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VectorRoll
super member


Reged: 11/27/12

Is Self Centering Adapter better for Collimating?
      #5794735 - 04/12/13 03:22 PM

I am wondering if it is better to use a Self Centering Adapter when Collimating with a Laser Collimator over using a regular Compression Ring Adapter. Any thoughts?

I ask because when collimating today I noticed that when using my Laser when I tighten down the Laser in mt 1.25" Adapter I can see the laser point shifts position on the Primary and on the Diaginal in the Collimator. It also shifts when I turn the Adapter itself.

The Laser itself is collimated with a V-Block. At least it hits the same spot when rotating the Collimator and having the laser hit the wall a couple of feet away. I'll recheck the Laser at an even longer distance, but I am wondering if this is a common thing with compression rings, since the ring pushes the eyepiece on one or two sides.

I fear that they adapter making the Laser Collimator not being centered just makes the Collimation to always be off.

I am going to be buying a Cheshire as well as I wanted one anyways to learn how to use it as well. But I am wondering if getting a Self Centering Adapter to be a good Idea as well. Any thoughts on if a Self Centering Adapter is worth purchasing.


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Vic Menard
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Reged: 07/21/04

Loc: Bradenton, FL
Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5794762 - 04/12/13 03:37 PM

I would suggest you consider this adapter: http://www.collimator.com and click on the link, "NEW - The Parallizer".

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Jon Isaacs
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5794773 - 04/12/13 03:41 PM

Quote:

But I am wondering if getting a Self Centering Adapter to be a good Idea as well. Any thoughts on if a Self Centering Adapter is worth purchasing.




It could be worth purchasing.

First I would make sure your laser is properly seated in the adapter. The laser has a shoulder that is supposed to fit up against the adapter, that is what ensures the alignment. Push on the laser and rotate it to make sure the shoulder is up against the adapter flange all the way around as you tighten up the adapter.

Jon


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VectorRoll
super member


Reged: 11/27/12

Re: Is Self Centering Adapter better for Collimating? new [Re: Jon Isaacs]
      #5794873 - 04/12/13 04:40 PM

Quote:

I would suggest you consider this adapter: http://www.collimator.com and click on the link, "NEW - The Parallizer".



That is pretty nice. I watched the video on there site where the guy explains it. I like it plus it does not cost to much. I think I may just pick one of those up.

I wonder if they make a Focuser with it built in for 2" eyepieces.?
Quote:

Quote:

But I am wondering if getting a Self Centering Adapter to be a good Idea as well. Any thoughts on if a Self Centering Adapter is worth purchasing.




It could be worth purchasing.

First I would make sure your laser is properly seated in the adapter. The laser has a shoulder that is supposed to fit up against the adapter, that is what ensures the alignment. Push on the laser and rotate it to make sure the shoulder is up against the adapter flange all the way around as you tighten up the adapter.

Jon



If you saying to pretty much push it down all the way to the rim where it can not go any further, that is pretty much what I do for both the Collimator and 1.25" Adapter. I'll double check it though just to make sure.


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Vic Menard
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Reged: 07/21/04

Loc: Bradenton, FL
Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5794900 - 04/12/13 04:58 PM

Quote:

...I wonder if they make a Focuser with it built in for 2" eyepieces.?



That's a good question (and one I've discussed with Howie)--they don't, yet.
FWIW, my 2-inch tools and eyepieces seem to be less susceptible to registration errors than my 1.25-inch gear. But my Parallizer has fixed the 1.25-inch registration issues.


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DaveJ
Carpal Tunnel
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Reged: 01/07/05

Loc: NE Ohio
Re: Is Self Centering Adapter better for Collimating? new [Re: Vic Menard]
      #5794986 - 04/12/13 05:29 PM

Quote:

Quote:

...I wonder if they make a Focuser with it built in for 2" eyepieces.?



That's a good question (and one I've discussed with Howie)--they don't, yet.
FWIW, my 2-inch tools and eyepieces seem to be less susceptible to registration errors than my 1.25-inch gear. But my Parallizer has fixed the 1.25-inch registration issues.




This part from Agena Astro works perfectly well, also.


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beatlejuice
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Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5795200 - 04/12/13 06:48 PM

The Parallizer certainly works, but when I got the Self-centering adapter from Agena it worked as well. I would collimate with one or the other and then check with the one I didn't use to find that nothing had changed. This is after adjusting the secondary and also using the Tublug for primary adjustments. Some, (myself included), think that there is another advantage with the self-centering adapter with the ease of changing eyepieces. I'm keeping both since I like the confirmation aspect, but you might want to consider the other possible advantage to the self-centering adapter when you make a purchasing decision.

