discardedastro

Keep sensors/alarm stuff separate from CCTV. Makes life much easier and you can always do simple contact-closure links if you want e.g. alarm to trigger CCTV.

Reolink are pretty well regarded for CCTV. They have turnkey kits with a network video recorder and cameras, but you can assemble your own. Avoid the white light ones, make sure all your imaging filters have IR cut and you'll be fine in practice. PoE makes life much easier for cabling, too. Wire everything - wireless can be done but in my experience isn't worth the hassle- better to get the hassle over and done with once by putting cables in and usually very easy on outbuildings anyway!

Alarms - lots of cheap and cheerful solutions out there. Again would opt for wired "dumb" alarms over wireless fancy things any day of the week, but I'm allergic to cloud stuff! Texecom do some cheaper options e.g. Veritas series, or smaller all-in-one panels which can be IP/LAN/cloud enabled if you want via ComIP modules. Those will just make lots of noise if they get triggered. Which then begs the question of detection. PIRs and other motion tech will get triggered on a moving roof or telescope (or airflow, sudden illumination changes, etc) so if you're aiming for unattended operation you'll need to consider that. You can of course still go for e.g. contact closures and/or shock sensors to detect people breaking the door down, beam-break sensors, and so on.

Exterior lighting - just get a dumb PIR and wire up a regular outside light. But think about how you isolate this if you want to maintain a dark environment for observing nights! False positives will happen a lot with external PIRs due to wind, swaying plants, etc etc. You should also think carefully about glare. If you're lighting from the observatory, for instance, you're probably going to be blinded by the light if you're looking towards it. Effective security lighting should mostly light the ground up, avoid shining you in the eyes, etc. So probably best on your house shining out towards the observatory.

We have two sheds with kit in and will be adding an observatory; the back garden doesn't have any PIR sensors but the approaches (front/side) do and lighting on the walls facing down so false activations don't upset the telescopes. Alarm likewise covers the approaches, as does CCTV, but there's more CCTV covering the outbuildings and telescope (all IR lit).

Surge protection and local earth is definitely the way to go as others have said. Couple of long earth rods will work better (and be cheaper!) than lots of short ones. The overall surface area is what you're after, coupled with low resistivity. Don't forget they need regular inspections. If you want a lower-maintenance solution then "conductive concrete" is a thing. Pretty widely used in telecoms these days for earths for street cabinets as they don't need the depth (often a problem near buried utilities!) and are maintenance-free - they can't corrode as such.

UPS-wise, definitely look for "online" topology which has the UPS constantly generating its own clean AC. As others have noted, that won't help you with surge current and it won't provide protection from lighting. However, lightning causes all sorts of fun transient currents and issues that can still cause problems for kit. Line-interactive won't respond quickly enough, but online doesn't really have to be quick because it's always on. Note some online UPSes do have an efficiency bypass mode which you'll want to disable for this sort of thing.

I'd go for something reasonably robust and ideally designed for unattended operation - small form factor servers like those used for edge computing which are set up to boot remotely, reliably. Whatever you go for, make sure you can get it booted up on just power (not needing the power button to be pushed - usually an option available in BIOS for "power on state") and go for as reliable you can on components - good-quality SSD of some sort, ECC memory, etc.

Bandwidth-wise, don't underestimate how much time you've got in daytime, I guess. If you're not getting frames back realtime, if you're moving files at just 1Mbps, in 12 hours that's over 40 gigabytes.

I'd focus on making your remote side ultra-reliable, ultra-robust, and just enough computer to do what you need for capture. If you're familiar enough or willing to learn, Linux will be far more reliable in general than Windows (don't have to worry about Windows Update halfway through a session, etc). If you've used the INDI stack before then KStars+INDI can be a very powerful setup on Linux, and pretty reliable. Otherwise, still focus on keeping the remote side simple. Keep the complex stuff and powerful machines close to home where you can apply percussive maintenance when they keel over!

For less than the (sexy, small, more-astro-features-in-one-box) Eagle you can pick up a brand new Supermicro tower server (e.g. this) with a reliable Xeon server processor, 32G of error-correcting reliable ECC RAM, dual 480GB Micron 7450 M.2 NVMe disks in RAID1 for redundancy for your operating system, dual 960GB Micron 5400 MAX SSDs in RAID1 with redundancy for your image data, out-of-band remote management through Supermicro IPMI, and expansion capability for days. For a splash more you could drop in a beefier CPU and GPU and have a very capable remote PixInsight box.

