Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Orion EQ-2 Motor Clock drive NOT working

  • Please log in to reply
44 replies to this topic

#1 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 14 July 2020 - 02:30 PM

Hi,

 

I have an Orion Spaceprobe 130ST Equatorial Reflector Telescope and recently bought a clockdrive for it that I don't think is working properly. I've followed the instructions step by step by making sure that my telescope is polar aligned (pointing at polaris at a latitude of 40 degrees where I'm currently located) but when I turn on the clockdrive, the celestial object that I have my telescope pointed at doesn't stay in the center of my eyepiece's field of view. It always drifts downwards and to the left. What could I possibly be doing wrong?



#2 hcf

hcf

    Messenger

  • -----
  • Posts: 451
  • Joined: 01 Dec 2017

Posted 14 July 2020 - 03:26 PM

Which clock drive?

 

Does the clockdrive have a speed adjuster and have you adjusted it?

Does it have a North/South switch, and have you tried both?


  • newtoastronomy1993 likes this

#3 Loren Gibson

Loren Gibson

    Mariner 2

  • -----
  • Posts: 246
  • Joined: 04 Jun 2013
  • Loc: Northern Florida, USA

Posted 14 July 2020 - 03:35 PM

Is the pilot light on when you turn on the drive, selecting the correct hemisphere? Are the drive gears engaged, done by moving the lever which cams the drive motor in and out of engagement with the drive gear?

 

If the answer to the above questions are both yes, if you turn the drive off (or cam the drive gears apart to disengage the motor), is the direction and speed of the subject's drift the same as when the drive is on and engaged?

 

Loren


  • newtoastronomy1993 likes this

#4 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,153
  • Joined: 13 Jan 2013

Posted 14 July 2020 - 03:44 PM

The most likely and manageable culprit is the low accuracy of your polar alignment (that explain the drift along the N/S axis).

I do so with my clock-driven mount

a)place the tripod along a N/S line facing N, and level as best as can

b)match the wedge's angle with the latitude

c)aim a star roughly at S, near the celestial equator (just move the mount to have the CW bar parallel to ground, and the telescope parallel to the mount's body), turn on the drive and see where the star drift, whether up or down (in your case "up" should be S). If the star drifts S, adjust the azimuth through that little knobs westward, if drifts N, eastward

d)once satisfied, if there is still drift, aim an object somewhat near the eastern (or western, but in such case mind that have to invert everything) horizon: if the eastern star drifts northward, you have to lower the altitude through the wedge's knob; if drifts southward, raise it.

 

A single iteration should be enough; if want to be accurate, use high powers and follow the drift for a couple of minutes each for azimuth and altitude.



#5 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 14 July 2020 - 03:58 PM

Which clock drive?

 

Does the clockdrive have a speed adjuster and have you adjusted it?

Does it have a North/South switch, and have you tried both?

 

The Orion EQ-2 Motor:
https://www.amazon.c...e/dp/B0069VZQ44

 

It does have speed adjusting buttons that I've tried, all 4 of them. And I have tried switching it from N to S and vice versa, but  nothing :(



#6 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 14 July 2020 - 04:03 PM

Is the pilot light on when you turn on the drive, selecting the correct hemisphere? Are the drive gears engaged, done by moving the lever which cams the drive motor in and out of engagement with the drive gear?

 

If the answer to the above questions are both yes, if you turn the drive off (or cam the drive gears apart to disengage the motor), is the direction and speed of the subject's drift the same as when the drive is on and engaged?

 

Loren

By pilot light I'm assuming you're talking about the green light in the top left corner that shows up whenever I flip the on switch. Yes that shows up.

 

And yes, I have it set to the correct hemisphere (North) and have also checked the drive gears and the two are properly engaged.

 

When I turn the drive off and disengage the motor, the direction of the drift doesn't change, but the speed of the drift sometimes goes slower. Honestly, sometimes I can't tell.



#7 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 14 July 2020 - 04:06 PM

The most likely and manageable culprit is the low accuracy of your polar alignment (that explain the drift along the N/S axis).

I do so with my clock-driven mount

a)place the tripod along a N/S line facing N, and level as best as can

b)match the wedge's angle with the latitude

c)aim a star roughly at S, near the celestial equator (just move the mount to have the CW bar parallel to ground, and the telescope parallel to the mount's body), turn on the drive and see where the star drift, whether up or down (in your case "up" should be S). If the star drifts S, adjust the azimuth through that little knobs westward, if drifts N, eastward

d)once satisfied, if there is still drift, aim an object somewhat near the eastern (or western, but in such case mind that have to invert everything) horizon: if the eastern star drifts northward, you have to lower the altitude through the wedge's knob; if drifts southward, raise it.

