Date   

Re: Dovelm162 springs too short or assembled wrong?

Woody Schlom
 

I wonder if over time, some of the springs are compressing and not fully extending?  As if the metal wasn't tempered correctly. Perhaps an entire batch wasn't tempered correctly.  So those of us who got "good" springs don't have this problem at all. But others got all "bad" springs,  or even a mix of good and bad springs.

New they all worked. But years later,  some of the springs are getting tired?  

Woody 

On September 16, 2021 12:13:25 PM "Bill Long" <bill@...> wrote:

Okay, that makes sense. Thanks for the explanation. I use this saddle and have never run into this problem myself, but I could see how this would be impactful to someone. Good to see there is a solution in store.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of ap@... <ap@...>
Sent: Thursday, September 16, 2021 11:50 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?
 

From Bill Long:

 

  • I am having a hard time determining what the problem is exactly. 

 

I can explain from my perspective.  Picture the saddle in Park 3, so facing north and level side to side, empty, and the knobs mostly all the way in (just for this example).

 

I want to install my C11.  I loosen the knobs to make room.  As I continue loosening them, before the clamps clear the dovetail area, the spring runs out and they just sit there as I loosen more and more, still blocking the area.

 

I grab them with my finger as I loosen and push to the left, and repeat until the clamp clears the area.  Needing to push them by hand is a very, very minor nuisance.  Not worth fixing for that.

 

Now I go pick up the OTA and go to lower it into the saddle.  If I hit it square, great.  If it drags slightly on the left side because it’s heavy and it’s dark and I’m clumsy, the clamp flops back over into the dovetail area and you can’t sit the dovetail into the saddle.  Now (holding the large OTA with two hands) I reach with my third hand and shift the clamp back out of the way.   Except, well, for the lack of a third hand, so I have to set the OTA down on the grass, reset the clamps, pick it up and repeat.  This is the somewhat more serious nuisance, still fairly minor .

 

I didn’t even think to ask about them, I just assumed it was as designed.  I mean, I came from a MyT where you cannot drop in a dovetail, period – you have to slide them in from the end.  So I was absolutely delighted I could drop it in at all.

 

But being able to open the clamps up and have them stay open would be very nice.

 

Linwood

 



Re: Erratic behavior, possibly contact related

Roland Christen
 


Does the fact that the motors continued to be powered despite the stop operation point to another possible fault?
Stop is a software command, so it requires a working servo system. Once the encoder connection fails, the servo loop is broken and no software commands will do anything. In later versions of the servo software there is a motor fail limit which will stop power to the motors after approx 2 seconds. You may have an older version of the software in your CP3.

Roland


-----Original Message-----
From: M. Collins <aegle_observatory@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 16, 2021 1:33 pm
Subject: Re: [ap-gto] Erratic behavior, possibly contact related

On Thu, Sep 16, 2021 at 09:43 AM, Roland Christen wrote:
You probably had corrosion on the pins of the Y cable and possibly on the motor box as well.
  This seems to be the most plausible explanation. It's odd that everything worked during bench testing and the first night at the site, then the problem surfaced and persisted after cycling the connectors, replacing the mount controller, etc., and finally went away without any actions which involved the Y cable connections. But I've seen enough strange failure modes involving old equipment and poor contacts to know that almost anything is possible.

  Are there any common connections through the Y cable, e.g., a signal ground pin which is connected to both motor assemblies? Poor contact at one pin which can affect both motor drives would fully explain the symptoms observed last week. (The mount is at one of our remote sites, so I can't readily pull the cable to see how it's wired.)
Runaways occur when the encoder signals don't reach the servo controller, so the controller thinks that the motor is not turning and supplies more and more voltage and current to turn the motor shaft. Of course, the motor shaft is turning, but without the encoder feedback, the controller runs open loop.
  A question about this. On more than one occasion when one or both axes were running away, pressing the stop button on the hand controller had no effect and it was only possible to stop the motors by pulling the power connection. Does the fact that the motors continued to be powered despite the stop operation point to another possible fault?

  Thanks for the details regarding the servo loops and hand controller interface.

--
Roland Christen
Astro-Physics


Re: Dovelm162 springs too short or assembled wrong?

Bill Long
 

Okay, that makes sense. Thanks for the explanation. I use this saddle and have never run into this problem myself, but I could see how this would be impactful to someone. Good to see there is a solution in store.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of ap@... <ap@...>
Sent: Thursday, September 16, 2021 11:50 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?
 

From Bill Long:

 

  • I am having a hard time determining what the problem is exactly. 

 

I can explain from my perspective.  Picture the saddle in Park 3, so facing north and level side to side, empty, and the knobs mostly all the way in (just for this example).

 

I want to install my C11.  I loosen the knobs to make room.  As I continue loosening them, before the clamps clear the dovetail area, the spring runs out and they just sit there as I loosen more and more, still blocking the area.

 

I grab them with my finger as I loosen and push to the left, and repeat until the clamp clears the area.  Needing to push them by hand is a very, very minor nuisance.  Not worth fixing for that.

 

Now I go pick up the OTA and go to lower it into the saddle.  If I hit it square, great.  If it drags slightly on the left side because it’s heavy and it’s dark and I’m clumsy, the clamp flops back over into the dovetail area and you can’t sit the dovetail into the saddle.  Now (holding the large OTA with two hands) I reach with my third hand and shift the clamp back out of the way.   Except, well, for the lack of a third hand, so I have to set the OTA down on the grass, reset the clamps, pick it up and repeat.  This is the somewhat more serious nuisance, still fairly minor .

 

I didn’t even think to ask about them, I just assumed it was as designed.  I mean, I came from a MyT where you cannot drop in a dovetail, period – you have to slide them in from the end.  So I was absolutely delighted I could drop it in at all.

 

But being able to open the clamps up and have them stay open would be very nice.

 

Linwood

 


Re: Dovelm162 springs too short or assembled wrong?

ap@CaptivePhotons.com
 

From Bill Long:

 

  • I am having a hard time determining what the problem is exactly. 

 

I can explain from my perspective.  Picture the saddle in Park 3, so facing north and level side to side, empty, and the knobs mostly all the way in (just for this example).

 

I want to install my C11.  I loosen the knobs to make room.  As I continue loosening them, before the clamps clear the dovetail area, the spring runs out and they just sit there as I loosen more and more, still blocking the area.

 

I grab them with my finger as I loosen and push to the left, and repeat until the clamp clears the area.  Needing to push them by hand is a very, very minor nuisance.  Not worth fixing for that.

 

Now I go pick up the OTA and go to lower it into the saddle.  If I hit it square, great.  If it drags slightly on the left side because it’s heavy and it’s dark and I’m clumsy, the clamp flops back over into the dovetail area and you can’t sit the dovetail into the saddle.  Now (holding the large OTA with two hands) I reach with my third hand and shift the clamp back out of the way.   Except, well, for the lack of a third hand, so I have to set the OTA down on the grass, reset the clamps, pick it up and repeat.  This is the somewhat more serious nuisance, still fairly minor .

 

I didn’t even think to ask about them, I just assumed it was as designed.  I mean, I came from a MyT where you cannot drop in a dovetail, period – you have to slide them in from the end.  So I was absolutely delighted I could drop it in at all.

 

But being able to open the clamps up and have them stay open would be very nice.

 

Linwood

 


Re: Dovelm162 springs too short or assembled wrong?

Bill Long
 

I am having a hard time determining what the problem is exactly. 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Woody Schlom <woody_is@...>
Sent: Thursday, September 16, 2021 11:12 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?
 
Marj,

I don't have this problem but I sure appreciate how AP is going about dealing with it.  You guys (and gals) are the best!

Woody 

On September 16, 2021 9:21:35 AM "Marj Christen" <marj@...> wrote:

Tom,

 

The assembly procedure and components have not changed for many years. Your is the first concern that I am aware of regarding this issue. I suspect that many users orient the plate so the clamps are down and gravity has assisted the clamp to move away from the center channel. When the clamps are down, you don’t have to reach over the scope to tighten the knobs.

 

Nevertheless, we have ordered springs that are longer than what we have used. Once we have tested them to be sure that they have the correct compression, we will send some to you.

 

I apologize for the inconvenience.

 

Clear Skies,

Marj Christen

Astro-Physics

11250 Forest Hills Road

Machesney Park, IL 61115

Phone: 815-282-1513

www.astro-physics.com

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Tom Blahovici
Sent: Wednesday, September 15, 2021 10:16 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?