I'd suggest a CCTV camera if one isn't already provided. Vital to be able to see what you're doing when operating completely remotely. Reolink make perfectly good cheap IP cameras which also support turning the IR lamps off for (slow) low-light views.

With all the wind, definitely plan for securing everything down firmly if leaving outside, is my only advice! My VX16 dob stayed dry (condensation aside) in its TG365 cover outside, but the wind was enough to blow it right over; it landed on the Feathertouch focuser which now squeaks, so I have a project, but the rest seems to have survived.

2 hours ago, dk101 said:

I am not familiar with the UK wiring rules but is it ok to put a copper network and mains power cables through the same conduit underground? I hear that in some countries this is a no-no and this is where fibre comes in to play as fibre data can go with mains power while copper would not be allowed.

Is this even an issue over here?

 

I don't think it matters by the book - I have a copy of the regs but I'm not a practitioner!

Over short distances in practice it'll be fine, I think.

Over longer distances, there is risk of induced current causing problems with potential difference between ends, and grounding etc becomes problematic.

There is a practical benefit in terms of electrical safety if you're just considering the network cable, which is lightning protection. I have seen cases of lightning hitting one building and toasting the network (in one case where the conductor of a lightning rod ran parallel to a bundle of Cat5e, without direct connection toasting a whole office's worth of computers). But if you're running mains alongside - which is likely - there's probably not much benefit.

7 hours ago, powerlord said:

It is a bit overkill, ethernet will run 100m easy. And shielded cat6 is available if required.  If you want 10gb then go fibre, but otherwise...does seem a bit overkill - but nowt wrong with that if it floats yer boat! 🙂

 

Ethernet will run 100 metres quite readily, yes - in theory

However, here's the thing; how that Ethernet cable was installed will determine how well stuff runs over the Ethernet link. This is one of the great challenges in copper cabling (and why things called cable certifiers exist, and form part of any competent cabling installation work in the commercial world - because they can verify the RF performance post-installation).

Cat6 and Cat6A run as far as each other; Cat5e runs shorter distances at higher speed due to lower RF performance. 6A is practically irrelevant for homes, because the situation for which it was designed - high alien crosstalk - will never occur. Shielding only really factors in when you have bundles of dozens or hundreds of cables running alongside each other (causing noise between 10-600MHz) - this happens a lot in large businesses and datacentres, but rarely otherwise. Save your money and don't bother with shielding for home! 50Hz from mains simply doesn't matter; Ethernet over Cat5e can reject this just fine (induced DC voltages aside).

If you kink the cable, even temporarily, beyond its bend limit during installation; or over-strain it, or secure it with clips that pinch it too tightly, you can very easily deform the copper and this will have an impact on performance. The interesting thing is that it has to be really bad to be visible easily. You'll plug those things together, and they'll negotiate a gigabit link! The negotiation only requires very basic signalling at low speeds. If you start using this on a LAN, it'll be fine. If you then try and actually throw gigabit speeds around, particularly with protocols based on TCP, if the cable isn't performing well you'll see performance fall short. Frames will be dropped; TCP will start retransmitting more. Applications like INDI or ASCOM will start having to work harder (at the transport layer) if they're working on a link which is dropping packets/frames.

This is, incidentally, a significant problem for ISPs offering gigabit speeds! Lots of people have home wiring which is just fine at 100Mbps or 80Mbps or whatever their home internet can provide. Then they upgrade, their home internet can do 940Mbps, and suddenly they complain they can't get more than 300Mbps on a speed test while plugged in at the back of their house over some Ethernet installed by a telephone/aerial engineer a decade prior, even on a short run...

Fibre is actually rather a lot more forgiving in a lot of respects! While older glass was hard to handle, modern cables using G.657.A1 or even G.657.B1-3 have better bending radius limits than copper and suffer no appreciable damage if radius limits are exceeded temporarily during installation. Some fibre cables can tolerate being stapled directly to walls or bent less than 5mm.

And crucially, on short links - under a kilometer - even if you damage the cable quite badly there's enough link budget left for everything to work. A typical gigabit transceiver has a launch power of around -3dBm, and a receive sensitivity of -23dBm. This means you have 20dB of link budget. For reference, a "bad" fibre fault might introduce between 1-3dB of loss, and you normally lose around 0.3dB for every 1000m of cable. Compare this to copper where a "perfect" installation of a Cat6 link might have about 0.5-1dB of link budget remaining - and remember dB is a log scale!

