Centring the collimator

[johnb]

Hi

Kit is in sig. I do always collimate every time I set up. I have a hot tech laser and it works well. My issue is it's placement in the focuser, as I rotate the collimator the reflected beam moves a little because there is give in the focuser it's self. Is there a fix.

Regards

John b

[ollypenrice]

They say that the aluminiumized sellotape stuff is the answer. Trouble is, although I could visualize it in my imagination - chrome sellotape, sometimes red, sometimes green, I could by no means find any anywhere!

I have just replaced the focuser on my Dob with a basic one from Telescope Service and there is no longer any significant play.

Olly

[StevieDvd]

If it suits you can get a self centering adapter - look for Orion precision centering adapter.

[johnb]

If it suits you can get a self centering adapter - look for Orion precision centering adapter.

Excellent thanks.

John B

[Damo636]

Second the self centering adapter.

[pook]

If it suits you can get a self centering adapter - look for Orion precision centering adapter.

But then there's the issue as to whether THAT is centred properly in your 2" draw tube!

Grrr.. always something.

[Doc]

You say you use a hotech, well that has a self centering mechanism, so once tightened the laser will be centred.

[TheThing]

Does your scope really need collimating every time you use it? I've got a 200p which I collimated last summer and it's held collimation perfectly since. I'd be more worried about why collimation keeps going out then whether the laser is perfectly centred first!

Just IMHO...

[Damo636]

Does your scope really need collimating every time you use it? I've got a 200p which I collimated last summer and it's held collimation perfectly since. I'd be more worried about why collimation keeps going out then whether the laser is perfectly centred first!

Just IMHO...

I agree, my 200p holds collimation really well also. I think i last tweaked mine over Christmas!

[johnb]

Does it need doing every time I believe so as I drive it to my imaging location every week I'm careful but it gets bounced around a bit every week and it only takes 5 mins. John b

[Rob]

I primary collimate every time the scope is placed on the mount. I then collimate 2/3 times while observing because of tube flex when you move it in the rings..

I seek perfection it has to be said.. I collimate this much when planet viewing.

Rob

[Damo636]

But then there's the issue as to whether THAT is centred properly in your 2" draw tube!

Grrr.. always something.

The Hotech centres exactly in your focuser. But when the eyepiece is then inserted it is pushed off centre with the thumbscrews. By using the self centering adapter this offset is taken out of the equation meaning your collimation device and eyepiece will be following the same light path.