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Stu1smartcookie

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Posts posted by Stu1smartcookie

  1. This is right up my street ! 

    I bought a 12" dob from another SGL member and the only thing "wrong" was that the primary was really dusty . I actually had to get the primary recoated in the end because it was quite badly stained. BUT... when my mirror was caked in dust etc i still got acceptable views through it  maybe just losing a bit of contrast . I took the mirror out and cleaned it which made a difference. The views became sharp again , despite the staining 

    The point i am trying to make is that the primary on my scope was in a very poor state but still produced fine viewing . If you are getting great views then why clean it although i bet you are like me ,can't stand seeing dust on the primary :) . But  cleaning a mirror isn't the perilous procedure that we are led to believe . 

     

  2. 4 hours ago, grjsk said:

    a solid 1.75 inch steel tripod is a no-brainer

    I concur with this . The skywatcher steel tripod was one of the best things i bought ( and i regret selling) . There is no getting away with the tried and tested " a solid mount is imperitave " that is always written when people ask about new equipment . Many , including myself have tried to get round this but failed . Learn by others mistakes . 

    • Like 1
  3. Unexpectededly clear last night , out with the 12" Dob , looking at M13 ( my first ever sighting of this ) and of course the Ring Neb . No Freak rain but a chill breeze which heralds the cold nights to come . You know , the ones where you look like a complete idiot sitting outside whilst everyone is warm indoors  🤣

    • Like 2
  4. 4 minutes ago, Tiny Clanger said:

    Stu, any luck for you ?

    Alas no, Heather ... i packed away at about 10;30 last night as i have a 5;30 alarm call during the week . Tonight is not looking too promising but , if its ok i will be out a bit later :) 

    Isn't it nice to at least be outside and able to view the night sky ? Remembering the shocking weather we experienced last month , September is proving to be a god send for astronomers . 

     

  5. 1 hour ago, Tiny Clanger said:

    Doesn't help that it's behind the annoying tree when at its highest, in the sky over a couple of street lamps earlier on before current moonrise, and a bad skyglow area for me as it gets further west later ... If a settled weather pattern suggested to me that a drive out to slightly darker skies with a clearer horizon would be worthwhile I'd do it, but not for half an hour of cloud dodging while swamped by moonlight !

    Absolutely , Heather .. i feel even more annoyed as i have such a large aperture scope  and i still haven't bagged the little blighter. lol. The street light acutally gets turned off at 1am ( or so i'm told ) . I have a fairly good southern sky , although no southern horizon to speak of . I think tonight is going to be the last one thats really clear in my area for a few nights so i am going to try and make the most of it . As for the Moon , it rises tonight at 20.05 so its going to be a pest although , Neptune should be do-able . Watch this space ! ( er , no pun intended )

     

    • Like 2
  6. 32 minutes ago, Nik271 said:

    You will need some optical finder: step from Saturn to Jupiter and continue the same distance east to Lambda Aqr. Then look for Phi Aqr further east and continue a bit less than the distance from Lambda to Phi further east. HD221148 is one of the few 6-th magnitude stars in the field and hopefully it will be recognizable as a 'double' star with a faint bluish companion - Neptune

    Thanks for the tips Nik ... one bonus is that the moon rises just a little later every night . I only observe up until around 11pm on a school night but im going to give it a go . 

     

    • Like 1
  7. 12 hours ago, Nik271 said:

    I just packed up for the night. The seeing is meh, waited an hour but it's not improving, even at the zenith the stars are wobbly. It's very strange because otherwise is a still and clear night. Grabbed a quick view of M2 and Neptune, but at high magnification it's a lost cause ☹️

    I think we were spoilt with the previous night being so wonderful for observations . I was a bit disapointed last night if i am honest and Neptune is still an enigma for me ( damn street light washes a lot out ) . But , a fairly clear night forecast tonight , hopefully better seeing . 

    • Like 1
  8. 5 hours ago, Nik271 said:

    On Saturn I could trace the Cassinig division all the way around the ring. I was really obvious, like a groove in a vinyl record.

    Nice report Nik... and for our younger readers , ask an older person about vinyl records 🤣

    Can't wait to get out tonight ! 

    • Like 1
  9. 34 minutes ago, Goose0211 said:

    What are your thoughts on the StarDiscovery150i @ScouseSpaceCadet - pre doing your mods!

    Looks to be a sensible option 'swapping' to this. One question - do you need to align the goto each evening or time you go out or are they clever enough to 'remember' the alignment?  I'd have to store this in with the OTA off the GOTO mount and tripod after each use so wondering how much setup id need to do each time I use it.

     

    You certainly need to do a North level alignement , at least , everytime you set up but it takes 5 minutes ... the beauty of the 150i scope is i believe it has a fixed primary mirror which means it rarely need collimating . ( although its a good skill to learn ) 

     

  10. 18 hours ago, Zermelo said:

    Was that with the Star Discovery, Stu? I didn't know that was possible (unlike the AZ-GTi).

