Date
1 - 20 of 24
400 GTO First report
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Jeffrey D. Gortatowsky
I am on my way back out to Anza tonight in a moment but wanted to let you,
and maybe the folks at AP know, the 400GTO worked very well. As an aside, while I have never been to Mount Pinos, the S&T article was a bit harsh on Anza. Anyways I used a 400GTO with a 130EDT f/8. I installed the 15DOVE which came with the scope but oddly enough the scope came from it's previous owner with a GM8 and Losmandy D series plates as well. I thought Christine was send me the screws for the 15 inch plate but I misunderstood. There is a flat plate as well and she sent me the screws for that. As you know, is you use those cap screws with the dove plate, the sliding bar does not slide. <g> So I order and got some flat head socket screws from McMaster online. I am not exactly sure how to secure a safety screw to keep the scope from sliding accidentally, but I was just darn careful when loosening the locks on the dove plate. Anyway I secured the rings, still with the 'adaptor blocks' on the bottom of them, to the sliding bar using one 1 1/2 inch 1/4-20 screw. I don't thing I need the blocks. If fact they may cause the dreaded 'orthogonality' problems. Beats me. I followed the manual and setup the wood tripod and mount with no scope on it and waited for Polaris. I sighted Polaris through the hole in the RA axis and put the scope on the mount. Whoa! Waaaay outta balance BIG time and the Dec and RA locks won't hold it. Gotta be REAL careful and learn where the setup balance points are. I needed both 6 and 9 pound counterweights. Apparently Roland does not believe the locks should be like vises.<g> They are there to provide 'enough friction' when the scope is balanced. <sigh> Later this was to be a real pain as the 4mm Takahashi EP and the 31mm Terminagler are like the odd couple of EPs when it comes to mass. 8^) Okay, so the time of year is right and I can follow the manual! Sight Vega (I used a 7.5mm EP as I forgot my 6mm illuminated crosshair EP). Back to Polaris. Whoa! Outta balance and the objective end of the tube headed south down the Dec axis! Fortunately I was right there. Okay move the tube back a bit in the rings and start over. Vega, Goto, Polaris. Whoa!<g> Not even within the quickfinder's 2 degree circle! Grunt grunt, wrestle, wrestle and I moved the tripod, scope and all. Ow! Okay, I _gotta_ balance that tube some more in declination... <g>. Okay Polaris is in the quickfinder, and I played with the fine adjustments to center Polaris in the EP. Oooooh NOW I see what Ron Wodaski means about tighten the screws after an azimuth adjustment! You have to 'lead them' in the EP. 8^| Oh well. What do I care, I am not imaging. <g> Back to Vega. Off by 3 degrees! Back to Polaris, off by 2.5... I see a trend<g>. And so it went for about 6 times. But it did converged. Cool. It took about 30 to 45 minutes for this 'first timer'. I figured six times meant I might have the dreaded 'orthogonalilty' problem. Now how in @^#$ am I suppose to shim this scope when it's mounted. Man that looks like a non-newmoon night task. I am not gonna try that in the complete dark! I'll take those 'adaptor' blocks off the rings next time and try that first. Then it'll be an ALL AP setup. So ff I went to quantify that orthogonality problem. Follow directions... hmm... it's 9:30PDT on 6/30/2000, Arcturus might work just like the directions say. It slewed to Arcturus. Whallala-be-darned. It's right there! Center it and choose epsilon. (or was it eta? dunno the manual is downstairs) Whats this? The scope just move slightly and it center epsilon. Darn! (and it was dangerously close to the tripod leg<g>!). Maybe I should have had a safe zone defined? Or maybe the people who wrote the manual did. Or maybe it was just too late and both stars were across the meridian. Anyhoo I used Zeta Herc and Alpha CrB and that worked. What a cool mount. All that movement to completely the other side and Alpha CrB was in the FOV of the 7.5mm and the R.A. error was quite small. I'll of course need a crosshair EP to quantify it. I decided that was *good* enough. Bottom line was, it was a very accurate mount. I messed up the balance (31mm T5) and it moved on me in declination once or twice. So I did a N Pole alignment using the 7.5 and a 1.8x TV barlow and it was as good as I left it the first time. Then, I left the 7.5 and 1.8x barlow in (249x, 6' FOV) and slewed to Zeta Boo and was virtually centered. Not bad guys. No HPP mode needed! <g> The mount was VERY stable. As good or actually IMO better than the GM8. That tripod is a gem. You can whack it and it damps in second. I rap tested the tube and it was steady in 1-2 seconds. Soooo my only buggaboo is the balance thing. I guess I'll just get used to it. Or I'll have to remember to start using that brass equalizer I bought a year or two ago. Clear skies, Jeff
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steppzimmr@...
