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Z10 First Light

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#1 bluelick

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Posted 06 January 2022 - 02:12 PM

Hi folks,

 

I'm a recent joiner here and still pretty new to astronomical telescopes although I have been dabbling for a few years, ever since a colleague gave me a 114mm Orion StarBlast Dobsonian that his kids weren't using. I put it in the tea house by our pond next to the plastic Jason refractor I had picked up years before at a junk store and never really used. I figured if nothing else I could watch the geese when they nest in the Spring, which I did, although Mother Goose was upside down!

 

A few things nudged me further into this field. I went on a retreat in Maine's North Woods with a nonprofit board I serve on, and there was an intern on site at the retreat center with a portable scope she set up and then showed us Jupiter's moons and the rings of Saturn. I was fascinated. When I got home I wondered if the StarBlast would show those planets and behold! Then on a trip to Yellowstone I saw wildlife watchers using spotting scopes with iPhones clamped to the lens to watch wolves, bears, bison, and antelope--wow! So when work took me back out there the next year I too had a spotting scope and an iPhone clamp for it. I was also able to use that iPhone clamp and a homemade filter with the StarBlast to view the 2017 total eclipse, driving to western KY for the totality. Awesome.

 

Bit by bit I was getting sucked in. I had picked up an old tripod with a German Equatorial Mount at a college surplus auction so I've recently gotten that out, fabricated parts for the broken or missing pieces that probably landed it in the surplus auction, and have recently played with the StarBlast on that mount a little to learn how to align and use it.

 

And I joined this site. And you know how it goes from there...I've already made my first buy from the classifieds here, a Meade 140 2x Barlow that I look forward to trying out. And I've ordered a Svobony 4mm 62 degree 1.25 eyepiece. With the Barlow that would reach the far end of the theoretical limit of the Orion 114.

 

As I said, you probably know how this goes.

 

I had begun watching FaceBook Marketplace for used scopes nearby. If you followed the first part of this you get the idea that I've drifted into this accumulating bits and pieces for next to nothing. My budding case of aperture fever was running into the dual obstacles of the fact the interesting scopes I was seeing were many hours' drive away as well as the number of Benjamin Franklins required at the other end of the drive. Then two days ago I spotted an ad for a "10-inch Dobsonian telescope, $200" not too far away, and I jumped on it. I figured it was worth that for parts just based on the pictures.

 

I brought it home yesterday afternoon and got it set up out in the field on the front of my property just at sunset, in time to catch the crescent moon, Jupiter and even a fuzzy Saturn low in the sky. Pretty satisfying considering I just dragged it out of the back seat and set it up.

 

The good: I discovered it was a Zhumell Z10 (I had thought so from the pictures online but there was no indication from the seller). The mirror looks pretty good just looking down the tube. The 2" focuser looks nice and beefy, and all metal, making me think maybe this is an older model. The Zhumell 2" Wide Field 30mm lens is just lovely and gave me good views last night.

 

The bad: the home-made base is so wobbly that even after I jammed cardboard shims between the top and bottom of the turntable the wind was still rocking it like crazy. I gave up trying to use any magnification higher than the 30mm. I will build a new base. The scope has obviously fallen at some point, and the lens of the finder scope is chipped at the edge; the diagonal end was screwed into the tube cross-threaded; the finder was inserted in its mount backwards (see pic, took me a while to figure that one out); and the O-ring, or whatever snugs the finder to the mount at the narrow end, was gone, and the mount itself was loose and wobbly on the tube. I got the finder sort of working while I was out in the field, enough to help me find the planets, but to call it marginal would be generous. OK, that gave me a first project last night after I came inside. The fall (which probable started all the trouble with the finder) pushed the finder mount into the tube indenting the tube, so I shimmed the mount which was very loose and got it close to right. Took the finder apart and put it back together with a rubber band around the tube to snug it at the narrow end, and have mounted it back ready for another try. Hopefully better now.

