To grease or not to grease

[Lordspace]

If you have been following my troubles with this hobby then you will know I had to replace a gear in my etx 90 mount.

While I was in there I decided to clean of all the sticky grease from both axis,

I used lithium grease as the new grease but not both axis stutter and malfunction in every speed but Maximum.

Will the grease have a negative affect on the gears?? 

If anyone can recommend better grease or if it's better to just not use any.

(Nothing but trouble so far and only been back in the hobby a few weeks)

Cheers

[NGC 1502]

A great source of all things ETX, fixes, upgrades, etc is      www.weasners.com     If you search the site, everything is covered often in great detail.

Hope you sort it, Ed.

[Alan64]

This is the actual link to Michael Weasner's site... http://www.weasner.com/etx/menu.html

Enter key-words within the "Looking for something on the ETX Site?" search-engine near the bottom of the page.  I entered "lubrication", for example, and was led to numerous others' reports on how they had re-lubricated their ETX mounts.

[Peter Drew]

With a good choice of affordable greases easily available, why would a large scale manufacturer of telescopes use an unsuitable grease?     🤨

[Waldemar]

27 minutes ago, Peter Drew said:

With a good choice of affordable greases easily available, why would a large scale manufacturer of telescopes use an unsuitable grease?     🤨

Because manufacturers are not interested in making equipment that lasts a life time... They need turn-over.

edit:  Btw, the best grease to use is one that is PTFE (Teflon) based like SuperLube. Don't use too much, packing bearings is a no-go, use it sparingly. 
Mount bearings do not have heavy loads like car wheel bearings.

Edited February 29, 2020 by Waldemar

[JamesF]

I'm sure the manufacturers don't use grease that is unsuitable for the purpose.  Perhaps the question should be more along the lines of "What purpose do they intend it to serve?"  It may be ideal for the way they expect many mounts to be treated on average and/or for smoothing out inconsistencies in machining in the environments they generally expect them to be used in whilst being completely the wrong thing for, say, running accurately and predictably and requiring very little effort to move when imaging at temperatures below freezing.

James

[Lordspace]

I think my mounts issue was not down to any particular grease but the light diode or whatever it is called. 

The is a clear part then the gear with teeth spaced apart and a blue part on the other side...

Well the blue part had been tilted back away from the gear so I pushed it back towards the gear and the strange slew problems seem to have gone. So hopefully the grease will work fine and the mount will be usable again.

[NGC 1502]

Hope you can sort it.   However, last resort is to remove the optical tube from the mount, known as “deforking”.  Simple job that leaves the optical tube fully functioning and you can mount it on something else, perhaps a small equatorial.   When the tube is removed, that reveals two threaded holes below the back end, they are standard 1/4 20 thread, in other words same as a photo tripod.

Ed.

[JamesF]

3 hours ago, Lordspace said:

I think my mounts issue was not down to any particular grease but the light diode or whatever it is called. 

The is a clear part then the gear with teeth spaced apart and a blue part on the other side...

Well the blue part had been tilted back away from the gear so I pushed it back towards the gear and the strange slew problems seem to have gone. So hopefully the grease will work fine and the mount will be usable again.

Some sort of optical sensor to give feedback on the gear rotation, perhaps?

James

[Louis D]

16 hours ago, JamesF said:

Some sort of optical sensor to give feedback on the gear rotation, perhaps?

James

Sounds like it.  The controller was running open loop and didn't know how to cope with that mode.

[Alien 13]

On 29/02/2020 at 11:34, JamesF said:

I'm sure the manufacturers don't use grease that is unsuitable for the purpose.  Perhaps the question should be more along the lines of "What purpose do they intend it to serve?"  It may be ideal for the way they expect many mounts to be treated on average and/or for smoothing out inconsistencies in machining in the environments they generally expect them to be used in whilst being completely the wrong thing for, say, running accurately and predictably and requiring very little effort to move when imaging at temperatures below freezing.

James

I agree, the sticky grease fills in imperfections/loose tolerances and is exactly whats needed for cheaper mounts. It is also less likely to sheer under load which would cause the bearings to run dry.

Alan