 

That's interesting but the saddle is not new. Since I have to seen any other complaints in the past it must be something different now. What's AP going to do about this?
Tom



Re: Erratic behavior, possibly contact related

M. Collins
 

On Thu, Sep 16, 2021 at 09:43 AM, Roland Christen wrote:
You probably had corrosion on the pins of the Y cable and possibly on the motor box as well.
  This seems to be the most plausible explanation. It's odd that everything worked during bench testing and the first night at the site, then the problem surfaced and persisted after cycling the connectors, replacing the mount controller, etc., and finally went away without any actions which involved the Y cable connections. But I've seen enough strange failure modes involving old equipment and poor contacts to know that almost anything is possible.

  Are there any common connections through the Y cable, e.g., a signal ground pin which is connected to both motor assemblies? Poor contact at one pin which can affect both motor drives would fully explain the symptoms observed last week. (The mount is at one of our remote sites, so I can't readily pull the cable to see how it's wired.)
Runaways occur when the encoder signals don't reach the servo controller, so the controller thinks that the motor is not turning and supplies more and more voltage and current to turn the motor shaft. Of course, the motor shaft is turning, but without the encoder feedback, the controller runs open loop.
  A question about this. On more than one occasion when one or both axes were running away, pressing the stop button on the hand controller had no effect and it was only possible to stop the motors by pulling the power connection. Does the fact that the motors continued to be powered despite the stop operation point to another possible fault?

  Thanks for the details regarding the servo loops and hand controller interface.


Re: APPM - error

 

hmmm

i have used pinpoint for a year or so, and now ASTAP with APPM since the 1.9 release. I have not had any errors doing all sky modeling




On Thu, Sep 16, 2021 at 11:00 AM Sergei <sergei@...> wrote:
Hi Ray,

I'm also using ASTAP and get quite a few errors on plate solving points in APPM models. Failures also seem to occur very quickly - within a couple of seconds of APPM making a call to ASTAP. Is there a better solver you'd recommend that works more reliably with APPM? I use ASTAP from SGP as well and usually it's quite reliable there, but the sample size is much smaller of course.

Thank you for a terrific piece of software in APCC btw - couldn't imagine using my 1100-AE without it!

Sergei



--
Brian 



Brian Valente


Re: Dovelm162 springs too short or assembled wrong?

Woody Schlom
 

Marj,

I don't have this problem but I sure appreciate how AP is going about dealing with it.  You guys (and gals) are the best!

Woody 

On September 16, 2021 9:21:35 AM "Marj Christen" <marj@...> wrote:

Tom,

 

The assembly procedure and components have not changed for many years. Your is the first concern that I am aware of regarding this issue. I suspect that many users orient the plate so the clamps are down and gravity has assisted the clamp to move away from the center channel. When the clamps are down, you don’t have to reach over the scope to tighten the knobs.

 

Nevertheless, we have ordered springs that are longer than what we have used. Once we have tested them to be sure that they have the correct compression, we will send some to you.

 

I apologize for the inconvenience.

 

Clear Skies,

Marj Christen

Astro-Physics

11250 Forest Hills Road

Machesney Park, IL 61115

Phone: 815-282-1513

www.astro-physics.com

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Tom Blahovici
Sent: Wednesday, September 15, 2021 10:16 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?

 

That's interesting but the saddle is not new. Since I have to seen any other complaints in the past it must be something different now. What's AP going to do about this?
Tom



Re: APPM - error

Dean Jacobsen
 

Sergi, I have been using Platesolve 2 with SGP for APPM data collection for more than a year now without problem.  The only glitches have been when I forgot to change the image scale parameters in APPM when I changed cameras. 
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Re: APPM - error

ap@CaptivePhotons.com
 

Sergei wrote:

 

  • I'm also using ASTAP and get quite a few errors on plate solving points in APPM models. Failures also seem to occur very quickly - within a couple of seconds of APPM making a call to ASTAP. Is there a better solver you'd recommend that works more reliably with APPM? I use ASTAP from SGP as well and usually it's quite reliable there, but the sample size is much smaller of course.

    Thank you for a terrific piece of software in APCC btw - couldn't imagine using my 1100-AE without it!

I use ASTAP for NINA continually, and now use it for APPM (with NINA as a camera).  I have never had it give an error.  I have had it fail occasionally to find a solution, especially if you give it bad image scale, but never had it throw an error like that.   And I know a lot of other NINA users with similar experience.

 

That’s not to say it doesn’t, I do not doubt the reports… I am just curious what’s different about how people are using it through APPM?

 

Are those for whom it is failing using APPM to control the camera (as opposed to another software like TSX or NINA to control the camera)?  Could it be something about the FITS headers that variers depending on the capture program?

 

Speculation purely.

But from what I recall the list of other solvers includes some hefty associated software, e.g. to use imagelink from Bisque you need TSX, which is a pretty massive set of software for just a solver.   ASTAP is the lean version.

 

Linwood


Re: APPM - error

Sergei
 

Hi Ray,

I'm also using ASTAP and get quite a few errors on plate solving points in APPM models. Failures also seem to occur very quickly - within a couple of seconds of APPM making a call to ASTAP. Is there a better solver you'd recommend that works more reliably with APPM? I use ASTAP from SGP as well and usually it's quite reliable there, but the sample size is much smaller of course.

Thank you for a terrific piece of software in APCC btw - couldn't imagine using my 1100-AE without it!

Sergei


Re: #APCC #APCC

Rouz
 

Hi Roland,

Yes that's what I thought, its is fine balanced.

I remember with my old Losmandy mounts bias was usually better but I feel no backlash with these CP4 worms. That was one of the main reasons I went for the CP4!


Re: #APCC #APCC

Rouz
 

On Thu, Sep 16, 2021 at 04:50 AM, Ray Gralak wrote:

Hi Ray, 

Ok will try an all-sky model soon.

I don't have much in the south but even that with the 3 x 3 degree point spacing ends up with 1500 points which is not feasible.

I remember you mentioned something with 400 points should work well.  I'll adjust the spacing to get something in that ballpark.

I'm assuming its more important to have the Ra points closer together than the Dec?

-Rouz





Re: Dovelm162 springs too short or assembled wrong?

Tom Blahovici
 

Thanks Marj, 
The nice thing about the knobs up is that there is a grouve that the dovetail sites in solidly and that allows you to pivot the dovetail into place. When the knobs are down this is not the case. Its loads easier when the knobs are up.
I don't have this issue with the ap600e and it's saddle at all. 
Best regards, Tom


Re: Dovelm162 springs too short or assembled wrong?

 

I’ll do that.

 

Clear Skies,

Marj Christen

Astro-Physics

11250 Forest Hills Road

Machesney Park, IL 61115

Phone: 815-282-1513

www.astro-physics.com

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of ap@...
Sent: Thursday, September 16, 2021 11:29 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?

 

Marj Christen wrote:

 

  • The assembly procedure and components have not changed for many years. Your is the first concern that I am aware of regarding this issue. I suspect that many users orient the plate so the clamps are down and gravity has assisted the clamp to move away from the center channel. When the clamps are down, you don’t have to reach over the scope to tighten the knobs.

 

I tend to load and unload from Park 3, so it’s pulling them out by finger, and hoping the dovetail doesn’t hit them during insertion and push them back.  But it’s a very minor issue for me.  In removing the dovetail it’s moot.  Nonetheless…

 

  • Nevertheless, we have ordered springs that are longer than what we have used. Once we have tested them to be sure that they have the correct compression, we will send some to you.

 

Could you put me down as well?  I’m happy to purchase them.   It’s a minor nuisance but also looks like a minor cost to solve it.

 

Linwood Ferguson

 


Re: #APCC #APCC

Roland Christen
 


Perhaps a slight bias might ensure the gears are meshed better
No, false. Gears do not mesh better with an off-balance bias.

Rolando


-----Original Message-----
From: Rouz <rbidshahri@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 16, 2021 2:39 am
Subject: Re: [ap-gto] #APCC

Yes I believe so. Disengaged the worms and fine tuned the balance in all axis.

I'm wondering if that actually is the best thing to do? Perhaps a slight bias might ensure the gears are meshed better, but these CP4 do have spring loaded worms.

-Rouz

--
Roland Christen
Astro-Physics


Re: Erratic behavior, possibly contact related

Roland Christen
 


So at best, there was an fault somewhere which had cleared coincidentally when the hand controller was reconnected.
You probably had corrosion on the pins of the Y cable and possibly on the motor box as well. Inserting the cable a couple of times might have wiped the pins somewhat clean, but there might still be a poor contact. You might want to clean all the pins of the cable and mating connectors with a contact cleaner and perhaps add some anti-corrosion lube to them to prevent problems in the future. Pins can deteriorate over time, especially if they are subjected to high humidity.

