oymd

12 hours ago, wimvb said:

@oymd

Btw, I wouldn't put grease on the surface of the RA worm ring. The whole clutch mechanism depends on that the worm ring gets compressed to the DEC housing and the bearing between the ring and this housing. Grease can prevent enough compression. So, on the RA shaft from DEC housing outwards:

metal washer, greased bearing, metal washer, (no grease), brass worm ring with only grease around its gear teeth NOT on top or bottom, (no grease), clutch plate.

I rechecked. Grease is only in the edges and not the surfaces. 
 

I am thinking that I am doing the tightening of the lock nut wrong. 
 

There are THREE ELEMENTS:

1- The silver collar with the holes in it

2- The black lock ring

3- three grub screws. 
 

I am confused about the SILVER COLLAR and where it’s starting position should be?

I think my problem is here. 
 

On reassembly, SHOULD THE SILVER COLLAR be screwed all the way clockwise? Clockwise RELEASES THE CLUTCH  and exposes more of the BLACK LOCK NUT and moves the silver collar up flush with the mount  

Or should I assemble with the SILVER COLLAR screwed OUT COUBTERCLOCKWISE? Counterclockwise STIFFENS THE RA and covers more of the black lock nut?

As you can see in the Pic, there is now a SPACE between the silver collar and the mount, which I think is WRONG?

So should I try to redo with the silver collar screwed all the way UP TO THE MOUNT BODY IN THE RELEASE POSITION?

1 hour ago, ONIKKINEN said:

Actually my brand new mount has this issue, the locknut is too tight. Difficult to balance with stiction in RA with the clutch off. What is the proper tool to open this if i may ask?

56 minutes ago, wimvb said:

On most skywatcher mounts, the RA lock nut is itself locked in place by three small grub screws around its circumference (you'll need to check this on your mount). These grub screws need to be loosened or removed before the lock nut can be loosened, or you'll strip the thread on the RA shaft. The lock nut probably has two holes on either side of the shaft. The video in the beginning of this thread shows this. You need a tool that can grip the lock nut in these holes, and then you can loosen the nut by no more than a quarte of a turn. Just enough that the RA axis moves a little more freely. The nut shouldn't be so loose as to introduce play in the RA axis. There's a reason for it being where it is, so this is a balancing act.

Hope this helps.

My problem is the other way around. 
the RA is loose and won’t lock

21 minutes ago, ONIKKINEN said:

Thought so, grubscrews are off but still it wont budge with my McGyver'd tools made with what i have (some bolts and leverage, bolts broke off). Probably need to head to the hardware store to buy the proper pliers for this. Its unnecessarily tight for me, but its only an issue with the latitude set to higher than 45, so where gravity no longer helps with the movement. The synta factory at Taiwan latitudes does not have this issue since its at an easier angle where gravity helps with RA movement. At 60 degrees north not so much.

CIRCLIP PLIERS. THE BENT ONES

1 hour ago, ONIKKINEN said:

I dont know if this gear is supposed to be able to move or not so wont comment on that, but definitely dont file anything off it.

You can heat fit it back in pretty easily. Its not rare for gears and fittings made of different materials to be stuck, and especially once they have been used. Heat the brass gear and cool down the inner axle and it will go in with less use of force. Maybe throw the axle in the fridge for a while and the brass gear into an oven at low heat. Dont heat it so hot that you cant touch it with gloves, so just a while in the oven. This way you can fit it back in pretty easily, but i dont know if its supposed to be able to move on its own so maybe dont do that until you know.

Ok. I’m ready to put everything back. 
 

I assembled the RA. IT ROTATES VERY VERY SMOOTHLY. 

ONLY PROBLEM IS: NO MATTER HOW TIGHT I PULL THE RA CLUTCH, it still moves with minimal force?

Is that normal, since I have not assembled the DEC yet?

I made sure that there was no grease on the black cardboard clutch plate? 
 

And tightened the black bottom ring and 3 grub screws VERY TIGHT?

1 hour ago, ONIKKINEN said:

I dont know if this gear is supposed to be able to move or not so wont comment on that, but definitely dont file anything off it.

You can heat fit it back in pretty easily. Its not rare for gears and fittings made of different materials to be stuck, and especially once they have been used. Heat the brass gear and cool down the inner axle and it will go in with less use of force. Maybe throw the axle in the fridge for a while and the brass gear into an oven at low heat. Dont heat it so hot that you cant touch it with gloves, so just a while in the oven. This way you can fit it back in pretty easily, but i dont know if its supposed to be able to move on its own so maybe dont do that until you know.

