Help please! Dec axis stuck!

[oymd]

5 minutes ago, wimvb said:

Does the DEC setting circle move freely when you unlock it? It looks to me as if there is something blocking free movement in DEC, just as Tomatobro suggested.

Yes, indeed, I undid the two small thumb screws on the DEC setting circle and it rotates freely!

Im losing my mind here!!

I think I am missing something VERY OBVIOUS and SIMPLE!!

There’s this loud audible knock as you mentioned!

There must be something VERY LARGE AND SIMPLE that is blocking the DEC axis’ rotation!!!

What am I missing….

[AstroKeith]

In your videos you have something inserted into the polar scope top orifice. What is it? Can it be removed?

[oymd]

6 minutes ago, AstroKeith said:

In your videos you have something inserted into the polar scope top orifice. What is it? Can it be removed?

Thanks Keith

what do you mean by the polar scopes top orifice?

do you mean the opening on the front of the mount’s body?

that’s an IOptron iPolar camera. 
 

I did remove it, as I used the opening to insert the endoscope to look inside the mount body. 
 

I also used my little finger and palpated all round the inside of the hole. The adapter that is fixed to the mount is not catching or touching anything other that the edges of the hole itself. 

[wimvb]

Here's how the DEC clutch works on the AZ-EQ6. I took the polar scope cap off to show the inside.

 

 

[oymd]

8 hours ago, wimvb said:

Here's how the DEC clutch works on the AZ-EQ6. I took the polar scope cap off to show the inside.

 

 

Thanks Wim. 
 

What should I do now?

The mount is abroad, so sending it to FLO is not an option. 
 

What’s the safest approach I can take without  risking damaging anything?

I am worried about stripping the mount myself. 

[MikeP]

Just a thought ... are both the DEC grub screws still in place?  If something small has fallen in to the workings somewhere, it could be one of the grub screws.  When you re-balanced it could have moved and is now jamming.

Bit of a long shot but only a few seconds to check.

Mike

[AstroKeith]

Your videos are showing (and sounding!)  exactly like something hard has dropped into the 'works'. A grub screw or similar.

Last resort (before disassembly) might be to turn the mount upside down, try and shake it (or at least waggle the Dec axis as bit) and hope the 'item' drops down and out of the polar scope hole!

[wimvb]

2 hours ago, oymd said:

What should I do now?

@AstroKeith and @MikeP have sound suggestions. Try those first. If that doesn't work, use yor endoscope to look around in the DEC housing while trying to move the DEC axis. Look for any loose part or anything that may have caught where it shouldn't. If you have checked all this, and still haven't found anything, you probably have to remove the DEC assembly. For that you need to remove the DEC encoder cover (gray) and the CW shaft lock and DEC clutch. Follow the steps in the video below until 11 minutes in. You shouldn't need to remove any bearings. Only DEC disassembly is necessary. Be careful with the DEC encoder ring; it is a delicate part. You will need a few allen keys and a phillips screw driver. I don't think you will need to remove both the timing belts only the DEC. (Not relevant to this problem, but near the chuck on the motor side, there is a hidden grub screw to adjust the timing belt tension. It is hidden, because you first need to remove another grub screw from the outside to reach it.)

 

Edited January 6, 2022 by wimvb

[oymd]

3 hours ago, MikeP said:

Just a thought ... are both the DEC grub screws still in place?  If something small has fallen in to the workings somewhere, it could be one of the grub screws.  When you re-balanced it could have moved and is now jamming.

Bit of a long shot but only a few seconds to check.

Mike

 

3 hours ago, AstroKeith said:

Your videos are showing (and sounding!)  exactly like something hard has dropped into the 'works'. A grub screw or similar.

Last resort (before disassembly) might be to turn the mount upside down, try and shake it (or at least waggle the Dec axis as bit) and hope the 'item' drops down and out of the polar scope hole!

 

3 hours ago, wimvb said:

@AstroKeith and @MikeP have sound suggestions. Try those first. If that doesn't work, use yor endoscope to look around in the DEC housing while trying to move the DEC axis. Look for any loose part or anything that may have caught where it shouldn't. If you have checked all this, and still haven't found anything, you probably have to remove the DEC assembly. For that you need to remove the DEC encoder cover (gray) and the CW shaft lock and DEC clutch. Follow the steps in the video below until 11 minutes in. You shouldn't need to remove any bearings. Only DEC disassembly is necessary. Be careful with the DEC encoder ring; it is a delicate part. You will need a few allen keys and a phillips screw driver. I don't think you will need to remove both the timing belts only the DEC. (Not relevant to this problem, but near the chuck on the motor side, there is a hidden grub screw to adjust the timing belt tension. It is hidden, because you first need to remove another grub screw from the outside to reach it.)

 

Thanks Wim

I will try that.