 

This scope has, for certain, been "rode hard and put up wet" as we say. But I would say the same about my 1984 Kubota, and it takes a licking an keeps on ticking. I think it's a testament to this scope's potential that I was able to see what I did last night with no more "improvement" than some cardboard shims and a bit of dead reckoning. I look forward to seeing where I can go with it and I'm sure I'll be seeking help here along the way!

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#2 John Miele

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Posted 06 January 2022 - 02:53 PM

Only 200 bucks? Zhumell has a pretty good rep for decent optics, so I think you got a pretty good deal and fixer uppers are fun and satisfying when you are done.


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#3 bluelick

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Posted 06 January 2022 - 05:09 PM

Only 200 bucks? Zhumell has a pretty good rep for decent optics, so I think you got a pretty good deal and fixer uppers are fun and satisfying when you are done.

John, I couldn't agree more. I haven't any 10" scopes in this area for less than 2 or 3 times that price. It was such a good deal that at first I had to wonder about the provenance of the scope or whether I was taking unfair advantage of an unknowing seller. But he clearly demonstrated knowledge of concepts like Dobsonian mounts and collimation. Of the four lenses included at least the Zhumell 30mm seems like a gem. I haven't had the chance to assess the other three yet. The seller even included a new laser collimator in the deal, and drove half way to meet me. Super nice guy, and I'm going to have a good time working on this project.



#4 Sky_LO

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Posted 08 January 2022 - 01:14 AM

Our seeing here in Oregon isn't very good, with lots of upper atmosphere movement

being the norm.  When seeing is good, I can use a 5 mm EP in my 10 inch dob (218 X).

Most nights though, the limit of magnification the seeing will allow is the 9MM (130X)

I would probably never be able to use 4MM, especially with a barlow (except to split doubles). 

 

Consider going the other way with 2 inch wide angle eyepieces.  The average target can look a lot nicer framed by a larger background rather than filling the entire view - with the same magnification. Large open clusters need a large FOV to appreciate.  Be careful not to go too big on exit pupil. 

 

My Explore Scientific 18MM 82degree EP is one of my favorites

At 67X  and 1.23 degree FOV, you can just about observe all night without changing the EP 

 

 

-Lauren   


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#5 gnowellsct

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Posted 08 January 2022 - 02:17 AM

The ability to improvise with materials on hand is a notable characteristic of dob guys. This z10 came into the world looking for you and has found its home.
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#6 Waynosworld

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Posted 08 January 2022 - 04:16 AM

I bought a Z12 about a year ago that looked like it had been the target of a very unhappy person, now I am not a body guy, but I took the whole thing apart and used a hammer and dolly to take the worst of the dents out, one side it looked like someone had dropped it on the alt bearing, now I did not really notice all the damage in the dark garage, and the guys mom was the only one there, it had a brand new looking Moonlight focuser so I bought it.

 

It had another issue also, I could barely lift the base (particle board), I think it was water soaked, after I got it home I tried to fix everything wrong with the base, it was so heavy I tried taking it outside with a hand truck the next day, it fell apart when I lifted it, so I made a new base out of high grade plywood from Home Depot, it weighed less than half of what the original base weighed, if I remember it weighed around 25lbs using all the original base hardware, it is easy to deal with now.

 

The Z12 I bought has them adjustable side bearings, I cannot see what side bearings your scope has, I suspect yours is an earlier model, all I did was trace the original base pieces onto the new plywood and then cut the pieces out with a skill saw and a bandsaw, once put together I sealed it with a water based emulsion, and then called it good, it is a great scope now.

 

Here is a photo of my base with an extra board piece added to make the side uprights stronger/stiffer.

 

DSC00503.JPG


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#7 spaceoddity

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Posted 08 January 2022 - 10:58 PM

Nice! Good deal for $200. If you have basic woodworking skills and the necessary tools, it won't be too hard to build another base. I'm sure you can find some ideas with a google search or ask on the ATM forum if you need help with any of it. Sounds like a fun project. They can be bought but it would probably cost more than you paid for the scope. 