Well, I spent the past hour using steel wool from the kitchen and copper paste to smooth the inner surface. 
Still would not fit. 
finally put the worm gear in boiling water for about 30 seconds, burnt my hands, and finally it fit!!

Strange. Once it’s in place, rotates smoothly as butter. 

On 06/01/2022 at 20:45, ONIKKINEN said:

Does the dark stuff not come off? Difficult to tell without handling the bearing myself but looks slightly oxidized. If it feels slick when rolling then nothing to worry about, but if you can feel the dark stuff with your fingers or when rolling the bearing it should be taken off.

On 06/01/2022 at 22:01, ONIKKINEN said:

Looks like rust damage

On 06/01/2022 at 22:21, david_taurus83 said:

I'd imagine the bearing runs between the 2 washers.

On 06/01/2022 at 22:32, wimvb said:

The bearing between the washers, yes.

As per this old post (the second image shows the sandwich configuration of the washers and bearings. All bearings sit between two hardmetal washers, not directly against aluminium. Chemistry 101: two different metals in contact are more sensitive to corrosion. And aluminium is too soft and will eventually wear.

 

Sorry to resurrect this thread. 
 

Yesterday I had strange behaviour in RA, so I decided to completely strip the mount. DEC and RA. 

I followed the video to the letter, and it was actually easy, but I am STUCK AT A PROBLEM  

The RA axis is pristine, no rust at all. I replaced ALL the grease everywhere with the thick brown grease. 
 

I am faced with just one problem. 
 

And it’s not on the RA. It’s on the DEC. 

Last time when I dismantled the DEC, I did not touch the golden brass worm gear. 
 

This time I followed the video in detail, and tried to remove the golden brass worm gear on the DEC. 

It’s completely stuck!!

I had to go circumferentially very carefully and gently with a flat head screw driver to lift it off, and it took plenty of WD40 to get it done.
 

THERE IS NO RUST, but it was clearly stuck. In the video I can see it’s a VERY TIGHT FIT, but he removes it with ease, and puts it back with some pressure. 
 

In my case, I tried to put it back, but it will simply not go back in place without considerable force, and still gets stuck?!

Should I gently use a metal file and smooth the inner surface of the brass worm gear??

Or is it normal for it to be a VERY VERY tight fit so that it grabs the axis and forces it to rotate when the gear is rotating?

6 hours ago, iantaylor2uk said:

You'll have more light gathering capacity with the Esprit, due to its bigger aperture. Also 120 secs sounds way too long for Orion. I usually only do 30 secs and even that usually blows the core out.

7 hours ago, The Lazy Astronomer said:

Focus looks ok to me. If it's out, it's not out by much.

When you say 120s subs were 'flooded with LP', what precisely do you mean? Did you have the subs or happen to note some of the image statistics?

What gain and offset do you have set in NINA?

12 hours ago, wongataa said:

Did you see what happened if you removed the new Optolong filter?

Ok, so tonight I tried something different.

NO HAZE, and the sky is definitely cleaner, but NOT GREAT. I am in Bortle 7-8

I decided to image M31.

I had imaged it a couple of months ago using the same imaging train with the WO Star 71, and the result was quite good. I imaged 300s subs, Gain 120 and offset 30, which is the dfault. I NEVER CHANGED those settings, and was not aware that I should change them depending on the image or filter?

So tonight I decided to try with:

1- Optolong UV/IR filter

2- NO filter

3- Optolong L-eNhance, but on ANOTHER target, specifically IC1805.

ALL SUBS were 180s, Gain 120, Offset 30.

1- First sub of M31 with Optolong UV/IR. ABORTED obviously

2- First sub of M31 with NO filter.  ABORTED obviously. First one is stretched by NINA, and second one with stretch removed.

3- First sub of IC1805 with Optolong L-eNhance. Will continue a run of 60 subs and see what the result is.

13 minutes ago, iantaylor2uk said:

You'll have more light gathering capacity with the Esprit, due to its bigger aperture. Also 120 secs sounds way too long for Orion. I usually only do 30 secs and even that usually blows the core out.

Yes, its not the actual target that I am concerned about here.

It is the quality of the image and the sky around the nebula.

This is a CALIBRATED master image, processed in PI.

The sky is horrendous, and the dust motes are everywhere!

25 minutes ago, The Lazy Astronomer said:

Focus looks ok to me. If it's out, it's not out by much.

When you say 120s subs were 'flooded with LP', what precisely do you mean? Did you have the subs or happen to note some of the image statistics?