@AstroKeith @MikeP

I have indeed taken the mount off the tripod, turned it upside down, and shook it vigourously, but no loose sounds at all.

The only sound I hear is the small handle of the grub screw that fixes the CW shaft, as it moves up and down freely when I turn the mount upside down.

[oymd]

5 hours ago, wimvb said:

@AstroKeith and @MikeP have sound suggestions. Try those first. If that doesn't work, use yor endoscope to look around in the DEC housing while trying to move the DEC axis. Look for any loose part or anything that may have caught where it shouldn't. If you have checked all this, and still haven't found anything, you probably have to remove the DEC assembly. For that you need to remove the DEC encoder cover (gray) and the CW shaft lock and DEC clutch. Follow the steps in the video below until 11 minutes in. You shouldn't need to remove any bearings. Only DEC disassembly is necessary. Be careful with the DEC encoder ring; it is a delicate part. You will need a few allen keys and a phillips screw driver. I don't think you will need to remove both the timing belts only the DEC. (Not relevant to this problem, but near the chuck on the motor side, there is a hidden grub screw to adjust the timing belt tension. It is hidden, because you first need to remove another grub screw from the outside to reach it.)

 

Hi Wim

Will attempt the disassembly of the DEC tonight. 
 

I watched the video till 11:50 where he removed the whole DEC axis  

A few questions. 
 

1- At the start, do I need to remove the plate covering the belt drives and motors and remove the belts?

2- Do I need to remove the encoder cables on BOTH DEC & RA since I am only touching the DEC?

What do I need to watch out for?

I will be devastated if I damage anything. I’m quite handy with DIY, but still terrified. 
 

On reassembly, IF I FIND THE PROBLEM AND FIX IT, is it simply a reverse order of putting everything back?

WHAT WILL I NEED TO WATCH OUT FOR?

Thanks. 

[wimvb]

1 hour ago, oymd said:

1- At the start, do I need to remove the plate covering the belt drives and motors and remove the belts?

Yes, but only the DEC belt. After you've removed the cover, if you look closely just behind the larger DEC belt wheel, you see a grub screw pressing against the DEC motor. This is the belt tension screw. You don't need to touch that. You may be able to remove the belt without loosening anything, but if it won't come off easily, just loosen the three motor bolts, jus like in the video.

1 hour ago, oymd said:

2- Do I need to remove the encoder cables on BOTH DEC & RA since I am only touching the DEC?

No, only DEC. When you've removed the gray cover, you'll see a small printed circuit board (pcb, probably green) with one white connector. You have to take the connector off. Do this gently, because one half of the connector is surface mounted to the pcb. Hold this part down while you gently pull the other half out. It's a tight fit, so you probably have to wiggle it a bit. This shouldn't be a problem if you're gentle with it. BUT REMEMBER WHICH WAY IT WAS INSERTED, SO YOU KNOW HOW TO REINSERT IT LATER.

The encoder ring is shiny and has fine lines on it. Don't scratch this part, and don't get grease on it. Other than that, there is nothing critical here.

When you pull out the DEC with the CW bar, anything that may be lodged inside may fall out. If something falls out while you pull the DEC assembly out, then you probably don't have to remove the assembly completely.

1 hour ago, oymd said:

On reassembly, IF I FIND THE PROBLEM AND FIX IT, is it simply a reverse order of putting everything back?

Yes, just reversed order. 

1 hour ago, oymd said:

I’m quite handy with DIY, but still terrified. 

You'll be allright. SkyWatcher mounts can take a beating and most parts handle hard contact with a floor better than the floor itself (personal experience with a metal part and a wooden floor).

Good luck.

[wimvb]

1 hour ago, oymd said:

I watched the video till 11:50 where he removed the whole DEC axis

I believe that at about 11:30 minutes he starts to remove the DEC bearings. You shouldn't need to do this, but any cover rings may come loose while you pull the assembly out, this is no problem.

1 hour ago, oymd said:

WHAT WILL I NEED TO WATCH OUT FOR?

The most improtant thing is that you put any screws and bolts somewhere where they can't get lost. And remember in which order you do things. I always have my cellphone handy so I can take pictures while I do this kind of stuff.

Edited January 6, 2022 by wimvb

[oymd]

1 hour ago, wimvb said:

Yes, but only the DEC belt. After you've removed the cover, if you look closely just behind the larger DEC belt wheel, you see a grub screw pressing against the DEC motor. This is the belt tension screw. You don't need to touch that. You may be able to remove the belt without loosening anything, but if it won't come off easily, just loosen the three motor bolts, jus like in the video.

