Astro-Physics Right-Angle Polar Alignment Scope
Does the
Astro-Physics Right-Angle Polar Alignment
Scope
fit the losmandy
mounts?
?
Leroy
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Re: G11 on JMI Wheeley Bars
For a low cost version ($25) I made my own and use it on my Meade LX200GPS-14", works so well, my 4yo boy can roll it out (under my supervision).
Simply a 2x6, drywall screws, 1/2 inch all thread, six 1/2 inch nuts, 3 casters. I had the scopebuggy and got tired of hand screwing the jack screws down and up, so I just lock two nuts together at the top of the all-thread (with point at bottom) and use my cordless screw driver to lower and raise them in ~30 seconds (hex drive to 1/2 inch drive with socket), works very well and saved about $275 clams.
You could add a little protection for the legs moving, but in 7 years I have not had any issues with the legs moving, you could add anti-vib pads under the legs or rubber mat pieces. Could add a small piece of plywood to add more stuff below the tripod, it's childsplay making this thing and low cost. Have fun, clear skies.
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Re: Target Unreachable Message?
Figured it out. Corrupted model.
John C Golden Valley, AZ
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Re: Target Unreachable Message?
I used my mount (Titan 50 - Gemini-2) successfully on 10/10/17. Tonight, I tried to go to several objects and repeatedly got target unreachable, one of them was M31 - well above the horizon. The only targets I could access were those near the zenith. I checked the site settings and date/time - still good. I tried a default site setting for a major city near me - no change. I parked and started the mount up several times. I went through the process of setting the safety limits again - no change.
I gave in up total frustration after several attempts.
Would this have anything to do with the battery?
John C Golden Valley, AZ
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Re: G11 on JMI Wheeley Bars
dlbeaman I have JMI's Wheely Bar under my G11 G2 with a Meade 10" SCT.? I roll the scope out about 30' to a place where I can do polar alignment (see Polaris).? Small bumps exiting the garage then crossing a patch of asphalt and onto a concrete pad.? Being lazy, I don't bother with the jack screws.? I just point approximately toward the pole and lock the casters.? Polar alignment is with Pole Master.? Seems to work fine for me but I am beginning to develop a desire for a permanent observatory to avoid the set up and tear down of all of the imaging? equipment mostly cabling connections and power cord. Dave... Franktown, CO
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Re: "fast-set" function of Celestron's 492 system
Masami,
It should have the fast slew option, although I recently upgraded to Gemini 2 so can¡¯t test it.
Regards
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Maybe I should ask Scott of HGM instead.
I have a very original twenty-years old Celestron's 492 Digital Drive System.? It has not been used since I upgraded my CG-11 to Gemini-1 about fifteen years ago.? Quite recently I put everything on my desk, and powered it up.? Everything seemed to work fine except so-called "fast-set" function.? I pressed the button down, while holding the opposite button down on the hand controller.? The motor axis did not look running fast at the 16x speed.? Actually, I never used this function at that time if I recall correctly, because I didn't notice this function until now.? I thought the "fast-set" function was only for Gemini.
I'd like to know whether the system is faulty or the very original 492 does not have "fast-set" function or not.
Your any experience is welcome.
masami?
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"fast-set" function of Celestron's 492 system
Maybe I should ask Scott of HGM instead.
I have a very original twenty-years old Celestron's 492 Digital Drive System.? It has not been used since I upgraded my CG-11 to Gemini-1 about fifteen years ago.? Quite recently I put everything on my desk, and powered it up.? Everything seemed to work fine except so-called "fast-set" function.? I pressed the button down, while holding the opposite button down on the hand controller.? The motor axis did not look running fast at the 16x speed.? Actually, I never used this function at that time if I recall correctly, because I didn't notice this function until now.? I thought the "fast-set" function was only for Gemini.
I'd like to know whether the system is faulty or the very original 492 does not have "fast-set" function or not.
Your any experience is welcome.
masami?
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I intend to put a G11 with Gemini 2 on the JMI Wheeley Bars with a C14 on the mount (visual observing only). It will be a semi-permanent set up. Objective is to be able to simply roll the whole thing out from my garage to my observing pad - smooth level concrete all the way. Then roll it back at the end of my observing session. Would like to hear from anyone using the G11 on the JMI Wheeley Bars for comments, problems, etc. Especially any vibration damping problems. Thanks in advance.?