 

A single iteration should be enough; if want to be accurate, use high powers and follow the drift for a couple of minutes each for azimuth and altitude.

 

Ok thanks! I'll try it again tonight using that method
By the way, what is CW bar?



#8 hcf

hcf

    Messenger

  • -----
  • Posts: 451
  • Joined: 01 Dec 2017

Posted 14 July 2020 - 05:11 PM

The Orion EQ-2 Motor:
https://www.amazon.c...e/dp/B0069VZQ44

 

It does have speed adjusting buttons that I've tried, all 4 of them. And I have tried switching it from N to S and vice versa, but  nothing frown.gif

Does hitting the 2x,4x buttons change the drift rate visible in the eyepiece?

 

CW stands for Counter Weight


  • newtoastronomy1993 likes this

#9 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 14 July 2020 - 06:50 PM

Does hitting the 2x,4x buttons change the drift rate visible in the eyepiece?

 

CW stands for Counter Weight

I'll have to get back to you on that!



#10 Hesiod

Hesiod

    Skylab

  • *****
  • Posts: 4,153
  • Joined: 13 Jan 2013

Posted 15 July 2020 - 01:10 AM

Sorry, CW= counterweight

#11 Loren Gibson

Loren Gibson

    Mariner 2

  • -----
  • Posts: 246
  • Joined: 04 Jun 2013
  • Loc: Northern Florida, USA

Posted 15 July 2020 - 09:34 AM

By pilot light I'm assuming you're talking about the green light in the top left corner that shows up whenever I flip the on switch. Yes that shows up.

 

And yes, I have it set to the correct hemisphere (North) and have also checked the drive gears and the two are properly engaged.

 

When I turn the drive off and disengage the motor, the direction of the drift doesn't change, but the speed of the drift sometimes goes slower. Honestly, sometimes I can't tell.

 

When I asked the question about comparing the direction and speed of the drift with and without the motor driving the mount (either turned off or disengage the gears), I was trying to diagnose whether or not it's a polar alignment problem. You say the direction of the drift hasn't changed, but maybe there's a change in the speed. Hmmm... Here's another couple of things to check.

 

Be sure that the R.A. clamp is snugged down when your object is in the field of view. Snug it down when the object is in the field of view. Disengage the drive motor (using the cam lever) and adjust the pointing in declination and R.A. manually with the slow motion knobs to center the object, then re-engage the drive. When tightening the R.A. clamp, it does not require an enormous amount of force. Just "finger tight" or gentle hand force. The motor may not drive the telescope if the R.A. clamp is not tightened, especially if there's an out-of-balance condition.

 

Be sure the scope is properly balanced about both axes of motion, as described in the instruction manual. If it's too far out of balance, that could cause some slipping.

 

Note that the drive gear attached to the mount's R.A. worm is plastic and with shallow teeth. It's not likely, but I found out it's possible (due to some clumsiness on my part) that the gears can "skip," resulting in the motor not turning the worm even though the drive gears are engaged. The teeth will jump in preference to turning the worm shaft. When this happens, there's a somewhat quiet but still audible "click" noise when the gear teeth jump. If you're hearing this, it might be why it's not tracking. I wouldn't expect this to be the culprit, but if it is it might be that there's a significant imbalance problem overcoming the motor drive's ability to track.

 

Loren



#12 bignerdguy

bignerdguy

    Ranger 4

  • -----
  • Posts: 341
  • Joined: 31 Oct 2019
  • Loc: Lewisville, TX

Posted 15 July 2020 - 01:06 PM

Question: you say you are pointing the scope at Polaris itself or near it at the pole?  remember that Polaris isn't actually the pole, its Near enough to it that we use it as a reference but in actual fact the pole is slightly off from that point.  In order to polar align your scope you need to know the exact point in the sky that is the NCP (North Celestial Pole) and point the scope at that, otherwise you will see drift occur.  Pointing it at Polaris will get you close enough for visual work with the expectation that you will have to adjust the positioning once in a while. For Photographic work you would need to accurately polar align the scopeand as they say: "That's a whole nuther Animal."