Eric


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Don Taylor
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Reged: 07/12/09

Loc: South TEXAS
Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5795267 - 04/12/13 07:28 PM

My opinion (and only that) is that you should collimate with the same adapter you will subsequently use with your eyepieces.

The reason for this is that Collimation is aligning the optical axis of the scope's elements with that of the eyepiece

If you collimated with one centering adapter and then use a different one for viewing then you have just built in misalignment from any differences between the two.

Since You have checked the effect of rotating the Collimation tool and adapter together in the focuser and the point moves then I suggest you obtain a new adapter that can be used for both alignment and viewing.

Beyond that (as everything has some variation) it helps to orient eyepiece adapters exactly the same when using an eyepiece as when collimating taking care to register the adapter against the same feature of the focuser.

Edited by Don Taylor (04/12/13 07:32 PM)


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johnnyha
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Reged: 11/12/06

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Re: Is Self Centering Adapter better for Collimating? new [Re: Don Taylor]
      #5795539 - 04/12/13 10:42 PM

There are several schools of thought on this. I thought the same thing for awhile Don but came to realize, after reading many threads on this issue - the self-centering adapter is what works for me. You want the collimation to hit the center of the eyepiece (or the drawtube, if you will). The eyepiece can tilt quite a bit but it does not matter much, it's a "local tilt" and does not effect the image - the center is still pretty much centered and that is where the image is focused. However the laser OTOH when tilted by the setscrew, has to go all the way to the mirror (or lens), and any local tilt by the time it gets to the mirror has magnified by the distance and can be off quite a bit - and this can cause miscollimation of the return reflection, or the mirror might end up moved from its optimal position to accomodate the offset laser, or the secondary collimation may be thrown off.

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VectorRoll
super member


Reged: 11/27/12

Re: Is Self Centering Adapter better for Collimating? new [Re: johnnyha]
      #5796389 - 04/13/13 10:55 AM

Well I tried to buy one of those Parallizer's but for the life of me it seems I can not register an account in order to get through the CheckOut process.
Anyone have an Idea on how to register with them in order to buy things from them?

If I can not figure it out I'll just go for the other one from Agena.


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Howie Glatter
Vendor


Reged: 07/04/06

Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5796420 - 04/13/13 11:13 AM

Hi Vector,

Sorry about the ordering problem - I'll try to fix it asap. In the meantime, you can just e-mail me at howieglatter@mindspring.com or phone at 718 796 3203.
I'm checking a batch into stock now. Each one is tested in a long path laser set up with a "perfect" 1.25" collimator inside it, rolling it within a "perfect" cylinder as a stand-in for a drawtube.
Regarding the O.P.'s question in the title of this thread, I think we should stop worrying about the centering, and instead worry about the tipping.


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Jon Isaacs
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Is Self Centering Adapter better for Collimating? new [Re: johnnyha]
      #5796455 - 04/13/13 11:32 AM

Quote:

However the laser OTOH when tilted by the setscrew, has to go all the way to the mirror (or lens), and any local tilt by the time it gets to the mirror has magnified by the distance and can be off quite a bit - and this can cause miscollimation of the return reflection,




This is one of the several reasons the return reflection should not be used for aligning the primary mirror... If one is going to use a laser, it needs to be some form of the "Barlowed laser" as it is relatively insensitive to misalignments other than the primary tilt.

Jon


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precaud
scholastic sledgehammer
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Reged: 12/05/12

Loc: north central New Mexico
Re: Is Self Centering Adapter better for Collimating? new [Re: johnnyha]
      #5796541 - 04/13/13 12:27 PM

Quote:

You want the collimation to hit the center of the eyepiece (or the drawtube, if you will). The eyepiece can tilt quite a bit but it does not matter much, it's a "local tilt" and does not effect the image - the center is still pretty much centered and that is where the image is focused.




How can it possibly be true that the EP is so tolerant of axial misalignment as you suggest? It makes no sense to me.


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DaveJ
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Re: Is Self Centering Adapter better for Collimating? new [Re: precaud]
      #5796733 - 04/13/13 02:41 PM

Quote:

How can it possibly be true that the EP is so tolerant of axial misalignment as you suggest? It makes no sense to me.