What gain and offset do you have set in NINA?

The gain and offset have been the same, and I never changed them. I think it was 120 and 30, I'll check, but I never changed it in NINA, and I had imaged dozens of targets successfully over the past few months.

The only thing I changed was removing the WO Star 71 scope, and replacing it with the Esprit and the UV/IR filter, as I was aiming to image M33, but it was too low.

With regards to FLOODED WITH LP, what I meant was: In the IMAGING tab in NINA, just I saw the first sub come in, it was like I was imaging at dawn, or sunset. It was completely dark, but the image was just GREEN when NINA applied the debayer and autstretch to the sub preview

51 minutes ago, wongataa said:

Did you see what happened if you removed the new Optolong filter?

That was on my mind. That's why in my post I highlighted the fact it was brand new and in box, and it was clean and pristine.

I am planning on imaging without it tonight.

What do you think of the focus? NINA gave me a good V-Curve, but I do not have a bhatinov mask large enough to check visually.

Good evening everyone.

Had been away from my rig on travels abroad since 22nd November.

My Esprit was stored in a cupboard in a warm room inside the house, surrounded with desiccants, and a plastic bag including 5 desiccant pouches tied with a rubber band on the flatteners side.

Yesterday was my first night imaging. (This is NOT in the UK)

No clouds, temps were around 18C. There was some haze. Do not know how to describe it really. Sky was clear, but visually I could not see plenty of stars.

I am yet to configure the EAF properly on the Esprit. The BACKLASH setting is driving me crazy.

Anyways, after I think I got the autofocus set properly in NINA, and got a V curve, I attempted M42.

At 120s, all the subs were just FLOODED with light and overexposed. Tried M45, and again, anything over 120 seconds was just flooded with GREEN.

So, I tried M42 at 60s. I imaged 60x60s. 294MC Pro, with the Optolong UV/IR 2" filter (brand new and just taken out of its wrapping for this imaging session)

The first images coming in showed HORRENDOUS DUST and LP

Undid the imaging train, and everything VISUALLY looked fine.

Used my Giottas air blower on EVRYTHING, and redid M42. Less motes, but still plenty!

Took flats and Dark Flats with my Geoptik Flat panel.

WBPP in PI, and the result is TERRIBLE??

What's going on here?

Flats seem to be infective?

And the result is terrible.

At the very least, is the FOCUS good?

Attached is the processed image in PI, as well as raw Master Light, and Master Flat, as well as M42 imaged in early November with same exact rig and from same location, except with WO Star 71.

masterFlat_BIN-1_FILTER-NoFilter_CFA.xisf masterLight_BIN-1_EXPOSURE-60.00s_FILTER-60s_RGB.xisf

38 minutes ago, ONIKKINEN said:

Thanks for the recap, it all makes sense now how this happened! The rust markings are only on one spot, presumably the spot that was towards the ground when the mount was sitting for 40 days. I think if it had been in use faster after the water damage, this wouldn't have been nearly as bad or even rusted at all since the water could have had a chance to drain off.

Yes, agreed. 
 

It was unfortunate that I left the mount overnight in the garden, and even more unfortunate that the water incident was followed by a 40 day period of non use. 
 

A perfect recipe for rust!

Very careless and silly on my part. 

1 hour ago, wimvb said:

I noticed I was a bit sloppy in my previous image of the encoder disc/ring. Your image shows it better.

Btw, did you swap the washer and bearing? It was a while since I regreased my mount, but I'm pretty sure that the bearing should be sandwiched between the two washers.

For future reference, here's en excellent write up by Scott Cunnington that I had almost forgotten.

http://reset.cbm8bit.com/uploads/files/magazines/59ae571fe9ecb_AZEQ6 Stripdown guide final.pdf

Thanks Wim

Yes of course, it was silly of me to even ask that question. 
 

I reassembled with the bearing plate sandwiched between the 2 washer plates!

With regards to the encoder, I do not see any markings at all? Even on my image?

How does it work? I thought the encoder would have some kind of clear markings or grooves to tell whatever is scanning it some kind of positional information. 
 

And since I’ve dismantled and re constructed the mount tonight, do I need to do some kind of reset in software in EQMOD? Or just simply carry on like nothing happened?

46 minutes ago, wimvb said:

The encoder ring/disc is on the bottom side of the DEC head, as shown in this image. It is fixed to the DEC head and most likely made from glass, ceramic, or a highly polished metal.

1 hour ago, david_taurus83 said:

I'd imagine the bearing runs between the 2 washers.

