Yesterday I was balancing my 2008 Losmandy G11, Gemini-1 using servo-motor current draw to fine tune the balance. At one point I used the hand controller to move the telescope to point at the celestial pole with counterweight down. As it neared that position the mount gave a continuous tone like when a safety limit is reached. That was puzzling since it wasn't anywhere near the limit. So I switched the Gemini-1 off, thinking it just needed a reboot.
?
When I turned it back on there was no response, no startup beep, no lights on Gemini electronics chassis or hand controller. Then I saw the 17-volt power had no lights. So it seemed the power supply had died. So I brought out my old Pyramid 13.8 volt power supply and hooked it up. It too had the same symptom - when Gemini-1 was switched on, the power supply lights for voltage and current went off.
?
So two power supplies had same symptom - not supplying power with all lights on or connected to the Gemini-1 all lights go off. It's clear the problem lies with the Gemini-1, perhaps something like a dead short. I'll give another try today to see if a day's rest has corrected the problem. But the prognosis isn't good. Does anyone know if there is something that I can do, like a resettable circuit breaker or fuse?
?
I'll be contacting Michael Herman to see if he can resurrect my old Gemini-1. If that fails, perhaps buying a used Gemini-1 or new Gemini-2 would be the path forward. My 17 year old Losmandy G11 has been a stalwart in my astronomy adventure. It now resides inside Ocean Observatory, with slide off roof.
?
?
Presently the G11 is carrying a Celestron-8 with AT115EDT triplet refractor, like what is shown below.
?
?
So as can be expected, I'm eager to get my old Losmandy G11/G-1 back in service.
?
Best Regards,
Russ
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Re: Unable to fully lock RA axis on G11
Hi John?
?
I will take a look right now and report back.
?
Thanks.
?
Avi?
|
Re: Unable to fully lock RA axis on G11
Avi,
?
Chances are your clutch discs are very oil and/or severely worn. You will need to unscrew the clutch locks all the way off and pull the shaft up and out of the mount to inspect. Remember the order of the knob, washers are bearings and put back in the same order. Try wiping down the disc pad with alcohol or some other solvent. If the discs are worn like a phonograph record, they may need to be replaced. You can give them some extra life by doing a light sanding and again wiping clean. You will need to clean the respective upper and lower contact surfaces as well. But I would suggest ordering new ones from Lomandy if they are really worn. This should give you some extra stiction and allow the locks to grip down on something less slippery.
?
John
--
_____________________________________________________________________________________________________________________________________________________________________________
Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user
|
Re: Unable to fully lock RA axis on G11
On 2/7/2025 11:41 PM, avishekaiyar via groups.io wrote: No matter how much I tighten the RA clutch knob I am unable to fully lock the RA axis movement (and I really tightened the clutch). The Dec axis is fine....I am able to fully lock down that axis when I tighten the Dec clutch. The clutches are just that.... friction clutches.? If any grease has made it onto the friction surfaces (and it will) they cannot be "locked".? NOR SHOULD THEY.? The more you tighten the clutches the more load you put on the thrust bearings.? The thrust bearings use cylindrical rollers that roll in a circle.? And if you think about the geometry of a cylinder rolling in a circle, it will be obvious that it CAN'T unless one end or the other slips.? And if they slip unevenly, you can get RA jumps.? So the tighter the clutches, the more drag and unevenness from the rollers. Once I realized this I tried running with very loose clutches and all my RA jumping went away.? I don't know if it made a difference but I also cleaned the thrust bearings and re-greased with MP-50 since in essence, the rollers are a high pressure sliding interface.? I normally tighten until I feel contact and then go a maximum of 1/8 to 1/4 turn farther.? But, I can even run with the RA clutch fully loosened..... the rig is well balanced (that is key) and simply the weight of the rest of the mount and load is sufficient to provide enough friction. My $0.02 anyway. Paul (another one) -- Paul Goelz Rochester Hills, MI USA pgoelz@... www.pgoelz.com
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Re: Unable to fully lock RA axis on G11
Hi Paul
?
This is super valuable. I will try to take a video tomorrow and share it but based on what you are saying I think the mount is functioning normally.?
