Focus issue cpc800

[proflight2000]

Hi all, before I start pulling things apart, just want to pass this by you to see if you have any ideas. On my cpc800 when I turn the focuser it focuses fine, both in and out, however and a certain point as the focuser is being turned it jolts the mirror as such so instead of focusing an object, it seems to pull the object sideways, it is a very small pull, but you can see it. Does anyone have any ideas please??  thank you.

[Psychobilly]

IIRC The mirror "slides" on the baffle tube work the mirror all the way back and fore through the full range of the focuser a few times  to spread out the lube and see if it improves... 

Peter...

[PeterCPC]

Have you added anything to the back of the scope such as a piggy back fitting etc? It sounds as if there is a screw protruding into the tube too far and snagging the mirror. Shine a bright torch in the front and check for too long screws.

Peter

[Uplooker]

If I am understanding you correctly and depending quite how severe this is, I suspect that this may well just be mirror flop that is experienced with all SCTs. That is why people fit an external / additional focuser.

Ian

[proflight2000]

Not sure what you mean Ian on the external focuser, the focusers on cpc's are external. i.e. they are at the back of the scope, there is a micro 1/10 focuser attached but the screws do not protrude into the scope itself. I have turned the focuser as such, there is no end or beginning in respect of the turning, i.e. it never goes tight then stops, but this was the same as my last one. Strange indeed.

[Uplooker]

Such as the one shown in this link:-

http://www.firstlightoptics.com/baader-steeltrack-focusers/baader-steeltrack-sct-focuser.html

Ian

[proflight2000]

Ah right. yes I see what you mean. I will just put up with it for now, it isn't something that is causing me a problem as such, I just cannot work out why, don't think I will go for the option of taking things apart, with my luck the whole thing will come crumbling down.

[lguise]

You should find end stops at each end of travel but it takes a great number of turns between them. Spreading the grease out by doing this may well help.

[haitch]

I was afraid of my mirror dropping off the end of the tube or some other such disaster when I first owned a C8 but I can confirm what Linton says that there are end stops so rack away! You will likely always suffer some degree of mirror flop though.