You can mess up really, really badly on a fibre link over short distances (up to 3-5km) and not notice a thing. Kinks/macrobends, dirty connectors full of mud, etc etc. If you don't unwind the cable properly while installing 100m of copper and induce a kink, you can easily fail to achieve much more than 100Mbps of performance. So that's where fibre can really provide a benefit over copper on longer cable runs.

22 minutes ago, malc-c said:

Sounds like you are you doing a sales pitch 🤔?

My observatory is around 50 feet away, and I used standard cat5  cable between the PC in the observatory and the switch in the house.  The cable was tacked to the fence and has lasted more than 13 years without any issues.  The home network is gigabite  speed which is ample for remote desktop sessions.

Totalling up the cost of fibre, there won't be much change out of £150 for a similar arrangement... but what would I gain... nothing as the fibre link is rated at the same speed, plus fibre is more fragile than cat5/6.   Now where you would gain is in distance, as the max cat6 length is around 100m.... but I don't know many who have 100m+ long gardens.

I don't make any money from any of the above, I've just spent enough time explaining to people why their 150m bit of cat5 directly buried/submerged/nailed to fenceposts/jointed with wire nuts wasn't performing very well to feel like writing it down once to refer to...!

You're quite right though that on short runs, you can certainly get away with copper. I use copper for my own telescope (not an observatory, but left outside), but then it's a 10 metre patch cord! I use fibre for other runs - some IP cameras 100m away get DC power on some tri-rated cable and fibre for connectivity, for instance.

Fibre isn't actually more fragile - copper cable does need to be treated more carefully than fibre to maintain its performance, and is harder to verify if damaged. Armoured fibre cables are very robust, and modern fibre (G.657.A1/A2) has a minimum bend radius so small as to be practically irrelevant (50mm in the worst case). Copper has similar bend radius requirements, but also doesn't tend to recover if this is ever exceeded in installation.

In practice, if there's significant risk of lightning, or the structure is >50m away as the cable runs, fibre is more appropriate (as a rule of thumb).

Lots of people will reach for a long bit of Cat5e cable, maybe even outdoor-rated, when wiring a new observatory into their home. This can work, but can also lead to all sorts of Fun and performance issues over longer distances.

Fortunately there's an alternative that's more appropriate for permanent or semi-permanent installations - fibre optics - and it doesn't cost much more. Using fibre means no (active) electrical elements outside, simpler grounding for any armour, no risk of interference from mains or other electrical sources, and no distance limits.

I've ended up explaining bits of this a few times (my background is in fibre to the home optical architecture and engineering), so thought it might be helpful for some to have a single guide.

Firstly, a bit of a primer on fibre optics.

Terminating and splicing

Fibre itself is a very, very thin (125um) strand of glass, usually coated (250um) and then buffered within a gel-filled tube, which is then armoured or further protected with e.g. kevlar strands within a cable.

Putting connectors on fibre is very hard. Even professionals with tooling leave termination to labs; field termination is normaly done by splicing on a pre-made connector.

Splicing involves melting two fibres together while mechanically pressing them together. It requires specialist equipment (on the order of £2k for the cheap stuff) and skill.

All of which is to say - this is hard. But the good news is we don't need to do any of this, because we'll buy pre-made assembled cables!

Cleanliness

Connectors are easily damaged or affected by dirt and debris. Again, normally in a professional environment you'd use a microscope to check for cleanliness and to check cleaning results. We're talking short distances here, though, so in practice if you keep the dust caps on till you're ready to connect stuff, you'll be fine.

Fibre types

There's two types of fibre - single and multi mode. These differ in their core geometry, and by consequence the modes of light that can propogate within them.

In practice in 2023, ignore multi mode; it has limited applications and is falling out of favour even in those applications. Single mode fibres use near-infrared (NIR) light between around 1260nm-1650nm. This is what you want!

Connectors and cable types

All fibre terminates in connectors to connect to equipment or patch panels, keystone modules, etc.

There are many, many connectors out there. In practice all you need to know about is LC - small, 1.25mm ferrule connector often used for duplex connections - and SC, a 2.5mm ferrule square connector most commonly used for simplex connections (though that isn't what SC stands for!).

