bosun21

The tape on the tube is so that the fixing screw holes on the tube line up accurately with the primary mirror cell. The mirror itself can be collimated correctly regardless of the rotation position as it's a parabolic mirror.

On removing the primary mirror on my 10" Skywatcher the springs already fitted were a heavier gauge than the ones I bought to replace them. A pleasant surprise.

I thought that 6 times was a tad excessive 😂. I must have read it wrong. I actually went to change the springs on my 10" and on removing the mirror I was pleased to see good heavy springs already fitted. It's worth checking though as the 12" mirror is a good bit heavier. Good springs are a must if you want to preserve the accurate collimation. I don't think the central screw on the secondary mirror holder has anything to do with it as they are all standardised parts on an assembly line. I am confident in finding the problem in a matter of minutes and then collimating the scope correctly while taking you through each step.

If he's had the primary mirror out 6 times in a relatively short period in addition to not having the required skillset is a perfect recipe for errors to occur. There's a good chance he has maybe changed the primary springs with all his tinkering. He's probably realised that he has messed things up badly hence him selling it at such a good price. Don't worry we'll soon have it as good as new. I also have extra springs that I bought for my 12' should you need them

It's a simple matter of removing the primary and reinstalling it properly and back to it's proper position. You could wash the mirror while you have it out but only if there is dirt on the mirror otherwise leave it. The 12" mirror is easy to remove and replace. I had the mirror out several times with my 12" for modifications.

I have collimated 8" 10" and 12" Flextube dobsonians and left the springs in place.

There is a bit of tilt error but It's more than close enough for visual at low to medium magnification. At higher power the collimation error becomes noticeable.

Much closer but I definitely wouldn't remove the springs. They are there for a solid reason which is to keep tension on the secondary mirror holder at all times. This helps the secondary to be held in the correct position and stay there. You can get yourself tied up and chasing your tail with the secondary but never seem to get it just right. The telescope will most definitely be able to achieve collimation with them in place. The fact that you couldn't with them fitted tells me something else is wrong. I just want you to get it bang on for the 12"to enable you and I to draw the views and planetary images from both our 10" & 12" dobsonians. If you can't get it just right i would be more than happy to assist you with it (springs in place) as we are pretty close to each other.

I also suffer from this affliction.

I have managed to get my 10" Flextube bang on. It's also a F4.8 and I found that the secondary mirror is the crucial factor with these. I don't know whether it's due to them having an oversize secondary mirror but I used a 2" Concenter which accurately allowed me to position the mirror on all the axes especially for the mirror itself with the pitch, yaw and roll to achieve a perfect circular disc and positioned correctly as pertaining to the focuser draw tube and focuser itself. Now I can get my Hotech laser, Cheshire and collimation cap to all correspond perfectly.

A Concenter is the most visually accurate for getting the secondary perfectly set. It positions the secondary accurately centered in the focuser draw tube and more importantly it sets the secondary mirror tilt for all of its axes. A laser can not do this neither can a Cheshire accurately. Once I get the collimation bang on the difference is very noticeable.

That's the only regret I have with my astronomy journey in that I didn't start a detailed journal of my observing sessions. As the saying goes, better late than never as I have just ordered a proper bound journal and was actually brave enough to include some sketching materials. Wish me luck 🤞.

Your post has made me feel a little bit better regarding a (possible 😉) third purchase of the Svbony 3-8mm zoom. Funny enough the small eye lens and shorter eye relief doesn't seem to stop me from using and lauding over the 10mm BCO on the planets. I would love to hear your assessment and comparison to the TV zoom under good conditions on a tracked mount. No disrespect to others but an experienced observer such as yourself would pick up on small points perhaps missed by others. Perhaps if the UK weather improves you may actually have the clear sky time in order to carry the assessment out.

If you are viewing from your back garden I would opt for the Nevada power supply. I use mine and run a silicone Lynx astro cable to the mount. This ensures that I am always getting 12v + at the mount. Skywatcher mounts can be quite temperamental if supplied with less than 12v which will happen when most standard batteries are running down.

I have previously owned two of them and sold them on due to the relatively small eye lens and shorter than what I am used to eye relief. Now on reflection and after reading so many recommendations from members I think I may have been a tad hasty in giving up with them. Not that I will ever confess to buying a (cough, cough) third one 🙄.

Well when you put it that way you definitely have a valid point 😂.

Where are you roughly located Kostas? I can only dream of a bright Milky way despite not living that far apart from each other. Thank god that planetary doesn't really require dark skies(within reason). I see you are looking for a short Cheshire on the wanted adds. Is this to align your secondary mirror and see the primary clips? I could borrow you my 2" Concenter to allow you to set your secondary mirror if you like. PM me if interested.

The Clear Outside app provides the Bortle scale number for your area.

If you have 2" low power eyepieces with large field stops then be careful that the field stops of your eyepieces fit inside the restricted eyepiece holder of the WO diagonal. All my eyepieces were fine and I fought the diagonal to be excellent. With its 1/12th wave lambda mirror it's nice and sharp.

Well done for grabbing the slightest opportunity. An EQ6R Pro isn't exactly a grab and go setup.

For the budget you quoted I would get myself an ST80 and a barlow. You can stick it on a photographic tripod or any other tripod You will be pleased with the views. For the moon close up use the barlow and the same for the planets when they come back later in the year. I reckon that if some folk hadn't mentioned CA I'd wager that you wouldn't have noticed and had a great first night observing the cosmos.

Lovely focuser on your Tak Michael. How long did you have to wait for delivery? I heard that the man that started the company sadly passed away and that they encountered some manufacturing problems due to this. .Looks to me that they are back on track.

I know. I don't know what to do. I want a Tak and it will have to be one of.the 100mm models as they skyrocket as you increase the aperture. I could get a 120 mm triplet or even a 140mm Askar model. I'm also looking at the Stella Lyra 125. The snap to focus of the fracs has pushed me over the edge. Decisions, decisions 🙄. The Vixen I just sold is an excellent telescope but by being F9 it's a visual scope and I need something around F7 as I indulge in a bit of EAA from time to time.

You could get the pier extension for the HEQ5. 👇

The rod is to stabilise the telescope for the latitude movement (up and down). Are the brackets missing as well? A couple of photos will help us a lot.