Padraic M

2 hours ago, Jezphil said:

Thanks for this. Would it be this you are using?...  https://www.firstlightoptics.com/batteries-powerpacks/nevada-ps-08-6a-8a-regulated-linear-power-supply.html

It's actually this one... https://www.firstlightoptics.com/batteries-powerpacks/nevada-psw-30-25-30a-switch-mode-power-supply.html

I was using as 12V 10A generic brand power brick so when I needed to upscale I went for 30A. It's way more than enough to power the mount, camera cooler, dew bands, Mini PC etc.. and it never draws more than ~3A even when slewing.

Yes the HEQ5 doesn't like a voltage below ~11.5V. When you draw current from the PSU, the voltage will drop and the mount can behave erratically. I use a 13.8V Nevada Radio PSU and it works perfectly.

Good luck with that upgrade Jim; it's relatively straightforward, and well worth doing. You have nailed the main areas that can cause problems. Belt alignment is important as is belt tension. There are plenty of posts offering guidance on how to do both here and on YouTube. If you've bought the gear puller, removing the old gears will not be an issue. You will also need to spend some time resetting the backlash on your worm gear when you're finished. Neutral balance is important, but that's not specifically related to the belt mod - you need to do that anyway if there's any weight in your payload.

Don't overtighten any bolts (especially those holding the motors to the chassis) as the threads in the aluminium body can be stripped easily.

Be careful removing the wiring looms as I've heard of people lifting the connectors off the motherboard.

Richard that really is spectacular. There's so much detail to take in and lots of food for thought for future study. I love the "mermaid's purse" NGC2261 in the bottom left.

26 minutes ago, scotty38 said:

I use one of these together with a USB C cable to power my Mele Quieter 2, works just fine.

https://www.amazon.co.uk/gp/product/B09F5W2NCR/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I use the Quieter2 for capture control and it works great. Wifi is only ok (my house wifi isn't great anyway) so I'll buy a 5m Cat 6 cable at some stage instead.

For running Nina, Ascom and Phd2 the performance is more than good enough. I can also copy images off the PC to the local network while imaging is in progress, and it doesn't miss a beat.

I use this adapter https://www.amazon.de/dp/B07XZ7Q2N7?ref_=pe_27091401_487187591_302_E_DDE_dt_1&th=1 so that all of my power cables are the same; I run everything from a 13.8V Nevada Radio PSU through a Pocket Powerbox Advance.

PC spec is 256G embedded SSD, with an additional 1GB SSD which I have remapped as the boot partition - that way, if the SSD fails it doesn't brick the PC.

As an extra note, the PC does support NVMe SSDs as well as SATA SSDs, but as it's a single-lane PCIe bus you don't get any speed bonus.

Here's Nina in operation, although hopefully you'll only need to see this from the warm indoors.

I have a mini PC on the mount, and I have to bring the laptop outside for the few minutes while I polar align with Sharpcap. Not an issue for me but not ideal for you if you don't have a laptop or very long arms.

I just opened up the Remote Desktop client on my Samsung Android phone and it worked perfectly - actually very easy to use once you understand how to move the mouse pointer and how to click. Screenshot below.

So it looks like you can prop your phone up somewhere (maybe get a car phone holder and attach it to the mount?) while you adjust alt and az bolts.

I removed the mirror cell, removed the screws from the mirror clips, and reset them loosely with enough space to slide a business card through. The mirror clips can now be rocked slightly from side to side with no movement in the mirror.

I left the clips and baffle in place as the baffle is supposed to increase contrast by blocking reflections from the edge of the mirror. I'll take a look at the stats when I'm finished this run tonight.

I don't think collimation is 100% - I redid it after fixing the mirror but using a cheap laser.

Lovely job! I never saw that starburst detail in the companion before.

2 hours ago, ollypenrice said:

by sucking on a tube connected to the chamber

Thanks @ollypenricebut I'm not sure this vari-focal scope will catch on if you have to suck through a tube to set the focal length. Imaging nights are difficult enough as it is!!! It would certainly limit exposure lengths to about 60 seconds before you collapse from oxygen deprivation.