The eyepiece can tolerate a bit of tilt just fine. A tilted laser, on the other hand, causes extreme mis-collimation which screws up everything.


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Vic Menard
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Reged: 07/21/04

Loc: Bradenton, FL
Re: Is Self Centering Adapter better for Collimating? new [Re: DaveJ]
      #5796789 - 04/13/13 03:16 PM

The axial alignments are responsible for axial performance. The two axes are the optical, or primary mirror, axis, and the eyepiece axis (often referred to as the focuser axis).

Each axis has defined tolerances. For high magnification performance, the optical axis must be centered in the eyepiece field stop to a tolerance of +/-0.0055mm times the focal ratio cubed (Everhart). This effectively "centers" the coma "free" field in the center of the eyepiece field stop.

Similarly, for high magnification performance, the eyepiece axis must be tilted so it is aimed at the center of the primary mirror to a tolerance of about 3-percent of the primary mirror diameter (+/-). This tilt adjustment is usually imparted by adjusting the secondary mirror tilt. If a Paracorr is used, the tolerance is tightened by a factor of 6, or about 0.5-percent of the primary mirror diameter (+/-). This effectively keeps the defocusing contribution from a tilted focal plane below that of the coma contribution and ensures snap focus when combined with a well corrected optical axial alignment.

And I agree with Don Taylor that collimating tools should be subject to the same registration as the eyepieces or imaging accessories you'll be using with your scope. By using the same adapter for collimation and observing/imaging, the eyepiece/camera will benefit from the same axial alignment corrections.


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VectorRoll
super member


Reged: 11/27/12

Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5796896 - 04/13/13 03:52 PM

Quote:

Hi Vector,

Sorry about the ordering problem - I'll try to fix it asap. In the meantime, you can just e-mail me at howieglatter@mindspring.com or phone at 718 796 3203.
I'm checking a batch into stock now. Each one is tested in a long path laser set up with a "perfect" 1.25" collimator inside it, rolling it within a "perfect" cylinder as a stand-in for a drawtube.
Regarding the O.P.'s question in the title of this thread, I think we should stop worrying about the centering, and instead worry about the tipping.



Thanks for the Reply. I went ahead and Emailed you.

Being the OP and since you mentioned the tiping. I take it you mean the laser itself. I just went through the collimation of the laser again to double check it. I know it is not as good as one of your laser's but if you have any further insight on how to improve any tilt I might have I am curious.

One thing about my Laser that I did notice is that when I took the end off today to see what size batteries it takes, which are dieing already even though I have only had it for about two weeks , I noticed that the laser is set in there at an angle. Yet when I do the V-Block test it does seem to be dead on. I have done the test at about twenty feet.
I am wondering is it common for the laser to coming out of the actual houseing at an angle like that?


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Howie Glatter
Vendor


Reged: 07/04/06

Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5797298 - 04/13/13 06:32 PM

". . since you mentioned the tiping. I take it you mean the laser itself"

I don't mean tipping of the laser beam with respect to the laser collimator housing. Let's theoretically assume a perfect collimator - I mean the tipping of the entire laser collimator, or eyepiece, or camera nosepiece, within the holder (drawtube or adapter). This is what creates the optical problems; not a small sideways offset of the accessory. As long as the axis remain parallel, you are o.k.
As has been mentioned, tip seems less of a problem for one-eyed visual observing. I think that's because of the capability of our visual system to accomodate small amounts of misfocus. Imaging chips can't do that yet :-) Tipping is a problem for high power bino-viewing, because the image moves in the field, and then inter-ocular collimation is lost. And of course, tipping is a terrible problem when using collimation tools.

"I noticed that the laser is set in there at an angle . . is it common for the laser to coming out of the actual houseing at an angle like that?"

Yes. Many low-quality laser collimators use cheap key-chain type laser pointers, which have infinitely permissive tolerance on beam alignment. They are typically powered by three small button cells that last many minutes.

Vector, at the moment I can receive but not send e-mail, so I will reply to your e-mail tomorrow, or send you a PM here.


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Starman1
Vendor (EyepiecesEtc.com)
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Reged: 06/24/03

Loc: Los Angeles
Re: Is Self Centering Adapter better for Collimating? new [Re: beatlejuice]
      #5797304 - 04/13/13 06:38 PM

Quote:

The Parallizer certainly works, but when I got the Self-centering adapter from Agena it worked as well. I would collimate with one or the other and then check with the one I didn't use to find that nothing had changed. This is after adjusting the secondary and also using the Tublug for primary adjustments. Some, (myself included), think that there is another advantage with the self-centering adapter with the ease of changing eyepieces. I'm keeping both since I like the confirmation aspect, but you might want to consider the other possible advantage to the self-centering adapter when you make a purchasing decision.

