Tracking Motors

[Stu1smartcookie]

Hi , I’ve just purchased the dual motor system , to use with my EQ5 .. i tried them out last night but when I returned to the scope , the target had disappeared from view . I know both motors are working because I can press the handset directional buttons and the cogs can be seen rotating . I know I need to polar align the scope , something I didn’t do ! Can anyone think of anything I’m not doing or should be doing ? Sorry this is a bit vague , but maybe someone can just shout the word “idiot” at me and offer some advice , as , let’s face it there are precious few instructions in the box . Thanks in advance .

stu 

[Stu]

Well, polar aligning is important, without it being roughly correct the target will quickly drift out of view. You also need to make sure the handset is set to North as in the Northern Hemisphere so that it tracks the right way. Apart from that it should just work.

EDIT, just to add that I use a Vixen GP mount with dual drives, very similar to the EQ5, for solar, lunar and planetary observing. I do just plonk it down level and North and it tracks very well for visual.

[Geoff Lister]

I'm an Az/Alt mount user; manual/tracking/full GoTo; but these are my thoughts:-

Is sidereal tracking turned ON? During the day, point the 'scope at a distant ground object, in an easterly or westerly direction - if it stays central then tracking is OFF.

Do you need to perform a 1/2/3- star alignment for this dual-motor system? If not, the tracking (RA axis is the moving one in a polar-aligned EQ system) may need to start from a "Home" position.

Is the tripod level?

Geoff

[Stu]

34 minutes ago, Geoff Lister said:

Do you need to perform a 1/2/3- star alignment for this dual-motor system? If not, the tracking (RA axis is the moving one in a polar-aligned EQ system) may need to start from a "Home" position.

It's not goto Geoff, so no need for star alignment or home position. Polar alignment and making sure the tracking is on (as you said), and in the right direction are my best guesses.

[Stu1smartcookie]

Hi guys , I polar aligned the scope tonight and still the stars moved out of view .. i have to say that I’m not 100% sure I aligned it correctly but it certainly was near . I am really not sure what to do next .

[Guest]

Have you calibrated the polar scope?

[happy-kat]

Is your telescope reasonably balanced.

[Geoff Lister]

On ‎26‎/‎09‎/‎2018 at 05:41, Stu1smartcookie said:

I’ve just purchased the dual motor system , to use with my EQ5

Do you have details of the system?

On an EQ mount, tracking is only active in the RA axis (my Astromaster 130 has a little box with a variable resistor, between the battery and motor, to adjust the sidereal tracking speed). Try setting up your system in daylight, but as you would for night-time, with the OTA pointing at a distant ground object, roughly east or west, and leave it running. After an hour, the RA axis should have moved by 360 degrees/24 hours = 15 degrees, and the DEC axis unmoved. If the RA axis has not moved, tracking is not enabled. If only the DEC axis has moved (and possibly by 15 degrees), you need to swap the leads to the 2 motors.

Geoff

[Stu]

10 hours ago, Stu1smartcookie said:

Hi guys , I polar aligned the scope tonight and still the stars moved out of view .. i have to say that I’m not 100% sure I aligned it correctly but it certainly was near . I am really not sure what to do next .

How quickly did they drift out of view?

Why don’t you post up a picture of the controller? Did you check the things I suggested, mainly that the correct hemisphere is selected ie N.

Geoff’s suggestion of the plugs being the wrong way round is another good one to check.

[Stu1smartcookie]

Hi Stu ... yes , good idea about the picture ...will include one tonight .. i checked the leads , when i swapped them the motors stopped working all together ! I've definitely got the Northern Hemisphere setting on ... i think it must be down to incorrect polar alignment ... and incorrect levelling of the scope . These motors have three speeds 16 , 2 & 0.5 ... And three settings , sun , moon , and stars .. i assume i should be using the settings , Stars and 0.5 (maybe i'm wrong here) By the way , the star drifted out of view within 10 minutes

[Cosmic Geoff]

Did you lock the RA clutch so that the motor moves the scope? I don't see that mentioned above. Do the handset slow-motion buttons move the image around in the eyepiece?

 Is there a difference in drift rate between 'drive on" and 'drive off'?

[Stu1smartcookie]

12 hours ago, Sland said:

Have you calibrated the polar scope?

