EQ6-R Pro Teardown

[discardedastro]

Right - given I can't find one, here's a bit of an addendum to Astro-Baby's excellent EQ6 teardown guide, updated for the EQ6-R Pro.

Mine is the original version but I don't think anything changed mechanically on the facelift version - YMMV.

I'm tearing mine down to give it a proper clean and service throughout, and to proactively change the bearings to proper quality SKF bearings throughout. Mine lives outside year-round under a Telegizmos cover - but we're in a very humid spot (there is what the EA calls main river about 20m from the mount - in reality it's a drainage ditch but it is full of water most of the year). Consequently lots of the low-quality bolts, as well as the counterweight shaft, are corroded badly. It's been outside for about 3-4 years.

 

All of this assumes you're reading primarily this thing:

https://www.astro-baby.com/astrobaby/help/rebuilding-the-skywatcher-eq6orion-atlas-mount/

I do intend to follow the "supertuning" offsetting/shimming procedure if it looks like mine needs it. Before teardown this mount was running OK and managing reliably 1-2 arcseconds RMS guided, which is fairly standard for these out of the factory, but I do a lot of high-scale oversampled imaging so good mount performance is nice to have!

 

Electronics and prep

I dismounted the mount from the tripod and got all the snail excrement out of the az/el wedge. This turned out to be quite tricky and I let it dry completely before getting in with a narrow vacuum nozzle which did the trick. They haven't found a way into the mount, happily, but I am going to try copper tape on the tripod legs - works for slugs on pots...

Getting the electronics board off isn't strictly needed for much stuff but on the -R it's pretty much mandatory to get the belts freed off when we get there, so best to get it out of the way early.

Usual set of (outer) pozi screws to get the cover off, and then a small screwdriver and gentle wiggling to get the connectors out of the back. Put the PCB to the side and then tape up the connectors/cables. Very easy for these to fall outside the case and get trapped under the mount otherwise.

At this stage it's easy enough to do a quick look for debris and see how it all looks. In my case, pretty decent, all-told. The R has a pretty similar mechanical setup to the NEQ6. Of note though is the RA indexing optical encoder which is used for periodic PEC (not an absolute encoder, just generates a pulse once per worm rotation based on a slotted disk on the end of the worm shaft).

Dec axis

The saddle comes off nice and easy. These are 5mm hex head bolts rather than the inset hex screws used on the NEQ6. Better, but note corrosion (the counterweight bar bolt is also shown for reference).

Pushing the counterweight bar up through the middle of the axis worked, but only after I'd sanded the corrosion off the bar. Will probably look to polish that back and coat it with something to try and eke a bit more life out of it, but a decent stainless bar would be better.

The clutch lever assembly came off easy - pozi screw and again corroded. The brass insert on the end of the screw came with the screw, which confused the hell out of me while I spent 5 minutes trying to find it.

Also of note is that the clamp on the counterweight bar is done via a small, black plastic (delrin?) insert. This is not obvious and falls out readily.

The screwing off of the main nut here was straightforward - no real resistance once the (M2, I think) grubs were slackened. Design a little different to NEQ6.

Likewise the removal of the dec shaft at this point went as you'd hope. The revealed bearing (which is still a 30206, as on the NEQ6) is easily removed thereafter without any effort.

The shaft came out easily. Generally looks fine - I don't know if the blackened portions are painted or treated in some other way, but they're not in great shape - I presume that this is largely done to avoid reflections for the polarscope.

The bearings used along the shafts are JESA W2 series 6008 RZ bearings. I've opted for SKF 6008 2RS1 as a replacement.

The grease used throughout looks to be reasonable quality lithium stuff rather than the dreaded black Synta grease. It is worth noting that I could not find any washers at this stage. Whereas the NEQ6 has a teflon washer on the top of the bearing surface.