Eric



The self-centering adapter adequately centers and aligns the tool in the adapter, but the exterior of the adapter is still a smooth cylinder, and a fairly short one at that (to improve registration and safety for 2" filters threaded onto the bottom, I recommend using this adapter with an eyepiece barrel extender or a Baader Fine Tuning Ring. Both additions lengthen the adapter and improve its registration). In high-end focusers, the fit may be tight enough to avoid misregistration, but, unlike the Glatter Parallizer, it CAN still be mis-registered in the focuser's drawtube. Since any 1.25" collimation tool has the possibility of TWO misregistrations when used in a 2" focuser, I always recommend 2" tools with a 2" focuser.
The Glatter Parallizer may eliminate that objection, but if you have a 2" focuser, you might as well use 2" collimation tools.

As for the ease of changing eyepieces, I agree with you. The self-centering adapter is a smooth-sided collet, and, as such, doesn't hang up on the 'safety grooves' cut into eyepieces. Plus, unlike an adapter with a brass ring inside, it actually supports the eyepiece all the way to the shoulder.


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VectorRoll
super member


Reged: 11/27/12

Re: Is Self Centering Adapter better for Collimating? new [Re: Starman1]
      #5797340 - 04/13/13 07:05 PM

Quote:

". . since you mentioned the tiping. I take it you mean the laser itself"

I don't mean tipping of the laser beam with respect to the laser collimator housing. Let's theoretically assume a perfect collimator - I mean the tipping of the entire laser collimator, or eyepiece, or camera nosepiece, within the holder (drawtube or adapter). This is what creates the optical problems; not a small sideways offset of the accessory. As long as the axis remain parallel, you are o.k.
As has been mentioned, tip seems less of a problem for one-eyed visual observing. I think that's because of the capability of our visual system to accomodate small amounts of misfocus. Imaging chips can't do that yet :-) Tipping is a problem for high power bino-viewing, because the image moves in the field, and then inter-ocular collimation is lost. And of course, tipping is a terrible problem when using collimation tools.

"I noticed that the laser is set in there at an angle . . is it common for the laser to coming out of the actual houseing at an angle like that?"

Yes. Many low-quality laser collimators use cheap key-chain type laser pointers, which have infinitely permissive tolerance on beam alignment. They are typically powered by three small button cells that last many minutes.

Vector, at the moment I can receive but not send e-mail, so I will reply to your e-mail tomorrow, or send you a PM here.



Thanks for your reply. Everything in it was very helpful for me. I am learning more every day.
I also look forward to your reply to my Email.


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beatlejuice
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Re: Is Self Centering Adapter better for Collimating? new [Re: Starman1]
      #5797376 - 04/13/13 07:38 PM

Quote:

I recommend using this adapter with an eyepiece barrel extender or a Baader Fine Tuning Ring.




Thanks Don,
I like the barrel extender idea. I didn't know about these. Pretty inexpensive and might be worth experimenting with. I also like the way it will solve the filter problem.

Eric


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VectorRoll
super member


Reged: 11/27/12

Re: Is Self Centering Adapter better for Collimating? new [Re: beatlejuice]
      #5809131 - 04/19/13 05:25 PM

Well I got my Paralizer from Howie Glatter today.
Great service by the way Howie.

I am loving it. It works perfectly. It fits nicely in my 2" focuser and the 1.25" pieces fit nicely in it. The threading on the end is also perfect. I was able to attach my Barlow lens to it perfectlty and smoothly. So any 2" filters and extenson tube I may get should work perfectly as well.

Another thing is that it is just visibly beautiful. The milling work you all did on it is great. It looks perfect on my scope. Like it was meant to be a part of it.

The last thing I noticed is that the inset design allows for you to get about a 1/4" closer to the Secondary than you would with a flat end.

I have already used it to re-collimate my scope. Now I just need to get some ClearSkies in order to use it.


If you all decide to make a 2" Focuser with this design, let me know. Or even some sort of Draw Tube Mod for my exsisting focuser. I would love to have it for my scope.


