Regarding your DEC backlash, Skywatcher's default mechanical tuning tends to be pretty 'loose'. There are three easy things you can do to improve backlash (in this order): 1/ adjust the worm engagement with the DEC gear (the worm carrier has external adjustment bolts), 2/ adjust the worm end float nut to reduce lateral play of the worm (under the black plastic cover), and 3/ adjust your belt tension (adjustment bolt under the belt gear cover). There are numerous videos out there explaining how to do this properly. It's worth it.
Excellent suggestions, Andre’! I will definitely go down that path once I have a good read on how the mount behaves before I screw it up. Thanks for watching!
The Voltage is the first thing I would attend to, it will need to be above 12.5v at all times, even though the mount is rated from 11v to 13v it prefers to be above 12v. If you can maintain an overall voltage of 12.8, then this will be perfect. The Pegasus Box you have is great for checking this out, particularly when it is slewing. The mount can also indicate some information by the power light flashing signal.
In the EQ mod module that comes up that shows ride Ascension and declination you can click on the Green Plus button at the top of the module on the screen and rotate and tell the different screens and you can find right Ascension and declination adjustment and very the amount of gain that will change the duration of correction so if you have Corrections that are above and below the line you can decrease the gain to a point where you're just correcting on one side
Thanks. Since I published this video, the declination backlash has been resolved and the mount is doing great (considering its price point). Thanks for watching.
Great thorough video. As far as the shaft collar use, I too became concerned with the ability of the cheap looking/feeling weight locking knobs to stay tightly secured. I slid a garden hose rubber washer up the shaft and up against the lowest counterweight. It took some effort, but be sure to do it on a dry shaft for a good friction fit. I placed the scope in the home position and released the weight locking screw. The weight did not drop, as it cannot overcome the tight fit/friction between the rubber washer and the shaft. No marking or damage on the shaft using this method. I always keep the safety cap on the end of the shaft.
As someone new to the hobby (with an EQ6-R Pro), thanks for ALL of your magnificently informative videos! This tip with the shaft collar is going to save me much worry... did not trust those "locking" knobs either. One less thing to sweat. Thanks! PPEC next...
The shaft collar works well. I bought a few extra and use the other two above the weights to set the position on the bar for balance positions for other scopes. That way, when I tear down and re-assemble the setup, the position of the weights for balance is already set - - just slide them up to contact with the collar.
Hi James, I also purchased the EQ6R pro and now used it for 4 imaging sessions and have had great results. I run it with a Esprit 80 scope and my guiding has never been above .6, most of the time its guiding at .4 / .45. I’m surprised you chose a guiding rate of .8x, I set mine to .5x. I think it’s a great mount for the money and great informative videos. All the best.
I'm glad to hear about your good experience with the EQ6R! 0.5x guide speed is the default. However, when you're trying to use PHD2's DEC backlash compensation, PHD2 wants to be able to compensate for the backlash in less than 3 sec (3000 ms pulse). You can eliminate more backlash in a 3-sec period if the guide rate is higher. That's the idea anyway. I'll keep working on my setup. I'd be perfectly happy with the results you're getting. Enjoy!
I enjoyed watching your video James. Detail oriented with no fluff. I also have the EQ6R, just started auto guiding and I had an anomaly last week but I believe mine is cable related (rat's nest) so I just purchased the Pegasus Powerbox for cable management. I captured the Lobster Claw last week, it's a beautiful and interesting target. Looking forward to seeing your final images.
Thanks for watching! So far, so good with my EQ6. The Powerbox is expensive, but it is an awesome product. I only have two cables coming off the scope. Makes cable management much easier. Good luck!
I get the same oblong stars with my OAG as well. I tried adjusting everything I could, but as you said it really doesn't affect the guiding, that I've seen. It still seems to find the centroid. My guiding seems to be consistently .5" or less all night, so I'm not going to worry about it anymore 😀 Glad you have some better results with your new mount!
Thanks for this video...I will be giving that GSS software a go! I just got an EQ6-R as well, and I'm surprised at your dec backlash compensation of ~2.5 seconds. After running the guiding assistant mine came in much lower at around 150ms. I'm a bit surprised at that much variation, but maybe I shouldn't be. That said, you sound quite pleased with your new mount and I am as well. It's a huge improvement over my AZ-EQ5. Clear skies!
Congratulations! I need to re-run the Guiding Assistant. I think the PHD2 algorithm has significantly dialed back the backlash number after running several nights. So it's quite likely PHD2 recognized that number was out of whack and "fixed" it. I hope you have as good, if not better, a first experience with your EQ6-R!