Moving on to the worm gear carrier, instructions are per the NEQ6 guide. However - there's a belt drive here! Hat-tip to Tom Boland on Twitter for pointing out that the motors themselves need to be released to free up the belt. Undo the tension screw, then the three (4mm, I think) hex bolts accessed behind the electronics panel associated with the motor. Just slacken off. Then use a narrow screwdriver to guide the belt off the large gear. The gear can't be removed yet - but note the flathead screw (how many screwheads! Pick one!) plug in the worm gear carrier to allow access to the set screws in the large gear for later...

Undo the top and bottom set screws, the 5 M5 bolts, and with the belt released this just lifted off nicely. Set screws were again corroded so will be replaced.

This yielded our worm carrier, shown below - you of course don't need access to the top of the assembly to get at the set screws for the gear here, which makes the decision to put another external penetration in the casing a bit weird! I wonder if there's some form of setup at the factory that requires this, or similar. The surface finish here is okay, but I'll give it a few rounds on a surface plate with some wet and dry to clean it up before it goes back together.

Interestingly the grease distribution here is less than uniform and the right hand side of the worm is basically dry. Note quite a bit of visible burring around the edges of the casting and paint flecks that will want cleaning up.

The end float adjustment plate is here and looks fine. The bearings used in here seem to be the same manufacturer, 608 Z family. I've ordered 608-2RSH SKF parts as a replacement.

Back to the brass...

This is as it was just after removing the worm. You can see the freed up belt and the contact surface for the clutch. I've not inspected this in tons of detail but will give it a full degrease and surface polish before it goes back in. There's some indication of wear on the gears but I've not had a really good look yet!

This is the only washer I found in the entire Dec assembly - sat between the bottom of the brass gear and the top of the bearing supporting it. Teflon, some signs of cracking/damage - this is well on the way to become another cracked and broken washer, I think. Sadly my calipers have failed so I haven't measured this yet.

The last bearing popped out with just a little wiggling. The brass blocks top and bottom are the points your set screws are pushing against when adjusting the worm positioning for backlash.

Again lots of tool marks - this'll get cleaned up before it goes back together.

 

And that's all for now! I've made a bit of a start on the RA but I'm waiting for some tooling to arrive, so in the meantime figured I'd write this up as the guide I wish I'd had when I started. I'll add to this as I do the RA, clean up, worm position tweaking, and rebuild/testing.

[nfotis]

Thanks for the guide. Maybe you could do a Youtube version of this guide?

N.F.

 

[bluesilver]

This is a very good run down on the procedure,  and gives yo a good idea on how to go about it.

I am planning to do my AZ/EQ6 next week when i get a bit of bench room cleared up form another project.

The AZ/EQ6 is slightly different from the EQ6,  so will be interesting just to see how much different they are.

There is a few things i would change though in regards to grease, and highly recommend it.

For the worm gears,  i will be using  EP grease and plenty of it on them hat i have here,   this is the grease designed for worm drives / gears,  ( EP stands for extream  pressure )

For the other grease i will just be using Synthetic grease which is designed for wheel bearings that i have here also.

For bearings, i will be using the equivalent of SKF which is FAG here.

Not sure about shims yet,  will wait until i get it apart to have a look at what they have done there.

 

 

 

 

 

 

[discardedastro]

3 hours ago, nfotis said:

Thanks for the guide. Maybe you could do a Youtube version of this guide?

N.F.

 

Personally I find videos can be helpful in parts but nothing beats carefully taken photos and text. Having said that I'll try and film some bits of the reassembly and do a bit of a video about it all - I'm short a video camera but phones work pretty well and I might be able to borrow work's proper camera for a few days.

Bearings arrive tomorrow along with some of the missing tools - I have some things to do at the weekend but will try and make some progress on Sunday. The main nut (smooth) on RA Is an absolute nightmare so far - a chain-style oil filter remover has done nothing but marr the surface (even with some amalgamating tape to protect/grip) so am hoping a rubber version of the same tool will do the trick. I suspect Skywatcher have a specific tool that engages with the recesses on the back like a giant pair of circlip pliers!