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precaud
scholastic sledgehammer
*****

Reged: 12/05/12

Loc: north central New Mexico
Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5809772 - 04/19/13 10:45 PM

You have chosen... wisely...

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B. Cook
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Reged: 10/18/10

Loc: No. California
Re: Is Self Centering Adapter better for Collimating? new [Re: precaud]
      #5809841 - 04/19/13 11:36 PM

I got my Parallizer today and it is the best thing I have used. It is rock solid in the Moonlite focuser and the Glatter laser is solid. This is something everyone should have. I have tried the twist lock type of several makes. I tell you they will never do what this does for keeping the laser where it should be. This is a winner. Thank you Bill

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Jeff Morgan
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Is Self Centering Adapter better for Collimating? new [Re: Vic Menard]
      #5833373 - 04/30/13 10:44 PM Attachment (14 downloads)

Last month I ordered a new FeatherTouch LW focuser, and came across the Parallizer on the Starlight web site. In theory it sounded great and I ordered it instead of the regular 1-1/4" adapter.

I just received my order, including the Parallizer. It is nicely made of course (I was told that Starlight Instruments does the manufacturing). Testing on Brandons and Delos reveals a very precise (tight!) fit. Obviously it is made to a high tolerance. Fit to the focuser is somewhat looser, but still very good. However I must say I have some apprehensions about it.

Firstly, the eyepiece end is a rather deeply inverted volcano top - this end is not shown in the advertisements. The depth could be very problematic for shorter eye relief eyepieces and/or eyeglass wearers. I tested it in the office with a 6 mm Brandon and I may be ok on this, but it needs to be verified under the stars.

Secondly and more troubling is the securing method. There is no compression ring, a brass set screw bears directly against the eyepiece barrel. The set screw appears to have some sort of rubberized coating dabbed on the tip, but how durable will that prove to be? I'm not keen on the idea of marring my eyepieces with set screw marks. Replacement with a nylon screw may be a better idea.

On a Dob there is no real danger of the eyepiece sliding out under gravity, so a very light touch on set screw will work. Or, I can just limit use to a laser collimator. But I can not see myself using this with eyepieces in my refractor where gravity can be an issue and therefore more tightening is required.

Since the scope I purchased this for will not be complete within normal return periods, I may just exchange it now for the regular FeatherTouch adapter.


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Jeff Morgan
Postmaster
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5833376 - 04/30/13 10:45 PM Attachment (15 downloads)

Here is a photo showing a 6 Brandon well-recessed into the Parallizer.

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Jeff Morgan
Postmaster
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5833380 - 04/30/13 10:45 PM Attachment (15 downloads)

One more angle to show the depth of the inverted volcano.

BTW, the new lightweight FT is a work of art!

Edited by Jeff Morgan (04/30/13 10:47 PM)


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okieav8r
I'd rather be flying!
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Reged: 03/01/09

Loc: Oklahoma!
Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5833398 - 04/30/13 10:53 PM

Brass is a softer metal than that of your eyepiece barrels, so it shouldn't mar them. When working on stainless steel aircraft parts, such as turbine shafts, mechanics use vices with brass jaws to hold parts while doing deburring and finish work on them, so that the parts will not be damaged. I've been using a Parallizer for two years, and it hasn't marred any of my eyepieces. And, due to the angle at which the set screw goes into the adapter, only a very light amount of applied pressure is needed to hold the eyepiece. Also, the pointed end of the screw is at such an angle that, for the most part, the flat of it is parallel to the eyepiece barrel. I have some University orthos that sit pretty low into the bowl of the adapter, but I haven't had any problems viewing through them. I'm going to purchase another Parallizer soon.

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Howie Glatter
Vendor


Reged: 07/04/06

Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5833704 - 05/01/13 06:13 AM

Hi Jeff,

"Secondly and more troubling is the securing method. There is no compression ring, a brass set screw bears directly against the eyepiece barrel. The set screw appears to have some sort of rubberized coating dabbed on the tip, but how durable will that prove to be?"

I'm happy to tell you that you've got that wrong. The clamp screw has an acetyl (Delrin) tip, which is a very tough plastic, not a "rubberized coating", and it is permanently fixed deep into the brass screw. You can crank it down as hard as you like without danger of the metal contacting the eyepiece. So called "compression rings" do protect the eyepiece barrel from marring, but do not compress the eyepiece all around like a collet or split-ring, and create problems with eyepiece registration and eyepiece "saftey groove" lock-up.