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#8 bluelick

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Posted 09 January 2022 - 12:18 AM

Thanks all for your replies. I spent some years in my earlier life building custom kitchen cabinets, and still have a full shop so I don't think building a new base will be much of a challenge from a technical perspective. I probably have most of the materials lying around here, including a ball bearing Lazy Susan or two. I'd be interested in templates or plans if anyone has those since I don't have the original to work from. I'm thinking maybe a combination of a Lazy Susan center with some nylon feet around the perimeter to make it stable, but rather than embark on an extended round of trial and error I'd love to capitalize on what others have learned with their base designs.

 

I think I'm going to need to at least adjust the secondary to get it collimated properly, and I'm still learning about those processes. The spider is pretty bent up so I can straighten that out when I pull the secondary, and then also install some milk jug washers as I read about on the big Zhumell thread here. I'm hoping that and a new base will get me to the point where I can begin to use it a little while I figure out next steps.

 

I have been wondering about hammering out the dents, glad to hear that worked. That would require a full disassembly which would also provide the opportunity to clean the primary. And then think about more EP's, filters, etc. All that is down the road, but as some of you noted, this is going to be a fun project and I expect it will carry me a good way along this path. Again, thanks!

IMG_5400.JPG


Edited by bluelick, 09 January 2022 - 12:21 AM.


#9 Waynosworld

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Posted 09 January 2022 - 04:15 AM

Personally, I would not pull the scope apart, especially remove the secondary until you understand how to center it in height/tilt/rotation, it is likely close right now height and tilt wise, rotation maybe not, it is hard to tell unless the photo taken thru the eyepiece hole is exactly centered, I was lucky that my cameras lens housing was almost the same size as the focuser hole so I can get the camera perfectly centered, then when I posted the photo Vic, Dave, and others could tell me what I needed to do.

 

It took me a while to understand what they were talking about, but if they chime in and you do not fully understand what they mean, tell them you do not understand, getting the secondary height, tilt, and rotation right is everything, once that is right adjusting the primary mirror is easy.

 

It would be a lot easier if you have a good laser, I went the cheap route and bought cheap lasers off ebay, most of them were not collimated themselves, I will not get into how to collimate them as I came to the conclusion that getting them perfectly centered/aligned was more luck than anything, in the end I bought a Farpoint laser from Starman1 at eyepieces etc, best money I ever spent, that one tool does both the secondary and primary if you understand the tool although learning to use a collimation cap would be a good idea.


Edited by Waynosworld, 09 January 2022 - 04:16 AM.

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#10 Haris Desdenova

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Posted 09 January 2022 - 07:33 AM

Enjoy!: 

https://www.cloudyni...r-zhumell-dobs/


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#11 bluelick

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Posted 09 January 2022 - 08:52 AM

Personally, I would not pull the scope apart, especially remove the secondary until you understand how to center it in height/tilt/rotation, it is likely close right now height and tilt wise, rotation maybe not, it is hard to tell unless the photo taken thru the eyepiece hole is exactly centered, I was lucky that my cameras lens housing was almost the same size as the focuser hole so I can get the camera perfectly centered, then when I posted the photo Vic, Dave, and others could tell me what I needed to do.

 

It took me a while to understand what they were talking about, but if they chime in and you do not fully understand what they mean, tell them you do not understand, getting the secondary height, tilt, and rotation right is everything, once that is right adjusting the primary mirror is easy.

 

It would be a lot easier if you have a good laser, I went the cheap route and bought cheap lasers off ebay, most of them were not collimated themselves, I will not get into how to collimate them as I came to the conclusion that getting them perfectly centered/aligned was more luck than anything, in the end I bought a Farpoint laser from Starman1 at eyepieces etc, best money I ever spent, that one tool does both the secondary and primary if you understand the tool although learning to use a collimation cap would be a good idea.

