Michael, What is the principal differences?between?PemPro and PECPre? The last is free, the first is not cheap. Does the upgrading Tucked? Motors any impact on the GoTo or tracking precisi¨®n, or is only aesthetic) Thanks
Luis Barneo
El jue, 4 mar 2021 a las 2:23, Michael Herman (< mherman346@...>) escribi¨®: I have that mount and successfully upgraded it.
I used the original long OPW (no longer in production), replaced the old steel worm on RA with a new brass one, added an R4 Belleville spring washer to both axes, replaced the RA worm bearings with R4ZZ ABEC-7, and lastly a McLennan 25:1 metal gearbox on RA. Also using a Gemini-1 and new high torque motors.
I use high friction clutch disks to prevent clutch slippage during imaging.? I have a 12 inch Meade SCT on it these days.??
?PE was down to under 1 arcsec RMS (about 2.8 arcsec peak to peak). Reports attached.? Contact me privately if you have further questions,
Michael?
On Wed, Mar 3, 2021, 4:35 PM wa1vta01452 < loeblt@...> wrote: I have some very specific questions for someone familiar with the early G11/CG11 mounts? DEC axis assembly.? Anyone out there before I continue with the details?
Thanks
Tom
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Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
I¡¯ve been using PHD2 for the last 3 or 4 months. The best guiding I¡¯ve had is 0.8¡± RMS (about 0.7¡± RA and 0.5¡± DEC) but I¡¯ve also seen it go as high as 1.5¡±. It is very dependent on seeing, and how windy it is, or whether any cables are dragging or snagging. It also depends on where you aim the telescope. I usually see slightly worse figures for RA than for DEC (maybe 30% or so higher). The worst guiding for me is objects at around zero DEC (such as Orion). The guiding gets better for me as you get higher up in DEC, most likely because periodic error is less there. Even though I am imaging at a scale of about 1.4¡± per pixel, the guiding i have been getting seems good enough. I think I am in a place where the seeing is not great and there is also light pollution.
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Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
Stuck at home, I decided to learn more about phd2, and try to tweak my mount.? ?All my efforts did not seem to have much of an effect.? ?I generally achieve RMS of about? .25px ,? and about 1.0" to 1.6 ".? ?This doesn't sound great to me, I was hoping for about half of that - but my images seem to be ok.? ?(Guide camera is QHY 5L-II with 3.75 um, with 130mm QHY mini guide scope.? ?Camera for imaging is a K5 Pentax dslr.? Imaging scope is an 80mm f6 APO with a Televue 0.8x flattener.)? ?
The most irritating part has been trying to reduce the Dec backlash measured by PHd2 - which has stayed at 6 - 9 seconds despite numerous lubes, adjustments, and even Belleview washers.? ? Motor is attached very tight.? I have tried changing the balance, tight axis, loose axis.? Everything I know to try other than replacing the motors or the little plastic motor connectors - but they seem tight.? ?I tried switching the motors, but no change in Dec backlash.? ?Any thoughts?
The mount has the separate worm blocks and brass worms.? ?Using the 492 controller and the ST4 camera controlled interface and USB 3.0.
Thanks, Gil
Ventura, CA
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Re: Used GM-8 Guiding Help
When neutrally balanced it's high up, like an inch from the top, then my east bias I would move it down maybe 1/4" (when weight was on east). I'll definitely try out moving down at least an inch next time. I still would like to try increasing overall load as well, I wonder if the light breezes are affecting my mount big time since it's so light. As for the hemisphere, I actually have that part correct haha
Thanks again!
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Re: Used GM-8 Guiding Help
Is
your 7lb weight at the end of the CW Shaft, in the middle, or up close to the
scope??
?
Either
way, for that setup, I would move it an inch if only for testing purposes..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Nick
Sent: Wednesday, March 03, 2021
7:43 PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Now that's a sight hah! I think I'm going to move forward with cleaning
the mount again now that I'm much more familiar with all the parts. I do think
a larger east (or west, I've seen Rainer vouch it worked better for him even
though it's against the norm)bias will help. My current "bias" is the
mount slowly rotating if I let go with clutch all the way loose, and this is a
very light rig (73mm refractor, 7lb counterweight). I would also like to try
and add some load on the scope side, I can start to understand how a mount
would perform better under higher loads.
Thanks for hanging with me everyone, didn't really expect to have this going 90
posts later hah, it's definitely a humbling journey, but I enjoy it
?