?
The clutches do hold the telescope. But as you said, if the load isn't properly balanced, it no long holds it in place.?
?
But I definitely feel that that Dec axis "holds" better than RA.?
?
Many thanks.
?
Avi?
|
Re: Unable to fully lock RA axis on G11
Avi,
It is difficult to judge without seeing what you are doing.
You should always be reasonably balanced, the clutches are not designed to hold an unbalanced setup.
You should not tighten the clutches more than necessary, they are designed to be tightened by hand and should hold the telescope but if you knock it they may slip.
The clutches do not lock the mount axes, they hold them.
If you are easily able to move either axis it may indicate that grease has made its way onto the clutch plate(s), which would require a partial strip down and clean.
toggle quoted message
Show quoted text
On 8 Feb 2025, at 3:41?pm, avishekaiyar via groups.io <avishekaiyar@...> wrote:
Hello All?
?
I am a brand new user of Losmandy mounts. My past experience with GEMs has been limited to the iOptron SGP and the Vixen GPDX.?
?
I recently acquired a Celestron Losmandy G11.?
?
I tried to counterbalance my setup today and had a clarification about the RA axis.?
?
No matter how much I tighten the RA clutch knob I am unable to fully lock the RA axis movement (and I really tightened the clutch). The Dec axis is fine....I am able to fully lock down that axis when I tighten the Dec clutch.?
?
Is this normal ? As an example when I deliberately throw the RA axis off balance by moving the 11lb counterweight all the way towards the end of the shaft, the mount easily rotates about the RA axis even when fully tightened down.?
?
This has definitely not been my experience on the other gems I have used...
?
Would appreciate any advice.?
?
Sincerely?
?
Avi?
|
Unable to fully lock RA axis on G11
Hello All?
?
I am a brand new user of Losmandy mounts. My past experience with GEMs has been limited to the iOptron SGP and the Vixen GPDX.?
?
I recently acquired a Celestron Losmandy G11.?
?
I tried to counterbalance my setup today and had a clarification about the RA axis.?
?
No matter how much I tighten the RA clutch knob I am unable to fully lock the RA axis movement (and I really tightened the clutch). The Dec axis is fine....I am able to fully lock down that axis when I tighten the Dec clutch.?
?
Is this normal ? As an example when I deliberately throw the RA axis off balance by moving the 11lb counterweight all the way towards the end of the shaft, the mount easily rotates about the RA axis even when fully tightened down.?
?
This has definitely not been my experience on the other gems I have used...
?
Would appreciate any advice.?
?
Sincerely?
?
Avi?
|
Re: RA guiding awful after upgrade
On Fri, Jan 31, 2025 at 03:00 PM, Thomas Kallenbach wrote:
I appreciate your comments and no, I am not looking for perfect guiding.? What is the saying...The perfect is the enemy of the good.? I did have one thought; could the camera fan, if it is out of balance cause the problems I am experiencing?? I seem to remember hearing that some 2600MM cameras had fan vibration problems.? If that is possible I can swap cameras and see if there is a difference in the guiding.? What do you think?
Hi Tom,
?
I did the fan change on the 2600MM and I can't say it ever improved any of my images. But I don't think that would affect guiding on one side of the meridian versus the other. It sounds like you got a mount with low mileage so it most likely was set well at the factory. But there is no way to judge guiding performance until you actually get it out under the stars. Perhaps your mount got jarred during handling or transportation. But back to the worm gear - each one made at HGM is unique and has its own profile/personality even though they pass QC inspection. Sometimes you can get lucky swapping the RA and Dec worms to get better performance.? The RA worm is always turning and will wear more quickly than the Dec worm which just rocks back and forth. Once you have a very good polar alignment, Dec adjustments through a guide cam arrangement will be making only minor moves. So the latter will have a different thread wear which can serve for better RA tracking. The worms are made of brass and are easily bent on nicked when removed from the mount so be careful if trying this swap. As was already mentioned these mounts can be rebuilt more easily than other brands. You have something mechanical going on, so it all depends on how much you want/need to chase down the true cause.
?