The camera may not be perfectly centered on that picture, but it is at least similar to what I see with my collimation cap. I'm using the 1.25 collimation cap from my 114 with the 1.25 to 2" adapter that came with the laser. I haven't tried the laser yet but I have read up on the process for collimating the laser itself so I will at least check the laser for true before I try to use it, but for now I think the collimation cap can get it at least closer that where it is. I have also read up on adjusting the secondary, and I don't think that I have a lot to lose in terms of where it is now (I may be wrong). I'm trying to tread a reasonable line between "don't be afraid to work on it" and "go slow and don't screw it up" but from what I have seen so far, I don't have a lot to lose in terms of the current state of set up on this scope. The finder scope being assembled backwards when I got it (see picture) was my first index point on that! I don't have a picture of the spider but it is pretty bent up, and until I added washers to the outside of the tube, it had 1/16" of side to side play in it from the tube being dented where it is attached.

 

I really appreciate the input and would be glad to have further assistance going forward!

 

Finder scope.JPG



#12 Mountaineer370

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Posted 09 January 2022 - 09:23 AM

Congratulations on acquiring your Z10!  They are fine Dobs, and pretty impossible to find right now.  I've been trying, lol.  Lucky for you, too, that you have the carpentry know-how and DIY skills to fix this one up nicely.  The thread linked above in Post #10 should give you lots of reading material and many ideas. waytogo.gif



#13 Waynosworld

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Posted 09 January 2022 - 02:05 PM

That photo looking down the focuser hole may be centered, but it is too far back, the photos needed need to be taken like this in the photo below, and the camera needs to be perfectly centered.

 

DSC00545.JPG

 

You want a photo that looks something like this in the photo below, it helps if you tape a piece of white paper onto the inner tube assembly behind the secondary, this makes the secondary clearly stand out so Vic and others can do their thing, Vic wrote a book on this subject and has a thread on how to collimate a Newtonian in the reflector section as I recall.

 

post-345792-0-88114200-1609631058.jpg

 

You can see that the photo shows a lot more than just the secondary, the members on here have tools they use with different color circles that tell them and you exactly what needs to be done, understanding what they tell you to do is the hard part/another subject all together, that is why I said if you do not understand what they are saying tell them you do not understand.

 

 


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#14 bluelick

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Posted 09 January 2022 - 05:04 PM

That photo looking down the focuser hole may be centered, but it is too far back, the photos needed need to be taken like this in the photo below, and the camera needs to be perfectly centered.

 

attachicon.gifDSC00545.JPG

 

You want a photo that looks something like this in the photo below, it helps if you tape a piece of white paper onto the inner tube assembly behind the secondary, this makes the secondary clearly stand out so Vic and others can do their thing, Vic wrote a book on this subject and has a thread on how to collimate a Newtonian in the reflector section as I recall.

 

attachicon.gifpost-345792-0-88114200-1609631058.jpg

 

You can see that the photo shows a lot more than just the secondary, the members on here have tools they use with different color circles that tell them and you exactly what needs to be done, understanding what they tell you to do is the hard part/another subject all together, that is why I said if you do not understand what they are saying tell them you do not understand.

Thank you, that's very helpful! Just before I saw your post I had stuck a piece of paper just where you said so I could see better! I'll see what I can do about better pics and post them.


Edited by bluelick, 09 January 2022 - 05:05 PM.


#15 bluelick

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Posted 09 January 2022 - 08:10 PM

Not sure if these images show enough to be more useful or not, a couple down the eyepiece tube and one through the collimating cap.

 

 

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#16 Waynosworld

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Posted 10 January 2022 - 12:25 AM

I am not the one to tell you what to do, but the secondary appears to be very close to being centered thru/under the focuser, but the rotation of the secondary is slightly off, otherwise I know nothing. lol.gif

The rotation is not really that far off, a tweak in the right direction while you are looking thru the eyepiece hole or collimation cap will tell you which way it needs turned, just do not touch the secondary mirror surface, I can actually see all 3 mirror holder arms/clips (10/2/6 on a clock face), it might be easy to turn since it somehow got rotated to where it is now.

Then someone that knows how to communicate what needs to be done needs to chime in, I can figure it out, but I have my scope right in front of me and can see real time results.

The rotation needs to be dealt with first, then the experts can tell you if something else is off before you align the secondary to the primary.