No, only DEC. When you've removed the gray cover, you'll see a small printed circuit board (pcb, probably green) with one white connector. You have to take the connector off. Do this gently, because one half of the connector is surface mounted to the pcb. Hold this part down while you gently pull the other half out. It's a tight fit, so you probably have to wiggle it a bit. This shouldn't be a problem if you're gentle with it. BUT REMEMBER WHICH WAY IT WAS INSERTED, SO YOU KNOW HOW TO REINSERT IT LATER.

The encoder ring is shiny and has fine lines on it. Don't scratch this part, and don't get grease on it. Other than that, there is nothing critical here.

When you pull out the DEC with the CW bar, anything that may be lodged inside may fall out. If something falls out while you pull the DEC assembly out, then you probably don't have to remove the assembly completely.

Yes, just reversed order. 

You'll be allright. SkyWatcher mounts can take a beating and most parts handle hard contact with a floor better than the floor itself (personal experience with a metal part and a wooden floor).

Good luck.

 

1 hour ago, wimvb said:

I believe that at about 11:30 minutes he starts to remove the DEC bearings. You shouldn't need to do this, but any cover rings may come loose while you pull the assembly out, this is no problem.

The most improtant thing is that you put any screws and bolts somewhere where they can't get lost. And remember in which order you do things. I always have my cellphone handy so I can take pictures while I do this kind of stuff.

I’m mid way through!

I think I’ve found the problem. 
 

when putting the things back, can I use COPPER GREASE I have for my bikes, or white lithium grease?

Nit sure what the shiny encoder ring is?

[ONIKKINEN]

4 minutes ago, oymd said:

 

I’m mid way through!

I think I’ve found the problem. 
 

when putting the things back, can I use COPPER GREASE I have for my bikes, or white lithium grease?

Nit sure what the shiny encoder ring is?

Use high quality lithium grease, leave the copper paste out. Copper paste is very durable and tough but also abrasive, so not a good choice for mounts. Copper paste is good for brakepad holders and other things that must not seize but also do not need to be perfectly slick and fluid all the time.

[AstroKeith]

Definitely not copper grease - its not really meant as a lubricant. Lithium is good IMO.

[wimvb]

16 minutes ago, oymd said:

think I’ve found the problem

What was it?

[oymd]

2 minutes ago, wimvb said:

What was it?

RUST!!!!!!!!!!!!!!!!

[oymd]

13 minutes ago, ONIKKINEN said:

Use high quality lithium grease, leave the copper paste out. Copper paste is very durable and tough but also abrasive, so not a good choice for mounts. Copper paste is good for brakepad holders and other things that must not seize but also do not need to be perfectly slick and fluid all the time.

 

13 minutes ago, AstroKeith said:

Definitely not copper grease - its not really meant as a lubricant. Lithium is good IMO.

 

3 minutes ago, wimvb said:

What was it?

Ok. I’ll use white lithium grease. 
 

I think I forgot the sequence of the BOTTOM RINGS just above the clutch. 
 

THERE ARE THREE. 

ONE HAS SMALL BALLS AND BEARINGS AND TWO ARE SMOOTH. 

AM I RIGHT AT:

THE ONE WITH BEARINGS GOES FIRST ON TOP THEN THE TWO SMOOTH ONES, THEN THE CLUTCH, THEN THE LOCKING RING?

[oymd]

THIS ONE GOES FIRST:

Right?

 

[ONIKKINEN]

2 minutes ago, oymd said:

RUST!!!!!!!!!!!!!!!!

Surprising for sure. Good grease will deter rust from forming on surfaces you apply it on, so its unlikely you'll run into this issue again. Although this brings a question to my mind: How did the rust get there? Either something was improperly assembled and water/humidity was in there since new or water has a way to get to the inner workings of the mount. Both are bad options, but its not that rare for rust to form in weird places. If the mount has been outside in the rain it would explain how it happened. Do try to clean off the rust that has already formed to stop it from spreading, but dont use unnecessary force as to not scratch anything that shouldn't be scratched.

[oymd]

5 minutes ago, oymd said:

THIS ONE GOES FIRST:

Right?

 

And then TWO OF THESE ABOVE EACH OTHER THEN THE CLUTCH?

 

[david_taurus83]

6 minutes ago, oymd said:

THIS ONE GOES FIRST:

Right?

 

I'd order a new bearing if it was me. Good quality SKF

[oymd]

LAST QUESTION

DO I GREASE THESE THREE RINGS?

THE ONE WITH THE BEARINGS IS COVERED IN RUST. I’LL TRY TO CKEAN IT WITH WD40 AND A TOOTHBRUSH

[oymd]

1 minute ago, david_taurus83 said:

I'd order a new bearing if it was me. Good quality SKF

When I’m back in London for sure. 
 

Im currently abroad, so no option but to use these. 

[david_taurus83]

Are you sure that's what's blocking the axis from turning though? Even with a rusty bearing I'd have thought it would still turn albeit be very rough and stiff.