    Hi, yeah , i used the weight arm because i was at the time using celestron 102 mak , which has a fixed dovetail ...the trouble with the star discovery is that the scope has to be mounted on the left side whereas the 102 celestron had to be mounted on the right ( it has a non rotatable 90 degree eyepiece holder ) .. it actually worked really well . 

  11. 16 minutes ago, Goose0211 said:

    Ah I see, so perhaps an Alt-AZ mount is more suited...

    Which brings us all back to your first choices :) . Personally i think your flextube dob is already on the best mount . I know you want goto functionality though ( and i understand that its an attractive proposition ) . Having used both AZ-Gti and Star Discovery the star discovery acually has a slightly better payload capacity ( the orion version sold in the USA is the  same as the one here and quotes 6kgs ).I actually used a weight arm that added a counterweight system to the mount and my scope sat directly above the mount . I was using a smaller scope though than the heritage 150 but it did seem to work very well 

  12. 40 minutes ago, Ricochet said:

    believe the rating of the azgti with the heavy duty tripod is actually 9kg so may be a better option than initially thought. 

    Your logic regarding the EQ5 is pretty sound and on reflection i agree .. however the AZ-Gti would never be able to take 9kgs ... think about the motors and gears. I used the AZ-Gti with a WO ZS73 together with a dslr and various other bits and pieces and to be honest it was heavy enough . The thing about weight ratings for mounts is that you shouldnt go anywhere near the limit . 

  13. i think at some stage most of us have tried to cut a corner or two where load capacity is concerned , but , in reality you have to have stability . I may be wrong but a flextube scope on an AZ-Gti may introduce balance issues as well . As has been written above , its best to get an EQ5 . Of course a lot more expensive than a Gti and it will be a lot more bulky too . Its a difficult balancing act ( no pun intended) but , im afraid the old rule is still the best rule that you buy the best , most sturdy mount you can afford and then worry about the scope later .

  14. On 07/09/2021 at 22:37, Orange Smartie said:

    Re cleaning the mirror, does it definitely need it? I'm no expert, but I gather that it's something you shouldn't do unless really necessary and could cause more harm than good. Your telescope will tolerate a bit of dust or dirt on the mirror as discussed in many threads on this forum. Personally, I've learnt not to look too hard at mine!

    Collimation on the other hand, is something you should learn to do.

    Pete

    Honestly , if you would have seen my primary mirror prior to recoating ... full of caked on dust , it still gave really good views . Even after recoating there was some "staining " on the glass that couldnt be removed but the views i get are absolutely stunning . I think people get hung up on this and every spec of dust is seen as an enemy . It really makes no difference . 

    • Like 1
  15. Thanks to everyone for the replies .. I fixed the cork pads with  the sticky dots  . I replaced the collimation screws with the bobs nobs but reverted back to the original locking screws which I barely tightened . The secondary is fine @Pixiesas the laser dot doesn’t move out of the doughnut . Anyway it’s better than it was but although I have better springs than the original I am going to buy some stronger springs . 

    • Like 2
  16. 9 hours ago, John said:

    I've forgotten what scope you have Stu ?

    My 12 inch Orion Optics has the older 3-point primary cell with fairly simple mirror clips and lateral nylon screws to hold the mirror central. I keep the clips slightly off the mirror surface and the 3 nylon screws gently touching the mirror to keep it's optical axis central. The mirror is resting on nylon pads but is not stuck to the cell.

    I don't use the locking screws unless taking the scope for a journey because they do impact the collimation.

    Other than that, mine holds collimation pretty well.

    oo12cell.jpg.4334753b65326589b71a430fcc2a6e20.jpg

     

     

    Hi John .. a revelation 12” which is basically a GSO …I’ve uploaded a picture of the layout .. a fairly standard one .. I changed the screws back to the original but will be changing them back to bobs knobs shortly . I am certainly going to follow Ed’s suggestion about the clip screws . I like the idea of not “sticking “ the  cork pads to the mirror although if it helps keep the mirror from movement then I will fix it . 

    FE4C6BB7-39F1-4645-AC9D-70802671DB0E.jpeg

  17. Yes Ed , thats a really good point about the clips . There is so much empathise put on a gap of a "card " . As you quite rightly point out , that gap is in fact abe to introduce a fairly substantial error . I will certainly re check this tomorrow morning . i also believe that paper thickness is more than adequate . 

    Stu

    • Like 1
  18. Thanks guys , I bought some strong sticky dots to put on the cork pads today .. going to try them tonight . It’s strange but I collimate the scope and then when I check collimation after pointing the scope to the zenith the collimation has slipped ( as per the laser dot has reappeared outside the centre hole . It can only be a bit of mirror movement . I used bobs nobs from RVO and stronger springs from them but I have to say I may get some heavy duty ones from Amazon .. apparently 3D printer springs ( green colour are the ones to go for ) . 
    Stu 

    • Like 1
  19. As Pixies said ... best do a star test . I think collimation is made harder by the fact that we are always critical of our own efforts ... the proof of this particular pudding is to look through the scope and defocus on a bright star ( use a low-ish power EP) If you see concentric circles and  the donut is in the middle then its fine . Don't get too hung up on collimation if you are just into viewing .  :)

    • Thanks 1
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