"the eyepiece end is a rather deeply inverted volcano top - . . The depth could be very problematic"

In my opinion, you've got this wrong, too. The conical recess is there so that there is no loss of in-travel for situations where the eyepiece needs it. Eyepieces seat at the same depth as the 2" drawtube lip, as can be clearly seen in your photo.
The recess has to be conical in my design to clear the clamp screw shaft. While some eyepieces with wide upper bodies will not seat all the way down, they will still work fine with the Parallizer if the extra in-travel is not needed.


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Jeff Morgan
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5835919 - 05/02/13 10:01 AM Attachment (10 downloads)

Quote:

Hi Jeff,

"Secondly and more troubling is the securing method. There is no compression ring, a brass set screw bears directly against the eyepiece barrel. The set screw appears to have some sort of rubberized coating dabbed on the tip, but how durable will that prove to be?"

I'm happy to tell you that you've got that wrong. The clamp screw has an acetyl (Delrin) tip, which is a very tough plastic, not a "rubberized coating", and it is permanently fixed deep into the brass screw. You can crank it down as hard as you like without danger of the metal contacting the eyepiece. So called "compression rings" do protect the eyepiece barrel from marring, but do not compress the eyepiece all around like a collet or split-ring, and create problems with eyepiece registration and eyepiece "saftey groove" lock-up.





And I'm happy to say that you're right, and my concerns were unfounded. I tested this against anodized 6061-T6 tubing (a remnant of a truss tube purchased from Moonlight) and tightened it several times. From light contact to normal to as hard as I could finger-tighten the knob (which would never be done in actual use). No marks left on the aluminum. So long as the Delrin remains in place this should not marr an eyepiece barrel.

The impression that the tip was dabbed on was due to a flaw in the finishing process in the area of the screw passage. Perhaps oil from the thread cutting process remained in the threads after cleaning and leached out before the coating bath. The blem is on the internal surface and IMO in no way detracts from the product. I do have some past experience with metal coatings and know these things happen from time to time. Certainly not an issue worth complaining about (let alone a return) in any event.


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Jeff Morgan
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Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5835953 - 05/02/13 10:19 AM Attachment (6 downloads)

Quote:

"the eyepiece end is a rather deeply inverted volcano top - . . The depth could be very problematic"

In my opinion, you've got this wrong, too. The conical recess is there so that there is no loss of in-travel for situations where the eyepiece needs it. Eyepieces seat at the same depth as the 2" drawtube lip, as can be clearly seen in your photo.
The recess has to be conical in my design to clear the clamp screw shaft. While some eyepieces with wide upper bodies will not seat all the way down, they will still work fine with the Parallizer if the extra in-travel is not needed.




My concern was not about focus travel - I didn't even mention it.

Rather, the concern was about loss of eye relief on short focal length planetary eyepieces (of which the list is numerous). Even the twist mechanism for the Nagler Zoom is swallowed into the recess. I can adjust it with an ungloved hand, albeit awkwardly.

Since I have satisfied myself that the adapter will not marr eyepieces, I'll test the eye relief issue out this weekend in my refractor. Given the width at the top of the adapter, I'm hopeful that I can press the orbit of my eye deep enough in to see.

But would it be acceptable to not fully seat these types of eyepieces? For example, place the eyepiece in the adapter such that it is flush with the top?


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Howie Glatter
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Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5836431 - 05/02/13 02:20 PM

Hi Jeff,

Yes, you raise some very valid points about the Parallizer.

"So long as the Delrin remains in place this should not marr an eyepiece barrel."

I press fit the Delrin tip about 4mm into a hole in the screw end, and it took a while to get my machining tuned so that the press fit was super-tight with no danger of tip loss. I know of one failure from my first run where the tip worked loose and fell out. Fortunately, the user noticed it right away and did not mark an eyepiece. Although that problem is solved, if anyone experiences it, please contact me and I'll supply a good replacement screw.

"The impression that the tip was dabbed on was due to a flaw in the finishing process in the area of the screw passage."

Those marks, which your photo shows so embarrassingly well, are a consequence of the method that was used to remove any burr from the tapped hole, protruding into the 1.25" bore. We are working on a better method that will have little or no cosmetic consequence.

The issue of eye-socket clearance with the conical recess at the adapter top, when eyepieces with short relief and short upper bodies, like that one that you show are used, is something I had to compromise on in order to get to the design goal of no loss of in-travel. Hopefully, the clearance problem will not arise, or if it does, be very rare.