31 minutes ago, alacant said:

Although I must say that your stars are certainly on the social-media side of scientific, verging on the artistic even. Post it on Instagram? It could catch on:) 

Yes I was very impressed myself! they look very cool. Not sure about Instagram though there are enough alien invasion force theories circulating there already.

Will strip it down today, so I'm ready for the next imaging opportunity (whenever that might be).

Thanks @ONIKKINEN  I tightened the retaining screws finger-tight so there's no way you'd slip a credit card or even a slip of paper between clips and mirror. Sounds like they are over-tightened. I'll strip it down tomorrow and redo.

Pretty amazing that you can warp the mirror so easily!

I recently fitted a mirror baffle to the SW 150PDS Newtonian. It's this one.... https://www.teleskop-express.de/shop/product_info.php/info/p12359

I didn't really have anything particularly wrong with the stars beforehand, but I certainly have now! All stars across the image are Y-shaped. Have I tightened the mirror retaining screws too much? Have I ruined collimation?

The mirror retaining clips were just about visible when the baffle was fitted.

The first image below is out of focus to the long side by 5 auto-focus steps.

This image is after autofocus is run i.e. the best focus achievable. HFR is 5.87.

Any ideas what I've done wrong/how to fix it?

Here's the full range of focus, from long to short in intervals of 5 autofocus steps.

As above - you don't need to do flips if you're not going to hit anything. SW EQ5/EQ6 mounts don't have fixed limits but there may be limits set in EQMOD that can be cleared.

That said, I've had tripod crashes with the Esprit 80 which is not a big scope, and it looks really weird to see a scope hanging over backwards on a mount and still tracking. With NINA, flips are not that big a deal. I'm happy now to let a sequence run overnight, with automated flips, and a park to home at the end, while I sleep. I've rarely had an issue.

You don't need new flats as nothing is changing in the optical path, and your processing software will automatically register and rotate the lights when stacking.

21 hours ago, adyj1 said:

Fusion 360 is still free for personal use

I don't have a 3D printer (yet - and this thread is telling me I don't need yet another time-consuming hobby!!!) but I have designed a few things (custom project boxes) for printing in the local 3D print shop. They charge me €50 a go though, so I don't do it often 😲. At that price, printing my own would pay for itself in a few weeks if I don't charge for my time.

I use Fusion 360, because I had been using Eagle CAD for circuit boards for a few years before AutoCAD bought it and integrated it with Fusion 360. The two work well together - you can render a 3D model of your board layout and insert it into the box design.

Nice video Frank! Good luck in Tenerife, probably the only way to get clear skies.

For future reference for anyone doing this mod. I searched and I couldn't find any definitive instructions, although it's a very straight-forward procedure.

The mask is designed to improve images in two ways:
1. The edge of the primary mirror reflects light irregularly across the image plane, depending on its design or its imperfections. This can cause star halos/bloat, and can reduce contrast generally in the image.
2. The primary mirror is held in place by three mirror clips. These clips protrude over the edge of the mirror by ~5mm and can cause secondary refraction spikes on stars - or in fact, they show as interruptions in a star halo.

Both of these issues can be reduced or removed by masking off the outside edge of the mirror by a few millimeters, at the expense of those few millimeters of aperture. You can cut a mask from a variety of non-reflective materials; 3d-print your own (patterns available online) or you can buy one ready-made from the astro retailers. I bought a Wega primary mirror mask from teleskop-service. I'm sure Wega are the big name in mirror masks 🙂

1. Remove the primary mirror cell
On the 150PDS, the primary mirror cell is held in place by four Philips-head screws on the side of the OTA - not the collimation screws on the bottom. Once these are removed, the cell lifts out easily. Be careful not to drop the cell - I stood the OTA upright on the floor, mirror-end up.
Stand the mirror cell on a good surface, mirror facing up.

2. Remove the three mirror clips - there are two ~1" Philips-head screws holding each clip. The clips themselves consist of a large rubber-type block, with a metal face laid on top. Try not to drop the metal face on to the mirror surface.

3. Don't remove or move the mirror. Fit the mask in place over the mirror - I started by loosely fastening down one clip with the mask attached; then insert the other two clips between the mask and the mirror carefully. Screw them down incrementally until the six screws are all hand-tight. You might notice that the mask deforms slightly as you tighten the screws in turn so try to keep it circular. Not sure that it makes a huge difference to the image but you might as well be neat.

