More Crayford loathing.

[ollypenrice]

I'll gladly take any sub standard modern Mercs that are a disappointment to their owners...

Olly

[Ibbo!]

I did as a passenger on Dan Air (only for the people old enough)

I remember as we were in Greece at the time they went bust had a n extra day on the beech and a much better ride home

sorry to alter the thread

Back on thread that thing that came with my WO 132 is only worth using as a doorstop for the obs door but has been replaced by a moonlight and I can now use the 132 and my Tak R&P's are lovely

[michael8554]

I agree with Nightfisher:

"I think this crayford argument boils down to this, some crayfords are not suitable for imaging, but most are suitable for observing work"

The first time I saw a crayford I couldn't believe it would work without slipping, but I guess its a bit like steel train wheels on steel rails, if the pressure is high enough it doesn't slip.

There's an american focuser I've seen advertised that looks like a car scissor jack, and I guess helical focusers don't slip?

[Deneb]

eh Olly ! Try a Moonlite Tri-Knob with shaftlock, the best crayford you can get for imaging, the baader does not come close...

Nadeem.

[Jessun]

my JMI crayford (10 years old now) works well.

Mine works a treat as well so far! Knock on wood... Just have to remember to do the final adjustment inwards, otherwise the thing risks dropping back half a mm...

[ollypenrice]

I've seen those scissor jack focussers and they do look jolly fine! FLI do a 6000 dollar focusser as well. WHo buys these things??

Nadeem, I've always acknowledged that the Moonlite is probably an exception to the rule.

Olly

[EssexMigrant]

Can I just add an aside here. A good quality R & P focuser properly adjusted is as good as anything in MY opinion. The significant words here are 'properly adjusted'. Adjustment isn't just down to reducing backlash via pressure, it's GREATLY to do with proper grease. Proper grease in this case is damping grease; not cheap, but worth every penny. I think a lot of astronomers, in innocent ignorance, grease their rack and pinions with something like lithium grease; the worst possible type! Lithium has virtually no 'tack', which is a critical in astronomical situations, due to excess loads being applied when focusers with heavy loads on (diagonals; eyepieces; barlows etc) are in near vertical positions. Damping helps reduce backlash and 'drop' by INCREASING friction. So, if any of you have in blissful ignorance greased your R & P with lithium, clean it off thoroughly, and re-grease with a heavy damping grease.

Cheers

Max

[terrym2002uk]

So, if any of you have in blissful ignorance greased your R & P with lithium, clean it off thoroughly, and re-grease with a heavy damping grease.

Cheers

Max

Yep and you can get it here:

Damping Greases

[Gina]

The Crayford on my SW Evostar 80 ED DS Pro is superb and I have had no trouble with it but I haven't had much chance to use it a lot as yet. I guess it might want adjustment after a while, I would expect that. So far I am delighted with every aspect of my ED80 scope