Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Equipment

Pages: 1
KP0692
member


Reged: 01/04/14

Replacement for RA slow-motion cable?
      #6324652 - 01/20/14 05:33 PM

Hi guys,

I bought an Orion 130ST Space Probe Newtonian reflector about two months ago and it has been great, but one of the things that has been a nuisance is the RA slow-mo cable. If the tube is pointed at a fairly high altitude to the northwest, it will bump in to the cable and prevent any further movement of the tube in that direction when the mount is polar aligned.

I was wondering if anyone of you have had this issue and have found an alternative to this cable that will allow unrestricted motion in all parts of the sky?

Thanks!

Kyle


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom and Beth
Post Laureate


Reged: 01/08/07

Loc: Tucson, AZ
Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6324745 - 01/20/14 06:29 PM

This?

Or attach a shortie to the other side of the head


Post Extras: Print Post   Remind Me!   Notify Moderator  
KP0692
member


Reged: 01/04/14

Re: Replacement for RA slow-motion cable? new [Re: Tom and Beth]
      #6324770 - 01/20/14 06:44 PM

That is the style of cable that came with my telescope. I'm thinking just a knob that threads in to the mount would be just fine. Any suggestions as to where I can find one?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike Lynch
sage
*****

Reged: 04/07/06

Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6324851 - 01/20/14 07:43 PM

Quote:

I'm thinking just a knob that threads in to the mount would be just fine.




Does the cable attach to the mount by "threading" into it, as you indicate? Or does it fit over a rotating metal shaft with one flat side?

If that's the case, there would be a set screw on the cable that is tightened against the flat side of the shaft. And you may find a knob at a place like Radio Shack that fits over that shaft and tightens with a set screw in the knob.

That's what I've done for this very purpose!


Post Extras: Print Post   Remind Me!   Notify Moderator  
KP0692
member


Reged: 01/04/14

Re: Replacement for RA slow-motion cable? new [Re: Mike Lynch]
      #6324979 - 01/20/14 08:34 PM Attachment (9 downloads)

Thanks for the reply, Mike. It goes over a shaft and is fixed by a set screw on the cable.

Here is a picture of the cable attached to my equatorial mount.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rdandrea
Carpal Tunnel
*****

Reged: 06/13/10

Loc: Colorado, USA DM59ra
Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6325007 - 01/20/14 08:46 PM

Call Bill Vorce at Telescope Warehouse. See what he has in the way of a cable that isn't on his web site. This is a fairly common part that comes in lots of flavors.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike Lynch
sage
*****

Reged: 04/07/06

Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6325116 - 01/20/14 09:49 PM

Quote:

It goes over a shaft and is fixed by a set screw on the cable.

Here is a picture of the cable attached to my equatorial mount.




That picture seems to show that a knob by itself might rub against the setting circle, unless the shaft is long enough to allow you to tighten the knob back enough to avoid coming into contact with the setting circle.

If not, you might, indeed, need to search for a similar--but very short--slow motion cable.


Post Extras: Print Post   Remind Me!   Notify Moderator  
KP0692
member


Reged: 01/04/14

Re: Replacement for RA slow-motion cable? new [Re: Mike Lynch]
      #6325281 - 01/20/14 11:34 PM

You are correct that a knob placed directly onto the shaft will bump the RA circle. I'm thinking a shorter cable would fit the ticket.

Post Extras: Print Post   Remind Me!   Notify Moderator  
hottr6
Carpal Tunnel
*****

Reged: 06/28/09

Loc: 7,500', Magdalena Mtns, NM
Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6325647 - 01/21/14 08:16 AM

focusknobs.com to the rescue!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike Lynch
sage
*****

Reged: 04/07/06

Re: Replacement for RA slow-motion cable? new [Re: hottr6]
      #6325667 - 01/21/14 08:37 AM

Heavens above!! There's a knob (and knob dealer!) for all seasons... uh, I mean REASONS!!

Post Extras: Print Post   Remind Me!   Notify Moderator  
SteveG
Post Laureate
*****

Reged: 09/27/06

Loc: Seattle, WA
Re: Replacement for RA slow-motion cable? new [Re: Mike Lynch]
      #6326875 - 01/21/14 07:45 PM

The focusknobs are really nice - I was going to recommend them. Orion used to sell similar knobs - I have a brass version of the short one with no stem.

Post Extras: Print Post   Remind Me!   Notify Moderator  
KP0692
member


Reged: 01/04/14

Re: Replacement for RA slow-motion cable? new [Re: SteveG]
      #6327168 - 01/21/14 09:48 PM Attachment (8 downloads)

Thank you all for the replies! I ended up going with a $3 knob from Radio Shack. Now my telescope is completely unrestricted with respect to it's range of motion.

Clear skies!

Kyle

Edited by KP0692 (01/21/14 09:51 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike Lynch
sage
*****

Reged: 04/07/06

Re: Replacement for RA slow-motion cable? new [Re: KP0692]
      #6327742 - 01/22/14 07:52 AM

Great, Kyle!

Glad that knob worked out!


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Replacement for RA slow-motion cable? new [Re: Mike Lynch]
      #6327787 - 01/22/14 08:21 AM

Won't that tend to vibrate a bit more then the older setup when making adjustments? But as long as it settles down quickly.......

Post Extras: Print Post   Remind Me!   Notify Moderator  
KP0692
member


Reged: 01/04/14

Re: Replacement for RA slow-motion cable? new [Re: csrlice12]
      #6327830 - 01/22/14 08:44 AM

Smaller diameter knob = more rotations for same RA movement as the bigger knob. So yeah, if I really crank on it the telescope vibrates a lot but if I take it slow it isn't really noticeable. The mount that I have isn't very stable anyways and if there is a good amount of wind there is vibration present.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Suburban Maryland, USA
Re: Replacement for RA slow-motion cable? new [Re: hottr6]
      #6328326 - 01/22/14 12:55 PM

Quote:

focusknobs.com to the rescue!




Nice! This goes on my Favorites.

Thanks,
Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1


Extra information
11 registered and 31 anonymous users are browsing this forum.

Moderator:  zjc26138, tecmage, rflinn68 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 394

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics