Re: Suddendly developed backlash on the Alt
Was this backlash from an Obsession Classic or Ultra Compact??
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Re: Suddendly developed backlash on the Alt
Note that the spiral search function is really tightly designed and coded.... and that it does take backlash compensation in to account. So indeed if you don't adjust the backlash compensation (the users responsibility as it has to be done in situ) you'll see less than an ideal pattern.
Gary Myers
------ Original Message ------
Date 11/3/2023 2:38:33 PM
Subject Re: [ServoCAT] Suddendly developed backlash on the Alt
Mickey, ? Good to know.? BTW, a quick way to test for backlash is the ServoCAT spiral search where it becomes obvious. ? Richard
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Re: Suddendly developed backlash on the Alt
Mickey, ? Good to know.? BTW, a quick way to test for backlash is the ServoCAT spiral search where it becomes obvious. ? Richard
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Re: Suddendly developed backlash on the Alt
As it turns out my slippage was not the set screw (apparently Mike Zammit) uses blue loctite. The problem was silicone over spray from when I cleaned the Teflon pads.?
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On Nov 3, 2023, at 11:57 AM, wilson_buster <retsub@...> wrote:
?A couple more thoughts about set screws. It’s good to have a flat area for the set screws to make up to. Can’t remember the name but some set screws had serrations on the tip for a better grip. In previous shop work before Loctite came on the market we used double set screws if needed and there was enough thread depth to do so. BW?
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Re: Suddendly developed backlash on the Alt
A couple more thoughts about set screws. It’s good to have a flat area for the set screws to make up to. Can’t remember the name but some set screws had serrations on the tip for a better grip. In previous shop work before Loctite came on the market we used double set screws if needed and there was enough thread depth to do so. BW?
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Re: Suddendly developed backlash on the Alt
one more note on the subject: of necessity the set screws, when shipped, are dry (i.e. no locktite) of course since the roller is separate from the drive shaft. It has to be placed in situ. And I know a number of - let me state that a different way, only a few telescope makers actually put locktite on the set screw when they do place the roller on the shaft/scope.?
So be aware: there's a good chance if you've not done it - there's none there!?
Gary?
and NEVER use red locktite on any of the hardware! I used it internally on the gears/pulleys to ensure they wouldn't slip - but anything external should not use red. It is for the most part a PERMANENT bonding agent. I had one case where a user used it on an AZ roller - LOTS of it. I needed to work on something for him and to do that I needed to remove the roller. I could not, even with heat, get it off. I had to saw the roller/shaft!?
------ Original Message ------
Date 11/2/2023 11:25:21 AM
Subject Re: [ServoCAT] Suddendly developed backlash on the Alt
NOTE: Blue locktite has a quite low viscosity. Almost like water. And the tapped hole on the drive rollers is long. My recommendation, what I do myself, is I put locktite on the set screw (NEVER in the hole) and screw it in - remove it and repeat a number of times. This helps to ensure that the locktite is actually ON the set screw/internal threads at the bottom of its travels. If you do it once you're almost guaranteed to have none on it when its finally in place. Of course the bigger the roller - the more this is the case.
Gary Myers
------ Original Message ------
Date 11/2/2023 11:14:41 AM
Subject Re: [ServoCAT] Suddendly developed backlash on the Alt
I find that screw constantly loosens particularly on long drives across country.? Even blue Loctite did not keep it.? But that is the best I can do.? So I try to remember to test it by hand trying to rock it back an forth on the shaft.
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Re: Suddendly developed backlash on the Alt
NOTE: Blue locktite has a quite low viscosity. Almost like water. And the tapped hole on the drive rollers is long. My recommendation, what I do myself, is I put locktite on the set screw (NEVER in the hole) and screw it in - remove it and repeat a number of times. This helps to ensure that the locktite is actually ON the set screw/internal threads at the bottom of its travels. If you do it once you're almost guaranteed to have none on it when its finally in place. Of course the bigger the roller - the more this is the case.
Gary Myers
------ Original Message ------
Date 11/2/2023 11:14:41 AM
Subject Re: [ServoCAT] Suddendly developed backlash on the Alt
I find that screw constantly loosens particularly on long drives across country.? Even blue Loctite did not keep it.? But that is the best I can do.? So I try to remember to test it by hand trying to rock it back an forth on the shaft.
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Re: Suddendly developed backlash on the Alt
I find that screw constantly loosens particularly on long drives across country.? Even blue Loctite did not keep it.? But that is the best I can do.? So I try to remember to test it by hand trying to rock it back an forth on the shaft.
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Re: Suddendly developed backlash on the Alt
Richard, It was 28 degrees last night and I had the same problem, thought it was the cold and will check it out in the daylight today. Thank you
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On Nov 1, 2023, at 8:47 PM, Richard <rmille64@...> wrote:
?All,
My Alt movement just developed about 15 degrees of backlash.
I removed the brass "spool" to inspect the belt driven shaft and confirmed the shaft also has the backlash--meaning the brass spool set screw was properly set on the shaft.??
The belt that drives the shaft does not have any backlash.? So...I think that means the shaft that goes into the belt driven sprocket must have some issue.?
Any advice?
Richard?
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Re: Suddendly developed backlash on the Alt
Found the issue.? The set screw on the sprocket (under the belt) was loose by more than one turn.
Tightened up that set screw and restored operation.
Will put some locktite blue on it tomorrow in the daylight.
Richard
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Suddendly developed backlash on the Alt
All,
My Alt movement just developed about 15 degrees of backlash.
I removed the brass "spool" to inspect the belt driven shaft and confirmed the shaft also has the backlash--meaning the brass spool set screw was properly set on the shaft.??
