Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Donut for primary

todd8137

Recommended Posts

  • Replies 25
  • Created
  • Last Reply
cantab

cantab

Posted
Posted

They're exactly what I used. Putting it on was a bit tricky, I ended up blu-tacking the top side of the ring to a stick and pressing it down, took a couple of goes for the blu-tack to come away without bringing the ring off again.

Link to comment
Share on other sites
Charic

Charic

Posted
Posted

I painted mine black and centered it using a sheet of paper. Lay the mirror face down over the paper, trace the circle. Cut out the circle, then fold the paper in half, then half again. This will centre mark the paper at the point? Cut the point off the paper when folded (just cut enough to create a small circle in the centre) to allow the placement of the Ring Binder  sticker, when the paper is opened out and placed over the mirror for protection. This way, you wont actually touch the mirror with greasy fingers/hands even after washing them. I did all this to a Celestron 127EQ just for fun, although a spherical mirror does not really need spotting?

Link to comment
Share on other sites
Mike73

Mike73

Posted
Posted

Pat

Charic's suggestion is good but when you have found the centre, measure the radius to find your outside edge, then put a very small hole in the centre where the spot goes, put some selotape over this hole and stick your centre spot underneath so the selotape just grips it. Then place the template over your mirror and line it up so its in the correct place when you are sure its right then lightly press the centre spot to the mirror and the selotape should release the spot in the right place.

:)

Link to comment
Share on other sites
Charic

Charic

Posted
Posted

 ///

|  °>

Lol!..... the above is supposed to look like a chicken?  Yeah, The mirror will be a little heavy, but well worth the exercise, and a learning exercise too. I've been messing with my Celestron 127EQ over the Months.  I can totally strip it and rebuild in 40 mins - collimated.

I intend to wash my  200P mirror sometime soon, and its only 4 Months old? Despite all the talk of leave it, it won't hurt. But cosmetically, when I look inside with a torch, its just too much dust for me,  I store it fully assembled, and covered, so all particles fall to the mirror. Its just another learning curve and more experience for me, and a chance to shim the secondary with some  milk carton washers.

As long as your Oh so careful, should be ok. I've no fear of dismantling. Its in my nature! Only way to learn. Even if it aint broken?

Link to comment
Share on other sites
Mike73

Mike73

Posted
Posted

Pat just to make myself clear, the selotape is stuck to the top of the tracing paper and the ring goes underneath so that there is no way for the selotape to come into contact with the mirror! 

I had to come back to this as I'd hate to hear that you put a dirty great sticky mark on your primary because I explained it poorly!!  :grin:

You can buy Catseye respoting kits from FLO and the above method is exactly how its done in the kits.

Link to comment
Share on other sites
Langy

Langy

Posted
Posted

Yes I may have to do this sometime for my Astromaster 130 as that doesn't have a center spot.

I watched a video on YouTube, thing it was Astronomy Shed which explained the cleaning and spotting in great detail, done just as described above with a bit of sellotape. I think at the moment I will not even think of doing it until I really need to collimate the scope.

Link to comment
Share on other sites
todd8137

todd8137

Posted
  • Author
Posted

///

|  °>

Lol!..... the above is supposed to look like a chicken?  Yeah, The mirror will be a little heavy, but well worth the exercise, and a learning exercise too. I've been messing with my Celestron 127EQ over the Months.  I can totally strip it and rebuild in 40 mins - collimated.

I intend to wash my  200P mirror sometime soon, and its only 4 Months old? Despite all the talk of leave it, it won't hurt. But cosmetically, when I look inside with a torch, its just too much dust for me,  I store it fully assembled, and covered, so all particles fall to the mirror. Its just another learning curve and more experience for me, and a chance to shim the secondary with some  milk carton washers.

As long as your Oh so careful, should be ok. I've no fear of dismantling. Its in my nature! Only way to learn. Even if it aint broken?

