Re: My first ServoCAT Autoguide "production" images
That sounds like a great tip, big thanks!
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/Gabriel
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Re: My first ServoCAT Autoguide "production" images
As for the azimuth bearings, take a piece of 24 or 26 gauge sheet metal, cut it about 2 inches or 50mm wide about 12 to 16 inches or 355mm long, then get some Velcro use the fuzzy piece and cut a 2inch by 2inch square and the stick that piece to the end of the metal strip. Now spray the Velcro piece with whatever substance you use, the with the Velcro fuzzy side up place it next to one of the 3 plastic bearing with pressure and by hand spin the scope slowly, do it 3 times by going to each plastic bearing, no runs, no drip, no errors.?
? That is a trick Mike Zammit taught me.
Mickey
Thank you Mickey! Actually i did just that for the altitude bearings, but for the azimuth i could not access the surface with a cloth so i "cheated" but i know not to take corners again, not worth the risk!
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/Gabriel
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Re: My first ServoCAT Autoguide "production" images
Thank you Mickey! Actually i did just that for the altitude bearings, but for the azimuth i could not access the surface with a cloth so i "cheated" but i know not to take corners again, not worth the risk!
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/Gabriel
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Re: My first ServoCAT Autoguide "production" images
Beautiful image Gabriel , an important note about applying spray to the bearings, never spray directly to the bearings, because of the mirror and the over spray, always take a cloth or paper towel and apply the spray to the towel and rub on the bearing both to clean and reapply.
Mickey
Here is 1 hour and 15 minutes on The Pinwheel Galaxy from yesterday. Last time i imaged this galaxy the seeing was very bad, i had better luck this time.
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226 x 20s using ServoCAT Autoguide in PHD2. Speaking of guiding i made a discovery a few days ago, i wiped the Alt bearing surface just in case there was dirt there, that removed the layer of silicon spray that was there which i had applied for pherhaps 1 month ago.
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This caused the Alt guiding to go crazy, probably due to stiction. So i applied a new layer of silicon spray and like magic the guiding was back to around 1 arc second again.
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However one has to be very careful that the silconspray does not end up on the groundboard where the roller rides since it will loose grip. (happened last time). Apart from that when spraying the Az surface it can end up on the power rail under the center bolt, and silicon does not transmit electric current (also learnt that the hard way).
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And Like Gary has mentioned, it can attract dirt, but in my case it has not done that since it's winter here when i observe with no desert dust or so.
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 ? ?
Clear skies
/Gabriel
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Re: My first ServoCAT Autoguide "production" images
Here is 1 hour and 15 minutes on The Pinwheel Galaxy from yesterday. Last time i imaged this galaxy the seeing was very bad, i had better luck this time.
?
226 x 20s using ServoCAT Autoguide in PHD2. Speaking of guiding i made a discovery a few days ago, i wiped the Alt bearing surface just in case there was dirt there, that removed the layer of silicon spray that was there which i had applied for pherhaps 1 month ago.
?
This caused the Alt guiding to go crazy, probably due to stiction. So i applied a new layer of silicon spray and like magic the guiding was back to around 1 arc second again.
?
However one has to be very careful that the silconspray does not end up on the groundboard where the roller rides since it will loose grip. (happened last time). Apart from that when spraying the Az surface it can end up on the power rail under the center bolt, and silicon does not transmit electric current (also learnt that the hard way).
?
And Like Gary has mentioned, it can attract dirt, but in my case it has not done that since it's winter here when i observe with no desert dust or so.
?
 ? ?
Clear skies
/Gabriel
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Re: Argo-Navis & ServoCat off in AZ
Hi Sam,
Your scope is fitted with incremental encoders and they have no inherent zero reference point.
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The zero reference point for the altitude encoder when the unit is first powered on is determined by whatever angle you have in the FIX ALT REF menu (typical) 90 and whatever angle in altitude the OTA happens to be.
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When the FIX ALT REF step is performed, the altitude zero reference point is re-established by it.
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If you are using AUTO ADJUST ON (and you should) when you perform the two-star alignment or any subsequent alignment, the altitude zero reference point can be automatically adjusted. Usually this is a "tweak" from the reference point you initially established when you did the FIX ALT REF.
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So that's the altitude encoder but you are asking about the azimuth encoder. How is its zero reference point established, you may ask?
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The rule for it is simple. The zero reference point is the arbitrary orientation the scope happens to be in azimuth when you power it on.
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Whereas the zero reference point for the altitude encoder is important, for the azimuth encoder it matters not.
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So for example if the scope happened to be oriented to the north when you powered it on, the zero reference point would be 0.
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MODE ENCODER provides a readout of the encoders within "encoder space".