A good and interesting tutorial James. I have the same mount that came in May. I am currently guiding at about 0.8 t 0.9 with the Orion EON 130 refractor and using a 240mm fl 60mm guide scope. Yes, I would love to get it down to 0.5, but hey, I am getting round stars on 5 minutes exposures so I am happy ... for now.
Hey Pat, Funny. I was setting up for my first night of imaging with the EQ6 and was watching some of your videos (misery loves company, I guess) and noticed you have one too now. I did have to laugh. I've got my tripod legs fully retracted so the telescope is only chest-high. Then I see you climbing a ladder to remove the lens cap! I lucked out: my house blocks my view to the south. Different story when the house blocks the north view. Looking forward to sharing the new EQ6 journey with you, Clear Skies!
Hi James . What would we do without your amazing Graphs and Spreadsheets ? LOL . I can see a Retirement Project for you where you apply your Testing to various Mounts and Accessories . The Astrophotography Community would be forever grateful . Excellent Video ! /Cheers SRK
Good idea. I found a "shaft collar" for about $6 on Amazon. I show a picture of it in the video. Works much better than those knobs! Thanks for watching.
I did a lot of tests on this mount : the best is between12.6/12.9 V. It really makes a noticable difference. If you stay under 12.2V, you will have noticable tracking issues (above 12KG payload i had about 13KG on it during tests). The best solution is to buy an adjustable powerbox for cars/bikes. You can buy one for 100e and it is very precise on voltage. Pegasus powerbox allows you to checks voltage but i don't think you ca adjust it with a 0.1V precision :)
Thanks for the information. I could never get the PA UPBv2 to reliably power my Celestron CGEM, but I have had no problems with the EQ6-R. The voltage reading is 13.7 volts. Thanks for watching!
What happens when the voltage is above that voltage range? The power supply that I am using is outputting 13.7V. I am trying to find out why my mount performs so badly. The perriodic error is quite obvious for mine when guiding, but for everyone else guiding seems to be able to remove much of the periodic error, or at least make it much less obvious.
Hi Simon. I routinely run my setup at 13.6V and have no issues. Maybe run the PHD2 "Guiding Assistant" and let it record the position of the star while not guiding to see what you're dealing with. I believe my old CGEM and current EQ6-R have periodic error on the order of 20 arc-sec. PHD2 corrects for this level of PE quite well.
@@Aero19612 I see. As I said, my power supply outputs 13.7V, although the very same power supply is what is providing all of my equipment with power, so I do not really know what the voltage is at the mount. Is there any merit in having a power supply of its own for only the mount? The periodic error of my mount is slightly larger, around 25 arc seconds. It has been characterized as quite smooth and regular. I have also commented another one of your videos, but I'll bring those lines of inquiry here as well, they were regarding whether or not PHD2 can on its own, without any form of PEC, remove the periodic error. The periodic error basically only lessened in amplitude for me, but the shape is not really flattened that much, it still is obviously sinusoidal. So, I am trying to find out why that is. Why PHD2 is not able to remove the periodic error to the degree that it seems to be doing for pretty much everyone else. The graphs are also very spiky, both in RA and DEC.
Depends upon the mount. With my CGEM, I used a separate power supply. A lot of folks power their mount separately. Some mounts are very sensitive. So far, my EQ6-R works great operating off the common power source. I also power a dew strap, the imaging camera, guide camera, ride-along cloud cam, filter wheel, and focuser. If you run 3 dew straps, you might need to power the mount separately. Yes. PHD2 should handle 25 arc sec PE easily. Maybe the aggressiveness parameter is too high. Maybe the guide rate is too high. Try 50% sidereal and start with 50% aggressiveness and set exposure to about 2 sec. Increase aggressiveness if it takes several cycles to correct the error. Try sending a guide log to the PHD2 forum for input.
You got the skywatcher, what a difference huh. I hypertuned my brand new cgemll and it still guided bad. Now my eq6r is always around .70 or better. I’m pec training my mount now got about an half our left to see the curve .
Great, Dan! Yes, I am enjoying the EQ6-R. Had an odd thing happen though. I'd been repeating an imaging session and the first two nights went well. Then, on the last two nights, the EQ6-R would stop tracking after it slewed to one target. It did the same thing on the next night. Worked fine until about 0400 then stopped tracking. I could still talk to the mount. Anyway, gotta deal with that gremlin this weekend.
I’m getting pretty good and consistent guiding with the EQ6-R. Below 0.53 arc-sec 80% of the time ( see ua-cam.com/video/1NcPYaH65wg/v-deo.htmlsi=42lJsUmRe0yUf6op). Doesn’t really matter if I have the Redcat or the C9.25 on the mount. Given typical seeing for my area, the guiding has been as good as can be expected. Thanks for watching!