John
--
_____________________________________________________________________________________________________________________________________________________________________________
Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user
|
Re: RA guiding awful after upgrade
One thing from the comment Derek made, if I grab the CW shaft it will
move side to side slightly.
***
“slightly”
is good.. as in a 1/16th of an inch..
I
don’t use an ASIAir, but it sounds like things are “normal” so you should go
back to listening to the suggestions of others.. i.e. the same ones who taught
me.. Likely you will just do normal maintenance / learning what’s important and
it’ll work out.. The mounts are simple, but very well made and simple to work
on..
:-))
Derek
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Thomas Kallenbach via groups.io
Sent: Friday, January 31, 2025
8:36 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
RA guiding awful after upgrade
?
I contacted Losmandy but they weren't able to provide much help beyond
check for dragging cables.? I admit, the photos I sent do show a bit of a
cable mess but I am sure that is not the problem.? The scope had not been
used when I bought it, it was part of an estate sale (RIP) and didn't have any
nicks, scratches or blemishes.? Initially, I wrote to this forum because I
was having problems with the flips.? That was frustrating but was my
fault, not the mount.? The help I received here fixed my problem.?
?But, because the scope I bought this mount for (TS Optics Photoline 130)
is kind of long, I had to wait for the meridian flip to keep the scope from
crashing into the mount.? The extensions fixed that problem.? That
said, there are still several buggy aspects of the mount/asiair combination.
I am still a beginner.? I started with a Skywatcher EQ6 R a couple
of years ago so the Skywatcher is the only thing I have to compare to.? For
example, If I start a plan or auto run, the asiair will issue a goto to the
mount and the mount may or may not move.? The screen will indicate slewing
but the mount just sits there.? Other times the mount will move and get
stuck in auto-centering on the target.? It may indicate that the target is
centered but more often than not, I have to move it back to CWD shut everything
off and restart it.? ? Sometimes the mount/asiair has no idea where
it is and all of a sudden forgets where CWD is.? Meridian flips require at
least three commands from the asiair before the mount will move.? My guess
is the losmandy software and the asiair software do not communicate well
because the Skywatcher has none of these problems.? In my experience it
operates flawlessly.? And yes, all the software is up to date. It has been
cold recently but the RA guiding was bad in the warm weather.? I
understand that the G11 is in a different class than the eq6.??
One thing from the comment Derek made, if I grab the CW shaft it will
move side to side slightly.? Not at the connection of the shaft to the
mount but near the?
RA extension.? It is not much. It feels like slop in the gears.
But again it is not much but it is noticeable.? ?Derek, yes, I added
a 12 pier extension and RA extension at the same time.? Initially I
thought something was loose and that maybe I forgot to tighten a screw. I went
through it and made sure everything was tight.? I did not find any loose
screws.??
The mount still does a good job.? I had to toss a few subs for
sure but here is 33 hours with the G11:
?[URL=https://astrob.in/n0hff5/0/][IMG]https://astrob.in/n0hff5/0/rawthumb/gallery/get.jpg?insecure[/IMG][/URL]
|
Re: RA guiding awful after upgrade
Mark,
I appreciate your comments and no, I am not looking for perfect guiding.? What is the saying...The perfect is the enemy of the good.? I did have one thought; could the camera fan, if it is out of balance cause the problems I am experiencing?? I seem to remember hearing that some 2600MM cameras had fan vibration problems.? If that is possible I can swap cameras and see if there is a difference in the guiding.? What do you think?
Old...getting old is a drag but it beats the alternative.? I'm there too.
|
Re: RA guiding awful after upgrade
A tiny amount of wiggle in each axis is normal.
?
Without any "lash" (aka wiggle, slop, choose your word) in one position (location on the worm) there is risk that the gears will bind on another.
The center of the worm teeth pattern is never exactly (we're talking thousands here) at the center of rotation of the axis. Want that? Spend a lot
more money.
?
Most people overdo trying to get backlash out of their mounts. Usually a fool's errand, caused by their desire
for perfection without spending tens of thousands on a mount.
?
When I adjust mounts I always to try to be able to just feel the wiggle but not see it or hear it (at high speed).