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Re: Polar scope borehole...CG11
PoleMaster don't need no stinking blow hole - hehe
Jeff
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Re: Polar scope borehole...CG11
Maybe your saddle is not where it is
supposed to be / meant to be??
?
Derek
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Thursday, October 19, 2017
9:17 AM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re:
Polar scope borehole...CG11
?
?
Any offset angle moves the scope out of the way...that does save ones
noggin.?
That's why the polar scope hole should be at 90 degrees.? Why
would you want to put it at 60 degrees CW? ... Which is 120 degrees in the CCW
direction. ?
Just makes another IQ test in the dark.? You wouldn't want to
stick you finger in there or lop it off in the dark.? I will mark the
angle with a sticky label ...?
?
?
Hmmm, that's the reason why they say turn the
scope...?? I had no idea...Don't bang your head...(:>
Rod
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Re: Polar scope borehole...CG11
Michael,
I believe it a compromise between getting in the way of one¡¯s head and having to reach the altitude adjustment knob which having the scope at 90 degrees would be frustrating.
Regards
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Any offset angle moves the scope out of the way...that does save ones noggin.?
But but but...
That's why the polar scope hole should be at 90 degrees.? Why would you want to put it at 60 degrees CW? ... Which is 120 degrees in the CCW direction. ?
Just makes another IQ test in the dark.? You wouldn't want to stick you finger in there or lop it off in the dark.? I will mark the angle with a sticky label ...?
Michael
?Hmmm, that's the reason why they say turn the scope...?? I had no idea...Don't bang your head...(:>
Rod
--?
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Re: Polar scope borehole...CG11
Any offset angle moves the scope out of the way...that does save ones noggin.?
But but but...
That's why the polar scope hole should be at 90 degrees.? Why would you want to put it at 60 degrees CW? ... Which is 120 degrees in the CCW direction. ?
Just makes another IQ test in the dark.? You wouldn't want to stick you finger in there or lop it off in the dark.? I will mark the angle with a sticky label ...?
Michael
?
Hmmm, that's the reason why they say turn the scope...?? I had no idea...Don't bang your head...(:>
Rod
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Re: Lot of play on G11 RA with one piece worm
Ok.? I understand.
Sorry for the long winded comments following...
There are 2 directions the worm can move... That must be considered and minimized. ?one is the worm to ring gear spacing.? The second is worm side to side motion. ?
You are observing the problem of the worm teeth not fully engaging the Ring gear that it meshes with. ? You could have an OPW "one piece worm block", or original "2-piece" worm block on the critical RA drive.? The DEC usually has only got the 2-piece blocks.?
On the OPW you must loosen but not remove both hold down bolts, then back out (so the screw does not touch the contact point) ?the adjustment screw at the far end...it usually has the small T handle.? Then you must press the worm against the ring gear by hand, while you snug up three hold down bolts.? You then test with the motor for "Stall" errors and adjust the screw inward in very tiny steps moving the worm back off the ring gear til Stall errors go away. ?("Lags" messages are usually from a very heavy payload, or gummed up bearings, or payload off balance).?
?If you have the original "2-piece" worm blocks, you still must loosen both blocks.? The block closest to the gearbox acts like a pivot...but you should not use the bearing inside it like a pivot...Any angle in that bearing (or the far bearing) will cause one ball inside to get stressed periodically...the unwanted "76-sec" period that PEC can't clean up.? Anyway, while you try to keep both worm blocks in the same line as the worm axis, you also squeeze the worm against the ring gear.? Then snug down the hold down bolts and test with the motor for "Stall" errors. ?
The OPW and the Ovision worm systems mount the worm bearing holders on one metal rail system, always keeping the bearings in line with the worm axis, so you set that up ahead of attaching to the mount. ?(That helps friendless humans limited to 2 hands...). The Ovision system has designed in a far end Belleville spring washer to keep the worm from side to side motion along the worm axis.? The Losmandy system never designed that spring in, but it can be added with hand work...requires sanding/polishing the far bearing so it can slide in the cylinder...and lubricating the cylinder after adding the spring washer behind the far bearing. ?)
(On some mounts like my old Meade LX50, there was a spring mechanism to push the worm against the Ring gear...but not here on this design.)
Gently snug down the hold down bolts, then run that axis motor and look for error messages...you want to be free of "Stall" messages.? If you see a Stall error, you then start to tighten in the far T handle, that gives you some control of the additional worm to ring gear space as it pushes the worm away from the Ring gear.
Side to side worm movement also leads to worm hysteresis, just like too much worm to ring gap. It can make autoguiding difficult due to the time lag (does PHD sense this and adjust for that?) ?That problem is often treated by either hanging a weighted cord wrapped around the axis, or it can be treated by adding in a Belleville spring washer.? Many people like and use the cord method around the RA, because the angle is constant...just the polar axis.? To put in a Belleville washer requires some slight polishing of the far worm bearing so it can slip in its worm block cylinder.? Still other people leave a slight imbalance on the scope in the dovetail, or the counterweight, but those forces change with system pointing in the sky. ?
Anyway, you will figure all this out...by reading the several good websites by people who studied these problems.? Michael Sinescakchi was one..his site is called HelixGate. ?
Stay well and have fun, Michael
?
Michael, I took a look at what you sent me. I guess I didn't explain the problem well enough. It's not side to side movement on the worm gear, it's that the worm gear does not fit into the RA gear snugly. There's a small adjustment screw is used to back off the worm from the RA gear, but I can't use that because they are not even touching. If I keep it weighted on the east side I'm sure it will work but I just want to make it right.
John
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Re: Lot of play on G11 RA with one piece worm
Michael, I took a look at what you sent me. I guess I didn't explain the problem well enough. It's not side to side movement on the worm gear, it's that the worm gear does not fit into the RA gear snugly. There's a small adjustment screw is used to back off the worm from the RA gear, but I can't use that because they are not even touching. If I keep it weighted on the east side I'm sure it will work but I just want to make it right.
John
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Re: Lot of play on G11 RA with one piece worm
Thanks Michael, I need to check that out. I didn't realize that was in there. On another note, I am expecting delivery of a new Gemini 2 today to solve my problem.? Thanks again for helping me with that!
John
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Re: Polar scope borehole...CG11
Hmmm, that's the reason why they say turn the scope...?? I had no idea...Don't bang your head...(:>
Rod
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Re: Polar scope borehole...CG11
When I first took mine out of the box and set it up, I didn't know squat about an EQT mounting system, as I had always been a Dobs guy..
Anyway after I installed the mount to it's tripod in my house so I could play with the thing, I noticed that polar scope hole was partially covered. At that time not knowing about the DEC and RA clutches, and being able to turn everything like you want manually after loosening those up some...
As for that DEC ring there is something said in the manual about turning your scope parallel to Polar axis, and then it should read 90 degrees, duh...When I connected the motors and the scope and did a slew that ring was not even moving, About a week after this, someone told me you can turn this by hand.
I'm still scratching my head over this one. My goal as I learn this new mount system is to be able to look at the DEC and Alt numbers on an object and manually turn the scope there by using these rings....Maybe one day...Got a lot to learn...!
Rodney
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Re: Polar scope borehole...CG11
So you don¡¯t bang your head on a long ¡®scope while trying to polar align.
Dave
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: 19 October 2017 12:57
To: Losmandy_users@...
Subject: [Losmandy_users] Re: Polar scope borehole...CG11
maybe this is a dumb question..... but why is it offset at all?
just curious
-Jeff
[Non-text portions of this message have been removed]
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Re: Polar scope borehole...CG11
maybe this is a dumb question..... but why is it offset at all?
just curious
-Jeff
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Re: Lot of play on G11 RA with one piece worm
Hi John,
Yes...I saw the design problem... and wrote a description of a way to remedy that, that I just sent you.? Hopefully it cane through your indescribable email address...
-Michael?
?
Hello, I have a used G11 that I've bought. Seems to be in pretty good shape. I noticed a lot of play in the RA worm so I took it apart. What we have is a one piece worm assembly and brass worm. There is no way that I can see to bring the worm in close enough to eliminate any play. The little screw that backs it off is not effecting anything. Anyone see this or have any fixes?
Thanks
John
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David Cochrun
photon_trap
Michael Herman
David C. Partridge