimating the heritage 130p . sloppy focuser

[sockgoblin]

hello all

I have bought a laser collimator and following various guides and videos I have collimated my skywatcher heritage 130p.....or well I thought that I had.

10 minutes later I tried again and it appeared that the scope had gone out of alignment , the laser dot was no longer in the middle of the secondary. then I noticed that the collimator can move side to side in the focusser and indeed the focusser when turned also presents the laser at different points. spin the focusser and the laser does a 2cm circle on the mirror. I believe the laser is straight just that the focussed is sloppy and or not 90 degrees to the body of the telescope body...or something else.

appreciate some advice. ta

[Guest]

Can you not shim the internal tube of the focuser ?

 

[sockgoblin]

Its a screw type ,helical focuser, already ptfe on the threads

Would a Cheshire work any better?

[sockgoblin]

I used a barlowed laser and a collimating cap and its seems to have done the job

 

[sockgoblin]

A point to note for anyone trying to collimate with a Barlowed Laser. It is the shadow of the centre mark ( the doughnut shape) that is to be aligned with the centre point of the end of the Barlow, it is not the actual Barlowed laser splodge. I spend a half hour moving the reflected laser splodge around ( which does look like a little round doughnut) with the primary mirror adjusters ,only to find that the primary mirror was hopelessly misaligned, it was only when I realised that the shadow of the doughnut is the answer. When you realise this its a doddle ,and you can prove to yourself that alignment of the laser has no effect on the position of the shadow, wiggle it , spin it and the shadow stays in place.

[sockgoblin]

Collimation certainly made a difference, it's all in the detail. Jupiter's clouds ever so slightly well defined but definitely subtlety better

[happy-kat]

On my heritage I use just a collimating cap, works a treat.

[happy-kat]

Last night I saw Lo's transit shadow. Didn't find the look as good as a week ago think there was cloud haze.