The human hand is a very sensitive instrument as is the ear.
?
I seriously doubt that is your "problem". And if you are satisfied with the imaging performance that is all that really matters.
More than one person has created problems for themselves while chasing perfection.
?
The fact that the "problem" appears only on one side of that mount (so it seems) points to something with weight/balance, or cabling.
?
I run my G11 off of WiFi using OnStep normally. I occasionally use USB but then it goes directly from the PC to the mount controller and that isn't very often.
So usually I just have one USB 3.0 running to the camera which has a built in hub. The guider and (when used) focuser connect to that so there is only one wire
from the PC to the mount and one power line to the camera cooler/hub. The mount and the PC each have their own power source.
That way I don't have a lot of wires running around to trip over between the PC (on a small table) and the mount. And minimal wires to drag the OTA..
?
Just the advice of an old, old, dog.
?
Mark C
|
Re: RA guiding awful after upgrade
I contacted Losmandy but they weren't able to provide much help beyond check for dragging cables.? I admit, the photos I sent do show a bit of a cable mess but I am sure that is not the problem.? The scope had not been used when I bought it, it was part of an estate sale (RIP) and didn't have any nicks, scratches or blemishes.? Initially, I wrote to this forum because I was having problems with the flips.? That was frustrating but was my fault, not the mount.? The help I received here fixed my problem.? ?But, because the scope I bought this mount for (TS Optics Photoline 130) is kind of long, I had to wait for the meridian flip to keep the scope from crashing into the mount.? The extensions fixed that problem.? That said, there are still several buggy aspects of the mount/asiair combination.
?
I am still a beginner.? I started with a Skywatcher EQ6 R a couple of years ago so the Skywatcher is the only thing I have to compare to.? For example, If I start a plan or auto run, the asiair will issue a goto to the mount and the mount may or may not move.? The screen will indicate slewing but the mount just sits there.? Other times the mount will move and get stuck in auto-centering on the target.? It may indicate that the target is centered but more often than not, I have to move it back to CWD shut everything off and restart it.? ? Sometimes the mount/asiair has no idea where it is and all of a sudden forgets where CWD is.? Meridian flips require at least three commands from the asiair before the mount will move.? My guess is the losmandy software and the asiair software do not communicate well because the Skywatcher has none of these problems.? In my experience it operates flawlessly.? And yes, all the software is up to date. It has been cold recently but the RA guiding was bad in the warm weather.? I understand that the G11 is in a different class than the eq6.??
?
One thing from the comment Derek made, if I grab the CW shaft it will move side to side slightly.? Not at the connection of the shaft to the mount but near the?
RA extension.? It is not much. It feels like slop in the gears. But again it is not much but it is noticeable.? ?Derek, yes, I added a 12 pier extension and RA extension at the same time.? Initially I thought something was loose and that maybe I forgot to tighten a screw. I went through it and made sure everything was tight.? I did not find any loose screws.??
?
The mount still does a good job.? I had to toss a few subs for sure but here is 33 hours with the G11: ?[URL=https://astrob.in/n0hff5/0/][IMG]https://astrob.in/n0hff5/0/rawthumb/gallery/get.jpg?insecure[/IMG][/URL]
?
?
?
|
Re: RA guiding awful after upgrade
On Fri, Jan 31, 2025 at 01:55 AM, John Kmetz wrote:
You can buy a new high precision brass worm from Losmandy which may give you better results
That seems unlikely to help in this case. The RA Worm appears to behave well, with low error and low PE on the east side of the mount. It's still a good idea to measure the unguided worm performance, but I doubt replacing the worm will improve on what Tom is reporting. Adjusting the worm/worm gear mesh might help. And rotating the worm gear to a different section, as was suggested earlier.
?
Regards,
?
? ?-Paul
|
Re: RA guiding awful after upgrade
On Thu, Jan 30, 2025 at 12:36 AM, Thomas Kallenbach wrote:
Thanks John.
I bought the mount used but it had never been opened or set up.? It came from company seven and I was told they test each mount.? The motors are not tucked.??