Hi , no...i haven't  ...something else to learn ..and something i didnt even think about to be honest

 

[Stu1smartcookie]

12 hours ago, happy-kat said:

Is your telescope reasonably balanced.

Yes ... its pretty well balanced 

[Guest]

9 hours ago, Stu1smartcookie said:

Hi , no...i haven't  ...something else to learn ..and something i didnt even think about to be honest

 

There you go, it's pretty straightfoward.

[Stu1smartcookie]

13 hours ago, Stu said:

How quickly did they drift out of view?

Why don’t you post up a picture of the controller? Did you check the things I suggested, mainly that the correct hemisphere is selected ie N.

Geoff’s suggestion of the plugs being the wrong way round is another good one to check.

Hi Stu , I’m checking whether the motors are actually moving ... I’ve taken a photo of the controller .. including the inv dec and inv ra .. not sure if they are in the right positions y

[Stu1smartcookie]

Why does the motor at the top of the mount  visibly move whilst the other motor doesn’t seem to move at all ( unless I press the buttons on the handset controller ? I’m sorry if this is an obvious question to you guys ... I know the motors are working because I can hear them . 

[Cornelius Varley]

It looks to me like the RA gears are not meshing correctly.

[lenscap]

16 minutes ago, Stu1smartcookie said:

Why does the motor at the top of the mount  visibly move whilst the other motor doesn’t seem to move at all ( unless I press the buttons on the handset controller ?

The motor at the top is the DEC drive. It should NOT move when tracking. Only the lower ( RA ) motor should move when tracking.

The power leads must be the wrong way round.

[Stu1smartcookie]

2 minutes ago, lenscap said:

The motor at the top is the DEC drive. It should NOT move when tracking. Only the lower ( RA ) motor should move when tracking.

The power leads must be the wrong way round.

Well , you are absolutely right ... contrary to the instructions .. it’s crazy how they printed this wrong . I’ve just swapped the leads and , hey presto ! The RA is now moving and the Dec is now still ... I hope that this solves my problem... Geoff also said about the leads , so thank you guys . Tell me why the dec doesn’t move please whilst tracking (sorry if I’m appearing as an idiot but unless you ask you will never know ) 

[Stu1smartcookie]

8 minutes ago, Cornelius Varley said:

It looks to me like the RA gears are not meshing correctly.

Hi Cornelius , I looked the gears but they are ok ...one is turning the other but I will check it again. Lol I’m starting to get paranoid about these motors 

[Guest]

4 minutes ago, Stu1smartcookie said:

Well , you are absolutely right ... contrary to the instructions .. it’s crazy how they printed this wrong . I’ve just swapped the leads and , hey presto ! The RA is now moving and the Dec is now still ... I hope that this solves my problem... Geoff also said about the leads , so thank you guys . Tell me why the dec doesn’t move please whilst tracking (sorry if I’m appearing as an idiot but unless you ask you will never know ) 

When you are tracking you have already set the correct declination but the object you are tracking is moving left to right not up and down so Declination is not required

[Stu1smartcookie]

 

2 minutes ago, Sland said:

When you are tracking you have already set the correct declination but the object you are tracking is moving left to right not up and down so Declination is not required

Lol , now I feel even worse because it’s so obvious .. thanks Sland and everyone else .. it just goes to show that people shouldn’t be afraid to ask anything . 

[Guest]

28 minutes ago, Stu1smartcookie said:

 

Lol , now I feel even worse because it’s so obvious .. thanks Sland and everyone else .. it just goes to show that people shouldn’t be afraid to ask anything . 

Absolutely correct.  The only stupid question is the one you don't ask!

[Stu]

34 minutes ago, Stu1smartcookie said:

Hi Cornelius , I looked the gears but they are ok ...one is turning the other but I will check it again. Lol I’m starting to get paranoid about these motors 

The gears look too loosely meshed to me, there will be loads of backlash. I would adjust them so they are closer, touching but not binding.

[Stu1smartcookie]

1 minute ago, Stu said:

The gears look too loosely meshed to me, there will be loads of backlash. I would adjust them so they are closer, touching but not binding.

Ok .. I will re align them, thanks  .. can I ask , if the Dec doesn’t move whilst tracking is there any purpose having power to that motor ? And , looking at the handset controller I am presuming that tracking stars requires the slowest speed , I.e the 0.5 setting .