You also need to be aware that there are two polishes of connector - UPC and APC (PC is just like UPC, but worse quality - rarely found now). APC is angled polished contact, and is mostly used on passive optical networks like the one BT and others are building in the UK at the moment where reflections are important; APC bounces any reflections off into the cladding instead of bouncing it right back down the fibre. In practice - APC has green connector bodies, UPC is blue. You want UPC, or blue. Connectors on equipment are almost always UPC.

Cables come in many varieties, to suit different applications. You'll find the most readily available off the shelf are patch cords, which are meant for indoor use. However, lots of people will also supply pre-made armoured cables suitable for outdoor use or burial. Note that short and long cables may cost similar amounts at the low end of things - most of the cost of a cable up to 50-100m is not in the cable, but in the labour to terminate each end with its connectors.

Optical signalling and duplex vs simplex

The simplest optical link requires two fibres. Each fibre is used by one transmitter at each end, and a receiver at the other end receives the light. This is a 2-fibre duplex link.

However, we can save some cash by making the link a bidirectional fibre link. This uses bidirectional optics- which use a different set of coloured lasers in each direction and filter the light received at each end. This means we now only need one fibre!

This is the hot plan most of the time - it saves you some cash on the cable.

Transceivers/optics

Transceivers - also called optics - do the actual talking optically. They're normally plug-in modules, with electrical contacts on one side and a fibre connector on the other.

These modules plug into switches with "cages" to receive them, or can be connected into devices called media converters which act to just translate from copper to fibre.

You'll often see these "coded" for specific vendors - some switch vendors only support "their" optics despite it all being an open standard, so often people will sell you parts that look like e.g. Cisco's parts.

For gigabit systems the most commonly used format is SFP. 10 Gigabit systems use SFP+.

Transceivers are also the defining element (aside from cable/connector quality) that define how far you can reach. On singlemode optics, 10km is the very shortest you can get - and in practice these are actually 20km parts that didn't quite make the cut during test. If you're doing more than 20km you probably should go hire someone to do this all for you! But it does highlight one of the huge upsides - no distance limits to worry about in practice.

Recommended system

What do you actually need to hook up your observatory?

You need a few things. In order, this is how we get from a network switch in the home to a network switch in the obsy:

1. Switch port
2. Cat5e patch cable
3. Media converter 1
4. Bidirectional optic in media converter 1
5. Fibre cable
6. Bidirectional optic in media converter 2
7. Media converter 2
8. Cat5e patch cable
9. Switch port

So to summarise: two media converters, two optics, a cable and some patchcords. I'll show some links to fs.com below, who are a reasonable supplier and quite cost-effective, but other vendors are of course available...

Media converters can be had for cheap - £30 an end: https://www.fs.com/uk/products/104628.html?attribute=49020&id=751923

Into these media converters you'll need a matching pair of bidirectional optics: https://www.fs.com/uk/products/75336.html and https://www.fs.com/uk/products/75335.html?attribute=47458&id=740510 for instance. TX and RX should be swapped on one.

Cables are easy enough. Armoured assemblies can be had for less than £60 for 30 metres, e.g. https://www.fs.com/uk/products/70220.html

If you want to run a lot of cable internally you might want indoor-rated cable (EuroClass Cca, LSZH, etc). You can join cables together with couplers, which let you plug a connector into another connector; for instance, https://www.fs.com/uk/products/76103.html is suitable for coupling LC to LC.

Assembly is simple - plug it all together and switch it on. Now you have a reliable, fibre optic gigabit link from building to building, with no earthing issues to worry about!

If you're using armoured cable you should still attach the shield to ground, but this has no impact on signalling. You can do this at both ends or the end with the best ground.

Hope this helps and happy to answer questions and expand this if people find it useful!

6 minutes ago, iapa said:

Goods points, and considered.

All electrical will be grounded at both ends.

As will the pier itself - separate to the electricals.

Albeit 40+ yrs ago now, I used to to be an Air Traffic Engineer (fancy title) with the CAA - so, am aware to consider this stuff.

Electrically, you can still have Interesting potentials with grounding at both ends, particularly on signalling - I may be teaching you to suck eggs but for Ethernet in particular some fun can occur...

You're best off going optical if it's any appreciable distance. A pair of media converters and optics doesn't cost much, and the cable required can be gotten pre-terminated. Plug-and-play and none of the surge protection/ground loop/interference issues!

I'd avoid wireless like the plague, unless you can do something "proper" like a 60GHz link or short-hop 5GHz, but it'd cost much more.