I was just outside with it and maybe it just doesn't play well with the asiair.? I generally have to go back to cwd, shut everything down, restart the mount, restart the air....it gets tedious.? I have avoided Nina because of windows.??
Ok. So it just flipped.? RA guiding went from around 2 before the flip to 0.5 now. And my stars are round.? It always improves after the flip with the scope on the east side.??
Tom,
?
It is possible that you have an RA worm gear which is rougher on one side of the threads than the other, which would explain the change in guide performance after a flip. But that should not have changed with the new extensions and would have been there all along. You can buy a new high precision brass worm from Losmandy which may give you better results. If you do go to that length of replacing it, you might want to consider a rebuild and change out the worm bearings, and the thrust bearings as well. Some time, elbow grease and determination are required here :).
?
John
--
_____________________________________________________________________________________________________________________________________________________________________________
Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user
|
Re: RA guiding awful after upgrade
Y’all
are leaving out the NEW pier extension.. .. You installed BOTH a new RA eXT *and*
a 12” pier extension, right??
My
suggestion would be to take the fully loaded setup and loosen and retighten all
the fasteners (used to install the extension to your mount, not any fasteners
used to assemble the extension itself..)..
Do
the same with the RA EXT.. I have the RA EXT, and no pier extension and never
had this issue.. To me it’s the pier extension..
?
My
second suggestion would be balance is not as east heavy as you think it is,
which is why it doesn’t work on one side but not the other..
?
Something
else.. You didn’t mention the weather.. has it been obviously colder than
when it work well?? How much does the bottom end of the counterweight shaft
move when you try and move it with your hand??
I
have other *simple* suggestions before you do anything drastic..
?
Derek
?
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Chip Louie
via groups.io
Sent: Thursday, January 30, 2025
4:30 PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
RA guiding awful after upgrade
?
On Wed, Jan 29, 2025 at 05:58 PM, Thomas Kallenbach wrote:
Thanks guys.? Do you think I would just be ahead to send the mount
into Losmandy and let them figure it out?? I could have them do the tucked
in motors at the same time.? I'm not sure I am comfortable with what may
be necessary.? That is why I still use the asiair, it hides a lot of the
complexity.
To follow up on my previous post Losmandy is an outstanding company in
that the people really do their best to support the Losmandy community.?
Losmandy fully, and I mean FULLY supports every mount new and used they have
ever produced including the Celestron branded mounts.? I mean nobody,
NOBODY will take a mount in they made 30+ years ago and rebuild it to the
current specs for that mount no matter how fancy the brand is considered
today.? Sure it's not free but you cannot get this from any other mount
maker in the normal course of business period.??Losmandy knows the value
of their mounts, it
just goes to show you what all the other telescope mount makers think of their
work and your investment.? ?
All it takes is money on your part.? Does it always make economic
sense?? In my experience no,? but it can be done for those mounts
with a special attachment or special history.? I've done it and IME it was
well worth the additional cost when it was all said and done.? But also I
think I need to say that unless you bought the mount for peanuts it will not
really be time or cost effective to have the old mount updated to current
specs.? At least you already have a Gemini (2??) so that makes it closer
to cost effective.??
I will say that as an owner of several G11 and GM8 mounts as well as my
original 20+ YO G11"s" model that over a few years I upgraded through
the full 30+ year progression from the original model G11s PUSH-TO #492 Digital
Drive mount which I fully disassembled to rebuild and lube the internal
bearings, then installing High Precision worms, aligning the gearbox output
shaft so the Oldham coupler connection to the worm was as straight as possible,
modifying the bearing blocks to encourage full worm bearing rotation and remove
worm endplay using Belleville springs, adding a new modern era double clamp
8" Losmandy dual D/V saddle, experimentally making a one piece worm block
with Belleville springs to use the bearings to preload the worms (this worked
very well so I told Scott about it who then showed me what he was working on in
secret which caused me to wait for over a year for the coming Losmandy spring
loaded OPW) installing a Gemini 1 controller, building a regulated
multi-voltage (13.5v & 17.5v) multi-bank power pack to support portable
field use for visual and imaging work for 2 Losmandy Gemini mounts, installing
a Gemini 2 system and then having Scott do the full update to the new OPWs, RA
extension etc. then at a later date once finalized Scott added the spring
loaded feature.? It has been a journey but what fun we had!? So was
it worth it?? As I said for me it most certainly was.??
