Date   

Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Wes Mcdonald
 

Dino.  

That sounds actually ok.  Put the explorestars into P mode and see how it changes sound.  That funny chugging sound is not unusual, at least I ha e heard it too.  But in truth seems like is is softer

Wes 

--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

nickerson.joseph@...
 

After watching the video provided by jdavis I am pretty convinced that is my issue. I have check and rechecked everything you have mentioned. I am hoping to get in touch with Explorer Scientifics customer service before I open it up given that the mount is only 6 months and still under warranty. Thanks for your suggestions.


Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Rix Yarbrough <yarbroughrix@...>
 

Yeah, AC cable. Also using the explorestars app set to iEXOS-100. Should be fine settings. I also heard the same noise when I tried ASCOM control, so I doubt it’s software- especially since slewing works fine and the dec motor sounds fine when it’s running. Might be time for a new motor. 

On Sun, Jan 10, 2021 at 17:06 Dino Monaco via groups.io <Dinomonaco=me.com@groups.io> wrote:
Ok. That’s interesting. So now we know it’s not the mechanicals.
Some more questions:
What type of power source? Direct AC or battery?
If your powering the system from an ac outlet then that rules out current fluctuations.
If software related then check in the settings for correct RA Steps for your mount. 
See if you could increase or decrease the step values and try running the motor without the belt attached. Does this alleviate the noise?
If no then I would swap out the motor.




On Jan 10, 2021, at 3:48 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Dino-
Hm. Just took the belt off, powered on, connected. I hear the sound from the motor even though it now has literally zero payload to move. This is concerning. Unless this is a problem with firmware, and software, or the connection, this motor could be the issue. I did buy this mount used...
Anyone know what I should do next? Contact ES, ask for a new motor? Play around with firm/software?

Virus-free. www.avast.com

On Sun, Jan 10, 2021 at 3:40 PM Dino Monaco via groups.io <Dinomonaco=me.com@groups.io> wrote:
Sorry I just joined the group and late to what you have already tried.
A curious question: if you remove the belt completely so that you can isolate only the motor,  
Then activate the RA do you still hear the sound?
If yes then motor is perhaps the issue.
If no, then try like you said and realign the worm not too tightly. 
Is the sound happening under full payload with all gear attached only?.
How about without the payload.
My apologies if you have already tried these simple checks


On Jan 10, 2021, at 3:22 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Just to update- still have not resolved my problem. I have adjusted backlash and balance to hell and back but no luck at all. Here is a video of the problem, which I hope will help someone identify it exactly. 
As you can (sort of) see; the RA motor is only able to chug the gear forward bit by bit, making an awful sound in the process. The payload is balanced in my opinion perfectly, but to be sure I have also tried moving the CW’s back and forth both tiny and large amounts, but in the very best circumstances the motion only becomes a slight bit more constant. Still it chugs and the noise continues. It is possible that I have messed something up in the gear adjustment process- I sometimes get side/side movement of the worm shaft which according to the tutorial aforementioned is solved by tightening a screw in the right block. However, my screw feels completely impossible to move, so my solution has been to loosen the blocks holding in both ends of the worm gear shaft, move them to one side, and tighten them again- which seems to fix the problem. I say seems because although the back/forth motion goes away, it *could* create some directional strain or make the gear meet the belt at a bad angle, but I have really no idea. The gear doesn't feel too tight to turn, so I sort of doubt it.
So what the actual hell is going on here? Open to crackpot theories, although I’m hoping the answer is simple and obvious to someone more knowledgeable than myself. 

Rix


On Tue, Dec 29, 2020 at 16:28 yarbroughrix via groups.io <yarbroughrix=gmail.com@groups.io> wrote:

Got a used iEXOS-100 and was finally able to diagnose my issue: it seems that the RA motor, in particular, is struggling to move the mount. When connected to the app and tracking, the motors can be heard "chugging" as if they are struggling. The explorestars app shows that when tracking, the RA axis just flips back and forth one arc second at a time rapidly (38, 39, 38, 39, etc), leading me to believe the motor is not putting out enough torque to turn the axis. When I attempt to slew at a high speed, and motor sounds like it is struggling, making a bad racket, but is able to rotate the axis. Seems like it's just facing more friction than it is expecting, perhaps? I've tried adjusting the backlash at three levels (tight, loose, medium) but it seems not to have an effect. Maybe I need to relubricate the RA gear teeth? Is WD-40 recommended, or something else? I'd like to not experiment much more until I know a fix, as I am worried about damaging the motor. Any advice is welcome.

 

Rix


--
Dino Monaco


Virus-free. www.avast.com

--
Dino Monaco


Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Dino Monaco
 

Ok. That’s interesting. So now we know it’s not the mechanicals.
Some more questions:
What type of power source? Direct AC or battery?
If your powering the system from an ac outlet then that rules out current fluctuations.
If software related then check in the settings for correct RA Steps for your mount. 
See if you could increase or decrease the step values and try running the motor without the belt attached. Does this alleviate the noise?
If no then I would swap out the motor.




On Jan 10, 2021, at 3:48 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Dino-
Hm. Just took the belt off, powered on, connected. I hear the sound from the motor even though it now has literally zero payload to move. This is concerning. Unless this is a problem with firmware, and software, or the connection, this motor could be the issue. I did buy this mount used...
Anyone know what I should do next? Contact ES, ask for a new motor? Play around with firm/software?

Virus-free. www.avast.com

On Sun, Jan 10, 2021 at 3:40 PM Dino Monaco via groups.io <Dinomonaco=me.com@groups.io> wrote:
Sorry I just joined the group and late to what you have already tried.
A curious question: if you remove the belt completely so that you can isolate only the motor,  
Then activate the RA do you still hear the sound?
If yes then motor is perhaps the issue.
If no, then try like you said and realign the worm not too tightly. 
Is the sound happening under full payload with all gear attached only?.
How about without the payload.
My apologies if you have already tried these simple checks


On Jan 10, 2021, at 3:22 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Just to update- still have not resolved my problem. I have adjusted backlash and balance to hell and back but no luck at all. Here is a video of the problem, which I hope will help someone identify it exactly. 
As you can (sort of) see; the RA motor is only able to chug the gear forward bit by bit, making an awful sound in the process. The payload is balanced in my opinion perfectly, but to be sure I have also tried moving the CW’s back and forth both tiny and large amounts, but in the very best circumstances the motion only becomes a slight bit more constant. Still it chugs and the noise continues. It is possible that I have messed something up in the gear adjustment process- I sometimes get side/side movement of the worm shaft which according to the tutorial aforementioned is solved by tightening a screw in the right block. However, my screw feels completely impossible to move, so my solution has been to loosen the blocks holding in both ends of the worm gear shaft, move them to one side, and tighten them again- which seems to fix the problem. I say seems because although the back/forth motion goes away, it *could* create some directional strain or make the gear meet the belt at a bad angle, but I have really no idea. The gear doesn't feel too tight to turn, so I sort of doubt it.
So what the actual hell is going on here? Open to crackpot theories, although I’m hoping the answer is simple and obvious to someone more knowledgeable than myself. 

Rix


On Tue, Dec 29, 2020 at 16:28 yarbroughrix via groups.io <yarbroughrix=gmail.com@groups.io> wrote:

Got a used iEXOS-100 and was finally able to diagnose my issue: it seems that the RA motor, in particular, is struggling to move the mount. When connected to the app and tracking, the motors can be heard "chugging" as if they are struggling. The explorestars app shows that when tracking, the RA axis just flips back and forth one arc second at a time rapidly (38, 39, 38, 39, etc), leading me to believe the motor is not putting out enough torque to turn the axis. When I attempt to slew at a high speed, and motor sounds like it is struggling, making a bad racket, but is able to rotate the axis. Seems like it's just facing more friction than it is expecting, perhaps? I've tried adjusting the backlash at three levels (tight, loose, medium) but it seems not to have an effect. Maybe I need to relubricate the RA gear teeth? Is WD-40 recommended, or something else? I'd like to not experiment much more until I know a fix, as I am worried about damaging the motor. Any advice is welcome.

 

Rix


--
Dino Monaco


Virus-free. www.avast.com

--
Dino Monaco


Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Rix Yarbrough <yarbroughrix@...>
 

Dino-
Hm. Just took the belt off, powered on, connected. I hear the sound from the motor even though it now has literally zero payload to move. This is concerning. Unless this is a problem with firmware, and software, or the connection, this motor could be the issue. I did buy this mount used...
Anyone know what I should do next? Contact ES, ask for a new motor? Play around with firm/software?

Virus-free. www.avast.com

On Sun, Jan 10, 2021 at 3:40 PM Dino Monaco via groups.io <Dinomonaco=me.com@groups.io> wrote:
Sorry I just joined the group and late to what you have already tried.
A curious question: if you remove the belt completely so that you can isolate only the motor,  
Then activate the RA do you still hear the sound?
If yes then motor is perhaps the issue.
If no, then try like you said and realign the worm not too tightly. 
Is the sound happening under full payload with all gear attached only?.
How about without the payload.
My apologies if you have already tried these simple checks


On Jan 10, 2021, at 3:22 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Just to update- still have not resolved my problem. I have adjusted backlash and balance to hell and back but no luck at all. Here is a video of the problem, which I hope will help someone identify it exactly. 
As you can (sort of) see; the RA motor is only able to chug the gear forward bit by bit, making an awful sound in the process. The payload is balanced in my opinion perfectly, but to be sure I have also tried moving the CW’s back and forth both tiny and large amounts, but in the very best circumstances the motion only becomes a slight bit more constant. Still it chugs and the noise continues. It is possible that I have messed something up in the gear adjustment process- I sometimes get side/side movement of the worm shaft which according to the tutorial aforementioned is solved by tightening a screw in the right block. However, my screw feels completely impossible to move, so my solution has been to loosen the blocks holding in both ends of the worm gear shaft, move them to one side, and tighten them again- which seems to fix the problem. I say seems because although the back/forth motion goes away, it *could* create some directional strain or make the gear meet the belt at a bad angle, but I have really no idea. The gear doesn't feel too tight to turn, so I sort of doubt it.
So what the actual hell is going on here? Open to crackpot theories, although I’m hoping the answer is simple and obvious to someone more knowledgeable than myself. 

Rix


On Tue, Dec 29, 2020 at 16:28 yarbroughrix via groups.io <yarbroughrix=gmail.com@groups.io> wrote:

Got a used iEXOS-100 and was finally able to diagnose my issue: it seems that the RA motor, in particular, is struggling to move the mount. When connected to the app and tracking, the motors can be heard "chugging" as if they are struggling. The explorestars app shows that when tracking, the RA axis just flips back and forth one arc second at a time rapidly (38, 39, 38, 39, etc), leading me to believe the motor is not putting out enough torque to turn the axis. When I attempt to slew at a high speed, and motor sounds like it is struggling, making a bad racket, but is able to rotate the axis. Seems like it's just facing more friction than it is expecting, perhaps? I've tried adjusting the backlash at three levels (tight, loose, medium) but it seems not to have an effect. Maybe I need to relubricate the RA gear teeth? Is WD-40 recommended, or something else? I'd like to not experiment much more until I know a fix, as I am worried about damaging the motor. Any advice is welcome.

 

Rix


--
Dino Monaco


Virus-free. www.avast.com


Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Dino Monaco
 

Sorry I just joined the group and late to what you have already tried.
A curious question: if you remove the belt completely so that you can isolate only the motor,  
Then activate the RA do you still hear the sound?
If yes then motor is perhaps the issue.
If no, then try like you said and realign the worm not too tightly. 
Is the sound happening under full payload with all gear attached only?.
How about without the payload.
My apologies if you have already tried these simple checks


On Jan 10, 2021, at 3:22 PM, Rix Yarbrough <yarbroughrix@...> wrote:


Just to update- still have not resolved my problem. I have adjusted backlash and balance to hell and back but no luck at all. Here is a video of the problem, which I hope will help someone identify it exactly. 
As you can (sort of) see; the RA motor is only able to chug the gear forward bit by bit, making an awful sound in the process. The payload is balanced in my opinion perfectly, but to be sure I have also tried moving the CW’s back and forth both tiny and large amounts, but in the very best circumstances the motion only becomes a slight bit more constant. Still it chugs and the noise continues. It is possible that I have messed something up in the gear adjustment process- I sometimes get side/side movement of the worm shaft which according to the tutorial aforementioned is solved by tightening a screw in the right block. However, my screw feels completely impossible to move, so my solution has been to loosen the blocks holding in both ends of the worm gear shaft, move them to one side, and tighten them again- which seems to fix the problem. I say seems because although the back/forth motion goes away, it *could* create some directional strain or make the gear meet the belt at a bad angle, but I have really no idea. The gear doesn't feel too tight to turn, so I sort of doubt it.
So what the actual hell is going on here? Open to crackpot theories, although I’m hoping the answer is simple and obvious to someone more knowledgeable than myself. 

Rix


On Tue, Dec 29, 2020 at 16:28 yarbroughrix via groups.io <yarbroughrix=gmail.com@groups.io> wrote:

Got a used iEXOS-100 and was finally able to diagnose my issue: it seems that the RA motor, in particular, is struggling to move the mount. When connected to the app and tracking, the motors can be heard "chugging" as if they are struggling. The explorestars app shows that when tracking, the RA axis just flips back and forth one arc second at a time rapidly (38, 39, 38, 39, etc), leading me to believe the motor is not putting out enough torque to turn the axis. When I attempt to slew at a high speed, and motor sounds like it is struggling, making a bad racket, but is able to rotate the axis. Seems like it's just facing more friction than it is expecting, perhaps? I've tried adjusting the backlash at three levels (tight, loose, medium) but it seems not to have an effect. Maybe I need to relubricate the RA gear teeth? Is WD-40 recommended, or something else? I'd like to not experiment much more until I know a fix, as I am worried about damaging the motor. Any advice is welcome.

 

Rix


--
Dino Monaco


Re: iEXOS-100 RA axis motor struggles, doesn't track #iEXOS-100 #goto #tracking

Rix Yarbrough <yarbroughrix@...>
 

Just to update- still have not resolved my problem. I have adjusted backlash and balance to hell and back but no luck at all. Here is a video of the problem, which I hope will help someone identify it exactly. 
As you can (sort of) see; the RA motor is only able to chug the gear forward bit by bit, making an awful sound in the process. The payload is balanced in my opinion perfectly, but to be sure I have also tried moving the CW’s back and forth both tiny and large amounts, but in the very best circumstances the motion only becomes a slight bit more constant. Still it chugs and the noise continues. It is possible that I have messed something up in the gear adjustment process- I sometimes get side/side movement of the worm shaft which according to the tutorial aforementioned is solved by tightening a screw in the right block. However, my screw feels completely impossible to move, so my solution has been to loosen the blocks holding in both ends of the worm gear shaft, move them to one side, and tighten them again- which seems to fix the problem. I say seems because although the back/forth motion goes away, it *could* create some directional strain or make the gear meet the belt at a bad angle, but I have really no idea. The gear doesn't feel too tight to turn, so I sort of doubt it.
So what the actual hell is going on here? Open to crackpot theories, although I’m hoping the answer is simple and obvious to someone more knowledgeable than myself. 

Rix


On Tue, Dec 29, 2020 at 16:28 yarbroughrix via groups.io <yarbroughrix=gmail.com@groups.io> wrote:

Got a used iEXOS-100 and was finally able to diagnose my issue: it seems that the RA motor, in particular, is struggling to move the mount. When connected to the app and tracking, the motors can be heard "chugging" as if they are struggling. The explorestars app shows that when tracking, the RA axis just flips back and forth one arc second at a time rapidly (38, 39, 38, 39, etc), leading me to believe the motor is not putting out enough torque to turn the axis. When I attempt to slew at a high speed, and motor sounds like it is struggling, making a bad racket, but is able to rotate the axis. Seems like it's just facing more friction than it is expecting, perhaps? I've tried adjusting the backlash at three levels (tight, loose, medium) but it seems not to have an effect. Maybe I need to relubricate the RA gear teeth? Is WD-40 recommended, or something else? I'd like to not experiment much more until I know a fix, as I am worried about damaging the motor. Any advice is welcome.

 

Rix


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

Jennifer Shelly
 

Joseph:

I used to own an Exos-2 PMC-8 and have been through the tuning exercise multiple times.  It appears your image of the star trail is exposing nice round stars for the majority of your exposure time then something happens and the stars appear to be shifting to the left for a small amount of the exposure time.  Does that sound correct?  The reason I say this is because it appears you have a bright star and a faint star right next to it like a ghost or like the mount is skipping.

A few things come to mind.  Is it possible a cable is getting snagged? Is your counterweight fully secured and not able to slide down the counterweight bar? Are you absolutely sure you are balanced in both the RA and DEC axis? My old Exos-2 had stiction in the RA axis and when I thought I balanced I really was not. Have you manually rotated the RA axis by hand to check for any tight spots on the worm ring gear? Try rotating by hand 180° and see if your wiggle is better or worse.  In the video you demonstrate wiggle by grabbing your guide scope and moving it side-to-side.  What does the wiggle look like when you do the same to the counterweight bar? If the wiggle is less then you will need to figure out what is causing the wiggle in your imaging train.  You mentioned that you have tightened the RA clutch as far as it will go.  Since the worm wheel gear is made out of aluminum it is possible create an indent in the worm wheel gear from over tightening which would be exaggerate the natural high and low spots on the worm ring gear.

Sorry if this is too much, I just wanted to list everything that came to mind. I hope this helps.
--
Sincerely,

Jennifer Shelly
AstroPorch, VA

Mounts
: ES PMC-8 G-11, ES PMC-8 iEXOS-100
Scopes: ES ED127 FCD-100, Askar FRA 400, ES Levy Comet Hunter, ES N208CF, QHY Mini Guide Scope, Solomark F60 Guide Scope
Cameras: QHY600M, QHY128C, QHY168C
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance, QHY CFW3-L, Baader 2” LRGBSHO CCD
Imaging Software:  NINA, APT, SharpCap Pro
Processing Software: PixInsight, Lightroom, Premiere Elements


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

jdavis1278@...
 

There are a couple of videos on Youtube about adjusting the RA wiggle that happens sometimes with the IExos100 and Exos2... I know the adjustment for the iexos100 requires you to take the cover off and do some simple adjusting to the screws holding the gears on. 

Iexos100 vid: https://youtu.be/mLXE_BMKVAw
I'm not sure if that's helpful or if they're too dis-similar for that to help


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

nickerson.joseph@...
 

Email is sent, when I clicked your link it posted as tyler@explorescien, I assumed it was tyler@... and sent it.


Re: IEXOS-100 can't get round stars due to RA erros? #iEXOS-100

Wes Mcdonald
 

Yi

1.  I saw PHD recommended you focus your guide camera.  PRobably should do that.

2.  MAke sure your guide star is not saturated.  

3.  Dont use PEC algorithm, ust go with the normal ysterisis and resist switch I believe.

4.  MAke sure your PA is pretty go so you do not get field rotation.  Field rotation will make the stars look like this even though the guiding is good.

5  What did you say your RMS total guide error was?  1.x arc seconds?  This is excellent.

If your RMS guide error is low like that then you have terrible PA.  

Ask PHD to evaluate your PA.  How are you polar aligning?

Just some thoughts.  

Wes.




--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

Tyler Bowman - Explore Scientific Customer Service <Tbowman@...>
 

Hey if you could send me a email at tyler@... we can figure out whats going on.


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

 

Joseph,
 
Re: The Clutch...
If you scroll down the stardeck observatory link, you'll see some rather decent exploded photos of an LXD75, our EXOS2's progenitor.  Our mounts have bearings on all axes and the bushings/spacers are a bit different, but the general arrangement of things is much the same. 
If you scroll to the RA assembly diagram, to the right is a dotted circle that encloses the "axis rotation lock assembly" (aka clutch, brake, etc.).  A lever, a screw, and a little dot of something, which is effectively a small brake shoe.  I've attached a photo of mine, taken when I had my mount apart.  Turn the lever and the brake shoe presses on the ring/drum gear's side.  This mechanically links the ring gear to the outer shell of a given axis, so the motor can rotate it for tracking and slewing.  Disengage the clutch and the axis is free to rotate for balancing.



There's not much to go wrong with it, or to adjust.  I believe that the screw in the lever can give you a bit of control over tension, but that's about it.  

Re: wiggling...
The ring gear is driven by a worm gear.  Worms drive, they aren't driven, so you won't see your motor pulley wiggle.  If the axis is moving, the usual cause is just normal backlash that you just have to manage around.  But there is one other possibility, and this might cause trailing. Take a look at Section 7.3 in the tuning doc I linked.  That deals with adjusting the tension on the worm gear shaft.  They are sometimes mis-tensioned, either too tight or too loose.  If too loose, the worm could shift along its length as rotational force on/from the axis varied.  While the worm will refuse to be driven, I suppose it's possible that it might shift.  Easy enough to check, but you'll need to pop the covers to do that.  
 
Hope this helps!
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2 290M
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Re: IEXOS-100 can't get round stars due to RA erros? #iEXOS-100

NewAP
 

Hi Brian, thanks for the input, I thought about it a bit, the focusing was not perfect but it always showed up along RA direction, so I suspect the RA movement has some impact, and it is true we can't rule out the possibility of lens or focusing.

Yi  

On Fri, Jan 8, 2021 at 10:02 AM brian skinner <brianjimskinner@...> wrote:
Hi there, I may be wrong here of course but it looks to me that your problem could be bad focusing??
--
Brian Skinner
iEXOS100
Canon 1300d dslr
Various lenses
ES Polar scope
Sequator image stacker
PIXR image editor


Re: IEXOS-100 can't get round stars due to RA erros? #iEXOS-100

brian skinner
 

Hi there, I may be wrong here of course but it looks to me that your problem could be bad focusing??
--
Brian Skinner
iEXOS100
Canon 1300d dslr
Various lenses
ES Polar scope
Sequator image stacker
PIXR image editor


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

nickerson.joseph@...
 

Robert I appreciate your help. I understand the concept of backlash. In the aircraft maintenance world we always called it play. Tomato, Tomato. I have been up and down my image train a half dozen times looking for unwanted motion and could find none. And it seems the issue is worsening over time and I can say with 90% assurance that backlash wasn't always there. I opened up the side panel for the RA to inspect the gears and saw nothing askew and when I wiggled the scope again on the RA, the gears did not move. Wouldn't the gears move if the play was indeed backlash. My gut/maintenance intuition is telling me that there is something wrong with the Clutch allowing the play which turns into a slight vibration that effect the image during a hard motor push, which is why not all my subs are bad, but enough to warrant mega frustration. I don't seem to have any issues with star trails along the DEC and that sucker is solid with zero wiggle/jiggle/backlash/play. In aircraft maintenance that is called check the other side to see if it's doing it, if its not then that is most likely the issue.  Also, does anyone know why Explore Scientific isn't answering their phone.... 