Here's the finished article. I took an air blower to any loose dust on the mirror but otherwise didn't do any deeper cleaning.

Here's an idea of how clear the aperture is with the mask fitted. It doesn't cover the clips 100% but it should make a big difference. I suspect it will also help block some of the light leaking in from the back.

Now that it's finished you will need to re-collimate. I found that it was only slightly out but needed some adjustment. I took care to fit the mirror cell back into the OTA in the same orientation as it was previously.

The Dark frames should be at or close to the temperature of the light frames. As you have the uncooled version of the 183 this can be tricky. Do you know what the sensor temp was for the lights? Some people pop the camera in the fridge (usually about 4 degrees C?) to get close. Full darkness required so put a lens cap on the camera. The exposure time, gain and offset should be the same as the lights.

Bias frames are not usually used for CMOS astro cameras.

Calibrated Flat frames remove vignetting and dust marks from lights. They're important. Flats don't need the same temp, exposure time, gain or offset as your lights, and the white t-shirt method is the easiest. Ideally point to the sky in early morning, but pointing at a well-lit blank wall will also work. The optical path should be identical to that used for the lights - so don't refocus or rotate the camera. If you're using filters you should take flats for each filter. 

You should also take Dark Flats to match your Flats - these use the same exposure time, temp, gain and offset as the flats, and they need full darkness so again pop on a lens cap, and/or stick the camera in a box.

Dark frames last for months, so once you have a set matching your common exposure times, gain and offset values, you can keep using them. Flats and Dark Flats though will have to be retaken reasonably regularly, especially if you dismantle your setup after every session. It's a bit of a pain, but you get used to it.

Taken over two nights last week, with my SW150PDS, ASI1600MM, Baader LRGB and 3.5nm Ha filters, Bortle 8 city lights. Processed in APP and Gimp as (Ha+L)(Ha+R)GB.

Red 27x60s
Green 25x60s
Blue 25x60s
Luminance 30x30s
Ha 19x300 + 2x600
Total 3hrs 17mins

No, I don't see any reason to use an OAG with this setup. OAGs are a complete pain to configure and for a short focal length scope like yours they're normally not used. 

Since you have the WO Zenithstar, why don't you get the WO 32mm guide scope? It looks like it should bolt to the top of the tube rings and it only weighs 240g. The ASI120mm will work just fine. I have used it and the 290mm Mini to guide both an 80mm refractor and a 150mm reflector and no problems whatsoever. 

I make the total weight of this package 3.63kg. Payload of the Skyguider Pro is given as 5kg, but I don't know if that's imaging payload - manufacturers often provide visual payload, and imaging is half of that. So you may be slightly overweight, but the guidescope is providing very little of that weight. With your scope and camera you're already overweight.

Also, the pixel scale ratio between the imaging scope and cam and the guide scope and cam is <4 which is perfect.

3 hours ago, Pixies said:

I'm inspired! This is in our back garden:

The kids' old playhouse, now a rabbit house with attached run. It's only 4'x6', but the paving it stands upon is 4' x 8'

That conduit down the wall is 240v down to the shed. The wall and trees are towards the south and west - local light pollution means those aren't the best directions anyway.

Now.... we just need the rabbits to have a little accident!

 

PS. Apologies for the state of the grass. The rabbits and dog have seen to that!

I think Canis Major already has his eye on it!

For short-term protection I have a clean 1-ton sand bag that gets put over the mount if I think the weather will hold for a few days. Beats polar aligning every night. I have 4 concrete blocks with expansion bolts and carabiners attached and I hook the loops (handles?) of the bag through carabiner clips. You might think this is overkill, but the wind blows up the valley straight from the Atlantic Ocean so if there's wind or rain expected, everything needs to be packed up and brought in. A proper wind there sounds like a train passing through the station - it's one of the reasons why I might hesitate to build an observatory. I would be afraid that a glass fibre dome would end up on the other side of the mountain fairly quickly!

https://www.amazon.co.uk/Tonne-Builders-Garden-Waste-Storage/dp/B01BYIORYQ/ref=asc_df_B01BYIORYQ/?tag=googshopuk-21&linkCode=df0&hvadid=309801358079&hvpos=&hvnetw=g&hvrand=13703509327759893315&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007850&hvtargid=pla-685044320831&psc=1

I would never have to worry about the mount over-heating 🙂 

3 minutes ago, Rodd said:

would not plate solve without an internet connection

It certainly can be done - I would need to check, but I think astrometry.net is the only plate solver that uses internet access (and even that can be installed locally). ASTAP and PS2 work fine without Internet. NINA lets you pick with plate solver(s) to use. 