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MODE AZ ALT provides a readout of which way the scope is pointing in a topographic sense, like that from a compass and sextaant, but only after you have performed a star alignment and if your location is established in SETUP LOCATION and time in SETUP TIME. It works by starting with the RA/Dec position the scope is pointing at and then performing the classical transformation to convert it to a topocentric geographic coordinate pair.
I hope this in-depth answer helps clarify things for you.
?
--
Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place
Mount Kuring-Gai NSW 2080
Australia
Phone +61-2-9457-9049
sales@...
https://www.wildcard-innovations.com.au
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Re: Argo-Navis & ServoCat off in AZ
Hey Sam... long long time no hear. I'm trying to remember - was it not you that (Jean and) I met way back in like 2001 or so - you had an observing site near I think it was Huachuca City??
Anyway... so first what I'd do is to go to MODE ENCODER and confirm the AZ axis is reading as you move the scope.?
Second are you sure you are hitting the FIX ALT REF twice ... once to get in to the mode and once to do the action??
Last check the MOUNT TYPE. Make sure it is set as I believe ALT AZ MOUNT.?
The sequence generally is - or at least what I do - point the scope roughly north and to the ALT REF position (most have this as 90)... turn on the system - hit enter twice. Now you can go to MODE ENCODER and the AZ should read 0 (the ALT the ALT REF value).?
g.
------ Original Message ------
Date 3/5/2025 9:34:46 AM
Subject [ServoCAT] Argo-Navis & ServoCat off in AZ
Maybe its old age, but I cant resolve this issue. When I set up (Obsession f5/20) I basically have the scope pointing North and at 90'. Power on the Cat and Argo and it goes through initialing and gives beep synch tone and do a fix alt ref. Now if I go to Mode Encoder I see my AZ is almost always about 90' as if pointing east? Why is it nolonger reporting 0 when pointing north? This deviation makes alignment and/manual targeting a bit more challenging. Did I miss somethin? Suggestions??
?
Thanks
?
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Argo-Navis & ServoCat off in AZ
Maybe its old age, but I cant resolve this issue. When I set up (Obsession f5/20) I basically have the scope pointing North and at 90'. Power on the Cat and Argo and it goes through initialing and gives beep synch tone and do a fix alt ref. Now if I go to Mode Encoder I see my AZ is almost always about 90' as if pointing east? Why is it nolonger reporting 0 when pointing north? This deviation makes alignment and/manual targeting a bit more challenging. Did I miss somethin? Suggestions??
?
Thanks
?
?
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Re: My first ServoCAT Autoguide "production" images
Thank you Mickey, very much appreciated!
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/Gabriel
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Re: My first ServoCAT Autoguide "production" images
Excellent images Gabriel, you keep improving with every run.
Mickey
As the weatherman promised our skies cleared up Wednesday and yesterday Thursday so i was finally able to test Autoguiding on actual capture.
It works well and i can confirm that dither also works very well with ServoCAT. It almost always settled from a dither without messsing up the next sub which was often not the case with my Sky-Watcher mount even though i used "Spiral" instead of "Random" for dither there as well (to avoid backlash).
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I dither 1 pixel on my guidecamera which is 4.30 arc seconds = about 14 pixels on my DSLR, it problably would not hurt to dither more than every 10 frames as i did.
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241 x 15s (1h 15s) on The Sunflower Galaxy. Large view on Astrobin recommended:
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449 x 20s (2.5h) on NGC 3180 (looks like a flower too in my opinion). Large view recommended:
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Astrobin link to a PHD2 screenshot: (the total RMS there is 0.94" arc seconds, for the most part during capture it was around 1.2 -1.3" arc seconds).
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PHD2 calibration (no warnings):
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At the moment i use a guidespeed of 7 arc seconds per second in ServoCAT Sky and 0.20 x Sidereal in PHD2.
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/Gabriel
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Re: Settings for use of AutoGUIDE
Update:
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I have come to the conclusion that 7 arc seconds per second in ServoCAT sky is not fast enough to calibrate or guide well between 160 Az? and 200 az (so +/- 20 degrees of south), same to the north 330 - 30 az. So in other words, stay away from the Meridian and 20 degrees on either side of it.
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At 75 z and 37 Alt i get a perfect calibration in PHD2 with 7 arc seconds / second set in ServoCAT Sky.
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Due to field rotation one would want to stay away from the meridian anyway, also considering objects are the highest above the horizon when passing the meridian.
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This is not really an issue if one plans the session: To give an example:
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If i was to image M106 tonight, and i would begin imaging at around 8 PM when it is at 67 az and 42 alt, i will still get 5 hours of imaging time before it reaches 160 az and 75 alt.
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I don't think it's worth changing the guidespeed for imaging around the meridian since, the span is a short, as mentioned field rotation and at least from my experience a fast guidespeed does not work well, at least with my Starstructure.
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/Gabriel?