I've got both EP and regular bearing-grade lithium grease on the way. I would say that generally the grease I've found so far is looking like decent lithium stuff. Not the notorious Synta Tar. Shims and replacement Teflon washers I'm just trying to find a good source of now - given the (theoretical) simplicity of the "hypertuning" of the worm gear alignment, i.e. make a few accurate measurements and shim accordingly, seems a no-brainer to do it while I've got it all open.

I am giving a bit of thought to what I might need to do to properly tune the alignment later on. Current-based measurement of motor load seems a sensible easy "precision" method beyond sticking an ear on it while adjusting worm gear offsets, belt tension etc. I've got a fairly accurate bench power supply handy (Rohde & Schwarz NGE100B - marginal but can do 6A in parallel mode) as well as a R&S Scope Rider with precision ammeter clamp probes, both borrowed from work, so I think I'll give that a go! I've also been giving some thought to vibration measurement; back in my drone engineering days we used to do FFT analysis of accelerometer data which would pretty readily show peaks at resonant frequencies relating to e.g. improperly balanced props, or damage in bearings. I have a few precise MEMS accelerometers handy so I figure it wouldn't hurt to just try doing some measurements with that and see if anything interesting falls out.

[bluesilver]

What would be nice is,  if i could make up a spring loaded worm gear drive mount,  something like you get on the higher cost mounts.

This at least will help keep a good constant tension on the worm gear and drives.

 

[discardedastro]

The RA procedure started fairly similarly to the AB guide. The polar scope alignment indicator comes off with a gentle twist of the inside ring. The indicator itself just pulls off.

The mounting ring for the polarscope cover comes off readily with a couple of grub screws. These also get replaced with stainless steel. I will shout out https://modelfixings.co.uk/ at this point - all the bolts/grub screws etc hardware I'm sourcing from them, they've been fantastic for years and do a great set of M2-M6 grub screws and good quality stainless bolts etc.

So the answer to the RA smooth nut is one of these rubber oil filter changers, for sure. But you will need to pull out the altitude adjustment bolt to get a good clean pull on the thing. I also fully removed the grub screws around the shaft just in case and will replace these with stainless also. After a lot of attempts, off it came....

Rear bearing exposed as per the AB guide. The axis came out good as gold, nice and easy, and the bearing fell out. I noted some debris in the bearing as I removed it which appeared metallic, but it's 50/50 if this was metal or some particularly robust bits of the earwigs I found above this bearing... either way, happily I will be replacing this with a brand new SKF 32208 J2/Q.

Extracting the shaft, the top bearing remained. This was removed pretty readily with a gentle bit of tapping from a rubber hammer - I'm replacing this so not precious about getting it off. The RA set ring comes off easily.

We also have a teflon washer below this bearing, less damaged than the other but will be trying to replace in any case.

Unfortunately I last tightened up the RA worm carrier bolts with a really hefty hex driver which I've since misplaced, so I'm now waiting on a bigger hex driver to make more progress. However, the big smooth nut was the last major challenge on the primary axis stripdown, so I am expecting that the rest should be fairly straightforward.

The only possible snag I can foresee is removing the bearings from the ends of the axes; these are pretty snug in their positions and because the rods are pretty long I'm not sure my bearing pullers will actually reach that far or fit into the recess. I suspect that I might need to do some unspeakable bodges to get that last bearing off.

I have also started looking at the worm carrier stripdown. Circlip pliers are a must for taking the end cap off and taking the slotted nut out.

Once I have absolutely everything stripped down and some basic cleaning done I plan to slather degreaser all over everything for a first pass and then take everything to work where I have a big enough ultrasonic cleaner in the lab I can make use of for an afternoon to get everything completely clean. Then it's on to the super fine wet and dry paper for surfaces and I'll have a look over the gears.

[Jiggy 67]

23 hours ago, discardedastro said:

Personally I find videos can be helpful in parts but nothing beats carefully taken photos and text. Having said that I'll try and film some bits of the reassembly and do a bit of a video about it all - I'm short a video camera but phones work pretty well and I might be able to borrow work's proper camera for a few days.