Now you're getting there! 

3 minutes ago, Rodd said:

frustratiion is commonplace

Why do you think I recommended a cup of tea earlier?? 🙂

Step 1 - relax and think it through.

20 minutes ago, Rodd said:

Not sure what requirements there would be.  All teh software I use does not need a very advanced computer--it all worked on my old one and that was many generations behind the new one in all respects--Pixinsight is the exception--they say it needs huge computer potential (but it worked on my old one too).  They want 64mb RAM, the best processor (2 acutally) and linux.  But its not needed.  I got an extremely powerful processor, 16 mb RAM, a TB of SSD storage, a higher end graphics card--certainly more than enough for capture software and camera/focuser/flatman, etc control.  

I do not want to bring my mount inside--I do not want to lose orientation and PA--not to mention talikng the entire optocal train apart.  I should be able to just download what I need--I do have a list, but its still overwhelming--especially when there are licenses involved.  

I mean software requirements. If you install ASTAP for plate solving, it requires a star database etc. I'm assuming that your new PC is capable of running everything if the old PC could do it.

My own list consisted of:

- ASCOM 6.5 SP1
--- MS .net framework v3.5 (required by ASCOM)
- PhD2 V2.6.10
--- Configure equipment profile, and build Dark library
- ASTAP
- ASTAP Star Database H18
- Stellarium
--- Configure the Remote Control plug-in and enable the web server
- EQMOD
- PrimaLuceLab Sesto Senso focuser driver and software application
- Pegasus Astro Pocket Powerbox Advance driver and software application
- Ascom Switch driver for PPBA (to integrate with NINA)
- ZWO ASCOM driver (All ASCOM drivers)
- ZWO ASI Camera Drivers (ZWO native drivers)
- NINA 2.0 Beta 026
--- Download the Sky Atlas Image Repository  and configure NINA to point to install directory
--- Configure NINA including equipment profile etc.
 

I don't have any SBIG cameras and I don't use SGP or MaximDL.

I don't think it will be a case of just downloading everything then off to the obsy - while you may not need the internet to install software, in my experience you will always need to download another program/another version/look up the documentation while you are installing, and you need the internet for that. 

Hi @Rodd good luck with that job, you may be in for a ride!

I've just rebuilt a mini PC with a full image capture stack, but there's very little overlap in our equipment sets so my detailed steps will be of very little use to you. As general advice though, I'd say:

- Separate image capture from image processing, and get them working separately rather than all together. I'd suggest capture first and test it, then do your processing software and test it.
- A good rule when configuring computers like this is to make one change at a time then test it thoroughly. At least you know what went wrong. If you install everything together in one go you will have no idea why it doesn't work.
- As Julian says, write a list of everything you need to install, and the pre-requisites for each as best as you can remember. If something goes wrong, you may need to retrace your steps or even start from scratch, and having a master list of requirements is important.
- Usually, install drivers first then the application. Let the installer decide which directories to use, so if you need to report issues to the various forums, you know where everything is.
- I have a directory called 'Install' where I download all of the installers, and keep them for future use. The installer name will usually include the version number, but add it if it doesn't.
- Do as much of this in the house as possible, where you have a comfortable seat, a cup of tea and reliable internet. Try to take as many variables out of the loop as possible so you know that any errors you find are to do with what you've done, and not some random coincidence. You might even find that bringing your mount head indoors might make things simpler.

I had to refine my list a few times as I built the mini PC. Then when I was finished, I blanked the disk and did a full reinstall using the final version of the list. Not essential, but it means that there's no **** hanging around from failed installs and second attempts etc.