Greasing an EQ8 Mount

[Chunky Wheeler]

I have an EQ8 Mount which I purchased SH from IIS a couple of years ago. It has performed reasonably well, but is very sensitive to balance.

However, that's not my problem. My problem is that it often makes grinding noises when slewing, particularly to the east. The other night it gave off a croaking noise when slewing as if a frog was living inside it. At this time of year? No way.


I'd like to service the gears with a little Inox PTFE grease, but before I start pulling the thing apart, I am looking for a set of instructions with cut away diagrams to show me what is behind cover plates etc.


Surely, I am not the first wanting to do this. Has anyone got any ideas/info/advice?


Thanks a million. Chunky

[LewisM]

https://www.youtube.com/watch?v=wLbiok7WJjE

http://www.dangl.at/ausruest/eq8/eq8_e4.htm

[jwoody]

Have a good look through the EQ8 Yahoo group also. Lots of information there.
https://groups.yahoo.com/neo/groups/SkywatcherEQ8/info

[thebonz]

Sometimes the motors can make all sorts of noises if the they are under strain, ie mount not properly balanced or the worm set too tight.
John

[Chunky Wheeler]

Thanks Jeremy. I joined the Group and had a good look, but I can't see anything on servicing.
However, I have watched a UTube clip on dismantling an EQ8 and have decided to take no action--too hard. Mount will have to keep on grumbling.
Chris

[Chunky Wheeler]

Thanks Lewis,
That Utube clip in particular was extremely informative.

What it did tell me, loud and clear, is that someone like me should leave the frigging thing alone and not tamper with it.

So from now on, it will just have to grind its little head off.

Cheers,

Chris

[Chunky Wheeler]

Thanks John,

Dunno about the setting of the worm gear, but she's balanced beautifully.

My 12"LX200 never ever liked having a guidesope attached on top. It always seems to bugger things up. Thats why I started using an off axis guider, but found finding a guide star difficult at times. in contrast, using an 80mm guidescope, as I do now, is a walk in the park when looking for a guide star.

However I see that ZWO have brought out a well designed and cheap off axis guider, and I am tempted to give it a try.

I shall triple check balance first before reaching for the credit card however.
Chris

[Shiraz]

does the ra axis move freely with the clutch disengaged? The bearing preload on mine was bit fierce and had to backed off bit - could cause motor loading.

the belt may need tightening - mine occasionally develops a resonance when slewing at medium speed and getting the belt tight helps with that. Sounds ordinary, but doesn't appear to do any harm.

It is possible that the worm is binding with the gear and the motor is stalling (that might possibly sound frog like?). It is a little fiddly, but fairly straightforward to adjust the worm clearance. You can also check if there is adequate lube if you take off the cover to adjust the worm.

yes, that video is scary. Fortunately, the bits that seem to need attention are easy to get at - some long Allen keys are useful. and carefully block any holes that screws can drop into.

cheers Ray

[Chunky Wheeler]

Thanks for that info Ray, both axis are perfectly free with the clutches off.

I shall see how it goes after re-balancing for the fourth time when I next use it (always at new moon) and, if the problem continues, may pluck up enough courage to start taking covers off. The problem I have is that the mount and scope sit in my observatory which is a four hour journey from home. It makes you disinclined to start something that you can't pause and re-think. You need to leave for home with job done. Skies are good out there though!

Chris

[Stonius]

What's the difference with teflon PTFE grease? I've been looking at the this for my Gemini - apparently at Losmandy they use molybdenum paste, but it's $$$.

Markus

[Chunky Wheeler]

I have no idea Markus. Maybe someone lese can help.
Chunky