Bearings arrive tomorrow along with some of the missing tools - I have some things to do at the weekend but will try and make some progress on Sunday. The main nut (smooth) on RA Is an absolute nightmare so far - a chain-style oil filter remover has done nothing but marr the surface (even with some amalgamating tape to protect/grip) so am hoping a rubber version of the same tool will do the trick. I suspect Skywatcher have a specific tool that engages with the recesses on the back like a giant pair of circlip pliers!

I've got both EP and regular bearing-grade lithium grease on the way. I would say that generally the grease I've found so far is looking like decent lithium stuff. Not the notorious Synta Tar. Shims and replacement Teflon washers I'm just trying to find a good source of now - given the (theoretical) simplicity of the "hypertuning" of the worm gear alignment, i.e. make a few accurate measurements and shim accordingly, seems a no-brainer to do it while I've got it all open.

I am giving a bit of thought to what I might need to do to properly tune the alignment later on. Current-based measurement of motor load seems a sensible easy "precision" method beyond sticking an ear on it while adjusting worm gear offsets, belt tension etc. I've got a fairly accurate bench power supply handy (Rohde & Schwarz NGE100B - marginal but can do 6A in parallel mode) as well as a R&S Scope Rider with precision ammeter clamp probes, both borrowed from work, so I think I'll give that a go! I've also been giving some thought to vibration measurement; back in my drone engineering days we used to do FFT analysis of accelerometer data which would pretty readily show peaks at resonant frequencies relating to e.g. improperly balanced props, or damage in bearings. I have a few precise MEMS accelerometers handy so I figure it wouldn't hurt to just try doing some measurements with that and see if anything interesting falls out.

I’m sorry…..but really????…Can’t anyone just be happy looking through a scope anymore on a reasonable mount. I don’t mean to offend but is any of the above necessary??

[discardedastro]

11 minutes ago, Jiggy 67 said:

I’m sorry…..but really????…Can’t anyone just be happy looking through a scope anymore on a reasonable mount. I don’t mean to offend but is any of the above necessary??

I have a big VX16 Dob I happily look through with my Mk. 1 eyeballs, dodgy as they are. I shove it around and the bearings on its mount are all a bit sticky and rubbish so it'll achieve probably a degree or two of pointing accuracy if I'm careful, maybe.

This mount hosts a modest little 200mm Newt - a 200PDS, like you - and a camera imaging at 0.5"/px for very high resolution galaxy imaging. For what I do the difference between mount performance of 1-2 arcseconds and 3-4 arcseconds of error is the difference between a superb image and a dissatisfying result.

Without all this faff I produced the below and a dozen other images I am very happy with.

Is any of this necessary? Well, no, probably not. Will it extend the life of this expensive bit of equipment? Certainly. Will it reduce the amount of time I spend swearing at my mount at 1AM when the tracking isn't quite perfect? Possibly. Will it improve the performance of my mount? Probably. Will I enjoy doing this, regardless of any of that? Absolutely!

For me, astrophotography is as much about the optomechanics, sensors, optics, and precision engineering as it is about the stars, galaxies, and nebulae that I get to image. I take great pleasure in knowing that mechanically, everything is sound, working well, and doing what I want, and that I am able to achieve such precision in my back garden. The skies above aren't the only thing we can marvel at - modern engineering and precision brings some of us joy, too.

You may as well ask a classic car enthusiast if it's really necessary to rebuild their car's engine or replace some rusty panels!

Edited September 4, 2021 by discardedastro

[Jiggy 67]

2 minutes ago, discardedastro said:

I have a big VX16 Dob I happily look through with my Mk. 1 eyeballs, dodgy as they are.

This mount hosts a modest little 200mm Newt and a camera imaging at 0.5"/px for very high resolution galaxy imaging. For what I do the difference between mount performance of 1-2 arcseconds and 3-4 arcseconds of error is the difference between a superb image and a dissatisfying result.

Without all this faff I produced the below and a dozen other images I am very happy with.

