EQ Mount Query

[Flakmunky]

Hi All,

I'm a new member, having just bought a a second-hand Sky Watcher 130P on an EQ2 with the standard 25mm & 10mm kit eyepieces and a Sky Watcher 7mm Plossl.

I have a couple of questions about the mount which I can't find an answer for, most likely because I don't know the names of these!

Anyway, what is the cam circled below used for?

 

And similarly what is the use of the grub screw highlighted below?

Thanks in advance!

Tim

 

 

[Albir phil]

43 minutes ago, Flakmunky said:

Hi All,

I'm a new member, having just bought a a second-hand Sky Watcher 130P on an EQ2 with the standard 25mm & 10mm kit eyepieces and a Sky Watcher 7mm Plossl.

I have a couple of questions about the mount which I can't find an answer for, most likely because I don't know the names of these!

Anyway, what is the cam circled below used for?

 

And similarly what is the use of the grub screw highlighted below?

Thanks in advance!

Tim

 

 

I think the cam is a clutch to disengage the slow motion worm so you can move the mount by hand to your target .  Not sure about the grub screw as I can't see it clearly on your pic have you tried undoing it,if it is more than finger tight I would leave it alone . someone else my advise you more on what it's purpose is.

[Rallemikken]

55 minutes ago, Flakmunky said:

Anyway, what is the cam circled below used for?

That's the RA axis. Maybe at one time a motor was fastened to the cam and meshed to the gear? Would make long-time exposures possible if PA was on spot.

[Flakmunky]

@Rallemikken @Albir phil

Thank you both for your replies. I attach a couple more pictures that better show the two elements. 

First, the cam, which presses against what looks to be a piece of PVC tubing. The cam is very loose, as can be seen in the first picture below. There is resistance as I press down on the lever, then the cam overcomes the PVC tube and goes loose again once it is 'engaged'. So it doesn't actually do anything. The second picture shows the PVC tubing.

The third picture is a better angle of the grub screw and I can confirm it is not tight.

You can also see there is some scraping / damage on the metalwork around the worm drive, I'm not sure what has caused this, nothing seems to be fouling. The original owner did mention something about how they found it difficult to assemble, so I wonder if they assembled it incorrectly and have since reassembled it properly?!

Thank you all in advance!

 

.

Edited March 13 by Flakmunky

[PeterStudz]

The “metal cam” is used to engage/disengage one of these motor drives. Since you don’t have one you can ignore it. 
 

https://www.microglobe.co.uk/skywatcher-ra-motor-drive-with-multi-speed-handset-for-eq2-mount-p-11423.html

[Flakmunky]

11 hours ago, PeterStudz said:

The “metal cam” is used to engage/disengage one of these motor drives. Since you don’t have one you can ignore it. 
 

https://www.microglobe.co.uk/skywatcher-ra-motor-drive-with-multi-speed-handset-for-eq2-mount-p-11423.html

Mystery solved! Why, you darned kids!

 

Thank you. @PeterStudz