In these mounts, runaways are almost always caused by poor connection between the motor encoder and the CP servo controller. Reason is that there is very low level signal with almost no current and fairly low voltage being run on these signal lines. Therefore if there is no current to speak of, the corrosion acts as a fairly good insulator. By contrast, the two power connections to the motors carry a fair amount of current, so the corrosion is easily bridged by the voltage present on those pins.

Runaways occur when the encoder signals don't reach the servo controller, so the controller thinks that the motor is not turning and supplies more and more voltage and current to turn the motor shaft. Of course, the motor shaft is turning, but without the encoder feedback, the controller runs open loop.

Rolando


-----Original Message-----
From: M. Collins <aegle_observatory@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 16, 2021 12:36 am
Subject: Re: [ap-gto] Erratic behavior, possibly contact related

  As I noted, the mount has operated without any errors over many hours in the past week, so at the moment there is nothing to investigate. Prior to exchanging any of the electronic components, I did check to see that all of the connections were sound, including the three associated with the Y cable. While I didn't remove the shells to inspect the soldered connections to the pins on the three connectors, the cable shows no sign of damage and it seems likely that an intermittent contact between the motor controller and motors would have resurfaced by now. So at best, there was an fault somewhere which had cleared coincidentally when the hand controller was reconnected.

  Also, the RA axis exhibited the same erratic behavior as reported for the declination axis when I was initially investigating last Wednesday, running away or rapidly stopping/starting during a slew. Whatever was causing problems appears to have been common to both axes. Perhaps a cable fault could cause such a thing. No other single element (other than the hand controller, which you've ruled out) was in place each time failures occurred. (And to be clear, only the hand controller, Y cable and power were connected to either the CP2 or CP3 during the initial investigation. The USB/serial translator was not connected until after the mount had operated using the hand controller for more than half an hour after the problems had disappeared.)

  If we see further issues, I'll start by checking the connections through the Y cable.

--
Roland Christen
Astro-Physics


Re: Dovelm162 springs too short or assembled wrong?

ap@CaptivePhotons.com
 

Marj Christen wrote:

 

  • The assembly procedure and components have not changed for many years. Your is the first concern that I am aware of regarding this issue. I suspect that many users orient the plate so the clamps are down and gravity has assisted the clamp to move away from the center channel. When the clamps are down, you don’t have to reach over the scope to tighten the knobs.

 

I tend to load and unload from Park 3, so it’s pulling them out by finger, and hoping the dovetail doesn’t hit them during insertion and push them back.  But it’s a very minor issue for me.  In removing the dovetail it’s moot.  Nonetheless…

 

  • Nevertheless, we have ordered springs that are longer than what we have used. Once we have tested them to be sure that they have the correct compression, we will send some to you.

 

Could you put me down as well?  I’m happy to purchase them.   It’s a minor nuisance but also looks like a minor cost to solve it.

 

Linwood Ferguson

 


Re: Dovelm162 springs too short or assembled wrong?

 

Tom,

 

The assembly procedure and components have not changed for many years. Your is the first concern that I am aware of regarding this issue. I suspect that many users orient the plate so the clamps are down and gravity has assisted the clamp to move away from the center channel. When the clamps are down, you don’t have to reach over the scope to tighten the knobs.

 

Nevertheless, we have ordered springs that are longer than what we have used. Once we have tested them to be sure that they have the correct compression, we will send some to you.

 

I apologize for the inconvenience.

 

Clear Skies,

Marj Christen

Astro-Physics

11250 Forest Hills Road

Machesney Park, IL 61115

Phone: 815-282-1513

www.astro-physics.com

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Tom Blahovici
Sent: Wednesday, September 15, 2021 10:16 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Dovelm162 springs too short or assembled wrong?

 

That's interesting but the saddle is not new. Since I have to seen any other complaints in the past it must be something different now. What's AP going to do about this?
Tom


Re: #APCC #APCC

Bill Long
 

Well its probably not related to what you are seeing, but the freshest guidance from AP has been to neutral balance. I made that change on my Mach 2 + AG 12.5" rig, and it definitely guided much better as a result. 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Rouz <rbidshahri@...>
Sent: Thursday, September 16, 2021 12:39 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] #APCC
 
Yes I believe so. Disengaged the worms and fine tuned the balance in all axis.

I'm wondering if that actually is the best thing to do? Perhaps a slight bias might ensure the gears are meshed better, but these CP4 do have spring loaded worms.

-Rouz

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