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Re: My first ServoCAT Autoguide "production" images
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Re: My first ServoCAT Autoguide "production" images
Congratulations Gabriel !
Really great?
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My first ServoCAT Autoguide "production" images
As the weatherman promised our skies cleared up Wednesday and yesterday Thursday so i was finally able to test Autoguiding on actual capture.
It works well and i can confirm that dither also works very well with ServoCAT. It almost always settled from a dither without messsing up the next sub which was often not the case with my Sky-Watcher mount even though i used "Spiral" instead of "Random" for dither there as well (to avoid backlash).
?
I dither 1 pixel on my guidecamera which is 4.30 arc seconds = about 14 pixels on my DSLR, it problably would not hurt to dither more than every 10 frames as i did.
?
?
241 x 15s (1h 15s) on The Sunflower Galaxy. Large view on Astrobin recommended:
?
?
?
?
449 x 20s (2.5h) on NGC 3180 (looks like a flower too in my opinion). Large view recommended:
?
?
?
Astrobin link to a PHD2 screenshot: (the total RMS there is 0.94" arc seconds, for the most part during capture it was around 1.2 -1.3" arc seconds).
?
?
PHD2 calibration (no warnings):
?
At the moment i use a guidespeed of 7 arc seconds per second in ServoCAT Sky and 0.20 x Sidereal in PHD2.
?
?
/Gabriel
?
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Re: Settings for use of AutoGUIDE
Your welcome Raphael, thank you. Happy to help!
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I don't see any advantage of imaging with autoguiding in combination with easytrack except if your DSC is not working, so a good backup solution!
PHD2 will not have to work/correct as much when you have done the 2-star alignment because of more accurate tracking, but it could potentially still correct to the same RMS error.
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PHD2 is very good, and made for correcting low frequency errors like slow drift. Which is the case when using easytrack compared to a good 2-star alignment.
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Edit: It is not possible to point at all with Easytrack, you would have to use a Telrad or similar, just like when doing visual.
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/Gabriel
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Re: Settings for use of AutoGUIDE
Thanks Gabriel
Even if don¡¯t understand everything detail you explain, all this will be of great use for community including me when I have a higher level in astrophotography
One question :?
With the very good result you have with auto guiding + easy track, do you see any advantage to make auto guiding with 2 alignment star versus auto guiding+ easy track ?
Pointing is more accurate with 2 stars alignment, but appart from this, any advantage of 1 method versus the other ?
thanks
Rapha?l?
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Re: Settings for use of AutoGUIDE
I made some new discoveries this morning when creating a new profile to improve my understanding of PHD2.
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1. It is not possible, when creating a new profile to enter a mount speed less then 0.20 x Sidereal. It's only possible when changing the settings later. (that would be 3.01 arc seconds per second in the Meade Generic driver (if used) before creating a new profile in PHD2 change that in the driver)
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2. The calibration step size is not only calculated from guidespeed, focal length, and pixel size but also which declination the calibration will be performed, this can be set under Advanced settings.
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This explains why the calibration step size suddenly changed for me, i was calibrating at a different declination and PHD2 used the pointing information from the Meade driver to use "dec compensation".
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Since the PHD2 documentation advises against changing guidespeed after creating a new profile, it's probably best to go with 0.20 x Sidereal from the start and leave it.
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The last calibration that i did, which was Orthogonal, completed in both axis within 8-12 steps and produced good guiding results was done at about 60 AZ and 38 ALT and declination of 46.
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I had changed guidespeed to 0.18 x Sidereal in PHD2 and as usual 6 arc seconds per second in Servocat Sky, Calibration step size was 4900 ms.
With the new profile i set all the values the same, including declination 46 for the calibration, produced a step size of 4300 ms, since guidespeed had been raised from 0.18 to 0.20 Sidereal.
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Since the step size is reduced, in order to not slow down the measured guidespeed with 0.20 x Sidereal set in PHD2 it's probably a good idea to use 7 arc seconds per second in ServoCAT sky instead of 6 arc seconds per second, i have changed this in ServoCAT sky.
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Will be interesting to see next clear night when i will be using the DSC Pro and hopefully do actual capture.
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Here is an extreme crop (to see the stars better) of 180 stacked subs, 20 seconds each processed in Siril on a random part of the sky near Ursa Major, it is from the night when i got around 0.95" RMS guiding with EasyTrack.
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The stack had a FWHM of 3.4 arc seconds, which is what i get when looping 1 second exposures on a night when seeing is above average from this location.
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Edit (correction): The measured guidespeed will not slow down because of increasing the guidespeed from 0.18 to 0.20 in PHD2, but it will send shorter pulse commands and that will increase the number of steps used during calibration, and to compensate for that it would not hurt to increase the guidespeed in ServoCAT Sky if the number of steps are more than 12.
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/Gabriel
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Re: Local SYNC activated or not ?