Hi James, I am still using an old cgem which is probably from your batch. What I have found that switching from OAG to guidescope and doing multistar guiding my guiding has improved a lot. Now I am getting total rms of 0.6-0.8 which was above 1.0 before. I am using a similar scope (78mm) as yours. I cannot explain it but I am not complaining. You may want to try using a guidescope with your new mount.
Hey Avi. I started out using a guide scope and got decent results. Guiding a 2000+ mm focal length scope with an OAG should be better since your guide scope is also 2000+ mm and the inertia of the imaging rig is a lot less, but you can't use multistar guiding most of the time because you don't have multiple stars. Multistar is good at ignoring seeing disturbances but doesn't help at all if gear mechanics is a big problem. Reading between the lines, sounds like you're lucky enough to have a CGEM with low-end gear noise. And you are correct: don't complain about it, just enjoy it!
Great video. Do you know how many worm gear cycle GSS performs for pec training ? I was under the impression it only does 1 cycle whereas eqmod does 6 and averages and smooths them. I have same mount and scopes so I will try and see how my mount does for comparison. I have seen several videos on adjusting mount backlash- some mounts seem to have some looseness of the belts
Looking at the logfile, GSS was in training mode for about 10 minutes. Just time for 1 cycle. I would think averaging 6 cycles is better, but I can't complain about the effectiveness of the GSS results. I'll check my belts. If you want to, run Guiding Assistant for 1500+ sec then email me your PHD2 guidelog file and I'll compare it to mine.
I think either I got lucky, or skywatcher is tightening down their QC. Out of the box I'm guiding around 0.6rms total with a 50mm guidescope, worst nights I see 0.8. Currently guiding with 1 sec intervals as well.
That sounds about right. I have more videos on this after additional time with the EQ6-R and various scopes with different weights. I find that I get total RMS < 0.6 over 80% of the time. I'm quite pleased with it. Thanks for watching!
Another very interesting and informative video James -Thanks! Did you compare GSS PPEC with using PHD2 RA Predictive PEC algorithm? I wonder whether GSS gives better results. i've not seen a huge difference with pHD2 PPEC algorithm.
Thanks for watching, David! Those are related, but different algorithms. The idea behind PPEC is to identify the biggest contributors to periodic error and have the mount (PPEC) remove it before PHD2 has to. Predictive PEC looks at its guiding commands in real time and try’s to subtract out the predictable periodic error, including higher frequency errors plus the fundamental worm gear period. I suspect PPEC could be turned off and Predictive PEC would still do about the same. That’s the way I ran my CGEM. PPEC won’t eliminate the need for PHD2 guiding.
Sort of. I have been pounding a 3/4" all-thread into the ground with 2 nuts on the end (the tope one only half on) to serve as "micro-piers" for each leg. This time, I bought some retaining wall cement bricks at Home Depot and dug them down into the ground (below mower level). Now I can keep the legs retracted because the bricks are set to provide a nearly level base. It's pretty easy to carry the assembled mount (minus weights and scope) back under the covered porch (love the handle on the back of the mount). I put a cover over it during the past few rainy nights. Supposed to clear up tonight so I'll set it back out there and try to do some actual imaging for the next four nights. Famous last words...
appreciate you sharing your analysis on this. A couple of things. I noticed on your comparison between Guiding assistant report. On your post PPEC analysis it suggested 2-4 second exposures. Although it appeared that you were running at 1 sec exposures for the test. Did you try longer exposures? Also, with the PA error between the two reports, this seems consistent with some of my tests when running much longer elapsed times for the guiding assistant. I've noticed that the PA error begins to increase after a certain period of time. Mine has all been with a CGX mount, so the comparison is not similar with regards to equipment, but wonder if that is something with PHD2. Anyway, thanks again. Your detail of analysis is unique with a lot of other channels, and it gives me a lot of ideas on how to test.
Yes. That's something I'm going to have to play with. They recommend long exposures (2-4 sec) to avoid "chasing the seeing". But, the algorithm does a better job of compensating for mechanical-induced errors the shorter the exposure you use (but then you have the risk of chasing the seeing). Pairing short exposures with multi-star guiding should be the best of both worlds: multi-star handles the seeing and short exposures handles the mechanical noise. In theory. You're probably right about the PA error. That said, I never saw 0.5 arcmin during the 2000-sec run, but did at the end of the 1000-sec run. Thanks for watching, Neil!
By now you might have figgered out 2.5 seconds is a good exposure time and 60 for ra and 90 or even 80 in dec for agr. I watched astrobloke for these numbers and also tuning out the backlash that I noticed after having the mount for awhile. This fire season here in Northern California I’ll hypertune the Mount. It’s 20 or three months of smoky conditions so no imaging. Now that you have tried the many things to improve performance , what I enjoy most about your videos , what results in total era do you have.
