Tak FSQ-85 focuser clamp

[strutsinaction]

Hi

Quick question for those of you with either the FSQ 85 (or 106). How is the focuser clamp supposed to work? When tightened I can still move the focuser knobs. I thought the clamp would prevent the focuser knobs from moving. Maybe I'm missing something here 

Thanks for any advice!

Regards

John

[sbooder]

I don't know this bit of kit but if it is a Crayford focuser then it will move but the tube will not.

[strutsinaction]

The draw tube is still moving when the focuser clamp is tightened. The manual says not to over tighten the focuser clamp. I suspect I'm being a little cautious but don't want to be too heavy handed until I know how tight it needs to be in order to lock the focus knobs (if that indeed what should happen).

I'm following this up with Ian King.

[kirkster501]

My FSQ-85 slips until the focuser lock is applied.  I find that annoying and would apparently rule out an autofocus.  You saying yours still slips even with the lock applied?

[strutsinaction]

Kirkster501

My FSQ85 hasn't had first light yet - I'm still playing with it indoors   I'm just trying to work out how the focuser clamp should work. When yours is tightened, can you still move the focus knobs? How tight do you have to apply the clamp in order to lock focus?

[ollypenrice]

I've used three FSQs, new and old, 85 and 106. I've never used the focus lock and never found that physical movement was an issue. None of them has ever slipped. This doesn't mean that it can't or doesn't happen, of course. It just hasn't happened to me.

A far more significant FSQ issue is focus drift due to temperature change. This affects the 85 and the old fluorite 106N less than the modern 106 ED from what I can gather. SInce Santa has not seen fit to send me a pair of 106EDs (I do insist on pairs!! ) I can't be dead sure of this.

Autofocus systems tend to hold the focus where it is, Steve, so the only issue would be making them work, which I'm told is possible though I'm yet to be convinced!!!

Olly

[kirkster501]

When the focus lock is tight then I cannot move the silver focuser knob unless extreme and brute force is applied.  I can turn the 1/10 focuser though because that is geared down.  So when focus lock is applied the focuser does not shift a fraction.  I'd suggest if you have slip even with the focus lock applied you should get a RMA on the scope and get it swapped for a new one, it would be useless.

I am tad disappointed with mine because with the scope pointing higher than about 45degrees then without the lock firmly applied the focuser slips out with the camera on.  I did not expect it to do this.  Does anyone know a way of tightening it?

[strutsinaction]

Kirkster501

Interesting you should mention the focuser slip. This is what Ian King had to say when I questioned him today:

"I think there will always be a small about of play in any rack and pinnion focuser. The focuser is fully adjustable though so you can experiment with tensioning it to your requirements. A word of advice though,  Takahashi put some kind of screw lock substance on the tension bolts.  My instructions from Takahashi Europe are that if customers wish to adjust the tension on the focuser they need to use some acetone or nail polish remover to remove the screw lock first.  In fact I am going to France in a few weeks to spend a day with Takahashi Europe to get first hand instruction on how best to adjust these focusers."

So, maybe Ian can help once he's been instructed on how to do the adjustment.

Regards

John

[kirkster501]

My focuser only slightly slips, but slip it does without the focus lock applied.  A millimetre or so a second.  It takes the edge of what is a fabulous scope because I have to slightly "break" the focuser with the focus lock as I am focusing, needing two hands to do so (causing more wobble to the star when trying to focus).  I would love to be able to sort this so it's good news about Ian finding out how to potentially correct this.  I will contact Ian in a month or so - he's a great guy. 

Thanks for the information John.

[strutsinaction]

Now fixed, simply by tightening the focuser clamp a bit more! Clearly I was being a bit too cautious.

Regards

John