Still not take in it out it's big and a do not one to get any marks on the mirror we have a club night coming up am sure we will all get it sorted or I will,get it done in the morning

Pat

Link to comment
Share on other sites
todd8137

todd8137

Posted
  • Author
Posted

Pat just to make myself clear, the selotape is stuck to the top of the tracing paper and the ring goes underneath so that there is no way for the selotape to come into contact with the mirror! 

I had to come back to this as I'd hate to hear that you put a dirty great sticky mark on your primary because I explained it poorly!!  :grin:

You can buy Catseye respoting kits from FLO and the above method is exactly how its done in the kits.

Hahahahahah no probs mate

Link to comment
Share on other sites
Siriusmeg

Siriusmeg

Posted
Posted

Yes I may have to do this sometime for my Astromaster 130 as that doesn't have a center spot.

I watched a video on YouTube, thing it was Astronomy Shed which explained the cleaning and spotting in great detail, done just as described above with a bit of sellotape. I think at the moment I will not even think of doing it until I really need to collimate the scope.

I did this for my astromaster and actually it was a lot more straightforward than I'd thought - go for it  :grin:

Link to comment
Share on other sites
Langy

Langy

Posted
Posted

I did this for my astromaster and actually it was a lot more straightforward than I'd thought - go for it  :grin:

I'll pull a computer, laptop, mobile and even my DSLR to pieces but strangely the scope has few parts and I'm not keen on pulling it apart without knowing I have some help close to hand the first time. I'd rather have a scope I can use straight away than having problems and delays in waiting for help. So at he moment until I actually do it I'm not keen on doing it. Almost the old saying of if it's not broke, but I know that is not a good way to live as things may not appear to be broken but could cause some very bad things in the future if you don't look at them.

Link to comment
Share on other sites
Charic

Charic

Posted
Posted

I think there's enough solutions here. Its just the 'Not Sure I want / can do it ' ' issue, which is a good thing., cautious, take your time. If there's a club meeting, you'll get help. Hopefully they will tell you what to do, so that its hand on, rather than just looking. 

Link to comment
Share on other sites
todd8137

todd8137

Posted
  • Author
Posted

Just found this sounds a bit wild of sky and telescope web site

To make collimation easy, the center of the mirror should be marked in some way. I recommend marking it with a piece of electrician's tape. Don't make it too small — a ½-inch-diameter (or even slightly larger) spot works well. As long as it is smaller than your diagonal mirror, it will not affect your telescope's performance. If you plan to use a laser collimator, make a hole in the center of your spot. (Another approach is to use an adhesive binder reinforcement ring, the kind used by generations of school children to keep their homework from flying out of their 3-ring binders.)

My lord half in a suppose a star test would be needed hahahahah

Pat

Link to comment
Share on other sites
Charic

Charic

Posted
Posted

How much error does it have without the centre spot?  De-focus on  Polaris and see if you get a tidy looking Airey Disk  with concentric circles around the centre. Problem is, I use a Laser, and should I try to get  accurate mm perfection. It would be nice, but not always possible, due to some imperfection with the laser collimation, or the fit in the focuser, or the secondary being off, or the primary slightly out? there's so many problems. I honestly prefer to manually collimate now with a 35mm film cap or a dust cap with a hole in it. Once everything looks set up, and a quick star test. I'll try the laser, and blow me down. it may be slightly off. I've got hole reinforcement stickers here that are 14mm wide with a centre hole of 6mm width. as long as the laser or setup is somewhere within the 14mm I wont be complaining.

Link to comment
Share on other sites
Charic

Charic

Posted
Posted

Pat........Whatever you do just take care and time and remember the sequence of collimation after...

1 centralise the secondary mirror to the focuser.
2 Centralise the secondary mirror to the Primary Mirror (looking for the mirror clips)
3 Centralise the primary mirror, Aligning the centre spot with the Collimation cap / sight-tube centre.
4 Star test.....Job Done :grin:  
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.