The belt that drives the shaft does not have any backlash.? So...I think that means the shaft that goes into the belt driven sprocket must have some issue.?
Any advice?
Richard?
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Re: ServoCAT on my DOB enables Astro Photos--M17 with stars removed.
Mike, ? 100 seconds total (with the Optolong LeNhance filter to deal with my streetlamp). ? Sony IMX287 is the sensor in this tiny camera. ? I usually do mosaics since the field of view is so tiny.? About like a 10mm eyepiece or smaller. ? Richard ?
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From: [email protected] < [email protected]> On Behalf Of Mike Sent: Tuesday, October 31, 2023 1:27 PM To: [email protected]Subject: Re: [ServoCAT] ServoCAT on my DOB enables Astro Photos--M17 with stars removed. ? Very nice image. Did I understand correctly it is a stack with total time of 100seconds?? What chip does that camera have? ?All,
ServoCAT enabled me to take this photo from my recliner using 10 second exposures for 10 stacked frames on my UC18 and DS287C.
Pixinsight was used to remove the stars and process the image with a bit of Gimp adjustments.
Can't wait for the next Gen of the ServoCAT. <M17_230922220209_GraXpert_starless.jpg>
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Re: ServoCAT on my DOB enables Astro Photos--M17 with stars removed.
Hi Richard, Very nice image. Did I understand correctly it is a stack with total time of 100seconds?? What chip does that camera have? Thanks Mike
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On Oct 31, 2023, at 1:06 PM, Richard <rmille64@...> wrote:
?All, ServoCAT enabled me to take this photo from my recliner using 10 second exposures for 10 stacked frames on my UC18 and DS287C. Pixinsight was used to remove the stars and process the image with a bit of Gimp adjustments. Can't wait for the next Gen of the ServoCAT. <M17_230922220209_GraXpert_starless.jpg>
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ServoCAT on my DOB enables Astro Photos--M17 with stars removed.
All, ServoCAT enabled me to take this photo from my recliner using 10 second exposures for 10 stacked frames on my UC18 and DS287C. Pixinsight was used to remove the stars and process the image with a bit of Gimp adjustments. Can't wait for the next Gen of the ServoCAT. 
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
Jordan,
?
Super! Thanks for getting back to us. I'm glad things worked out.?
?
I've seen this before - Windows has a mind of its own. It is rather unusual but I have seen cases where changing to a different computer causes it to work. it might be - just a grab at something here - it might be that the version of the driver for the USB was not up to date (one of the questions I had asked) ... but again I've seen cases where things appeared all correct and yet it took going to a different computer to 'fix it'.?
?
The ServoCAT has nothing it can do in these situations. Know that the comms are very basic - there's nothing high level going on here - just simple data transfer stuff.?
?
One final note - if you were plugged into a USB3 port (blue internal color for the jack) ... my bad for not telling you to move it to the older generation plug. It has been known to work on the USB3 jack but I've seen more problems with its use than with the older gen jacks.?
?
Gary Myers
StellarCAT
?
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
I wanted to leave a message on this thread saying that I resolved this issue by using an older laptop that still had Windows 10 on it. After the upgrade all the features of ServoCAT-Sky and SCU work great still on the Windows 11 computer so I only needed the older laptop to run the RFU to upgrade the firmware. It was also nice to have the box open to blow out all the dust and spiderwebs off the PCB in the servocat box. Happy to report I'm now off and running!
Cheers,
Jordan
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
Re using the SCU on an older firmware ServoCAT. I stand corrected... indeed it WILL connect and does show the current ALT/AZ location (assuming there is a DSC connected). It will not, of course, download any parameters beyond that, that takes version 7.0C of the firmware. My apologies for misremembering this. Apparently, Pete (the creator of the SCU program) and I decided to add support for older firmware by using the existing planetarium program commands to get something back - confirming that there is a connection. Apologies to Jordan for misspeaking... meanwhile we're still working on the fix for his upgrade issue.?
Gary?
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
Unfortunately my test stand doesn't exist anymore - everything was sent off to Bill.?
But I'm 98% sure what I said is correct. I don't remember having Pete add any coms to a pre-7.0 ServoCAT. The code is only in version 61B (extremely limited distribution - the previous, before 7.0C version was 6.0E) and after.?
Now that stated - its been a while since I ran a non-latest CAT on the SCU.... its possible I gave Pete some general PC commands (ones that a planetarium program would have used) to insert... but I seriously don't remember doing that. We are now talking mid 2014 though.?
g.
------ Original Message ------
Date 10/21/2023 11:35:58 AM
Subject Re: [ServoCAT] Firmware Upgrade Error in RFU: "Could not open serial port."
It does "Connect" in SCU, and reads out the current Alt/AZ, but no other info. When I get the port nunber wrong, it says can't connect, when I get it right, it gives the legacy error. Wouldn't this mean I've got the "correct" port?
-Jordan
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
It does "Connect" in SCU, and reads out the current Alt/AZ, but no other info. When I get the port nunber wrong, it says can't connect, when I get it right, it gives the legacy error. Wouldn't this mean I've got the "correct" port?
-Jordan
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Re: Firmware Upgrade Error in RFU: "Could not open serial port."
Just as a note: The SCU does NOT connect if you are using older version firmware! There's nothing in the ServoCAT to "look" for it!! It is only with the latest version firmware that you get a connection. And since you've not, yet, upgraded, you don't have the latest version firmware. Thus the "proof" that you have the right com port at least vis a vis the SCU, isn't there.?
Gary?
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Dale Eason
Mike
Jordan Ragsdale