Thanks Gary
"Try this as well: hold the CW and CCW buttons for I think it is 3 seconds - the yellow LED next to the CCW should come on. You can do this same test using the UP/DWN buttons (where the DWN comes on)"
I do this from time to time to reverse the guiding direction as my dob is a little special : it has 37¡ã secondary angle + a 120¡ã diagonal => from time to time I try to reverse the up/down or right/left guiding direction?
And yes, the yellow light near the CCW is then on (or the one near the down if I reverse up/down)
But I didn¡¯t do this for 2-3 months => maybe something happened since 2-3 month
Anyway, I will redo all the test and make videos in 3 weeks:?
Thanks Gary for giving each time your kind support !
Regards
try to be sure to hold the HC perpendicular to the camera - and in focus.?
That stated I suspect you are right. It however doesn't make sense that it powers up correctly (showing the lights as a check on their operation) and doesn't in use. Unless the other
lights aren't working. Try this as well: hold the CW and CCW buttons for I think it is 3 seconds - the yellow LED next to the CCW should come on. You can do this same test using the UP/DWN buttons (where the DWN comes on).
g.
toggle quoted message
Show quoted text
------ Original Message ------
Date 2/22/2025 10:15:44 AM
Subject Re: [ServoCAT] Local SYNC activated or not ?
Thanks Gary for quick answer !
Enclosed another video made the same day.
I'm not aware of any color shift affected my eye. I clearly see the yellow LS light on when turning on the servocat handpad with the same condition as video : in the dark, with my red headlamp on
It's difficult to make the video in the dark with 1 hand on handpad and 1 hand on cellphone. ;-)?
The thing is even when led are off, with my red headlamp on you could think that the yellow LED is on. Dim but on. For example see in the begininng or end of the below video : we could imagin that this led
is on, but it is not.
Anyway I will carefully recheck next time I go to observatory (in 3 weeks) and will ask someone to hold the camera to have better quality vid¨¦o.
I will also check if local synch is activated or not when pressing LC button, because at the end of the day, the important thing is the good activation of LC.... Even if my handpad yellow led is not activated,
if the local synch is on (and on servocat, the yellow LC LED IS on), it's ok. Just a little bit less friendly to use, but OK.
I will repost in 3 weeks with more accurate video
Regards
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Re: Settings for use of AutoGUIDE
Hello Gary,
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That is correct.
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However, when guiding at the bottom to the right you can set MAX pulse duration in AZ and ALT, default is 2500 ms which i have not found a reason to change.
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Even if you would change the calibration step size on brain -> guiding ->calibration step (ms): next to Advanced it will automatically change back to the value calculated by the values entered when creating the profile and also depending on guidspeed entered which is found when clicking on Advanced.
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You have to keep an eye on what the number is on calibration step (ms): since it could suddenly change for example if there is a different guidespeed in the Meade Generic driver if connected so the guidespeed there could overwrite the guidespeed in PHD2.
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It once changed to 2300ms for me and i am not sure why. PHD2 recommends that you should create a new profile if a parameter has changed and not do manual changes, pherhaps that is the reason.
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However i have found that, as long as you keep an eye on that number and it works i have not found a reason to create a profile from scratch.
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Best regards
Gabriel
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Re: Local SYNC activated or not ?
try to be sure to hold the HC perpendicular to the camera - and in focus.?
That stated I suspect you are right. It however doesn't make sense that it powers up correctly (showing the lights as a check on their operation) and doesn't in use. Unless the other lights aren't working. Try this as well: hold the CW and CCW buttons for I think it is 3 seconds - the yellow LED next to the CCW should come on. You can do this same test using the UP/DWN buttons (where the DWN comes on).
g.
------ Original Message ------
Date 2/22/2025 10:15:44 AM
Subject Re: [ServoCAT] Local SYNC activated or not ?
Thanks Gary for quick answer !
Enclosed another video made the same day.
I'm not aware of any color shift affected my eye. I clearly see the yellow LS light on when turning on the servocat handpad with the same condition as video : in the dark, with my red headlamp on
It's difficult to make the video in the dark with 1 hand on handpad and 1 hand on cellphone. ;-)?
The thing is even when led are off, with my red headlamp on you could think that the yellow LED is on. Dim but on. For example see in the begininng or end of the below video : we could imagin that this led is on, but it is not.
Anyway I will carefully recheck next time I go to observatory (in 3 weeks) and will ask someone to hold the camera to have better quality vid¨¦o.
I will also check if local synch is activated or not when pressing LC button, because at the end of the day, the important thing is the good activation of LC.... Even if my handpad yellow led is not activated, if the local synch is on (and on servocat, the yellow LC LED IS on), it's ok. Just a little bit less friendly to use, but OK.
I will repost in 3 weeks with more accurate video
Regards
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Gabriel Wiklund
Sam Selig