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Mesu mount (all versions) owner's thread


Jonk

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Help!  Turned on the mount (Mk 2) last night and the RA started slewing immediately until it suddenly stopped (some encoder limit??)  It does this every time if I manually turn the RA back to its usual park position.  The controller LED 1 blinks and the app shows "blinky" mode.

The servo obviously works, and perhaps the encoder, since it does come to a stop.  Perhaps a Sitech hardware issue?

Any advice / suggestions for further diagnostics welcomed.

Are new Sitechs easy to acquire?  The thought of having to ship something to Europe is dire in this post-Brexit world.

Thanks in advance.

Tony

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I 2nd that point. Remove all unnecessary connections and see what happens.

Moisture may be at play here.

If no joy and the controller moves the mount without any inout from a button or pc connection, visit the sitech groups.io forum and ask there, someone will be able to talk it through in a bit more detail.

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@whipdry @Jonk

Thanks both for the suggestions.  I’ve just given it a go and it shows the same symptoms without a handset attached. 

I’ve also posted on the groups.io forum, so we’ll see if that brings any joy.

Appreciate the help anyway. 

Tony

PS: this is after having put the controller itself in the airing cupboard for a while to see if moisture there was the issue!

Edited by AKB
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6 hours ago, AKB said:

@whipdry @Jonk

I’ve also posted on the groups.io forum, so we’ll see if that brings any joy.

I've just had a look and cannot see it on there - did you go to the right one?

https://groups.io/g/Sitechservo/topics

**EDIT** I have found it on the Mesu-mount page. You are better off using the link above to be honest, as the Mesu page isn't that busy, and is probably only good for Mesu related things.

Yours is definitely a Sitech controller issue and nothing to do with the mount itself.

Edited by Jonk
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Thought I'd try to offer a little more help, here's a list of things that I would try & why... 

1/ Maybe your controller config file has corrupted; reload your backup .cfg file into the controller...

Open Sitech & goto Config tab, click on Change Config! button, goto Misc. tab, click on Load Backup Config File

Mine is in; ProgramData/SiTech/SiTechExe/SiTech.cfg   Click on to load backup, go through shutdown & restart & try connecting your mount again... doesn't help try... 

2/ To check if the controller output forthe  motor/encoders swap both the encoder & motor cables, as you already know motor cables is an easy swap... on my mount the encoder cables have a connector that rests inside the wedge, just swap RA & Dec on one side of this... perhaps colour tape (mark) the RA before making this change! 

Following these suggestions should give you a better indication of the where the problem is. 

If you haven't already tried the above please post your findings.  

Fingers crossed for a corrupted config file! 

 

Peter 

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5 hours ago, whipdry said:

Thought I'd try to offer a little more help,

Much appreciated, Peter.

I will give #1 a go tomorrow.  I have tried #2 already, swapping both the drive and the encoders with the connectors you mentiond.  The other axis slews when I do that.

I've also sent a message to Lucas Mesu to see how familiar he might be with this problem.

Will let you know how the config files goes...

Thanks again,  Tony.

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That's a pity, guess it's time to check your cables for damage & do a continuity test if you haven't already? The RJ45 male connectors are easily damaged, all it takes is a small indentation in the plastic that separates the contact strips... I once had runaway on an LX200 fork mount for that reason! 

Just a thought perhaps you could look inside the Sitech case... not sure if a a small creature could short the curcuit board! 

Has Lucas offered any advice? 

 

Peter 

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  • 2 weeks later...
On 14/01/2023 at 13:13, AKB said:

Help!  Turned on the mount (Mk 2) last night and the RA started slewing immediately until it suddenly stopped (some encoder limit??)  It does this every time if I manually turn the RA back to its usual park position.  The controller LED 1 blinks and the app shows "blinky" mode.

The servo obviously works, and perhaps the encoder, since it does come to a stop.  Perhaps a Sitech hardware issue?

Any advice / suggestions for further diagnostics welcomed.

Are new Sitechs easy to acquire?  The thought of having to ship something to Europe is dire in this post-Brexit world.

Thanks in advance.

Tony

Hi Tony,

Just wondering if you managed to get your Mesu mount up & running again... perhaps you could give an update? 

 

Peter 

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12 hours ago, whipdry said:

Just wondering if you managed to get your Mesu mount up & running again... perhaps you could give an update? 