  • newtoastronomy1993 likes this

#13 Loren Gibson

Loren Gibson

    Mariner 2

  • -----
  • Posts: 246
  • Joined: 04 Jun 2013
  • Loc: Northern Florida, USA

Posted 15 July 2020 - 04:42 PM

If it is a polar alignment problem, I read this to be a very bad polar alignment, not something that's cured by touching up polar alignment with a drift method and making sure it's aligned to the north celestial pole rather than Polaris. I set mine up and point the polar axis north, by eyeball (using Polaris or even during the daytime with knowledge of the cardinal directions at the site), and having set the latitude fairly well using an inclinometer. I don't necessarily use an inclinometer each time. I think I probably have the R.A. axis oriented within a couple of degrees or so of being parallel to the Earth's axis of rotation when I set up, and that is good enough for casual visual use. Any drifting is slow, and probably not noticeable in, say, the same amount of time that the object would drift out of the field of view with the drive off.

 

I smell either radically bad polar alignment, poor drive engagement, poor balance, and/or a loose R.A. clamp at this point.

 

OP: As another check on things, you should be able to visually discern the rotation of the big plastic gear and the pinion gear if you watch it closely. That should tell you if the drive is actually turning the worm shaft when the drive is powered up.

 

Loren


Edited by Loren Gibson, 15 July 2020 - 04:42 PM.

  • newtoastronomy1993 likes this

#14 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 20 July 2020 - 10:50 AM

UPDATE: Sorry for the late update but the weather the last few days/nights has been pretty bad. It started getting clear again yesterday so I decided take my telescope back out again to write a few things down. I'll copy and paste what i wrote here:

 

I set my telescope up by:
- (1) Balancing the optical tube with the counter weight
- (2) Leveling the tripod by making sure its legs are extended at the same length
- (3) Having the declination pointer set to 90º so that the optical tube is now pointing in the general North direction and the optical tube is parallel with the RA axis and the ground
- (4) Polar aligning it — specifically by loosening the latitude lock T bolt and subsequently turning the latitude adjustment T bolt to the specific latitude number that my iPhone app “PS Align Pro” has determined to be the specific location of NCP (36º)

 

PS Align Pro screen shot: http://www.imagebam....d226c1349720226

 

Then after doing all of that, I spin my telescope around (by loosening the azimuth lock knob) so that I can then aim it at the specific object I want to look at (ie. Jupiter), and because sometimes, Jupiter will either be too low or too high up in the sky for me to find/see using the finder, I’ll loosen the RA knob to tilt the telescope in one direction or the other (left or right) so that then, the finder scope can be leveled enough to where I can actually see the planet in the right quadrant of the finder scope’s cross hairs, and can ultimately see it centered in the eyepiece.  At that point the optical tube is still parallel to the RA axis and the ground, but the RA knob is now locked in that position for keeping the object centered in the eyepiece; and the latitude scale is still locked in at 36º, in perfect alignment with the NCP, but the azimuth knob is loosened to allow for free rotation of the scope to compensate for any left/right, up/down drifting of the object. The declination knob is used occasionally, in combination with the azimuth axis, to recenter the object.

 

So this is where I'm at...whenever I engage and turn on the motor drive, I encounter 1 or 2 problems:

 

1) Drifting -  it always seems as though whenever I connect the cord to the motor drive, it doesn’t matter how well I think I’ve achieved polar alignment, the image in the eyepiece always seems to be drifting TO THE BOTTOM LEFT corner of the eyepiece and nowhere else. It doesn’t matter if I try changing the speed of rotation on the controller, it always goes to the bottom left corner and eventually out of my FOV.

 

2) Abrupt re-centering - sometimes when the optical tube is leaning a little too much to the right where it gets close to touching the RA knob, but not quite, the motor will make these weird knocking sounds where the circular gear and  gear won't be running as smoothly/quietly as before. Whenever I look in the eyepiece to see if the it's still working, I can see it trying to recenter the image but the recentering movements  seem so abrupt. It’s almost like it forces the image back down to the center but it ends up being off center. And then when the image drifts again the bottom left, it forces the image back down again, but it’s more off-center than before. I'm pretty sure it's not supposed to do that, but at this point, I’m at a complete loss and could use any help!

 

People online have made it seem like the clock drive should be easy to use and setup but I’ve spent the past 2 weeks trying to figure it out and still can't get it to work right.


Edited by newtoastronomy1993, 20 July 2020 - 06:34 PM.