Is any of this necessary? Well, no, probably not. Will it extend the life of this expensive bit of equipment? Certainly. Will it reduce the amount of time I spend swearing at my mount at 1AM when the tracking isn't quite perfect? Possibly. Will it improve the performance of my mount? Probably. Will I enjoy doing this, regardless of any of that? Absolutely!

For me, astrophotography is as much about the optomechanics, sensors, optics, and precision engineering as it is about the stars, galaxies, and nebulae that I get to image. I take great pleasure in knowing that mechanically, everything is sound, working well, and doing what I want, and that I am able to achieve such precision in my back garden. The skies above aren't the only thing we can marvel at - modern engineering and precision brings some of us joy, too.

You may as well ask a classic car enthusiast if it's really necessary to rebuild their car's engine or replace some rusty panels!

Good response, fair enough, crack on 👍👍

[bluesilver]

Just out of interest,  Was you planning on replacing all the bearings in this strip down/ rebuild?

 

[discardedastro]

10 hours ago, bluesilver said:

Just out of interest,  Was you planning on replacing all the bearings in this strip down/ rebuild?

 

I am, and am now the proud owner of a big pile of good quality SKF bearings with which to do this. The part codes listed above so far seem to have produced credible-looking parts though I've not done the worm carriers yet. It's definitely a bit marginal as to if it's worth it or not, but I figure the cost is not huge (total set of bits with spares was sub-£200 delivered) and I am a fan of doing things once and comprehensively/completely as far as possible - I'd prefer not to have this open again once I'm done!

There are a couple of bearings which may be a challenge to remove without tooling - mostly I'm thinking of the top bearing on the declination axis. This is pretty well recessed into the saddle "holder", and is going to be a pain to get a puller on, but I've not explored how that assembly might come apart yet. Every other bearing has either fallen out with a bit of gentle encouragement or come off with a very gentle tap or two with a plastic hammer. I've been out all day today but hopefully will finish tearing down RA and get the worm carriers apart/rebuilt tomorrow...

[bluesilver]

Definitely sounds like a good choice in regards to bearings if you are doing a complete tear down.

I think i might get stuck into my AZ/EQ6 today,  the RA axis on mine is not a free as the DEC Axis,  so looking to do the same as what you are doing,  complete strip down and rebuild.

Will be interested to see how you go with removal of the bearings and replacement.

[bluesilver]

Half way through my AZ/EQ6 strip down,  all going as planned.

I have now only just came across a full guide for the AZ/EQ6 ( now that i  am half way through it of course )

But just thought it might be of use to others that are thinking of doing the AZ/EQ6 version.

https://drive.google.com/file/d/1QEUMAUJR3MQMS55Vh0eY6M4WYKeGLWl5/view

Edited September 5, 2021 by bluesilver

[david_taurus83]

5 hours ago, bluesilver said:

Half way through my AZ/EQ6 strip down,  all going as planned.

I have now only just came across a full guide for the AZ/EQ6 ( now that i  am half way through it of course )

But just thought it might be of use to others that are thinking of doing the AZ/EQ6 version.

https://drive.google.com/file/d/1QEUMAUJR3MQMS55Vh0eY6M4WYKeGLWl5/view

Thanks for the link. I've just bought a new AZEQ6 so can't touch it until the warranty is out but handy to have anyway.

Astrobloke has also done a video on his rebuild and put a link to all the bearings on there.

 

[discardedastro]

4 hours ago, david_taurus83 said:

Thanks for the link. I've just bought a new AZEQ6 so can't touch it until the warranty is out but handy to have anyway.

Astrobloke has also done a video on his rebuild and put a link to all the bearings on there

That's really useful to see, so thanks for the link! I hadn't found that in my Googling.

He seems to have gotten rather luckier on tolerances on shafts etc.

Latest fun in my rebuild - the slotted nuts for adjusting the worm gear bearing float end are stuck in hard. Narrow nosed pliers just skipping out, can't get enough force on them. Rather futilely trying to find a slotted nut driver of roughly the right size and failing - I may need to ask a friend with a mill to grind back a cheap ~18mm socket to leave two slot-sized protrusions so I can get some force on them. The slots are about 1.5mm across and the bore is about 21mm, so it's a tad larger than a screwdriver will manage.