Fact is you can likely see the Moon and other things the way it is, but you're better off if it is collimated properly.

It also appears to have offset, I did such a good job centering my secondary on my 14.5" dob that I had no offset, I was scratching my head on that one for a while and the experts were balking on telling me what to do to fix it, they told me if everything looked good thru the eyepiece too me, it was fine the way it was, you can see the white circle perfectly centered in the black circle in my photo below, it is not supposed to be centered, it is supposed to off center like your photos show yours except you have more than one dot, that will be taken care of when you collimate your scope.

 

post-345792-0-41565500-1609630806.jpg


Edited by Waynosworld, 10 January 2022 - 12:27 AM.


#17 bluelick

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Posted 10 January 2022 - 08:00 AM

I am not the one to tell you what to do, but the secondary appears to be very close to being centered thru/under the focuser, but the rotation of the secondary is slightly off, otherwise I know nothing. lol.gif

The rotation is not really that far off, a tweak in the right direction while you are looking thru the eyepiece hole or collimation cap will tell you which way it needs turned, just do not touch the secondary mirror surface, I can actually see all 3 mirror holder arms/clips (10/2/6 on a clock face), it might be easy to turn since it somehow got rotated to where it is now.

Then someone that knows how to communicate what needs to be done needs to chime in, I can figure it out, but I have my scope right in front of me and can see real time results.

The rotation needs to be dealt with first, then the experts can tell you if something else is off before you align the secondary to the primary.

Fact is you can likely see the Moon and other things the way it is, but you're better off if it is collimated properly.

It also appears to have offset, I did such a good job centering my secondary on my 14.5" dob that I had no offset, I was scratching my head on that one for a while and the experts were balking on telling me what to do to fix it, they told me if everything looked good thru the eyepiece too me, it was fine the way it was, you can see the white circle perfectly centered in the black circle in my photo below, it is not supposed to be centered, it is supposed to off center like your photos show yours except you have more than one dot, that will be taken care of when you collimate your scope.

 

attachicon.gifpost-345792-0-41565500-1609630806.jpg

Thanks for all that. I agree that the rotation seems like a first step, it is clearly off and I can even see that just looking down the tube. I'll probably take a run at that and see what it does to the picture. You're right, it "works" as it is, and I got a nice view of the moon and Jupiter on my first outing with it. But I am interested in learning what I need to bring it along toward its best potential. Some of that will be optical but much of it will be simply mechanical and structural, like building a new base, which I plan to start once I get some time. But for today, time to go back to work--happy Monday!



#18 SteveG

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Posted 10 January 2022 - 04:19 PM

Not sure if these images show enough to be more useful or not, a couple down the eyepiece tube and one through the collimating cap.

Only the collimating cap is useful. I've reoriented the view now showing the open tube on the left, and the primary to the right. Your centering needs to be adjusted until the green lines are equal length. Fix this using the tilt screws. The front to back (left to right) in this view looks good. Once you get it centered, you need to adjust the tilt screws to get the focuser axis pointing at the center marker on the primary. Last step is to adjust the primary tilt, which is done with the cap.

 

What tool if any do you have for the focuser axis? You would need either a site tube with crosshairs, or a thin beam laser. Here's a tool I can highly recommend:

https://www.amazon.c...r/dp/B092ZW9X9M

 

Your spider vanes look wonky. Measure from the edge of the open tube to the center screw in the spider hub - they should all be equal length and straight. Once you get it here, tighten it up very snug - piano wire tight, then move on to better centering.

 

 

z10-1.jpg


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#19 bluelick

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Posted 12 January 2022 - 02:56 PM

Only the collimating cap is useful. I've reoriented the view now showing the open tube on the left, and the primary to the right. Your centering needs to be adjusted until the green lines are equal length. Fix this using the tilt screws. The front to back (left to right) in this view looks good. Once you get it centered, you need to adjust the tilt screws to get the focuser axis pointing at the center marker on the primary. Last step is to adjust the primary tilt, which is done with the cap.