#15 hcf

hcf

    Messenger

  • -----
  • Posts: 451
  • Joined: 01 Dec 2017

Posted 20 July 2020 - 11:10 AM


 

Then after doing all of that, I spin my telescope around (by loosening the azimuthal lock knob) so that I can then aim it at the specific object I want to look at (ie. Jupiter),

Do you mean the azimuth lock of the mount, or the RA lock (clutch) here?

Azimuth and Latitude are used for polar alignment only. Once you are polar aligned you should never touch them, and move the scope by RA and Dec only.


Edited by hcf, 20 July 2020 - 11:11 AM.


#16 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 20 July 2020 - 11:12 AM

Do you mean the azimuth lock of the mount, or the RA lock (clutch) here?

Azimuth and Latitude are used for polar alignment only. Once you are polar aligned you should never touch them, and move the scope by RA and Dec only.

Azimuth lock of the mount



#17 hcf

hcf

    Messenger

  • -----
  • Posts: 451
  • Joined: 01 Dec 2017

Posted 20 July 2020 - 11:22 AM

Here is a manual of the EQ2. Look at page 2.

https://www.telescop...29168_02-09.pdf

 

The Azimuth lock knob (from the picture on page 2) should not be loosened once you are polar aligned. Once you are polar aligned it is imperative not to move the mount at all. Only the scope should move after polar alignment.

 

You should be able to point the scope at Jupiter by moving in RA and DEC only.



#18 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 20 July 2020 - 11:58 AM

Here is a manual of the EQ2. Look at page 2.

https://www.telescop...29168_02-09.pdf

 

The Azimuth lock knob (from the picture on page 2) should not be loosened once you are polar aligned. Once you are polar aligned it is imperative not to move the mount at all. Only the scope should move after polar alignment.

 

You should be able to point the scope at Jupiter by moving in RA and DEC only.

Wait, but if I have it polar aligned and pointing in the north direction at the NCP, how do I rotate my telescope to aim at Jupiter if it's in another direction (ie. Southeast)? I thought that's what the azimuth lock knob was for.

 

If the azimuth has to stay locked, does that mean I have to physically carry the whole telescope to a location where I know Jupiter will align naturally with my polar aligned scope? that is, carry it to a location where I know it will just come into view through my finder scope after waiting a period of time?
 


Edited by newtoastronomy1993, 20 July 2020 - 12:03 PM.


#19 hcf

hcf

    Messenger

  • -----
  • Posts: 451
  • Joined: 01 Dec 2017

Posted 20 July 2020 - 12:23 PM

Wait, but if I have it polar aligned and pointing in the north direction at the NCP, how do I rotate my telescope to aim at Jupiter if it's in another direction (ie. Southeast)? I thought that's what the azimuth lock knob was for.

 

If the azimuth has to stay locked, does that mean I have to physically carry the whole telescope to a location where I know Jupiter will align naturally with my polar aligned scope? that is, carry it to a location where I know it will just come into view through my finder scope after waiting a period of time?
 

Look at this video... You can make the telescope point anywhere using RA and DEC motion alone.

 

https://www.youtube....h?v=F7HVDKAZ6eM


  • newtoastronomy1993 likes this

#20 KBHornblower

KBHornblower

    Vostok 1

  • -----
  • Posts: 129
  • Joined: 01 Jul 2020
  • Loc: Falls Church, VA (Washington DC suburb)

Posted 20 July 2020 - 12:51 PM

You appear to have the azimuth motion confused with the RA motion in this mount.  If you turn the mount around the azimuth adjustment after previously sighting in on Polaris, you are totally undoing the polar alignment.  That movement is only for aiming the RA axis at Polaris and keeping it locked.  The instructions say to rotate the scope around the RA and DEC shafts to point it at different parts of the sky.

 

The instructions are well written from my point of view, but with beginners a video demonstration can be worth more than a thousand words.

 

Edited to add: hcf beat me to it with a video.


Edited by KBHornblower, 20 July 2020 - 12:52 PM.


#21 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 20 July 2020 - 06:29 PM

You appear to have the azimuth motion confused with the RA motion in this mount.  If you turn the mount around the azimuth adjustment after previously sighting in on Polaris, you are totally undoing the polar alignment.  That movement is only for aiming the RA axis at Polaris and keeping it locked.  The instructions say to rotate the scope around the RA and DEC shafts to point it at different parts of the sky.