In a message dated 7/2/00 5:48:37 AM Eastern Daylight Time, maroth@...
writes: << I devised a daylight correct procedure to do so. If you ever need this procedure let me know. >> Hi Mike, I also am one such "lucky" person who had a non-ortho mount. If you have time would you please share your method? Previous efforts of mine have failed. Thanks for any help, Peter
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Michael Roth
Jeff:
I am one such person who received a non-orthogonal mount from AstroPhysics. You need a lot of time and some patience and DAYLIGHT to correct this problem. In fact, if you have the light and the time you might even enjoy it. I devised a daylight correct procedure to do so. If you ever need this procedure let me know. Sincerely, Mike Roth Incidentally, I sent my sliding bar BACK because I found it too dangerous to use. The simple flat plate is MUCH better and I have yet to have a single heart-stopping moment with it and I have a 155.
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Derek Wong <dawong@...>
I figured six times meant I might have the dreaded 'orthogonalilty' problem.Hi Jeff: You are right, it is frustrating wasting valuable time do orthogonality at a dark site (if we are at the same dark site I will bring a polar scope). You may not have as much problem with orthogonality as you think. Sometimes the alignment procedure does not converge very rapidly. For visual use, I still think the best way to align is to get a polar scope, which is rumored to be out soon from AP. For photos, Roland had some good suggestions which are in message 10 of this group. Other people use slightly different methods, but I can't remember where their messages are. Perhaps we should make a FAQ to this group, after this nearly born child lets me get some sleep... Derek
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Terry Johnson <tjohnson@...>
I would like to see your daylight procedure for correcting orthoganol
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alignment. Thanks...Terry Johnson
----- Original Message -----
From: "Michael A. Roth" <maroth@...> To: <ap-gto@...> Sent: Sunday, July 02, 2000 2:46 AM Subject: Re: [ap-gto] 400 GTO First report Jeff:
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rck <rkuberek@...>
"Michael A. Roth" wrote:
Jeff:Michael, I need to do this b/c the dp on my C11 is crooked. Could you send me your procedure? Regards, Bob K.
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Jeffrey D. Gortatowsky
In a message dated 7/2/00 5:48:37 AM Eastern Daylight Time,maroth@... Hi Mike,You mean a production defect? Or you are using something with the mount that is making it 'non-ortho'. Just how bad are we talking? My 400 GTO mount, when it slewed all the way from one side of the meridian to another still put the star in question with 3 arc-mins of the other star's position in the EP. The FOV of the EP was only 6'. clear skies, Jeff
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toddg18522@...
In a message dated 7/3/00 1:04:38 PM EST, ray@... writes:
<< Usually the 1/2 way won't work well if the mount is not very level. In that case, you will get one axis affecting the other. Otherwise it has always worked quite well for me (30+ times with my 1200). Of course the OTA has to be close to orthogonal too. -Ray >> okay, i've been doing this, but didn't realize about it needing to be level, thanks
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Mark B. Wilson <Markw@...>
I want a copy also.
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-----Original Message-----
From: Terry Johnson [mailto:tjohnson@...] Sent: Sunday, July 02, 2000 10:12 AM To: ap-gto@... Subject: Re: [ap-gto] 400 GTO First report I would like to see your daylight procedure for correcting orthoganol alignment. Thanks...Terry Johnson ----- Original Message ----- From: "Michael A. Roth" <maroth@...> To: <ap-gto@...> Sent: Sunday, July 02, 2000 2:46 AM Subject: Re: [ap-gto] 400 GTO First report Jeff: ------------------------------------------------------------------------ Was the salesman clueless? Productopia has the answers. http://click.egroups.com/1/4633/7/_/3615/_/962557894/ ------------------------------------------------------------------------
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Ray Gralak <ray@...>
Hi Jeff,I figured six times meant I might have the dreaded 'orthogonalilty' problem. To cut down on the iterations when polar aligning your scope for each iteration you should only adjust the altitude and azimuth adjustments to move Polaris half-way to the center of your finder (or eyepiece when you get sufficiently close). If you put Polaris in the center each time you will overshoot the correction and it will take more iterations. -Ray Gralak
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Ron Wodaski <ronw@...>
It's not always the case that half-way will work for you, and I wondered
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why. I have a theory, of course <g>. The basis of my theory is this (untested) assumption, but I think it's true: because the two coordinate systems (alt-az and equatorial) are oriented so differently, making a change to a single axis (alt or az) can affect position in the other coordinate system along two axes (RA and Dec). For example, if one axis (alt or az) is very close to correct, and the other is not, you should avoid making changes to the one that is close to correct, and concentrate on getting the other one close to correct, too. I haven't had to do this kind of polar alignment for several months, so my experience isn't fresh. I'm currently using a polar scope on an NJP 160, although I have a 400 GTO coming and will have to re-learn these skills. But as I recall, if one axis was close, and I made adjustments to two axes (alt and az), the axis that was close to correct would oscillate (overshoot). I would then move that axis to the mid position (between the extremes of the oscillation), and then leave it alone and concentrate on bringing the other axis close to correct position. Once both were of nearly equal magnitude, I could then quickly get a good alignment by adjusting both together. I have even had situations where I have had to go _double_ the distance, rather than half the distance, to get aligned in a reasonable number of iterations. If memory serves, that tended to be the case when I was aligning to stars on different sides of the meridian, but it has been a while and I'm not entirely sure. Ron Wodaski http://www.newastro.com