I did also find Facom's 117.B adjustable pin spanner which looks like it'd be just the job for refitting the RA nut (and removing it!) - so will see how that does.

However, I did get the worm carrier off the RA now and cleaned it all - quite a bit nastier than the Dec axis with more blackened lube on the gears and visible swarf in quite a few spots around the assembly.

The RA worm optical indexer is a trivial job to remove and as simple as you might imagine (circuit is just a pull-up resistor for the opto switch emitter, with the switch connecting pin 3 and ground on the connector.

The RA worm carrier otherwise looks pretty well identical to the Dec and suffers from very similar issues with respect to edges not being properly deburred, etc.

Edit: and just to add, while both the video linked above and this one below I also stumbled over from that video feature a teflon washer on the bottom of the RA shaft (i.e. between the lower pinion bearing and the mount head) this was not present on mine...

 

Edited September 5, 2021 by discardedastro

[discardedastro]

Just waiting for tools now - can't get the worm carriers out, though did get the worm drive gears off with some gentle encouragement from a screwdriver.

So while I can't really clean the worm carriers yet I figured I might as well make a start on the rest, so cleaned the worm pinions. I settled on a first pass of Jizer to degrease followed by a rinse, gentle dry, and then final chemical clean with Ambersil spray cleanser which was left to evaporate.

That's done quite a nice job of cleaning everything back to bare metal and removing all the grease from the pinions.

The RA has some marking from the clutch plate on about 1/3 of the gear's circumference which I think is very likely some damage from early in this mount's life when I was learning how this astrophotography thing worked and was unaware of the potential perils of mount crashes. I think I'll carefully give this a light pass of wet-and-dry to restore the surface finish, but it's not too bad as-is. There was certainly a fair bit of nasty black gunk and debris left in the pot after cleaning up, especially off the RA gear.

About the only other thing I can clean right now are the two shafts - which I will do, but need more drying space for first - and the RA half of the mount metalwork.

I pulled all the alt-az bolts from the base and gave them the same cleaning treatment which removed an absolute tonne of nasty black gunk, corrosion deposits, etc. I similarly washed out the holes in the mount with the same two-pass Jizer/Amberclene approach. These clearly need a gentle deburr and in some cases could use a bit of fresh enamel paint. I need to dig out my old modelmaking supplies - I'm pretty sure I have a pot of paint for a Saturn V model which will do just fine for this...

The screws cleaned up pretty good, though there's definitely some rusted bits left I might try and clean up further mechanically. The altitude bolt spring is well past saving but not the end of the world to lose. I'll give these all a coat with a corrosion inhibitor (ACF-50) before reassembling with Copaslip which should do well for keeping the threads happy long-term.

Lastly I cleaned up the inside of the RA bore. This featured quite a bit of debris, including some loose metal bits which are now gone. Everything's fairly well degreased in here, at least on contact surfaces.

Edited September 6, 2021 by discardedastro

[bluesilver]

Sorry, i should of made a note about getting that screw out of the worm carriers.

All i did was used a bit of 2 mm metal plate, or 2mm thick tin if you can find some laying around.

If you are handy with a hacksaw or girder,  i just cut the middle out and it worked a treat.

I have included a photo to try and show what i am talking about,  it is just a bit of metal i had laying around.

 

I have completed my rebuild and now just putting it all back together,  mine is the newer AZ/EQ6 mount with the USB hub.

So there is quiet a bit of difference between this and the AZ/EQ6

It is a very simple procedure to do once you get started.

 

[bluesilver]

I should also make a note that there are very tiny marks on the round plates that sit just above the encoders,  just make sure these are nice and clean when reinstalling.

I just used warm water and wiped them dry,  just incase you get a bit of dirt or grease on them while handing the plates while they are out.