Just to add to the above - which is all right - leaving the cap on is good advice while it cools down but once you're observing a dew shield will go a long way. Astrozap ones work very well and aren't too dear but a bit of foam wrapped round the end will do.

Dew heaters are probably excessive for the primary on a 200P; I've used mine in very humid conditions for all-night imaging without any issues (with a dew shield). However, they are useful for other optics like any coma corrector/eyepieces, finderscopes, and your secondary, which is all much more prone to dewing up.

I'll throw one vote out for Darn Tough socks - they're very hard-wearing and are guaranteed for life, but still comfy and warm merinio wool. I buy mine through Ultralight Outdoor Gear, but quite a few UK stockists now carry them.

https://www.logicalincrements.com/ is a great starting point.

Photoshop et al will use GPU for some stuff but so long as you have a basic one to offload the boring drawing from the CPU you don't need much.

RAM then disk then CPU then GPU is your hierarchy of needs for most of those tools and similar stuff like PixInsight.

32 or 64G of RAM is great - but it does ideally want to be reasonably fast, so dual channel rather than quad if possible.

Disk - go NVMe. If you can't splash on that for bulk storage, go for a SATA SSD for your OS and get a NVMe disk sized for your typical projects additionally.

CPU - as much as you can, budget permitting! I'd go AMD for bang-for-buck; AM4 stuff is a bit older and less upgradeable but that means it's a fair bit cheaper and still powerful.

GPU I'd stick to something cheap and cheerful. NVIDIA 10x0 series still stand up just fine, 20x0 better. Don't sweat about 30x0 or 40x0. AMD also fine.

Motherboard should be a decent model with a bit of room to grow in the way of storage etc.

Does PI freeze or crash? If it's freezing, then it's likely gotten stuck waiting for something. Network drives that no longer exist, disk issues, etc.

It could of course just be software in which case the tips above are good.

Unlikely to be graphics if it gets as far as rendering the UI initially, but possible - try a GPU benchmarking tool like Furmark and see if that falls over.

You can use a tool like Process Monitor to see what file accesses etc PI is trying to do when it hangs/crashes: https://learn.microsoft.com/en-us/sysinternals/downloads/procmon

4 hours ago, windjammer said:

 

Since you ask....and here is probably more than you wanted to know !

Please take this as the compliment that it is intended to be: you are quite insane. That's magnificently mad!

1 hour ago, rrbailey89 said:

Not to necro this thread but I came across it in all of its glorious information while searching for a question to a potential problem I have. 

I am wondering what level of water resistance if any the EQ6-R Pro has. I was out a few nights ago now and the sprinklers kicked on in my neighborhood, these are automated some way and do not turn on at the same time each night, they dont even turn on every day and I have no control over them. Regardless the mount was set up and It got wet (it was not plugged in). I am more curious if there are seals that help keep water out of the mount head or if I should break it down and examine the inside.

There's no seals, I'm afraid - so if it got sprayed with water, the odds are good there's some in there. Most of it is brass and aluminium, which is good, but the worm gears are mild steel, and I wouldn't swear to the materials used in the bearings!

If it got a light spritz I would just dry it out - stick it in a closed box with some silica gel or similar (you can get silica gel in bulk). For reference mine lives outside, under a Telegizmos cover, in a wet bit of the UK with high humidity and lots of local water and is absolutely fine with it. If it got a good drenching I would at least pop the cover off the motor area and see if that looks dry.

Try a torch held close in to the screen. Failing that, consider the bits to enable a firmware upgrade if you haven't already got them - probably cheaper than a new handset and I would bet flashing new firmware blows out those settings...

https://www.skywatcher.com/download/software/

First Contact if you want perfect...

https://www.photoniccleaning.com/default.asp

But for anything but semi-permanently-installed systems, probably overkill. Optic wonder works OK - I find Sticklers splice/connector cleaning fluid (designed for fibre optics) works well at removing smears. Nearly-neat IPA (90% or so) also works well.

I totally feel the frustration. I will say that the Pi 4 can absolutely reliably run Ekos/KStars/INDI, and a desktop session for it all, though - I would focus on configuration quirks.

I've had the tracking stop because the mount exceeded limits according to KStars - I found that going in and enabling and then disabling all of the limits at the start of a night resolved this. Odd meridian flip behaviour is definitely a KStars/Ekos issue - my only advice on that front is to update fully because there have been improvements in that logic of late.