-----Original Message-----
From: Ray Gralak [mailto:ray@...] Sent: Monday, July 03, 2000 10:27 AM To: ap-gto@... Subject: RE: [ap-gto] 400 GTO First report problem.I figured six times meant I might have the dreaded 'orthogonalilty' thatNow how in @^#$ am I suppose to shim this scope when it's mounted. Man completelooks like a non-newmoon night task. I am not gonna try that in the Hi Jeff,dark! To cut down on the iterations when polar aligning your scope for each iteration you should only adjust the altitude and azimuth adjustments to move Polaris half-way to the center of your finder (or eyepiece when you get sufficiently close). If you put Polaris in the center each time you will overshoot the correction and it will take more iterations. -Ray Gralak ------------------------------------------------------------------------ Life's too short to send boring email. Let SuperSig come to the rescue. http://click.egroups.com/1/6137/7/_/3615/_/962645188/ ------------------------------------------------------------------------
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Ray Gralak <ray@...>
Hi Ron,
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Usually the 1/2 way won't work well if the mount is not very level. In that case, you will get one axis affecting the other. Otherwise it has always worked quite well for me (30+ times with my 1200). Of course the OTA has to be close to orthogonal too. -Ray
-----Original Message-----
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Jeffrey D. Gortatowsky
Thanks for the tip Ray. You know the ortho check talks about moving halfway
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as does one of the polar alignment methods IIRC. My manuals are in the mount case so I can't refer to them right now. But I don't think method number one (N. Polar Align) calls for half movements. Thanks. I did level the mount (habit) so I'll give it a try. Wonder if the manuals are in Word or sompin'. I think I have a PDF writer printer driver.... Clear skies, Jeff
----- Original Message -----
From: "Ray Gralak" <ray@...> Hi Ron,
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Ron Wodaski <ronw@...>
The 1200 is also just plain better for polar aligning than the 600 GTO
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mount. There isn't much flexure in the 1200, while the 600 has enough to cause some trouble during polar alignment. I suppose the flexure will depend on the weight you've got on the mount. And I can't say that I've tested orthogonality, though my refractor was best for polar aligning; the 9.25" SCT was hopeless. <g> Ron Wodaski http://www.newastro.com
-----Original Message-----
From: Ray Gralak [mailto:ray@...] Sent: Monday, July 03, 2000 11:00 AM To: ap-gto@... Subject: RE: [ap-gto] 400 GTO First report Hi Ron, Usually the 1/2 way won't work well if the mount is not very level. In that case, you will get one axis affecting the other. Otherwise it has always worked quite well for me (30+ times with my 1200). Of course the OTA has to be close to orthogonal too. -Ray -----Original Message-----true: because the two coordinate systems (alt-az and equatorial) are oriented soother is not, you should avoid making changes to the one that is close tocorrect, and concentrate on getting the other one close to correct, too. I haven'texperience isn't fresh. I'm currently using a polar scope on an NJP 160, although Inearly equal magnitude, I could then quickly get a good alignment by adjustingboth together.aligning to stars on different sides of the meridian, but it has been a while andI'm not entirely sure.------------------------------------------------------------------------ 0% Introductory APR! Instant Approval! Aria Visa - get yours today. http://click.egroups.com/1/6035/7/_/3615/_/962647168/ ------------------------------------------------------------------------
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Ray Gralak <ray@...>
The 1200 is also just plain better for polar aligning than the 600 GTOPerhaps, but I learned this technique with my old Vixen GP + SS2000+ Tak FS-102. This mount is much more flexible than a 600<g>. It worked great then as long as the mount was level which was easy to do with the tripod. -Ray Gralak
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Jeffrey D. Gortatowsky
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----- Original Message -----
From: "Ron Wodaski" <ronw@...> orthogonality, though my refractor was best for polar aligning; the 9.25"Why? Because of the mirror shift I guess? I found that when you tighten the two azimuth lock screws the mount does shift. Of course there is 40 pounds or more of stress. I found the movement about 3 to 4 arc-minutes and I could 'lead' them (though a PITA). For imaging you want an alignment as close as possible if not perfect. But realistically how close is close enough? Clear skies, Jeff BTW: Can you autograph my copy of TNA? <vbg>
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Ron Wodaski <ronw@...>
I have never really tried to level the AP mount prior to polar aligning.