 

What tool if any do you have for the focuser axis? You would need either a site tube with crosshairs, or a thin beam laser. Here's a tool I can highly recommend:

https://www.amazon.c...r/dp/B092ZW9X9M

 

Your spider vanes look wonky. Measure from the edge of the open tube to the center screw in the spider hub - they should all be equal length and straight. Once you get it here, tighten it up very snug - piano wire tight, then move on to better centering.

 

 

attachicon.gifz10-1.jpg

Wow, thanks for that! This is very helpful. Your observation on the spider vanes is spot on, they are a twisted mess! The whole spider needs to come out and be straightened, then reinstalled and tightened up. One of the adjusting screws is rusted and frozen, so I'll tackle that when I have it out instead of messing with it in the tube, less likelihood of collateral damage. I just pulled the secondary and was interested to see it already had the milk jug washer installed. This scope shows an interesting mix of care and neglect, probably reflecting different ownership over time. Interesting project.

 

I have read elsewhere that in some scopes the spider vanes are intentionally offset, but it sounds like that is not the case for the Z10, correct?

 

Sorry, very much a beginner on the scope optics, can you explain what "focuser axis" is?

 

I don't have a Cheshire, but the seller included a generic laser. I will need to check it for accuracy before I can count on it to adjust the scope, and then will also have to learn how to use it! Step by step.



#20 bluelick

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Posted 12 January 2022 - 06:38 PM

Well, I removed the spider and with a good bit of effort, some heat and penetrating fluid I got the badly corroded secondary adjusting screws out of the holder. As near as I can tell they are M4 x .70 metric socket head screws (probably not original since there was also a milk jug washer in there). I often find small screws hard to measure, can anyone verify that size? I googled this on this site but didn't find the answer, maybe I overlooked it. Looked on the Bob's Knobs site but they don't list the screw size and pitch.

 

Also, I have straightened out the spider vanes in my vise (they looked like spaghetti). Now, how do I re-install the spider? Am I supposed to disassemble it to put it in (more corroded screws) or just bend the vanes a little?

 

Thanks all!



#21 SteveG

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Posted 12 January 2022 - 07:05 PM

Wow, thanks for that! This is very helpful. Your observation on the spider vanes is spot on, they are a twisted mess! The whole spider needs to come out and be straightened, then reinstalled and tightened up. One of the adjusting screws is rusted and frozen, so I'll tackle that when I have it out instead of messing with it in the tube, less likelihood of collateral damage. I just pulled the secondary and was interested to see it already had the milk jug washer installed. This scope shows an interesting mix of care and neglect, probably reflecting different ownership over time. Interesting project.

 

I have read elsewhere that in some scopes the spider vanes are intentionally offset, but it sounds like that is not the case for the Z10, correct?

 

Sorry, very much a beginner on the scope optics, can you explain what "focuser axis" is?

 

I don't have a Cheshire, but the seller included a generic laser. I will need to check it for accuracy before I can count on it to adjust the scope, and then will also have to learn how to use it! Step by step.

Vanes are never offset, but some times the hub or secondary mirror is glued in place with an offset away from the focuser. You should ignore all thoughts of offset, because that happens when you do a full and correct collimation.

 

Focuser axis is the tilt and rotation adjustment at the secondary.

 

If your laser is consistent, it should be useable. Place it in the focuser, tighten the setscrew and note where it hits on the primary. Now remove it and twist it 180 degrees, retighten. Does it hit in the same spot on your primary? If so, it should be fine.



#22 SteveG

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Posted 12 January 2022 - 07:16 PM

Well, I removed the spider and with a good bit of effort, some heat and penetrating fluid I got the badly corroded secondary adjusting screws out of the holder. As near as I can tell they are M4 x .70 metric socket head screws (probably not original since there was also a milk jug washer in there). I often find small screws hard to measure, can anyone verify that size? I googled this on this site but didn't find the answer, maybe I overlooked it. Looked on the Bob's Knobs site but they don't list the screw size and pitch.