I'd also get super methodical with what you do. Write a checklist for session startup and shutdown. If you can, use the Ekos scheduler - this way, if stuff fails then Ekos will at least retry things for you, and you can use it to plan your imaging for the night ahead.

Totally agree re making sure power and mechanics are all good and working properly. Make sure you can slew without seeing significant voltage drops on your power supply, for instance.

In terms of the reflections and optical issues - I would again just get very methodical. Start with a bare OTA and a flat field, and gradually build out your optical train (for components with glass), using spacers to replace parts as needed. This you can do on a kitchen table with a flat panel. If that doesn't show up an immediate culprit, repeat the same with a star test.

I'd also consider light leakage on the reflector, in addition to +1ing the coma corrector comment above. Flocking the tube and blocking up any ports/potential light leaks is cheap and easy to do, and will do no harm.

Mechanically, making sure your focuser is properly adjusted may help with any bending due to long optical train lever arms, especially tension and clamping onto the tube at the base. But I would say the biggest upgrade by far I did for my OTA and imaging stability/happiness was a focuser upgrade, and it's one of the cheaper things to do in any case (and portable, if you ever decide to upgrade your OTA!).

Bit more of a techie solution - I use a mix of local storage in my desktop (some fast NVMe disks) for stuff I'm actually working on in PI etc, and a file server (some hardware thrown out from a previous job, but it's a ZFS JBOD with about 60TB of disks for 30T of very, very redundant storage) stores all of the data long-term.

I still don't worry about much intermediate data - I store masters, PI projects, and raw subframes/calibration frames.

Performance-wise, PI's major bottleneck in most high-end PCs is usually storage, so fast local storage is definitely order of the day for performance. If you've not got NVMe disks, you can get PCIe to NVMe adapters really cheaply, and then use NVMe M.2 disks - an easy and cheap upgrade!

I have a stack of Python scripts and a PostgreSQL database I built to analyse and store all the subframes in an organised library so I can with a simple script automatically retrieve all the data I have for a given target along with calibration frames and metadata - and then I have a PixInsight script which automatically does all the calibrations for those collections so I can query any sky position and get to a big pile of calibrated subframes ready to process without having to manually go through all of it filter-by-filter, session-by-session.

https://www.talkunafraid.co.uk/2022/02/cataloguing-astrophotography-data-for-fun-and-profit/

Backups - I use Backblaze on the desktop which backs up everything there and keeps it for a year after deletion or moving back to the file store. This is pretty dependent on a fast internet connection but I have a gig symmetrical line. I also use ZFS snapshots, so if I accidentally delete everything on the store I have a full year to get it back from a snapshot. I use borg for most of my off-site stuff but don't currently back up my image data off-site - disks in a datacenter still cost quite a bit! I have pondered Amazon Glacier but it needs a bunch of tooling I've not played with yet.

Moving data from the ZFS pool to desktop is fast enough with gigabit Ethernet between both boxes. Might move to 10G soon but it's pretty decent at 1GE.

And we're back in business!

I've not yet sorted out the cable management - waiting on a few bits and pieces - but you can see some of the heaters and the handle on this photo.

All back together, re-collimated, and the views are great (as far as I can tell on a full moon light)!

Very happy with how it's all turned out. The car-polished and PTFE-lubricated bearing surfaces are much easier to move - much less stiction - and the handle is a serious upgrade (!). The Telrad and finder both worked great with some minor realignment, but mechanically are very solid compared to before.

I've fitted the heater controller between the rings and that seems to be working - given it was a light night I just left it all out there for a few hours with the heaters running. The Telrad and finder dewed up with heat on about 20%, the primary and secondary at around 25% were dew-free.

The eyepiece and the finder eyepiece both dewed up, which is a challenge - I might need to add a second dew heater controller and some more heating bands to have this work for long-term observing sessions where we are (which is a very damp area).

I've not done the tapping required to connect any encoders yet. I've not got these on order and it'll be pretty easy to do after the fact.

All in all, I'm going to call this "done" bar some cable ties and a new tube cover, which I'll make now I've got my workshop clear of the scope itself. Definitely worth the faff in my mind and I'm looking forward to some dark skies!