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Re: Used GM-8 Guiding Help
Now that's a sight hah! I think I'm going to move forward with cleaning the mount again now that I'm much more familiar with all the parts. I do think a larger east (or west, I've seen Rainer vouch it worked better for him even though it's against the norm)bias will help. My current "bias" is the mount slowly rotating if I let go with clutch all the way loose, and this is a very light rig (73mm refractor, 7lb counterweight). I would also like to try and add some load on the scope side, I can start to understand how a mount would perform better under higher loads.
Thanks for hanging with me everyone, didn't really expect to have this going 90 posts later hah, it's definitely a humbling journey, but I enjoy it
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Re: Used GM-8 Guiding Help
I will try a larger east bias, does anyone have a way to quantify this?
***
I
know of two ways.. My way is to balance my roughly 25# load to ¡°balance¡±..
Then I move the weights ¨C with the CW shaft horizontal ¨C about 3/8¡±
down the shaft if it is going to be East of the mount during imaging, or up the
shaft if on the West.. My weights are.. All three and they are bunched together
and are moved as if they were a single unit..
?
Alternatively,
if you have Gemini II (and/or Michael¡¯s power supply), you can use the ¡°Balance¡±
function and you¡¯ll have a repeatable graphical representation..
?
Either
way, bias East ¡°some¡±.. Like a pound or two.. And like the gain or
exposure, once it ¡°works¡± you can always adjust to make it better
to suit your actual unit, but for now you want to make sure your mount is on the
East gear face so the mount is always driving it to the West even in a bit of
breeze..
?
This
could be nothing, but ¡°RA Always in one direction¡±.. Could the
mount think it is in the Southern Hemisphere and is ¡°fighting¡± the
natural rotation of the celestial sphere (or would that be WAAAY obvious)???
?
Derek
?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Nick
Sent: Wednesday, March 03, 2021
3:50 PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Thank you all,
I was able to update the firmware and reinstall drivers for the asi120mm. I
also ordered a new cable as it seems to be a common problem. Last night I was
able to connect the camera and it seemed to be working better, no split framing
etc. I did play with the gain a little last night but not to 100 so I will give
it a shot. I may just get a 3.0 version in the near future anyways. Many times
I do 1sec exposures during unguided runs for PE evaluation, but you're correct
during guiding runs I try to remember to be at 2+ second exposures. I'll also
remove multistar just to be sure
Michael, you are correct even with the camera playing more nicely now, it's
separate from the mount issues, I still had a lot of jumpiness.
I believe at this point I'm going to take apart the mount again, and try to
more precisely degrease/regrease everything in case something was left behind,
it is a 2001 mount after all. I'll search through the group but also open to
any regreasing tips, tricks, critical things to watch for (lint? Degreasing
overnight?) I've seen Scotts videos on youtube and try to follow those. Another
thing is I will try a larger east bias, does anyone have a way to quantify
this? I saw someone balances neutral then ties a can of tomatoes on the end of
the CW shaft haha, that's definitely more bias than I've been doing, maybe
larger bias is worth a shot (not using cans though, I have enough issues!)
?
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Re: Used GM-8 Guiding Help
Nick,
I recently tied a 7 lbs cast iron pulley to a heavy clothesline cord and wrapped the cord around my RA axis so the weight hangs to the East.? See pictures.? That, and backing off my RA worm slightly, helped reduce my G11T PE substantially. ( I have not tried a West bias but it's on my long list of experiments to try.? ).
?The G11T has a massive Titan RA drive, and that system has a C14HD scope etc on it...about 100+ lbs total weight on that mount so high moment of inertia....hence the 7lbs off the about 4 inch radius RA did not seem an excessive torque.? On a G11 you might go lighter...I never tried a weighted cord on my G11 or GM8 systems.? ?? ?
I have not tried a can of tomatoes. ( Too many possible jokes come to mind.? Was there soup still in the can?? )??
Have fun, Michael
Thank you all,
I was able to update the firmware and reinstall drivers for the asi120mm. I also ordered a new cable as it seems to be a common problem. Last night I was able to connect the camera and it seemed to be working better, no split framing etc. I did play with the gain a little last night but not to 100 so I will give it a shot. I may just get a 3.0 version in the near future anyways. Many times I do 1sec exposures during unguided runs for PE evaluation, but you're correct during guiding runs I try to remember to be at 2+ second exposures. I'll also remove multistar just to be sure
Michael, you are correct even with the camera playing more nicely now, it's separate from the mount issues, I still had a lot of jumpiness.