Hey Dan. In general, I'm quite pleased with the EQ6-R. Finally, the mount is not my biggest concern. I have used 3 telescopes on the mount so far. I'm currently imaging with the heaviest scope I have (C9.25, 29 lb). My next videos will be: 1. What level of guiding (total RMS) do we need for a focal length/pixel size combo? 2. How does the EQ6-R perform (total RMS) for "light" and "heavy" payloads? So, I think I'll be answering your question in the second video. Stay tuned!
Thanks for another interesting video. Does your mount use PPEC while guiding? I am also confused about the guiding assistant. I thought it ran without guiding (which would explain the similar RA peak to peak). Can't wait to see some pics with your new system. Clear skies.
Hey Bob. I will use PPEC when guiding. That said, I don't expect guiding to be much, or any, better with PPEC. PHD2 does a good job with long period errors like worm gear periodic error. For the Guiding Assistant, you first start guiding on a star, then select GA from the tools menu. At that point, PHD2 monitors the guide star's motion but does not send corrections to the mount. The star motion is saved in the PHD2 guidelog-that's the data I was showing in those plots.
Hi James. for what it is worth with field flattener and focal reducer settings. I use a WO GT81 with the WO adjustable FF/FR (WO 6AIII x 0.8). No elongated stars whatsoever with my settings (thanks to the help of WO team). The space between the face of the locking ring and the upper body of the FF/FR (the gap where you can see the exposed threads) measures exactly 5.98mm with my digital calipers. Imaging camera is a Nikon D7500. Cheers.
Very thorough James, nicely made. Is there any difference between training PPEC through GS and EQMOD? If you train through GS, will that store on the mount and replay through EQMOD? Haven't yet jumped into PPEC on my EQ6R. I only ask as my imaging laptop is fairly under powered and I try to limit running more programs than necessary.
I have not tried EQMOD. I have heard that EQMOD records 6 worm periods and averages them before downloading into the mount. I think that is a good approach, but I must say, I have no reason to think I'd get better results than GSS gave me with one worm cycle. Once the PPEC data are downloaded to the mount, it should not matter if you switch between EQMOD, GSS, or SynScan. Once the PPEC is handed over to the mount, there is no demand on your PC as it is not doing the work. Thanks for watching!
Ha. Well, I've had many experiences when I'm certain I don't understand anything at all. The EQ6R is working well so far. Difficult to tighten the knobs when your fingers are crossed, though. Thanks for watching!
Ahhh. Yes, "de-coupled" is a nerdy engineering math term. What that means is that when your scope is pointed near the meridian and celestial equator, the RA motion and DEC motion make a 90-deg angle on your guide camera sensor which improves the accuracy of the calibration. In other orientations, pure RA motion also shows up, to some degree, in the pure DEC motion direction and vice versa. So you have to mathematically untangle the motions. It also helps to minimize the atmospheric disturbances that occur as you point closer to the horizon. Hope that helps!
I looked into this issue a bit further. First, I was surprised that the "Right Ascension Pk-to-Pk" did not go down when PPEC was enabled. Turns out I was interpreting "Right Ascension Pk-to-Pk" as the amplitude of the primary harmonic of the worm gear. It isn't. It's just a simple of max - min RA values. Second, I thought it odd that the polar alignment error dropped from 1.3 arc-min it 0.5 arc-min with PPEC enabled where there should be no effect at all. I got the higher polar alignment error without PPEC because of the slight coupling between RA and DEC with the star I was monitoring and the uncorrected periodic error was leaking into the DEC drift. Thanks for reminding me of this!
Hey Phil. Yes, it does have that capability. You need a software package to collect the data and download the PPEC correction into the mount. I think you can do it through the Synscan hand controller. EQMOD provides that functionality as well. In my case, I just used GSS to perform the training. Seems to be quite effective!
Regarding your DEC backlash, Skywatcher's default mechanical tuning tends to be pretty 'loose'. There are three easy things you can do to improve backlash (in this order): 1/ adjust the worm engagement with the DEC gear (the worm carrier has external adjustment bolts), 2/ adjust the worm end float nut to reduce lateral play of the worm (under the black plastic cover), and 3/ adjust your belt tension (adjustment bolt under the belt gear cover). There are numerous videos out there explaining how to do this properly. It's worth it.
Excellent suggestions, Andre’! I will definitely go down that path once I have a good read on how the mount behaves before I screw it up. Thanks for watching!
The Voltage is the first thing I would attend to, it will need to be above 12.5v at all times, even though the mount is rated from 11v to 13v it prefers to be above 12v. If you can maintain an overall voltage of 12.8, then this will be perfect. The Pegasus Box you have is great for checking this out, particularly when it is slewing. The mount can also indicate some information by the power light flashing signal.