1 hour ago, ONIKKINEN said:

Looks like rust damage

I would like to start by thanking everyone on this thread!

You have helped me immensely.

I think I also missed quoting @AstroKeith

So, I disassembled the mount tonight.
 

There was a large amount of RUST and the Dec axis was frozen at the part just above the clutch.
 

There was a fair amount of rust on the OUTSIDE OF THE CW BAR HOUSING and the INSIDE OF THE OPENING WHERE THE CW HOUSING EXITS THE MOUNT.

Now, you might ask, why the heck is there so much rust centered on the most dependant part it the mount?

I now can deduce what exactly happened?

Back in November last year, on my LAST imaging session, I left the mount outside in the garden to complete about 5 hours on the Rosette.

I planned to wake up early BEFORE the sprinklers came on in the garden at about 6am.
 

I did wake up on time, but I just missed the sprinklers by about 30 seconds.
 

There was very light water on the BOTTOM of the mount and tripod, but I managed to carry it back onto the porch away from the water.
 

I used my endoscope then to check inside the mount, and I could not see any water ingress, so did not really bother.
 

On looking on the OUTSIDE of the mount, there was some moist and damp at the area of the clutch.
 

I was travelling back to London in 48 hours, and had no plans to image again.
 

I used a hair blow dryer for about 20 minutes on the clutch area, and also wrapped it with a dew heater band for about 24 hours on maximum setting.
 

I travelled the next day, and COMPLETELY FORGOT ABOUT THE INCIDENT till I saw the rust tonight!!!

There must have been some ingress at the clutch area, and it had a full 40 days or so to rust happily until I tried to balance the Esprit a couple of days ago! 
 

I never gave the sprinklers incident a second thought, and I believed I got away with it!

Anyways, the reason that there was a few degrees of rotation, and then a KNOCK, is that there was rust seizing some kind of bearing on the INSIDE of the opening at the BOTTOM of the mount where the counter weight bar exits the mount. 
 

Tonght I could rotate it with my hand about a 10th of a full rotation either way, and then it would grind to a halt. 
 

I spend a good 4-5 hours brushing all the surfaces showing rust with a scotch brite sponge and a toothbrush with PLENTY of WD40

Everything was smooth and clean at the end  

As advised, I used White Lithium grease on all surfaces, and indeed, everything is smooth as butter now. 
 

Connected the mount in NINA, and slewed in all directions, sorted out the backlash and no binding to report. 
 

Will try an imaging session tomorrow. 
 

THANK YOU EVERYONE

Especially, thanks @wimvb

1 hour ago, ONIKKINEN said:

Try to clean all of the rollers and all the surfaces they roll on as thoroughly as possible and apply the new grease after that. There should be no feeling of grit or jerkiness in any of the bearings, if there are it means metal or rust has flaked off and is causing friction. Rust specks will act as sandpaper and will destroy the bearing, if it isn't already gone. It does look a bit rusty but i wouldn't call it ruined yet. But if not cleaned it will be ruined in use eventually. I think it can still be used without worry of further damage as long as its well cleaned and greased, but do keep in mind that eventually it should be replaced.

@wimvb

Can I please check. 
 

Is this the final correct sequence at the bottom?

Bearing, then 2 smooth rings then clutch?

2 minutes ago, ONIKKINEN said:

Does the dark stuff not come off? Difficult to tell without handling the bearing myself but looks slightly oxidized. If it feels slick when rolling then nothing to worry about, but if you can feel the dark stuff with your fingers or when rolling the bearing it should be taken off.

I’ve brushed it well. It’s rolling freely. 
 

What is this ring btw?

is this the encoder ring?

are these markers encoders or rust marks?

6 minutes ago, ONIKKINEN said:

Try to clean all of the rollers and all the surfaces they roll on as thoroughly as possible and apply the new grease after that. There should be no feeling of grit or jerkiness in any of the bearings, if there are it means metal or rust has flaked off and is causing friction. Rust specks will act as sandpaper and will destroy the bearing, if it isn't already gone. It does look a bit rusty but i wouldn't call it ruined yet. But if not cleaned it will be ruined in use eventually. I think it can still be used without worry of further damage as long as its well cleaned and greased, but do keep in mind that eventually it should be replaced.

Done. 

5 minutes ago, david_taurus83 said:

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.

That’s just one part. When I’m done I’ll update 

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. 

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

5 minutes ago, oymd said:

THIS ONE GOES FIRST:

Right?

 

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

THIS ONE GOES FIRST:

Right?

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?

2 minutes ago, wimvb said:

What was it?

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

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?