" would it be acceptable to not fully seat these types of eyepieces? For example, place the eyepiece in the adapter such that it is flush with the top?"

Of course! The Parallizer does not depend on the eyepiece bottoming-out to get great alignment.

I make the clamp screws, but you are correct, Starlight Instruments makes the Parallizer bodies for me. I want to take this opportunity to tell everyone how great Jon Joseph,the owner of Starlight has been in cooperating with me to produce the Parallizer. I have only manual machine tools, and I produced the first prototypes on them with great difficulty, transferring the lathe-turned adapter to the rotary table on my millling machine, to mill the Paralizer feature. I had to tweak the alignment of the adapter body to perfection with a very sensitve indicator when I clamped it to the rotary table in order to get it running true, so that the Parallizer would give the 2 arc minute alignment I was shooting for. If I did production this way, the Parallizers would cost $250.
Starlight has a CNC lathe with live axial tooling. It can produce a Parallizer in a single clamping, eliminating registration transfer errors. But this was not enough to hit 2 arc minute accuracy the first time. Even with the machine programmed to theoretically produce perfectly aligned features, the tiny tolerance necessary for 2 arc minute alignment was exceeded. This was where Jon went the extra light-year for me - I sent him a duplicate of the long path-length laser rig that I use to test and align collimators, and check Paralizers. After machining a Parallizer, He put it in the rig and determined how much it was off, and in which direction. He was then able to tweak his machine adjustments to bring it in, and consistantly hit and exceed the 2 arc minute criterion. This put a very big smile on my face, and I learned that it is not as easy to make high accuracy adapters as it is to make high accuracy collimators. By the way,in a stroke of brilliance, Jon was the one who came up with the name "Parallizer".


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SACK
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Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5836434 - 05/02/13 02:21 PM

Quote:


But would it be acceptable to not fully seat these types of eyepieces? For example, place the eyepiece in the adapter such that it is flush with the top?




Yes. After I got my Glatterizer and 1.25" glatter laser, I was curious about that, and inserted the laser into the glatterizer about halfway, turned it on, marked the position on the wall, turned it off. Then rotated it, again about halfway inserted, tightened it down, turn it on and it was johnny on the spot! It is the beauty of the design, it doesn't need large registration like others do.
Jonathan


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Jeff Morgan
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Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5836702 - 05/02/13 04:38 PM Attachment (5 downloads)

Thanks for the detailed reply Howie.

I guess I had a little shock with the idea that the eyepieces that would benefit most (the high power ones) might seat too deeply to be used. And the market as a whole has become accustomed to compression rings, so I may not be the only one needing re-education in the future.

Seating the eyepiece just a small distance taller in the adapter satisfies me completely. I must admit to feeling just a bit silly that such an obvious solution didn't immediately suggest itself to me, but it's good to hear from you this will not negate the benefits of the adapter.

I'm looking forward to using it for some high-power double star work tomorrow night in the refractor - and with my new Howie Glatter laser collimator.


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Starman1
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Re: Is Self Centering Adapter better for Collimating? new [Re: Jeff Morgan]
      #5836763 - 05/02/13 05:10 PM

Jeff,
Remember to follow the advice on how to insert the adapter, and only use one of your focuser's thumbscrews to tighten the adapter down or you will be defeating the purpose of the machined area on the outside of the adapter.


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nevy
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Re: Is Self Centering Adapter better for Collimating? new [Re: Starman1]
      #5836843 - 05/02/13 05:49 PM

Good point don.
A question for howie, would it be possible or worthwhile making a 2" diameter paralyser as an aftermarket accessorie that screws into the top of the draw tube to replace the usuall compression ring and or the set screw type for us dob owners to get perfect registration on our2" focusers ?


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Howie Glatter
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Re: Is Self Centering Adapter better for Collimating? new [Re: Starman1]
      #5836857 - 05/02/13 05:56 PM

For those who can't stop their fingers from using two clamp screws with the Parallizer, it is advised to rotate the Parallizer in the drawtube so that the two clamp screws are symmetrically disposed opposite the 1.25" clamp screw.

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Howie Glatter
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Re: Is Self Centering Adapter better for Collimating? new [Re: nevy]
      #5836877 - 05/02/13 06:10 PM

Hey Nevy,

"would it be possible or worthwhile making a 2" diameter paralyser as an aftermarket accessorie that screws into the top of the draw tube to replace the usuall compression ring and or the set screw type . ."