 

Also, I have straightened out the spider vanes in my vise (they looked like spaghetti). Now, how do I re-install the spider? Am I supposed to disassemble it to put it in (more corroded screws) or just bend the vanes a little?

 

Thanks all!

Sorry I don't the tilt screw threads. Take one to a hardware store?

 

Regarding the vanes, if you have all of the nuts removed, you can slightly warp the vanes to allow insertion into the tube. Make sure to keep that center screw on the hub of the secondary centered in the tube, and tighten the vanes piano wire tight!

 

Do you have a long barlow by chance? If the lens threads off the bottom, you can use it along with your collimating cap as a site tube - needed for centering the secondary.



#23 bluelick

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Posted 12 January 2022 - 07:47 PM

Sorry I don't the tilt screw threads. Take one to a hardware store?

 

Regarding the vanes, if you have all of the nuts removed, you can slightly warp the vanes to allow insertion into the tube. Make sure to keep that center screw on the hub of the secondary centered in the tube, and tighten the vanes piano wire tight!

 

Do you have a long barlow by chance? If the lens threads off the bottom, you can use it along with your collimating cap as a site tube - needed for centering the secondary.

Thanks, I did just fiddle with reinserting the spider and that seems like it will work fine. Before I put it back I need to press or pull out the indentations in the tube where the ends of the spider connect, this puppy had some hard knocks!

 

Hardware store would be my usual next stop, I'm just trying to not go anywhere until the Omicron settles down here, it's all around us, so we are holed up out here in the woods. I may order some based on my measurements and see if they work. The old ones are so bad I don't want to put them back in if I don't have to.

 

I just got a long Barlow, I will need to look at the bottom end to see if it threads off, it is a Meade 140. I also have the barrel of a shorty (no lenses) that along with the 2" to 1.25" adapter would be somewhat long (the adapter is an outie rather than an innie if that makes sense), so that might work also. I'll play with that. I feel like with the images from you and what I have read here and elsewhere on collimation I'll be able to get this at least close with what I have on hand, at least I can see how far I can go and what the results are. I'm pretty good at aligning things by sight, many years of construction and woodworking, and adjusting power tools with close tolerances. Although my eyes aren't what they used to be--bad timing for getting into this sport, right?

 

Again, sincere thanks!


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#24 bluelick

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Posted 13 January 2022 - 07:10 PM

Progress report--the good and the bad.

 

The good: I was able to clean up the secondary screws and get the threads cleared enough to reinstall the spider and the secondary. I put a little wax on the screws in the hopes they won't seize up again, at least not immediately. I worked on getting the secondary in the right alignment to the best of my ability and felt it was close enough to turn my attention to the primary.

 

The bad: more corroded screws on the primary. One of the adjusting screws was frozen solid and now the nob turns, but not the screw. I will have to cut the nob off to get vise grips on the screw. To get into all that, I think it might be smart to pull the whole end off and remove the primary from the cell so I don't have any chance of damaging the mirror. Can anyone tell me if the mirror is glued on or just sitting there held by the clamps?

 

Meanwhile, I got collimation as close as I could with only primary adjusting two screws to work with, and one of them bottoms out before I get it right where I would like it to be. See picture of current alignment. I hope someone can tell me if the secondary is still off or if I just need to address the primary at this point.

 

Good times!

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#25 Waynosworld

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Posted 13 January 2022 - 11:22 PM

I would mark each screw and tube hole with a mark(number?) so you can put the primary cell back in the same position, then I would remove it, the primary in your photo appears to have clips holding the primary mirror from falling out so you should be able to remove the clips and remove the primary mirror from the cell, I would then check every screw, nut, and bolt to make sure everything was not frozen, it is a lot easier to collimate the primary with 3 knobs instead of 2 knobs although I have read about members on here that only use 2 knobs.

 

The secondary does not look collimated properly, but I am not an expert, I also cannot tell if your photo is taken from the center of the draw tube, it has to be perfectly centered.

 

You likely can use it the way it is and see a lot, but it helps if everything is collimated properly.


Edited by Waynosworld, 13 January 2022 - 11:24 PM.

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