Finally someone shows a picture of where we should be calibrated! Congrats - great videos
Thanks, Marty!
In the EQ mod module that comes up that shows ride Ascension and declination you can click on the Green Plus button at the top of the module on the screen and rotate and tell the different screens and you can find right Ascension and declination adjustment and very the amount of gain that will change the duration of correction so if you have Corrections that are above and below the line you can decrease the gain to a point where you're just correcting on one side
Thanks. Since I published this video, the declination backlash has been resolved and the mount is doing great (considering its price point). Thanks for watching.
Great thorough video. As far as the shaft collar use, I too became concerned with the ability of the cheap looking/feeling weight locking knobs to stay tightly secured. I slid a garden hose rubber washer up the shaft and up against the lowest counterweight. It took some effort, but be sure to do it on a dry shaft for a good friction fit. I placed the scope in the home position and released the weight locking screw. The weight did not drop, as it cannot overcome the tight fit/friction between the rubber washer and the shaft. No marking or damage on the shaft using this method. I always keep the safety cap on the end of the shaft.
That's a good and cheap solution! Those knobs are just silly.
As someone new to the hobby (with an EQ6-R Pro), thanks for ALL of your magnificently informative videos! This tip with the shaft collar is going to save me much worry... did not trust those "locking" knobs either. One less thing to sweat. Thanks! PPEC next...
The shaft collar works well. I bought a few extra and use the other two above the weights to set the position on the bar for balance positions for other scopes. That way, when I tear down and re-assemble the setup, the position of the weights for balance is already set - - just slide them up to contact with the collar.
@@Aero19612 Excellent concept... much better than my "mark it with a Sharpie" idea for the upper positions.
Hi James, I also purchased the EQ6R pro and now used it for 4 imaging sessions and have had great results.
I run it with a Esprit 80 scope and my guiding has never been above .6, most of the time its guiding at .4 / .45.
I’m surprised you chose a guiding rate of .8x, I set mine to .5x.
I think it’s a great mount for the money and great informative videos.
All the best.
I'm glad to hear about your good experience with the EQ6R! 0.5x guide speed is the default. However, when you're trying to use PHD2's DEC backlash compensation, PHD2 wants to be able to compensate for the backlash in less than 3 sec (3000 ms pulse). You can eliminate more backlash in a 3-sec period if the guide rate is higher. That's the idea anyway. I'll keep working on my setup. I'd be perfectly happy with the results you're getting. Enjoy!
I enjoyed watching your video James. Detail oriented with no fluff. I also have the EQ6R, just started auto guiding and I had an anomaly last week but I believe mine is cable related (rat's nest) so I just purchased the Pegasus Powerbox for cable management. I captured the Lobster Claw last week, it's a beautiful and interesting target. Looking forward to seeing your final images.
Thanks for watching! So far, so good with my EQ6. The Powerbox is expensive, but it is an awesome product. I only have two cables coming off the scope. Makes cable management much easier. Good luck!
I get the same oblong stars with my OAG as well. I tried adjusting everything I could, but as you said it really doesn't affect the guiding, that I've seen. It still seems to find the centroid. My guiding seems to be consistently .5" or less all night, so I'm not going to worry about it anymore 😀 Glad you have some better results with your new mount!
Exactly, Chris. Lots of things we can worry about, but let's focus on those things that really matter. I'd be happy 0.5". Thanks for watching!
Thank you so much for the educational video.
Thanks for watching!
Thanks for this video...I will be giving that GSS software a go! I just got an EQ6-R as well, and I'm surprised at your dec backlash compensation of ~2.5 seconds. After running the guiding assistant mine came in much lower at around 150ms. I'm a bit surprised at that much variation, but maybe I shouldn't be. That said, you sound quite pleased with your new mount and I am as well. It's a huge improvement over my AZ-EQ5. Clear skies!
Congratulations! I need to re-run the Guiding Assistant. I think the PHD2 algorithm has significantly dialed back the backlash number after running several nights. So it's quite likely PHD2 recognized that number was out of whack and "fixed" it. I hope you have as good, if not better, a first experience with your EQ6-R!
@@Aero19612 Thank you!
A good and interesting tutorial James. I have the same mount that came in May. I am currently guiding at about 0.8 t 0.9 with the Orion EON 130 refractor and using a 240mm fl 60mm guide scope. Yes, I would love to get it down to 0.5, but hey, I am getting round stars on 5 minutes exposures so I am happy ... for now.