I believe at this point I'm going to take apart the mount again, and try to more precisely degrease/regrease everything in case something was left behind, it is a 2001 mount after all. I'll search through the group but also open to any regreasing tips, tricks, critical things to watch for (lint? Degreasing overnight?) I've seen Scotts videos on youtube and try to follow those. Another thing is I will try a larger east bias, does anyone have a way to quantify this? I saw someone balances neutral then ties a can of tomatoes on the end of the CW shaft haha, that's definitely more bias than I've been doing, maybe larger bias is worth a shot (not using cans though, I have enough issues!)
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Hi Michael,
this is a pre-OPW mount. Any chance you can pass along your number? I'm on the east coast and can give you a call. It would be easier to explain the issue that way.
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I have that mount and successfully upgraded it.
I used the original long OPW (no longer in production), replaced the old steel worm on RA with a new brass one, added an R4 Belleville spring washer to both axes, replaced the RA worm bearings with R4ZZ ABEC-7, and lastly a McLennan 25:1 metal gearbox on RA. Also using a Gemini-1 and new high torque motors.
I use high friction clutch disks to prevent clutch slippage during imaging.? I have a 12 inch Meade SCT on it these days.??
?PE was down to under 1 arcsec RMS (about 2.8 arcsec peak to peak). Reports attached.? Contact me privately if you have further questions,
Michael?
On Wed, Mar 3, 2021, 4:35 PM wa1vta01452 < loeblt@...> wrote: I have some very specific questions for someone familiar with the early G11/CG11 mounts? DEC axis assembly.? Anyone out there before I continue with the details?
Thanks
Tom
|
I have some very specific questions for someone familiar with the early G11/CG11 mounts? DEC axis assembly.? Anyone out there before I continue with the details?
Thanks
Tom
|
Re: Used GM-8 Guiding Help
Thank you all,
I was able to update the firmware and reinstall drivers for the asi120mm. I also ordered a new cable as it seems to be a common problem. Last night I was able to connect the camera and it seemed to be working better, no split framing etc. I did play with the gain a little last night but not to 100 so I will give it a shot. I may just get a 3.0 version in the near future anyways. Many times I do 1sec exposures during unguided runs for PE evaluation, but you're correct during guiding runs I try to remember to be at 2+ second exposures. I'll also remove multistar just to be sure
Michael, you are correct even with the camera playing more nicely now, it's separate from the mount issues, I still had a lot of jumpiness.
I believe at this point I'm going to take apart the mount again, and try to more precisely degrease/regrease everything in case something was left behind, it is a 2001 mount after all. I'll search through the group but also open to any regreasing tips, tricks, critical things to watch for (lint? Degreasing overnight?) I've seen Scotts videos on youtube and try to follow those. Another thing is I will try a larger east bias, does anyone have a way to quantify this? I saw someone balances neutral then ties a can of tomatoes on the end of the CW shaft haha, that's definitely more bias than I've been doing, maybe larger bias is worth a shot (not using cans though, I have enough issues!)
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Re: Used GM-8 Guiding Help
Nick,
I have seen the same trouble with the same ASI120 USB2 camera.? It is not the mount, only the camera.?
?I think the problem is with the driver.??
Look on the ZWO website for a new Win10 driver.?
It might require a USB 2 cable directiy to the laptop USB2 (not high-speed) USB port.? Try that too.??
I recommend the ASI USB3 cameras. I find no trouble with those, but the USB2 sometimes causes trouble with partial frames into the USB3 high speed ports.? Maybe I have an old driver on my laptop too...
Anyway, it is not related to the mount at all.
Best, Michael
Curious if anyone has input on this, article below. I have this same asi120mm usb2.0 "puck" version it's older, not the USB 3.0 or mini. I have similar weirdness, one example, when centering a star, sometimes there is a weird verticle line in the live preview and if the star crossed it the star just disappears...maybe there is some weird packet/misinformation being passed by the guide camera? I'm really struggling to blame anything on this mount...
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Re: Used GM-8 Guiding Help
Nick..
You
wrote..
