Loud Clicking noise from RA motor #EXOS2 #VIDEO


Wes Mcdonald
 

Symon

The worm is retained by a collet which screws into the end of the worm block.  This thing puts a pre-load on the worm bearings, and is often overtightened by the factory.  It makes things ratchety on rotation of the worm.  You can try backing this off a bit.  The collet is that threaded ring with the two notches.  What you would do is remove the worm block and make the collet adjustment until the worm moves smoothly with no axial play.  

If you were to try this, be aware the collet is kida fragile and is easy to deform, so if you don't have a tool that can pan those slots and engage correctly you can damage the collet.  Ordinarily ES would allow you to try to make this adjustment yourself, but you need to get them to clear this  to you directly, given the opportunity to foul up the collet.  BTW I ruined one of mine.

But I have to confess I don't believe anyone has had the click symptom you have from the overtightening.  Bob's idea that there is something wrong with the worm itself seems likely.

Wes.


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--
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


Symon@...
 

Thanks, I was hoping it would be something straightforward as hitting the plastic post you mentioned but it is definitely inside the mechanism connected to the large gear. it feels like when the bottom bracket on a bike has given up. I've compared it to the DEC axis which is really smooth. I'm a bit stuck now - it's brand new out of the box. I'm all for maintaining and fixing but would like to start from Ok. It really sticks - thus the click. I'm can't imagine it tracks very smoothly. Hopefully support can get it sorted.


 

Symon,
 
One of the nice things about these mounts is that they don't have a lot of moving parts and are easy to work on and keep in adjustment.
 
The simplest explanation for your click would have been the large pulley scraping on the nearby plastic post that receives the housing's screw.  Easy to fix in that case, but unfortunately it sounds like that's not it.  Perhaps an unhappy worm block bearing or a ding in the worm itself?  Best you can do is just keep going and investigate...
 
- Bob
 
 
 
--
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


Symon@...
 

Ok so can make it do it manually with no power. If I turn the larger gear with my finger it is smooth and then occasionally goes through a point of high friction - as if it is catching on something inside - that's when the click happens when you push through.


Symon@...
 

Ok, support gave me the ok to take the case off. I'll see what is going on inside.

Symon


Symon@...
 

Thanks all, that's a great pdf by the way. 


Chris Welliver <chriswelliver@...>
 

The second time I tightened up the backlash in
my #exos2 mount I noticed the set screws in the
R.A. axis belt gears were not tight and one, don’t remember which, had slipped a little on the shaft.
I would definitely check those and if they’re not tight, put a dab of medium Loc-Tite on them.


--
Chris Welliver
EXOS2 mount
ES 102EDAPO Carbon Fiber
ZWO asi178mc
ZWO asi120mm
PrimaLuceLab Sesto Senso focuser


Symon@...
 

Hi many thanks, thought it sounded odd. I've just put in a support request as just got the mount. Not sure I want to strip it just yet in case I do something to the warranty.

Symon


 

What Wes said...   The motor whirr is normal, but the ticking is not.  Should be easy to remedy, though.
 


On Mon, Sep 21, 2020, at 10:04, Wes Mcdonald wrote:
Symon 

No that is not right.   Something is slipping or some thing.  

1.  Suggest you pull it apart and check the set screws that hold the pulleys on the shafts of the worm and the motor.  If you look in the files section of the Main subgroup you will find a document by bob hoskins that outlines how to get thing s apart and do adjustments.  Lots of stuff in there so just do the things related to opening the motor case to gain access to the pulley set screws and maybe make sure the belt is not snagging in the case .  

Perhaps others have resolved an issue like this?  If so chime in!

Wes



On Mon, Sep 21, 2020 at 9:30 AM <Symon@...> wrote:
Hi I have just received my EXOS2-PMC8. It makes a quite pronounced clicking noise from the RA motor - mp4 attached. You can hear it at the start of the attached movie file. Is this normal - it is with an empty mount, i.e. no scope, just for testing but it makes the noise at all times.

Many thanks,

Symon












--
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


--
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


Wes Mcdonald
 

Symon 

No that is not right.   Something is slipping or some thing.  

1.  Suggest you pull it apart and check the set screws that hold the pulleys on the shafts of the worm and the motor.  If you look in the files section of the Main subgroup you will find a document by bob hoskins that outlines how to get thing s apart and do adjustments.  Lots of stuff in there so just do the things related to opening the motor case to gain access to the pulley set screws and maybe make sure the belt is not snagging in the case .  

Perhaps others have resolved an issue like this?  If so chime in!

Wes



On Mon, Sep 21, 2020 at 9:30 AM <Symon@...> wrote:
Hi I have just received my EXOS2-PMC8. It makes a quite pronounced clicking noise from the RA motor - mp4 attached. You can hear it at the start of the attached movie file. Is this normal - it is with an empty mount, i.e. no scope, just for testing but it makes the noise at all times.

Many thanks,

Symon










--
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


Symon@...
 

Hi I have just received my EXOS2-PMC8. It makes a quite pronounced clicking noise from the RA motor - mp4 attached. You can hear it at the start of the attached movie file. Is this normal - it is with an empty mount, i.e. no scope, just for testing but it makes the noise at all times.

Many thanks,

Symon