 

Have done all the diagnostics I can, and I think that I’ve narrowed it down to the controller itself.  I’ve exchanged emails with Lucas Mesu and I’m planning on sending him the SiTech box to check things out.  Complicated by the fact that Royal Mail isn’t sending parcels abroad at the moment.  Other couriers seem outrageously expensive…?  Lucas tells me that he’s never seen one go wrong before…

In the meantime, I’ve ripped all the kit out of the observatory and replaced the mount with my Avalon M-Uno and just my C9.25 Hyperstar for EEVA use.  Tonight’s the first one I could see any stars, but I had to go out to visit friends, so haven’t yet done a PA on the setup.  I doubt that I’ll get the Mesu running for the rest of this season, but perhaps I’m just being pessimistic. 

Thanks for asking!

Tony

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On 14/01/2023 at 15:13, AKB said:

Help!  Turned on the mount (Mk 2) last night and the RA started slewing immediately until it suddenly stopped (some encoder limit??)  It does this every time if I manually turn the RA back to its usual park position.  The controller LED 1 blinks and the app shows "blinky" mode.

The servo obviously works, and perhaps the encoder, since it does come to a stop.  Perhaps a Sitech hardware issue?

Any advice / suggestions for further diagnostics welcomed.

Are new Sitechs easy to acquire?  The thought of having to ship something to Europe is dire in this post-Brexit world.

Thanks in advance.

Tony

I did have a similar problem long ago. I my case it was a slightly loose wire connection on  the controller. This made the scope start moving on its own, and go blinky. Also be sure you are correctly initializing the mount. A bad init can cause lots of problems... 

Simple routine:

  • power up
  • unpark the mount
  • the tracking starts
  • do a photo init 
  • take pictures all night
  • do a photo init before parking
  • park the scope 
  • power off

All this implies you made correct settings in the software - sitech.exe

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5 hours ago, dan_adi said:

I did have a similar problem long ago. I my case it was a slightly loose wire connection on  the controller. This made the scope start moving on its own, and go blinky. Also be sure you are correctly initializing the mount. A bad init can cause lots of problems... 

Good to know.  Your procedure is very much what I had been doing for the last 18 months, until this happened.

What, then, should be required to “correctly initialise the mount”, seeing as its blinky now?

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On 04/02/2023 at 00:39, AKB said:

Good to know.  Your procedure is very much what I had been doing for the last 18 months, until this happened.

What, then, should be required to “correctly initialise the mount”, seeing as its blinky now?

Hello,

Did you manage to check the cable contacts to the controller?

To initialize the mount you need to unpark, and do a photo init from sitech.exe. the init pop up windows will show up.before you click ok, make sure looking east/west is selected appropriately. Also do not pick a region on the sky below your horizon file for an init.

On the sitech.exe forum you will get more help on from Don or Dan. They know their stuff.

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I've done as much checking on the cables as I can.  Even took the lid off the controller to check the connectors there.  There's nothing wrong I can find with the cables, so I am left with the conclusion that it must be the RA channel of the controller.  I will be send it to Lucas to check.

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  • 1 month later...
On 23/06/2022 at 01:58, astronomer2002 said:

Olly,

 

Thankyou for your offer, I was beginning to think there's no-one else out there running the Servocat/ArgoNavis control mechanism on a Mesu mount. What I need as well is the Servocat parameters which you can get from the Servocat setup program.

I had no difficulty getting Stellarium to talk to the ArgoNavis, after making up the correct serial cable and setting the com values the same at both ends. It is the only one I have tried, but I can say it does work.

 

Here's a page from the Servocat manual below:-

The encoder resolution is from the motors used, and seems to always be 2000. The gear ratio I got from Lucas, and he thought it was 2000 for the original Mesu.

I have no idea what the other values should be for the Mesu but the mount slews at a reasonable rate so is probably about right. The jog rate on mine seems slow. I don't know what to set for the accelerate/decelerate rate and wonder if my issue lies there.

The goto's would work fine if they actually ended up where the ArgoNavis told the mount to move to. Press the goto button once and the mount gets closer than a degree to the object before announcing the move completed successfully.  Unfortunately the mount requires the Servocat controller Goto but to be pressed again to encourage the mount to move closer (which it does).

 

 

image.thumb.png.5defb9f444e0ae1e253455a2d3580580.png

Hello, 

I am not sure if you have already addressed it. From my research I have found that a Mesu-mk1 usually has 1:2000 gear ratios (I think I have heard also of some examples with a 1:2800 ratio). The encoders at least in mine are 4,000 steps in the RA (HEDM-5500-B02) and 2,000 steps in the DEC (HEDS-5540-A02), for a total of around 8,000,000 and 4,000,000 ticks in the RA / DEC resp. Notice that for the encoders we use the CPR which is 4xPPR.

My second-hand mesu-200 which came with Argonavis/servocat has been converted to OnStepX (it still needs some fine-tuning though). Right now OnStepX is configured for 22229 ticks/degree and 11111 ticks/degree in the RA/DEC resp.

 

Edited by Panagiotis Papadakos
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