I know the mount
isnt perfect but seems
like PHD2 should be able to guide it a little better, something just isnt
clicking
***
And
Brian wrote (and I¡¯ve stopped looking past the next email, as my comments
address the same thing..)
shows a lot of lost guidestar problems and poor guidestar SNR
?
I
use the same guide camera, but my focal length is longer.. Mine 560mm (80mm
f/7).. And *everyone* knows I am no expert in guiding..
?
1)??????????
I would not be using MultiStar guiding, for no
other reason than it is a new feature and could still have kinks..
2)??????????
Your gain and exposure are both too low.. Jack the
gain up to 100.. and set the guide exposure to 2 seconds.. Then select your
guide star to a non saturated SNR as shown in one of the boxes at the bottom
right of the guiding screen..
?
Also,
previous comments mentioned Stiction, and you mentioned setting up the drive
components leaning toward ¡°looseness¡±, but when I heard ¡°stiction¡±,
I thought about the tightness of your clutches as well as the order of the
parts under the clutch knob.. The Wavy Washer needs to be between the clutch
knob and the spacer..
?
You
have plenty of help from others who know far more than me, so I¡¯ll stop
with the Gain and exposure of your 120mm guide camera..
(I
also use an IR Pass filter on the nosepiece of the camera to calm down the
seeing too)..
?
Derek
?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Nick
Sent: Monday, March 01, 2021 8:13
PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Update
So I went ahead with the changes - enlarged the gearbox holes and aligned the
shafts very well, worked with a much better polar alignment, adjusted worms to
be on the looser side, they could spin very freely, and also played with the RA
divisor in separate logs.
Derek, I'm all ears, I've been going with default settings based on various
advice to allow the logs to show a good baseline and applying guiding assistant
recommendations.
Michael, I was thinking the worm was possibly sticking so I adjusted it to be
more loose (end of counterweight shaft would have a deflection of 1-2mm). I'm
not sure where the axis would stick? I did a full cleaning and re-greasing of
the mount and the needle bearings move very freely, I suppose I could do it
again though. This is an old used mount, I did replace the worm bearings with
new ones and they rotate nice and smooth.
Wish I had more exciting news, more of the same unfortunately and started
getting some clouds toward the end of tonight. I'm really not sure why RA is
all on one side with the occasional bounce back. Attached are logs of guiding
assistant and guiding at default settings, the first 01 and 02 are with
sidereal rate, next logs 03 and 04 are using an RA divisor of 56115 in hopes of
slowing down the mount a little to bring the RA graph down. Didn't seem to help
too much.
Would bumping up guide speed to 0.8x help? Any other ideas? Maybe I'll try
re-installing ascom/phd2 etc but everything seems to communicate fine. Just
seems weird, I know the mount
isnt perfect but seems
like PHD2 should be able to guide it a little better, something just isnt
clicking
?
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Re: Esquema de agujeros en adaptadores para muelle
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Re: Esquema de agujeros en adaptadores para muelle
Hello David
The G11 uses the MA adapter
The G11T uses the larger diameter MAL adapter
I hope this answers your question
Brian
Hola David
El G11 utiliza el adaptador MA?
El G11T utiliza el adaptador MAL de mayor di¨¢metro?
Brian
On Wed, Mar 3, 2021 at 9:51 AM Davidspain via <algayaterro80= [email protected]> wrote: Hola grupo !. Tengo en el muelle permanente un adaptador para g11, mi duda es si el adaptador para la montura g11t tiene la misma distribuci¨®n de agujeros o deberia mecanizar la base del muelle ?. Saludos
-- Brian?
Brian Valente portfolio
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Esquema de agujeros en adaptadores para muelle
Hola grupo !. Tengo en el muelle permanente un adaptador para g11, mi duda es si el adaptador para la montura g11t tiene la misma distribuci¨®n de agujeros o deberia mecanizar la base del muelle ?. Saludos
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Re: Guiding without Gemini
Alex, I will provide them for $6 each plus the postage. The trick to turn them without excessive tool wear is to replace the grub screws with some?short enough?to keep clear of the tooling. I find M4 X 4 do this.?
I start with 0.75" diameter couplers that have 6mm grubs.
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Re: Polar Alignment Routine
Geoff,
For reference, you might find the polar scope description on pages 12-14 of this manual helpful.
That's from the Orion company for their Atlas mount series (Synta EQ6 mounts).
To answer?your question...on the 24 hour clock that goes in the "wrong" direction...