To answer the ASIAIR question it has been my experience that the ASIAIR
is not quite as good at autoguiding as using a laptop and PHD2 on the same
mount and imaging rig.? I say this because I relied on ASCOM and PHD2 and
SGP for imaging and 5 years ago PHD2 produced excellent guiding on the same 20+
YO mount using the same guide scope and ASI120MM mini and ASI290MM mini.?
The numbers are just not as good in absolute terms but what I have seen is that
if you are guiding well under 0.5" total error and then the ASIAIR comes
along and is guiding at 0.7" total error and I cannot see any advantage to
putting up with all the extra trouble of using a laptop and a dozen cables to
make it work I'm just not going to bother.? Give me the elegance of the
ASIAIR solution anyday.
Here is the small driveway imaging rig clamped to an old school
Losmandy S-B-S dovetail on the even older G11G, LWT and Wheelie Bar.? The
small imaging rig is an Askar FRA500 90mm f.5.6 Petzval working @ f/3.9, ASIAIR
Plus 256GB v3, ASI2600MC-Pro main camera, EFW 2"x5, EFA w/temp probe,
ASI678MM guide camera on Stellarvue 50mm f/4 guide scope, Deep Sky Dad Flat
Panel and a Stellarvue 50mm visual finder.? Waiting for the CAA to show
up, should be any day now LOL.? All of the components and most cables are
on the scope and move with the scope except for 2 independent power cords and
an Ethernet cord.? The ASIAIR Plus and Gemini 2 talk to each other through
a high performance Slate AX1800 travel router via Ethernet and the tablet or
phone use the Slate to connect over Wi-Fi.? ? ? ? ?
?
Chip Louie Chief
Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena,
CA?
|
Re: RA guiding awful after upgrade
On Wed, Jan 29, 2025 at 05:58 PM, Thomas Kallenbach wrote:
Thanks guys.? Do you think I would just be ahead to send the mount into Losmandy and let them figure it out?? I could have them do the tucked in motors at the same time.? I'm not sure I am comfortable with what may be necessary.? That is why I still use the asiair, it hides a lot of the complexity.
?
Where is the tip jar?
?
?
To follow up on my previous post Losmandy is an outstanding company in that the people really do their best to support the Losmandy community.? Losmandy fully, and I mean FULLY supports every mount new and used they have ever produced including the Celestron branded mounts.? I mean nobody, NOBODY will take a mount in they made 30+ years ago and rebuild it to the current specs for that mount no matter how fancy the brand is considered today.? Sure it's not free but you cannot get this from any other mount maker in the normal course of business period.??Losmandy knows the value of their mounts, it just goes to show you what all the other telescope mount makers think of their work and your investment.? ?
?
All it takes is money on your part.? Does it always make economic sense?? In my experience no,? but it can be done for those mounts with a special attachment or special history.? I've done it and IME it was well worth the additional cost when it was all said and done.? But also I think I need to say that unless you bought the mount for peanuts it will not really be time or cost effective to have the old mount updated to current specs.? At least you already have a Gemini (2??) so that makes it closer to cost effective.??
?
I will say that as an owner of several G11 and GM8 mounts as well as my original 20+ YO G11"s" model that over a few years I upgraded through the full 30+ year progression from the original model G11s PUSH-TO #492 Digital Drive mount which I fully disassembled to rebuild and lube the internal bearings, then installing High Precision worms, aligning the gearbox output shaft so the Oldham coupler connection to the worm was as straight as possible, modifying the bearing blocks to encourage full worm bearing rotation and remove worm endplay using Belleville springs, adding a new modern era double clamp 8" Losmandy dual D/V saddle, experimentally making a one piece worm block with Belleville springs to use the bearings to preload the worms (this worked very well so I told Scott about it who then showed me what he was working on in secret which caused me to wait for over a year for the coming Losmandy spring loaded OPW) installing a Gemini 1 controller, building a regulated multi-voltage (13.5v & 17.5v) multi-bank power pack to support portable field use for visual and imaging work for 2 Losmandy Gemini mounts, installing a Gemini 2 system and then having Scott do the full update to the new OPWs, RA extension etc. then at a later date once finalized Scott added the spring loaded feature.? It has been a journey but what fun we had!? So was it worth it?? As I said for me it most certainly was.??
