The point is: these 'mirrors' have to move a little bit between it's holders, a little bit of space. There should be no pressure from the side and also not from the holders itself from the top. We gonna say: you should be able to move a piece of paper between mirror and the holders. Of course it should be just enough space to hold the justage. For normally it's no problem if u don't flip from on side to the other between your photo session. The reason is simple: because it's a mirror, material no Zerodure for normally, the material is strechting between the temperature delta in the night. You get an Asti error (triangular stars for example...) if there is any pressure at the primary mirror. Btw same case for the secondary mirror! A lot of people gonna worry about this and gonna ask why they gonna have triangular stars in the newtonian or dobson... because the reseller or any idiot had too much power and didn't understood how a mirror works between temperature changes. Please make sure your screws are not closed too tight. If you would like to improve use silicon to the sides, it has to stay flexible. Greetings from Germany, german Andy
Nice video. I think my Skywatcher Quattro suffers from a loose mirror aswell. But since I already took it part i couldn't verify. Already flocked it, painted focusser tube black, 3D printed a mirror mask and a new spider. Going to put it back together tomorrow, thank you for your observation! My advice on cleaning a mirror: Clean the sink thorougly and then fill it a few centimeters with luke warm water and 1 drop of dish soap. Let the mirror soak for 2-3 minutes. Gently move the mirror in the water. Remove smears by gently rubbing a fresh cleaning wool micro firbe cloth for glasses above the mirrors surface underwater. Rinse the mirror with desalinated water afterwards so you'll have no stains when drying. Even though you were very gently with the kitchen paper on the mirror, keep in mind that kitchen paper is quite abrasive and easily scratches optics (i learned that the hard way). I highly recommend wool microfibre glass cleaning cloths and wash them after every cleaning session at 90°C or 95°C in order to solve all fats remaining in the fibres. I learned this when attempting to clean the lenses of by Bader CC MK3. It took me almost 20 hours on two days to clean it without any smear or residue and I almost lost my mind reassembling it without getting 1 speck of dust in between the lenses. Thanks once again
I have read about putting 3 dots of silicon under the mirror to bond it to the mirror housing. Let it set overnight with mirror face up so the weight of the mirror helps in the adhesion process. I have not used this method yet, but I had horrible pinched optics first time I stripped and reassembled my 200PDS. I could not believe how little force from the mirror clamps actually distort the mirror. Shocking!
Hi Andy. Very interesting. I also have a 130PDS and don't seem to be able get it to collomate properly, you have given me food for thought. So I will be checking my mirror to see if it's loose like yours. I'll let you know what I find. Cheers.
I just came across your video’s Andy. I had the same problems with my Sky-Watcher Quattro 200P scope using the Sky-Watcher coma corrector. I tried everything to eliminate the light ring but wasn’t successful. I too noticed the mirror shifting so I removed the mirror and placed 3 small circles of RTV Silicone in the mirror cell to hold the mirror in place. This didn’t fix the problem. I ended up selling the scope. Please post a follow-up video.
OMG - I have a 130pds and have struggled similar to you. I thought I was crap at flats, or it was my camera (an ASI 294MC Pro) - no - I think I have loose mirror!
Could well be the case. I got so fed up with my 200pds I have got rid of it! It's no fun if you put in months of effort only to find the equipment is letting you down. Hope you manage to sort the issues.
Making me worried a bit here haha Im in Canada and just ordered a 130pds from First Light Optics in the U.K. Im hoping not to have headaches with the telescope. Your 130pds was ok afterwards? Just the 200pds kept giving you problems? Thanks mate!
The 130pds needed a few bits and pieces to get it working well. It's a nice scope, and a very manageable size. My 130pds is great, in fact I've just acquired a second one second hand - I've got a project in mind for this one running two scopes at once.
It is always curious to watch what the other owner of 130 PDS does to it. In th-cam.com/video/T4l9e96MRh8/w-d-xo.html , the presenter says the screws holding the primary mirror are tightly screwed in, but they are in reality not. When installing the aperture ring, I discovered the manufacturer applied the Loctite threadlocker to the screws. I never noticed mentioning the use of Loctite by the other upgraders. My screws are now wobbling loose without Loctite, I might apply it later. I was horrified seeing that the presenter washed the primary mirror with the tap water, and then soaked the water droplets by the paper towel. The water would leave calcium residue. The paper towel would leave lint. I was taught to moisten a lint-free paper with isopropanol, and drag it on the surface of the mirror.