That's called the "hour angle" clock.? As you look at the stars around polaris, you see they rotate counterclockwise across the sky.? Imagine a clock face marked in 24 hours in a counterclockwise direction.? That's the "Hour Angle" ("HA") clock.? If you look at sky chart Stellarium for example it will tell you the HA of Polaris.? That is....where on its circle around the actual NCP north celestial pole that polaris is actually located at that moment.? It's not the same every day at the same hour because the Earth also moves around the sun...at an angle, and the Earth nutates/wobbles like a top, etc. It's why sidereal time differs from the solar 24 hour day.??
On many mounts, like the Atlas, you can rotate RA completely around in a circle.? That's because those mounts use internal motors and have no motor cables.? Because of that capability, you leave the polar scope in one place in the RA tube.? You do not rotate it, as you do in the Losmandy G11 and GM8 case.? So when you are reading general mount instructions that say to rotate the RA axis to rotate the polar scope, that's what they are thinking.??
You have a limited RA rotation on the G11 and GM8 mounts due to the DEC cable. If you take the DEC cable away, perhaps with tucked motors you can get full rotation with your scope DEC moved at near 90 degrees.? (You need to rotate the telescope DEC near 90 degrees to get the porthole of the polar scope open!) Just watch out...and enjoy learning all this stuff.??
?Best,
Michael
[Edited Message Follows]
Adjusting the Polar Alignment Reticle with Polar Scope Align Pro
?I have been working on fine tuning my PA process with the Losmandy Polar Scope and am using Polar Scope Align Pro with the Kenko reticle. My starting setup as I begin this process is RA pointed north, CWD position. I have been using my watch display (synced to my iPhone) to determine the setting of the reticle, and rotating the reticle to match my watch orientation, and going from there. But Tim says (post?#66181 )?the reticle can be find tuned (¡°adjusted¡±). I thought I would try it, but found myself confused.
Picking up Tim¡¯s guidance on adjusting the PS reticle, he writes:
There¡¯s is an iOS app called ¡°Polar Scope Align Pro¡± ...??Having done this, rotate the scope in RA until the Polaris line in the reticle is straight up/down (verticle). You can adjust the altitude knob on the mount to make sure Polaris glides up and down along this line.?
The?'scope'?in this sentence refers to the polar scope, not the OTA, correct? Actually, to do a PA with the polar scope, I don¡¯t need the OTA mounted at all, correct? If I ¡®rotate the?(polar)?²õ³¦´Ç±è±ð¡¯, I assume this means rotating it *within the RA axis housing*, not rotating the entire RA axis, correct?
Next, in the app, tap?the ¡°Set zero position¡± and a sub-menu asks you to read the current RA value on the ²õ³¦´Ç±è±ð¡¯s setting circle. ? ?Enter the value and click ¡®done¡¯. ?
This confuses me, b/c if I have rotated the polar scope within its housing, I have not changed the ¡°RA value on the ²õ³¦´Ç±è±ð¡¯s setting circle¡± at all. It has stayed the same, and was set when I started with the mount in the CWD position.??Is this correct?
Back on the main screen it will now provide a ¡°Zero Adjusted¡± RA time.? Rotate the mount in RA to the zero-adjusted value (watching the setting circle on the mount). ?
"Rotate the mount in RA" now means rotating the entire RA axis, housing, Polar Scope and all, either by hand or with the HC buttons, correct?
The?¡°Zero Adjusted¡± RA time?on the setting circles does not seem clear to me either. There are two scales of 24 hours on top of each other, counting in different directions. Which one is the proper one to calibrate?
That¡¯s it¡ your polar alignment reticle is now *perfectly* adjusted.?
But it does not match the orientation on my watch face anymore, because I just 'adjusted' it, does it?
I may be *way confused* on all this, and I¡¯d be glad for some clarity!!
Thanks,
Geoff
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Re: Used GM-8 Guiding Help
Curious if anyone has input on this, article below. I have this same asi120mm usb2.0 "puck" version it's older, not the USB 3.0 or mini. I have similar weirdness, one example, when centering a star, sometimes there is a weird verticle line in the live preview and if the star crossed it the star just disappears...maybe there is some weird packet/misinformation being passed by the guide camera? I'm really struggling to blame anything on this mount...
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Luis Barneo
McFarlane, Gilbert
Michael Herman
Davidspain