?
To answer the ASIAIR question it has been my experience that the ASIAIR is not quite as good at autoguiding as using a laptop and PHD2 on the same mount and imaging rig.? I say this because I relied on ASCOM and PHD2 and SGP for imaging and 5 years ago PHD2 produced excellent guiding on the same 20+ YO mount using the same guide scope and ASI120MM mini and ASI290MM mini.? The numbers are just not as good in absolute terms but what I have seen is that if you are guiding well under 0.5" total error and then the ASIAIR comes along and is guiding at 0.7" total error and I cannot see any advantage to putting up with all the extra trouble of using a laptop and a dozen cables to make it work I'm just not going to bother.? Give me the elegance of the ASIAIR solution anyday.
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Here is the small driveway imaging rig clamped to an old school Losmandy S-B-S dovetail on the even older G11G, LWT and Wheelie Bar.? The small imaging rig is an Askar FRA500 90mm f.5.6 Petzval working @ f/3.9, ASIAIR Plus 256GB v3, ASI2600MC-Pro main camera, EFW 2"x5, EFA w/temp probe, ASI678MM guide camera on Stellarvue 50mm f/4 guide scope, Deep Sky Dad Flat Panel and a Stellarvue 50mm visual finder.? Waiting for the CAA to show up, should be any day now LOL.? All of the components and most cables are on the scope and move with the scope except for 2 independent power cords and an Ethernet cord.? The ASIAIR Plus and Gemini 2 talk to each other through a high performance Slate AX1800 travel router via Ethernet and the tablet or phone use the Slate to connect over Wi-Fi.? ? ? ? ? ?
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Chip Louie Chief Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena, CA?
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Re: RA guiding awful after upgrade
On Thu, Jan 30, 2025 at 07:14 AM, Thomas Kallenbach wrote:
Can that be done in the day?
Just let it track?
Tom
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No. You use PHD2 to autoguide but turn off corrections.? This will display the guide scope data used for correction which will show you the mount's basic mechanical tracking accuracy.??
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Chip Louie Chief Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena, CA?
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Re: RA guiding awful after upgrade
Can that be done in the day?
Just let it track?
Tom
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Re: RA guiding awful after upgrade
On Thu, Jan 30, 2025 at 12:36 AM, Thomas Kallenbach wrote:
Thanks John.
I bought the mount used but it had never been opened or set up.? It came from company seven and I was told they test each mount.? The motors are not tucked.??
I was just outside with it and maybe it just doesn't play well with the asiair.? I generally have to go back to cwd, shut everything down, restart the mount, restart the air....it gets tedious.? I have avoided Nina because of windows.??
Ok. So it just flipped.? RA guiding went from around 2 before the flip to 0.5 now. And my stars are round.? It always improves after the flip with the scope on the east side.??
Tom, just making sure: the mount had no such problems before you installed the RA Extension? Did you test it well prior to the installation? As others have said, the extension should have no effect on guiding, especially on one side of the mount. Something isn't properly engaging on the west side of your mount causing frequent jumps. I see some similar errors on the east side, although they are fewer and lower in magnitude. That's why I suggest collecting an unguided autoguider log on both sides. This will tell you how the mount behaves with simple tracking.
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Re: RA guiding awful after upgrade
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There are many potential issues with used mounts and even more with the now classic Losmandy straight line drivetrain with the 2-piece worm bearing blocks.? There are several places where issues can crop up.? Backlash, bearing blocks square and worm loaded axially no end play, bearings sticking, Oldham coupler set screws, gearbox fasteners, servomotor pinion mesh, servo motor fasteners etc. I'd also look in the drivetrain for something loose.??
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Chip Louie Chief Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena, CA?
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Russell Milton
Paul Kanevsky
Chip Louie