Possible, yes, if the top of the drawtube was threaded and had an accurate shoulder to screw down to.
Worthwhile, I don't know about that. I think the best place to put the Parallizer feature is right in the 2" focuser drawtube. If I were a conspiracy theorist, this whole thread might be a plot to lure focuser manufacturers into adopting the idea.
I am thinking of producing visual backs, camera nose-pieces, and larger size down-adapters with the Parallizer feature.


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REC
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Re: Is Self Centering Adapter better for Collimating? new [Re: VectorRoll]
      #5836902 - 05/02/13 06:24 PM

Another booth I missed at NEAF:( I wanted to meet him!

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nevy
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Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5837139 - 05/02/13 08:03 PM

Quote:

Hey Nevy,

"would it be possible or worthwhile making a 2" diameter paralyser as an aftermarket accessorie that screws into the top of the draw tube to replace the usuall compression ring and or the set screw type . ."

Possible, yes, if the top of the drawtube was threaded and had an accurate shoulder to screw down to.
Worthwhile, I don't know about that. I think the best place to put the Parallizer feature is right in the 2" focuser drawtube. If I were a conspiracy theorist, this whole thread might be a plot to lure focuser manufacturers into adopting the idea.
I am thinking of producing visual backs, camera nose-pieces, and larger size down-adapters with the Parallizer feature.




I thought most focuser draw tube tops were threaded ( mine is ) I changed mine to a compression ring type , I would buy one if you could make em , I don't think theres any point for manufacterures of focusers to make them as they probly won't hit the accuracy that you aim for so it would be a wast of time , but I know you can do it.


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Starman1
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Re: Is Self Centering Adapter better for Collimating? new [Re: nevy]
      #5837204 - 05/02/13 08:45 PM

Alas, most focuser drawtube tops are not threaded. Many inexpensive refractors and reflectors have threaded focusers and a few dobs and newtonians from Synta, but they are the exception to the rule.
In order to make the focuser drawtubes the right way, many focusers would have to be redesigned to accept the different drawtube, and that probably isn't going to happen.


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Jeff Morgan
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Re: Is Self Centering Adapter better for Collimating? new [Re: Starman1]
      #5837488 - 05/02/13 11:50 PM

Thanks for mentioning that Don - in the excitement of getting a new astro-toy (as witnessed by styrofoam peanuts all over the office floor), that one completely escaped me.

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Jon Isaacs
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Re: Is Self Centering Adapter better for Collimating? new [Re: precaud]
      #5837635 - 05/03/13 03:56 AM

Quote:


How can it possibly be true that the EP is so tolerant of axial misalignment as you suggest? It makes no sense to me.





Try it, loosen the eyepiece and tilt it while maintaining focus. The amount of tilt possible due to slop is small and does not affect the image...

As I have said before, proper alignment of a cylinder in a tube is best done by seating the shoulder of the eyepiece/adapter/collimator against the top of the focuser drawtube, this ensures that the eyepiece/adapter/collimator is parallel to the drawtube axis.

Jon


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Howie Glatter
Vendor


Reged: 07/04/06

Re: Is Self Centering Adapter better for Collimating? new [Re: Jon Isaacs]
      #5837674 - 05/03/13 05:40 AM

Hi Jon,

"proper alignment of a cylinder in a tube is best done by seating the shoulder of the eyepiece/adapter/collimator against the top of the focuser drawtube, this ensures that the eyepiece/adapter/collimator is parallel to the drawtube axis."

If the top face of the drawtube is square to the drawtube bore, and the drawtube bore is an accurate cylinder, this is fine.

In the unlikely though possible case that the face of the drawtube is not square with the bore, or if the drawtube bore has any taper, tightening the clamp screw may tip the eyepiece, forcing it out of 360 degree contact with the drawtube face.


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precaud
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Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5837760 - 05/03/13 08:03 AM

I have four 2" to 1.25" adapters here. Three of them exhibit some combination of a) the top plate not being square to the drawtube, and b) the drawtube bore not being perfectly parallel to the outer adapter wall.

Since, when installed, the tool references the focuser drawtube, the top plate is guaranteed to reflect the inaccuracies of those other surfaces PLUS its own.

PS - I should have said, the Parallizer is the one good one.


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SACK
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Re: Is Self Centering Adapter better for Collimating? new [Re: Howie Glatter]
      #5838816 - 05/03/13 05:45 PM

A good tip there Howie.

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