Another EQ5 Question

[Glenhuon]

I'm a bit baffled by these scales on the rear of my EQ5, The wide one marked 0 - 24 hours with the vernier scale doesn't move with the RA shaft its held to the mount casting by the small locking screw which goes through a hole in the extended scale carrier (inside the casting). The one on the end is 0 -12 and is tied to the RA shaft but is movable by hand. Now, the first mention scale doesn't appear to do anything, or is there something missing from the mount ? Its confusing the hell out of me while trying to check the drive speed. Shown are the assembled scales, the only removable parts and the bare shaft.

[roccodm]

I am not familiar with your mount but the scale that appears to be similar on the mount of my AR5 LX55 is for doing a polar alignment with the polar scope =hope this helps clear skies rocco WB9QPU

[Glenhuon]

Hi rocco

I've since managed to find some instructions on the use of the scales and the rearward one marked 0 - 12 is for setting the month. Whats confusing me is the 0 - 24 scale doesn't move with the RA shaft and when the locking screw is loosened the scale ring is very loose, sort of flops about. I'm sure there's a part missing that keys it to the RA shaft but there's no exploded drawing of the parts in the manual to confirm this. Was just hoping someone else had pulled theirs apart.

Cheers
Bill

[JohnG]

Hi Bill

Don't know if this is any help at all, but, the RA Setting Circle is meant to be tight enough that it moves with the RA shaft but should be loose enough to allow it to be rotated by hand. The DEC Setting Circle is fixed in place by a small grub screw or similar.

Using Setting Circles is becoming a lost art, here is a bit of a tutorial.

http://www.astro-tom.com/telescopes/setting_circles.htm

Cheers

JohnG

[Glenhuon]

Hi John
It certainly isn't tight enough to be driven by the RA shaft, sort of flops about when you loosen the lock screw. :shrug: I've had a word with Lee Andrews (I think the mount was bought there) and he is going to ask Luke to contact me when he gets back this week and has a look at the parts list. Not into the Goto bit, much rather set things manually. If you don't know how it works, you can't fix it when it doesn't :lol:
Thanks for the link, very useful. :)

Cheers
Bill

[vinnie]

Hi Bill,

Here is a link to explain the use of the date circle.
http://www.skywatchertelescope.net/swtsupport/Instruction_Manuals/GENERAL_EQ3and5.pdf

My EQ3 (which is very much the same) shipped new with the RA Ring very loose. I cut a strip of thin Aluminium sheet to make a sleeve and slipped in between the RA shaft and the ring, with the addition of a bit of the ubiquitous vaseline. Needs to be snug enough for the ring to move in RA but can be adjusted by hand. 3 years down the track so far so good

Vinnie

[Glenhuon]

Thanks Vinnie
Looks like there may not be a piece missing, just poor machining tolerances. I'll try that with the shim and vaseline, have some brass sheet of various thicknesses in the shed. The .pdf file is very handy, downloaded and saved. :)

Cheers
Bill

[vinnie]

No Worries Bill,

Just don't shim it up too tight!

Other thing that I found was the DEC ring was about 10 degrees out in relation to the front tripod leg. This doesn't matter to your alignment, it just annoyed me as when I went to align the C/W shaft was away from the tripod leg. Easy fixed with an Allen key. I'm one of those types that if I came into your house I would be straightening any pictures on the wall that weren't perfectly level!

If you have probs with Polar Alignment drop me a PM. Got some good tips and links but a bit too big for a forum!

Vin