 

[discardedastro]

I do have some 1.5mm mild steel lying around and that's definitely where I was heading next. Very much feels like there should be tools for this - I have a similar slotted nut arrangement on some of my modular synths but there's a tool for that. I've got a thing designed for opening DSLR lenses on the way which is the best tool I've been able to find.

Be very careful with the optical encoder marks - best not to touch them at all (though if you have gotten dirt on them, then washing them is a good plan). The EQ6-R has no optical encoder so all we have to worry about is the end encoder for PPEC.

[bluesilver]

It would definitely be handy to have the correct tools,  You should of seen what i had to make up to use just get the locking nut off that sits behind the polar scope.

That was the hardest part of the disassembly for myself on this mount.

The 1.5mm mid steel might be sturdy enough, depends on how stuck the screw is,  it only just needs to be tight enough to stop the worm gear moving sideways,  I found if you do them up too tight it just binds the bearings and worm gear making the worm gear hard to turn.

But give the mild steel a try,  my very rough made up one works a treat for mine.

 

[discardedastro]

This is what I've got coming for the RA nut, since I will need to do that up again and the oil filter wrench doesn't quite feel right: https://www.facom.eu/ProductSheets/ProductSheet_374_1.pdf

That should do the trick nicely. The DSLR lens tool is one of these: https://www.ebay.co.uk/itm/264761144297 - looks cheap and nasty but so long as it holds for precisely two nuts, we're good!

[bluesilver]

Definitely look like they both will do the job just fine.

It took quiet a bit of effort for me to get the RA nut off,  not sure on the EQ6,  but with the AZ/EQ6 there are 3 grub screws that must be removed first,  I am sure that you would be aware of this,  but just though it was worth a mention.

I had to remove the actual housing that the mount sits in ( not sure of the technical name ) to be able to locate them.

Sounds like you are moving along fairly well with it though.

 

[discardedastro]

So the RA nut - that Facom tool is precisely what you need. Fits perfectly. What it won't do is the Dec axis top nut - which is recessed inside the saddle mount. I presume Skywatcher have a specific tool for that which is basically a big socket with some pins in it. However, you shouldn't need to get the Dec top nut off - though if you want to replace the top Dec bearing and can't get it to slide off readily, you may have no choice.

What has got me completely stumped is the slotted nut. The amount of force I'm applying absolutely should shift it - I think whoever at Skywatcher did mine up was not doing so with a torque wrench and just cinched it down *hard*. I've managed to get it to move about 30 degrees and then damaged the tool as it skipped out, and the nut was in serious danger of being damaged at that point so I figured a safe option was to stop and regroup.

I think the next step will be to carefully lubricate the threads with a penetrating lubricant - it'll all get degreased later anyway - and see if I can reduce the friction on the installed nut to ease it out. And then we're in to things like trying to freeze the nut with freezer spray and if that doesn't work I'm not sure what to do!

Bit of a setback, but there was bound to be something!

[bluesilver]

I am just trying to picture this slotted nut that you are referring to,  I might be wrong here, but i don't think i came across one on my AZ/EQ6

The only slotted nut that comes to mind for me is the ones holding the bearings on the worm gears,  but these wouldn't be that tight unless they have used something like Loctite or thread locker on them.

If this is the case,  then just warm it up with a hot air gun, if you don't have one, a hair dryer will work to get enough heat to let the locking compound go.

 

 

[discardedastro]

8 hours ago, bluesilver said:

I am just trying to picture this slotted nut that you are referring to,  I might be wrong here, but i don't think i came across one on my AZ/EQ6

The only slotted nut that comes to mind for me is the ones holding the bearings on the worm gears,  but these wouldn't be that tight unless they have used something like Loctite or thread locker on them.

If this is the case,  then just warm it up with a hot air gun, if you don't have one, a hair dryer will work to get enough heat to let the locking compound go.

Yep, those are the ones, on the end of the worm gear carrier. On mine they appear incredibly tightly fitted, and it doesn't appear to be threadlock.

I'm just drenching them in lubricant at the moment - we'll see how we go.