Hey Pat,
Funny. I was setting up for my first night of imaging with the EQ6 and was watching some of your videos (misery loves company, I guess) and noticed you have one too now. I did have to laugh. I've got my tripod legs fully retracted so the telescope is only chest-high. Then I see you climbing a ladder to remove the lens cap! I lucked out: my house blocks my view to the south. Different story when the house blocks the north view. Looking forward to sharing the new EQ6 journey with you, Clear Skies!
Hi James . What would we do without your amazing Graphs and Spreadsheets ? LOL . I can see a Retirement Project for you where you apply your Testing to various Mounts and Accessories . The Astrophotography Community would be forever grateful . Excellent Video ! /Cheers SRK
Haha. I think astrophotography is a retirement project. Thanks for sitting through another one, Scott!
I'm a heating and air guy. Look for a thrust collar at an hvac supply site.. wont corrode and will be around $4.
Good idea. I found a "shaft collar" for about $6 on Amazon. I show a picture of it in the video. Works much better than those knobs! Thanks for watching.
I did a lot of tests on this mount : the best is between12.6/12.9 V. It really makes a noticable difference. If you stay under 12.2V, you will have noticable tracking issues (above 12KG payload i had about 13KG on it during tests). The best solution is to buy an adjustable powerbox for cars/bikes. You can buy one for 100e and it is very precise on voltage. Pegasus powerbox allows you to checks voltage but i don't think you ca adjust it with a 0.1V precision :)
Thanks for the information. I could never get the PA UPBv2 to reliably power my Celestron CGEM, but I have had no problems with the EQ6-R. The voltage reading is 13.7 volts. Thanks for watching!
What happens when the voltage is above that voltage range? The power supply that I am using is outputting 13.7V. I am trying to find out why my mount performs so badly. The perriodic error is quite obvious for mine when guiding, but for everyone else guiding seems to be able to remove much of the periodic error, or at least make it much less obvious.
Hi Simon. I routinely run my setup at 13.6V and have no issues. Maybe run the PHD2 "Guiding Assistant" and let it record the position of the star while not guiding to see what you're dealing with. I believe my old CGEM and current EQ6-R have periodic error on the order of 20 arc-sec. PHD2 corrects for this level of PE quite well.
@@Aero19612 I see. As I said, my power supply outputs 13.7V, although the very same power supply is what is providing all of my equipment with power, so I do not really know what the voltage is at the mount. Is there any merit in having a power supply of its own for only the mount?
The periodic error of my mount is slightly larger, around 25 arc seconds. It has been characterized as quite smooth and regular. I have also commented another one of your videos, but I'll bring those lines of inquiry here as well, they were regarding whether or not PHD2 can on its own, without any form of PEC, remove the periodic error. The periodic error basically only lessened in amplitude for me, but the shape is not really flattened that much, it still is obviously sinusoidal. So, I am trying to find out why that is. Why PHD2 is not able to remove the periodic error to the degree that it seems to be doing for pretty much everyone else. The graphs are also very spiky, both in RA and DEC.
Depends upon the mount. With my CGEM, I used a separate power supply. A lot of folks power their mount separately. Some mounts are very sensitive. So far, my EQ6-R works great operating off the common power source. I also power a dew strap, the imaging camera, guide camera, ride-along cloud cam, filter wheel, and focuser. If you run 3 dew straps, you might need to power the mount separately.
Yes. PHD2 should handle 25 arc sec PE easily. Maybe the aggressiveness parameter is too high. Maybe the guide rate is too high. Try 50% sidereal and start with 50% aggressiveness and set exposure to about 2 sec. Increase aggressiveness if it takes several cycles to correct the error. Try sending a guide log to the PHD2 forum for input.
You got the skywatcher, what a difference huh. I hypertuned my brand new cgemll and it still guided bad. Now my eq6r is always around .70 or better. I’m pec training my mount now got about an half our left to see the curve .
Great, Dan! Yes, I am enjoying the EQ6-R. Had an odd thing happen though. I'd been repeating an imaging session and the first two nights went well. Then, on the last two nights, the EQ6-R would stop tracking after it slewed to one target. It did the same thing on the next night. Worked fine until about 0400 then stopped tracking. I could still talk to the mount. Anyway, gotta deal with that gremlin this weekend.
Honestly I have to say that with all that callbration and tuning i was expecting a much better result than 0.8 for this mount.
I’m getting pretty good and consistent guiding with the EQ6-R. Below 0.53 arc-sec 80% of the time ( see ua-cam.com/video/1NcPYaH65wg/v-deo.htmlsi=42lJsUmRe0yUf6op). Doesn’t really matter if I have the Redcat or the C9.25 on the mount. Given typical seeing for my area, the guiding has been as good as can be expected. Thanks for watching!