The point is: these 'mirrors' have to move a little bit between it's holders, a little bit of space. There should be no pressure from the side and also not from the holders itself from the top. We gonna say: you should be able to move a piece of paper between mirror and the holders. Of course it should be just enough space to hold the justage. For normally it's no problem if u don't flip from on side to the other between your photo session. The reason is simple: because it's a mirror, material no Zerodure for normally, the material is strechting between the temperature delta in the night. You get an Asti error (triangular stars for example...) if there is any pressure at the primary mirror. Btw same case for the secondary mirror! A lot of people gonna worry about this and gonna ask why they gonna have triangular stars in the newtonian or dobson... because the reseller or any idiot had too much power and didn't understood how a mirror works between temperature changes. Please make sure your screws are not closed too tight. If you would like to improve use silicon to the sides, it has to stay flexible.
Greetings from Germany, german Andy
Great news Andy let's hope you have finally got to the bottom of the problem , looking forward to seeing your next videos with these scopes
Nice video. I think my Skywatcher Quattro suffers from a loose mirror aswell. But since I already took it part i couldn't verify. Already flocked it, painted focusser tube black, 3D printed a mirror mask and a new spider. Going to put it back together tomorrow, thank you for your observation!
My advice on cleaning a mirror:
Clean the sink thorougly and then fill it a few centimeters with luke warm water and 1 drop of dish soap. Let the mirror soak for 2-3 minutes. Gently move the mirror in the water. Remove smears by gently rubbing a fresh cleaning wool micro firbe cloth for glasses above the mirrors surface underwater. Rinse the mirror with desalinated water afterwards so you'll have no stains when drying.
Even though you were very gently with the kitchen paper on the mirror, keep in mind that kitchen paper is quite abrasive and easily scratches optics (i learned that the hard way). I highly recommend wool microfibre glass cleaning cloths and wash them after every cleaning session at 90°C or 95°C in order to solve all fats remaining in the fibres.
I learned this when attempting to clean the lenses of by Bader CC MK3. It took me almost 20 hours on two days to clean it without any smear or residue and I almost lost my mind reassembling it without getting 1 speck of dust in between the lenses.
Thanks once again
I have read about putting 3 dots of silicon under the mirror to bond it to the mirror housing. Let it set overnight with mirror face up so the weight of the mirror helps in the adhesion process. I have not used this method yet, but I had horrible pinched optics first time I stripped and reassembled my 200PDS. I could not believe how little force from the mirror clamps actually distort the mirror. Shocking!
Hi Andy. Very interesting. I also have a 130PDS and don't seem to be able get it to collomate properly, you have given me food for thought. So I will be checking my mirror to see if it's loose like yours. I'll let you know what I find. Cheers.
It is definitely worth checking, I am sure this is the cause of my issues.
I just came across your video’s Andy. I had the same problems with my Sky-Watcher Quattro 200P scope using the Sky-Watcher coma corrector. I tried everything to eliminate the light ring but wasn’t successful. I too noticed the mirror shifting so I removed the mirror and placed 3 small circles of RTV Silicone in the mirror cell to hold the mirror in place. This didn’t fix the problem. I ended up selling the scope. Please post a follow-up video.
OMG - I have a 130pds and have struggled similar to you. I thought I was crap at flats, or it was my camera (an ASI 294MC Pro) - no - I think I have loose mirror!
Could well be the case. I got so fed up with my 200pds I have got rid of it! It's no fun if you put in months of effort only to find the equipment is letting you down. Hope you manage to sort the issues.
@AndyofAstro i have the same problem on my 130PDS. Did your little tune help?
I put some cork behind the primary mirror, it seems to have helped with movement.
Hi Andy, please tell me the dimensions of the mask for the main mirror, thickness and outer and inner diameter?
Making me worried a bit here haha Im in Canada and just ordered a 130pds from First Light Optics in the U.K. Im hoping not to have headaches with the telescope. Your 130pds was ok afterwards? Just the 200pds kept giving you problems? Thanks mate!
The 130pds needed a few bits and pieces to get it working well. It's a nice scope, and a very manageable size. My 130pds is great, in fact I've just acquired a second one second hand - I've got a project in mind for this one running two scopes at once.
@@AndyofAstro Fantastic to hear! Looking forward to your new project! Thank you! 👍
It is always curious to watch what the other owner of 130 PDS does to it. In th-cam.com/video/T4l9e96MRh8/w-d-xo.html , the presenter says the screws holding the primary mirror are tightly screwed in, but they are in reality not. When installing the aperture ring, I discovered the manufacturer applied the Loctite threadlocker to the screws. I never noticed mentioning the use of Loctite by the other upgraders. My screws are now wobbling loose without Loctite, I might apply it later.
I was horrified seeing that the presenter washed the primary mirror with the tap water, and then soaked the water droplets by the paper towel. The water would leave calcium residue. The paper towel would leave lint. I was taught to moisten a lint-free paper with isopropanol, and drag it on the surface of the mirror.