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I'll have to see if that makes a difference. I took literally the advice that leveling wasn't "necessary," but perhaps it is desirable. <g> Ron Wodaski http://www.newastro.com
-----Original Message-----
From: Ray Gralak [mailto:ray@...] Sent: Monday, July 03, 2000 11:48 AM To: ap-gto@... Subject: RE: [ap-gto] 400 GTO First report The 1200 is also just plain better for polar aligning than the 600 GTOdepend Perhaps, but I learned this technique with my old Vixen GP + SS2000+ Tak FS-102. This mount is much more flexible than a 600<g>. It worked great then as long as the mount was level which was easy to do with the tripod. -Ray Gralak ------------------------------------------------------------------------ Free Worldwide Calling with Firetalk! Click Here: http://click.egroups.com/1/5481/7/_/3615/_/962650079/ ------------------------------------------------------------------------
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Ron Wodaski <ronw@...>
You can actually get some advantages from not being perfectly polar aligned.
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You can cover backlash in Dec, for example, by deliberately mis-aligning so that the mount is always pushing the Dec in one direction, so that you never encounter the backlash. Have you seen my page on the "bat wing" handles for the az lockdowns on the 600? I also am using Mylar washers to reduce friction, so that I can tighten the az lockdowns and still move the mount well enough. I may have some of those around, if you can't find the washers at your local hardware store. Ron Wodaski http://www.newastro.com
-----Original Message-----
From: Jeffrey D. Gortatowsky [mailto:myrocketcatos@...] Sent: Monday, July 03, 2000 11:56 AM To: ap-gto@... Subject: Re: [ap-gto] 400 GTO First report ----- Original Message ----- From: "Ron Wodaski" <ronw@...> orthogonality, though my refractor was best for polar aligning; the 9.25"Why? Because of the mirror shift I guess? I found that when you tighten the two azimuth lock screws the mount does shift. Of course there is 40 pounds or more of stress. I found the movement about 3 to 4 arc-minutes and I could 'lead' them (though a PITA). For imaging you want an alignment as close as possible if not perfect. But realistically how close is close enough? Clear skies, Jeff BTW: Can you autograph my copy of TNA? <vbg> ------------------------------------------------------------------------ Was the salesman clueless? Productopia has the answers. http://click.egroups.com/1/4633/7/_/3615/_/962650430/ ------------------------------------------------------------------------
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Jeffrey D. Gortatowsky
Ron I had those 'bat handles' on order and delivered before the mount
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arrived! I just thought I'd try it 'stock' first in case there was a problem and it had to be returned. Remember who 'suggested' them? ;^D Thanks for the tip about pushing the Dec to take up the gear backlash. But I am not planning to start imaging for awhile (he says<g>). Too many things to see with my eyes first. Besides I am waiting for the FSQ156 and my AP900GTO first. Clear skies, Jeff
----- Original Message -----
From: "Ron Wodaski" <ronw@...> To: <ap-gto@...> Sent: Monday, July 03, 2000 12:12 PM Subject: RE: [ap-gto] 400 GTO First report You can actually get some advantages from not being perfectly polaraligned. You can cover backlash in Dec, for example, by deliberately mis-aligningso that the mount is always pushing the Dec in one direction, so that younever encounter the backlash.the 600? I also am using Mylar washers to reduce friction, so that I cantighten the az lockdowns and still move the mount well enough. I may have some of9.25" theSCT was hopeless. <g>Why? Because of the mirror shift I guess? I found that when you tighten two azimuth lock screws the mount does shift. Of course there is 40 poundscould 'lead' them (though a PITA). For imaging you want an alignment as close as
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Brian <brian@...>
I have gotten much better results when leveling the 400goto. When leveling
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and using an ap polar scope, the mount guides much easier and more accurately. Brian
-----Original Message-----
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