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

 

Joseph,

Play (backlash...) in the gears?  Some is indeed normal.

Gears, shafts, bearings...all have tolerances.
And the spacing between the ring and worm?  It's fixed.  No play in that. 
So the best you can do is adjust the two gears to be as close as possible without actually binding. 
And where the spacing opens up...you get play/backlash.  You counteract that by managing balance.

I'm looking at your setup picture, and I see a very long focuser tube with a (heavy) filter wheel and camera at the end of it.  Is there unwanted motion there, at the sensor end?  No idea, but given your problem description, I'd be taking a close look.  Remember, you're looking for microns...

Again, FWIW.  Hope this helps...



On Thu, Jan 7, 2021, at 17:09, nickerson.joseph@... wrote:

[Edited Message Follows]

The same issue was accuring with my guide scope mounted on center line, see attached picture. I am having a hard time rapping my head around any play in the mount with clutches locked down being normal.

Attachments:
  • 20210101_112422.jpg


--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2 290M
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

nickerson.joseph@...
 
Edited

The same issue was accuring with my guide scope mounted on center line, see attached picture. I am having a hard time rapping my head around any play in the mount with clutches locked down being normal.


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

Walter Vinci
 

Hi Joseph,

I am totally new to the hobby too (hi everyone :)! ), actually just a couple of nights out with autoguiding, but my ES PMC-8 EXOS2 has a similar (even wider I would say) play on RA and I have no such problem (doing about 2” RMS but with round stars). 

On Jan 7, 2021, at 2:56 PM, Robert Hoskin <devonshire@...> wrote:

Joseph,

This hobby is an endless source of problem-solving opportunities  :-)

Just tossing some things out as grist for your mill...

If you tell me that your mount axes wiggle, well, you may need some mechanical adjustment (see link below).  
BUT... some play in the ring/worm gear connection is entirely normal, so while it's good to keep a mount well-adjusted, there are limits to the mechanical perfection we can achieve. 

Having said that... if you tell me that your guiding looks good, but your stars trail anyway, then I'd wonder about the dreaded "differential flexure". 
Basically, guiding well requires that the two optical trains (guiding and imaging) be absolutely rigid relative to each other. 
Relative movement of scopes in rings, focuser rotators, cameras in focusers, etc... all bad.   
I would guess that if guiding looks good, there may be motion in your imaging train.  On my scope, it was a focuser rotator.  Very convenient for visual use, but its inherent play was a bad idea for my imaging.  I locked its little grub screws down with extreme prejudice and saved the day!  

FWIW...

https://espmc-eight.groups.io/g/MAIN/files/User%20Contributions/EXOS2PMC8_TuningNotes_v2.pdf

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2 290M
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Re: #EXOS2 My RA on my mount is wiggling, Causing Star Trailing!!! #EXOS2

 

Joseph,

This hobby is an endless source of problem-solving opportunities  :-)

Just tossing some things out as grist for your mill...

If you tell me that your mount axes wiggle, well, you may need some mechanical adjustment (see link below).  
BUT... some play in the ring/worm gear connection is entirely normal, so while it's good to keep a mount well-adjusted, there are limits to the mechanical perfection we can achieve. 

Having said that... if you tell me that your guiding looks good, but your stars trail anyway, then I'd wonder about the dreaded "differential flexure". 
Basically, guiding well requires that the two optical trains (guiding and imaging) be absolutely rigid relative to each other. 
Relative movement of scopes in rings, focuser rotators, cameras in focusers, etc... all bad.   
I would guess that if guiding looks good, there may be motion in your imaging train.  On my scope, it was a focuser rotator.  Very convenient for visual use, but its inherent play was a bad idea for my imaging.  I locked its little grub screws down with extreme prejudice and saved the day!  

FWIW...

https://espmc-eight.groups.io/g/MAIN/files/User%20Contributions/EXOS2PMC8_TuningNotes_v2.pdf

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2 290M
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

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