Hi James, I am still using an old cgem which is probably from your batch. What I have found that switching from OAG to guidescope and doing multistar guiding my guiding has improved a lot. Now I am getting total rms of 0.6-0.8 which was above 1.0 before. I am using a similar scope (78mm) as yours. I cannot explain it but I am not complaining. You may want to try using a guidescope with your new mount.
Hey Avi. I started out using a guide scope and got decent results. Guiding a 2000+ mm focal length scope with an OAG should be better since your guide scope is also 2000+ mm and the inertia of the imaging rig is a lot less, but you can't use multistar guiding most of the time because you don't have multiple stars. Multistar is good at ignoring seeing disturbances but doesn't help at all if gear mechanics is a big problem. Reading between the lines, sounds like you're lucky enough to have a CGEM with low-end gear noise. And you are correct: don't complain about it, just enjoy it!
Great video, I’m new to this hobby and my EQ6r pro isn’t producing a graph, nothing, just little dips from dithering?
Great video. Do you know how many worm gear cycle GSS performs for pec training ? I was under the impression it only does 1 cycle whereas eqmod does 6 and averages and smooths them. I have same mount and scopes so I will try and see how my mount does for comparison. I have seen several videos on adjusting mount backlash- some mounts seem to have some looseness of the belts
Looking at the logfile, GSS was in training mode for about 10 minutes. Just time for 1 cycle. I would think averaging 6 cycles is better, but I can't complain about the effectiveness of the GSS results. I'll check my belts. If you want to, run Guiding Assistant for 1500+ sec then email me your PHD2 guidelog file and I'll compare it to mine.
I think either I got lucky, or skywatcher is tightening down their QC. Out of the box I'm guiding around 0.6rms total with a 50mm guidescope, worst nights I see 0.8. Currently guiding with 1 sec intervals as well.
That sounds about right. I have more videos on this after additional time with the EQ6-R and various scopes with different weights. I find that I get total RMS < 0.6 over 80% of the time. I'm quite pleased with it. Thanks for watching!
Another very interesting and informative video James -Thanks!
Did you compare GSS PPEC with using PHD2 RA Predictive PEC algorithm? I wonder whether GSS gives better results. i've not seen a huge difference with pHD2 PPEC algorithm.
Thanks for watching, David! Those are related, but different algorithms. The idea behind PPEC is to identify the biggest contributors to periodic error and have the mount (PPEC) remove it before PHD2 has to. Predictive PEC looks at its guiding commands in real time and try’s to subtract out the predictable periodic error, including higher frequency errors plus the fundamental worm gear period. I suspect PPEC could be turned off and Predictive PEC would still do about the same. That’s the way I ran my CGEM. PPEC won’t eliminate the need for PHD2 guiding.
From the picture, it looks like you got your concrete pads put in. Probably a lot nicer then setting up on the grass.
Sort of. I have been pounding a 3/4" all-thread into the ground with 2 nuts on the end (the tope one only half on) to serve as "micro-piers" for each leg. This time, I bought some retaining wall cement bricks at Home Depot and dug them down into the ground (below mower level). Now I can keep the legs retracted because the bricks are set to provide a nearly level base. It's pretty easy to carry the assembled mount (minus weights and scope) back under the covered porch (love the handle on the back of the mount). I put a cover over it during the past few rainy nights. Supposed to clear up tonight so I'll set it back out there and try to do some actual imaging for the next four nights. Famous last words...
appreciate you sharing your analysis on this. A couple of things. I noticed on your comparison between Guiding assistant report. On your post PPEC analysis it suggested 2-4 second exposures. Although it appeared that you were running at 1 sec exposures for the test. Did you try longer exposures? Also, with the PA error between the two reports, this seems consistent with some of my tests when running much longer elapsed times for the guiding assistant. I've noticed that the PA error begins to increase after a certain period of time. Mine has all been with a CGX mount, so the comparison is not similar with regards to equipment, but wonder if that is something with PHD2. Anyway, thanks again. Your detail of analysis is unique with a lot of other channels, and it gives me a lot of ideas on how to test.
Yes. That's something I'm going to have to play with. They recommend long exposures (2-4 sec) to avoid "chasing the seeing". But, the algorithm does a better job of compensating for mechanical-induced errors the shorter the exposure you use (but then you have the risk of chasing the seeing). Pairing short exposures with multi-star guiding should be the best of both worlds: multi-star handles the seeing and short exposures handles the mechanical noise. In theory. You're probably right about the PA error. That said, I never saw 0.5 arcmin during the 2000-sec run, but did at the end of the 1000-sec run. Thanks for watching, Neil!
By now you might have figgered out 2.5 seconds is a good exposure time and 60 for ra and 90 or even 80 in dec for agr. I watched astrobloke for these numbers and also tuning out the backlash that I noticed after having the mount for awhile. This fire season here in Northern California I’ll hypertune the Mount. It’s 20 or three months of smoky conditions so no imaging. Now that you have tried the many things to improve performance , what I enjoy most about your videos , what results in total era do you have.
Hey Dan. In general, I'm quite pleased with the EQ6-R. Finally, the mount is not my biggest concern. I have used 3 telescopes on the mount so far. I'm currently imaging with the heaviest scope I have (C9.25, 29 lb). My next videos will be:
1. What level of guiding (total RMS) do we need for a focal length/pixel size combo?
2. How does the EQ6-R perform (total RMS) for "light" and "heavy" payloads?
So, I think I'll be answering your question in the second video. Stay tuned!
Thanks for another interesting video. Does your mount use PPEC while guiding? I am also confused about the guiding assistant. I thought it ran without guiding (which would explain the similar RA peak to peak). Can't wait to see some pics with your new system. Clear skies.
Hey Bob. I will use PPEC when guiding. That said, I don't expect guiding to be much, or any, better with PPEC. PHD2 does a good job with long period errors like worm gear periodic error. For the Guiding Assistant, you first start guiding on a star, then select GA from the tools menu. At that point, PHD2 monitors the guide star's motion but does not send corrections to the mount. The star motion is saved in the PHD2 guidelog-that's the data I was showing in those plots.
Hi James. for what it is worth with field flattener and focal reducer settings. I use a WO GT81 with the WO adjustable FF/FR (WO 6AIII x 0.8). No elongated stars whatsoever with my settings (thanks to the help of WO team). The space between the face of the locking ring and the upper body of the FF/FR (the gap where you can see the exposed threads) measures exactly 5.98mm with my digital calipers. Imaging camera is a Nikon D7500. Cheers.
Thanks! I think I have my flattener (same one) set properly. Probably worth a second look though.
Very thorough James, nicely made. Is there any difference between training PPEC through GS and EQMOD? If you train through GS, will that store on the mount and replay through EQMOD? Haven't yet jumped into PPEC on my EQ6R. I only ask as my imaging laptop is fairly under powered and I try to limit running more programs than necessary.
I have not tried EQMOD. I have heard that EQMOD records 6 worm periods and averages them before downloading into the mount. I think that is a good approach, but I must say, I have no reason to think I'd get better results than GSS gave me with one worm cycle. Once the PPEC data are downloaded to the mount, it should not matter if you switch between EQMOD, GSS, or SynScan. Once the PPEC is handed over to the mount, there is no demand on your PC as it is not doing the work. Thanks for watching!
Way more in depth than my knowledge... but fasinating non the less. Talk about understanding your equipment.
Ha. Well, I've had many experiences when I'm certain I don't understand anything at all. The EQ6R is working well so far. Difficult to tighten the knobs when your fingers are crossed, though. Thanks for watching!
Could you explian why calibration should be done near meridian and celestial equator? I'm not following the de-coupling RA and Dec.
Ahhh. Yes, "de-coupled" is a nerdy engineering math term. What that means is that when your scope is pointed near the meridian and celestial equator, the RA motion and DEC motion make a 90-deg angle on your guide camera sensor which improves the accuracy of the calibration. In other orientations, pure RA motion also shows up, to some degree, in the pure DEC motion direction and vice versa. So you have to mathematically untangle the motions. It also helps to minimize the atmospheric disturbances that occur as you point closer to the horizon. Hope that helps!
@@Aero19612 Thanks that does make sense now!
What did phd2 team say about discrepancy?
Darn it! I forgot all about this and didn't ask the question. I'll send the question today and let you know what they say. Thanks for the reminder!
I looked into this issue a bit further. First, I was surprised that the "Right Ascension Pk-to-Pk" did not go down when PPEC was enabled. Turns out I was interpreting "Right Ascension Pk-to-Pk" as the amplitude of the primary harmonic of the worm gear. It isn't. It's just a simple of max - min RA values. Second, I thought it odd that the polar alignment error dropped from 1.3 arc-min it 0.5 arc-min with PPEC enabled where there should be no effect at all. I got the higher polar alignment error without PPEC because of the slight coupling between RA and DEC with the star I was monitoring and the uncorrected periodic error was leaking into the DEC drift. Thanks for reminding me of this!
I thought the EQ6 R Pro had permanent PPEC training?
Hey Phil. Yes, it does have that capability. You need a software package to collect the data and download the PPEC correction into the mount. I think you can do it through the Synscan hand controller. EQMOD provides that functionality as well. In my case, I just used GSS to perform the training. Seems to be quite effective!
@@Aero19612 Ah, I had imagined it was just running in the background, a touch more fiddly than that. Thanks.