Bit of delay on finishing up, but the mirrors are - as-is - back in the tube and remounted. I'd planned to add a dew heater strip but realised on reassembly the mirror clips don't really accommodate anything much between the tube and the mirror, so I've spread it out behind the mirror to see if that can work acceptably. The fan in the mirror cell is in and sorted, at least. All much cleaner than when it started!

Mechanically, all looking OK - I've also added a set of cable tie anchors down the side so I can secure all the cables once it's back in the tube rings and remounted. The Telrad base and new finder base are all bolted in place now, and I've added just the one handle for now for maneuvering. My guess as to the right thumbscrews for the secondary turned out to be incorrect, so I'll need to source some extra long ones for that.

Now the mirror's off the workbench I've stripped the base and rings down and repainted most of the key surfaces. I've got some simple wax car polish to clean up the base and contact surfaces, so hopefully that'll help, but it's looking much tidier with a lick of paint on the damaged surfaces to start. I'm going to tap a few holes for future encoder mounting options and then reassemble so I can crack on with collimation and get it back in use.

I think if this comes apart again it'll be for a full service and recoating with OOUK, but it's in much better shape than it was a year ago! I need to get it out of the garage to make room to make the new tube cover, so that's the last thing I'll do, but that's about all I had left on my todo list - I'll fit the heaters once the scope's back in the tube rings.

So, taking some of the data from this attempt back in March I added a bit more data and had another go at processing.

Same acquisition setup, so see prior thread for that, but I'd picked up a few nights of extra data and decided to try reprocessing.

This is the first image for which I've automated much of the processing of subframes for, too - I've written up my development efforts over here, but the short version is that everything the telescope captures is automatically indexed, analysed, and catalogued into a database; subsequently, given a target NGC reference, everything is extracted in clusters corresponding to alignment groups (for mosaics) along with the relevant calibration data and metadata, and a script I've made for PixInsight takes that data and does all the "boring" bits of processing like calibration and cosmetic correction, before setting everything up for manual subframe selection.

https://www.talkunafraid.co.uk/2022/02/cataloguing-astrophotography-data-for-fun-and-profit/

So, after that, I had a big pile of sorted and calibrated/corrected subframes - I used blink to throw out anything with satellite trails and very poor SNR which left me with about 40-50 exposures per filter. After that I went through a pretty basic LRGB workflow in PI, with deconvolution and a couple of noise reduction passes, giving the below result! I was able to preserve more of the background in this version which I'm happy about for framing, though the contrast of details in tne nebula are still an area I would like to improve on.

Velcro!

Get yourself some nice long reels of Velcro, and some Velcro sticky-back hook tape.

The sticky-back tape can be used to anchor stuff directly - e.g. my Raspberry Pi, power distribution box, and temperature sensors all use that method. You can also take that long non-sticky-backed stuff, and wrap a loop tightly around the tube. This can rotate and move slightly but in practice won't shift about much, and you can use the sticky-backed stuff to anchor if needed. You can then add additional strips of velcro onto this loop to retain cables and so on. Bundle up cables with more velcro strips.

The Velcro approach is great because it's infinitely flexible and allows for motion along the cable assembly. It's also cheap as chips, super easy to adjust, and (largely) non-permanent, especially if you avoid the sticky-backed stuff.

On bigger scopes, it's worth having permanently fixed anchors - either adhesive or bolt mounted cable tie anchors are a good start.

8 hours ago, faulksy said:

have you tried putting a light under your primary mirror and view it from the mirror side. this will show you how thin your coatings are.

john will re coat your primary for around £150. might be worth getting your secondary done as well.

stiction in the azy motion is greatly reduced by applying car polish to the base then polishing by hand. you can do it on the alt bearings as well 😄

Car polish! Got that for days - is the goal there just to make the opposing surface as smooth as possible? I was thinking of taking a PTFE sheet - I've got a few - and covering the base as far as the pads on the bottom plate go, so the contact is PTFE-on-PTFE there.

Bit harder to do for the az-axis, though.

14 minutes ago, Paz said:

Are you getting replacement ptfe bits from OOUK? I am wondering about getting spares for my VX14 (although they don't need replacing yet).

My VX14 is a little flatter where the OTA joins but less so than yours. 

For the bearings? I've not considered getting new bits from OOUK, but there is a lot of stiction in it - once the mirror's back in the cell/tube I'll have room to pull the azimuth bearing apart fully and see if that's the problem, but the altitude bearing isn't super-smooth either. I do have some PTFE sheet to hand, but it's probably not thick enough to form bearings from.