 

The instructions are well written from my point of view, but with beginners a video demonstration can be worth more than a thousand words.

 

Edited to add: hcf beat me to it with a video.

Ok I'll try it again tonight.

So just to reiterate:

 

To polar align: adjust the azimuth + latitude scale on the telescope while using the PolarAlign App

Once polar aligned: lock the azimuth + latitude scale on the telescope before moving on to aiming

 

To aim the telescope at an object: loosen the RA and Dec lock knobs and use the RA and Dec slow motion control cables ONLY to rotate the optical tube around both axes accordingly to aim at a target

Once the target is found: lock the RA knob + engage and turn on the motor drive


Edited by newtoastronomy1993, 20 July 2020 - 06:31 PM.

  • bignerdguy likes this

#22 KBHornblower

KBHornblower

    Vostok 1

  • -----
  • Posts: 129
  • Joined: 01 Jul 2020
  • Loc: Falls Church, VA (Washington DC suburb)

Posted 20 July 2020 - 09:18 PM

Ok I'll try it again tonight.

So just to reiterate:

 

To polar align: adjust the azimuth + latitude scale on the telescope while using the PolarAlign App

Once polar aligned: lock the azimuth + latitude scale on the telescope before moving on to aiming

 

To aim the telescope at an object: loosen the RA and Dec lock knobs and use the RA and Dec slow motion control cables ONLY to rotate the optical tube around both axes accordingly to aim at a target

Once the target is found: lock the RA knob + engage and turn on the motor drive

I think you are on the right track, but just push the telescope around by hand after unlocking the RA and Dec knobs.  Unlocking them disengages the slo-mo cables.  Use them for fine adjustments after aiming the telescope roughly and locking the lock knobs.  It would take forever to go from Polaris to Jupiter by turning the slo-mo controls.



#23 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 23 July 2020 - 07:25 AM

UPDATE: So great news!! I've successfully polar aligned my scope and now there's no drifting at all from what I can tell! I'm super thrilled about that so thanks everyone for helping me sort that out, this is gonna completely change my stargazing experience :D

 

One more thing though -- there appears to be a problem with my motor drive. The motor gear and circular gear of the telescope won't mesh properly unless I untighten the locking T bolt or support the bottom of the drive with my thumb. I posted a link to the video below and was wondering if anyone could tell me what might be the problem behind this and if I can fix this

 

https://sendvid.com/...24-f4954d444323


  • Loren Gibson and hcf like this

#24 bignerdguy

bignerdguy

    Ranger 4

  • -----
  • Posts: 341
  • Joined: 31 Oct 2019
  • Loc: Lewisville, TX

Posted 23 July 2020 - 07:56 AM

Well if i am reading the instructions on the web of this mount correctly i believe the answer while simple may be a bit of a cost but would provide better tracking for you.  Orion sells a motor drive kit that works better and connects to the other side of the head.  See here:

 

https://www.telescop.../0/p/118235.uts

 

This one may also work and gives you more contrrol over the positioning:

 

https://www.telescop...rc/2160/e/6.uts

 

That second link has both single and dual drive models and is the better choice.  I used one of these on a EQ-2 mount (dual drive) and i liked it a lot.  The motor you use has been known to have the issue you are experiencing as the gears wear after a while and even new tend to skip on occasion.  The gear teeth aren't very deep so this is why it skips as it doesn't grab very well.  



#25 newtoastronomy1993

newtoastronomy1993

    Explorer 1

  • -----
  • topic starter
  • Posts: 53
  • Joined: 11 Jan 2020

Posted 23 July 2020 - 08:02 AM

Well if i am reading the instructions on the web of this mount correctly i believe the answer while simple may be a bit of a cost but would provide better tracking for you.  Orion sells a motor drive kit that works better and connects to the other side of the head.  See here:

 

https://www.telescop.../0/p/118235.uts

 

This one may also work and gives you more contrrol over the positioning:

 

https://www.telescop...rc/2160/e/6.uts

 

That second link has both single and dual drive models and is the better choice.  I used one of these on a EQ-2 mount (dual drive) and i liked it a lot.  The motor you use has been known to have the issue you are experiencing as the gears wear after a while and even new tend to skip on occasion.  The gear teeth aren't very deep so this is why it skips as it doesn't grab very well.  

Ok so should I go ahead and get the second one? I'm not sure what the difference is between a single and dual drive model.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics