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
?
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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
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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?
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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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Lot of play on G11 RA with one piece worm
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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Polar scope borehole...CG11
Hi gang,
There was a recent question about the polar scope borehole DEC angle.? Someone mentioned it was strange it was not at 90 degrees from CWD.?
Just now examining that on my (old) Celestron G11 ("CG11"),? I get exactly 90 degrees.? Just the same as on my Orion Atlas/Synta EQ6.??
But on my newer version GM8, that polar scope hole is 60° on the DEC axis where CWD is 0 ° DEC.? (That is, I must rotate my DEC axis 60 degrees CW as viewed from the top looking down. )
So somewhere in the annals of history, Losmandy changed its design spec for that polar scope through-hole angle.? Or maybe the G11 is different than the GM8... ???
Anyway...the answer is: there is no single answer at least at my house.??
Best regards, Michael?
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Re: Gemini II-GPS question?
Update: ?Got out to play some more. ?It seems that just setting time zone to zero does work when using the GPS. ? spent the evening running through the hand controller, setting limits, and building some models. ?Everything seems to be running smoothly. ?
JMD?
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Re: G1 on G-11 refuses to go to bright stars
Magnus,
Sounds like there is a data corruption issue.?
Chip
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HI All! I am new to Gemini and I am just getting familiar with its operation.?? I have a G11GT and I am using the Losmandy GPS unit to determine lat, Long and time.??? I am noticing some quirks with respect to how Gemini and the GPS interact.? Basically, if I go from a cold start(or quick start), Gemini automatically sets the time zone to -8(I assume California) and the corresponding time.? When the GPS is queried, the lat and long come back correctly, but the time zone and time on the hand controller do not reset. If I reset the time zone manually, and THEN requery the GPS, things seem to come back more or less correctly.??? My question is, when using the GPS, what is recommended practice for setting the time zone and time?? I have read a number of sources that suggest Gemini uses the information GPS and that the hand set time etc..? do not play a role in goto and pointing, but my experience suggests otherwise(I may be misunderstanding what people are saying!).? ?Another suggestion is to simply set the time zone to zero and go.? A third approach was to set the time zone directly (or one behind for daylight savings) to get the accurate time.? I have kind of played around with all of these with varying results. I should point out that I use pole master to polar align, so I am confident that the mount is level and aligned.? ? I would appreciate any insight this group could provide.? I am having fun with the mount, and am just working through this little wrinkle in an otherwise cool process! Thanks! JMD
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Re: G1 on G-11 refuses to go to bright stars
Magnus,
I have had similar issues when either the location or time are entered incorrectly.
Regards
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Hi!
I'm in Sweden, at 21, 22 in the evening. The stars I am trying to reach is about 45 degrees above the horizon. Mizar and Dubhe West-North-West, roughly. Earlier, the same thing happened with Altair and Deneb, a few weeks ago, when they were high, South and sligtly to the east.
As for safety limits, the location of the stars are way off the limits. And I can easily slew the mount to them. It is the GoTo that does something strange.?
As for battery - new as of 1 hour before trying this yesterday.?
Magnus
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Re: G1 on G-11 refuses to go to bright stars
Hi!
I'm in Sweden, at 21, 22 in the evening. The stars I am trying to reach is about 45 degrees above the horizon. Mizar and Dubhe West-North-West, roughly. Earlier, the same thing happened with Altair and Deneb, a few weeks ago, when they were high, South and sligtly to the east.
As for safety limits, the location of the stars are way off the limits. And I can easily slew the mount to them. It is the GoTo that does something strange.
As for battery - new as of 1 hour before trying this yesterday.
Magnus
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photon_trap
Michael Herman
David C. Partridge