Topics

iEXOS-100 worm gear jamming/crunching? #iEXOS-100 #FIRMWARE #goto


Matt Hallett
 

Ran a slewing test on my iEXOS-100 last night (relating to my alignment issues in another thread).

Gears started to make an unpleasant crunching noise, so took off the plastic housing to see what was going on.

Video is here - https://youtu.be/kPROlB3gjSc

Should I be worried?

---------------------

Mount: iexos-100 with PMC-8
Scopes: Startravel 102
Camera:  Nikon D7500
Software: Deep Sky Stacker, Siril, Photoshop


Yorksman
 

Are you powering it with mains or batteries? I found some batteries did not supply enough power and those that did ran low quickly and again gave the same problems. All this was fixed when I ran it from a mains supply.


Matt Hallett
 

Interesting.

It's running off batteries at the moment. Maybe Santa will bring me a mains supply!

---------------------

Mount: iexos-100 with PMC-8
Scopes: Startravel 102
Camera:  Nikon D7500
Software: Deep Sky Stacker, Siril, Photoshop


Ian Morison
 

Hi Matt,
    I am using a 22 ampere hour golf buggy battery and have had no problems with my mount.
Cheers,

Ian

Virus-free. www.avast.com


On Fri, Dec 11, 2020 at 9:56 AM Matt Hallett <hello.matthallett@...> wrote:
Interesting.

It's running off batteries at the moment. Maybe Santa will bring me a mains supply!

---------------------

Mount: iexos-100 with PMC-8
Scopes: Startravel 102
Camera:  Nikon D7500
Software: Deep Sky Stacker, Siril, Photoshop


Wes Mcdonald
 

Matt

Your mount bound where the thing stalled.   The mesh of the worm and wheel gear is too tight.  You need to adjust it.   

This video shows how 


--
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


Matt Hallett
 

Hi Wes,

Just to be clear, is the bit I would adjust relating to the video at 5:56 (where he loosens/tightens the worm gear shaft with a dime, or the adjustment he goes through at 3:49 with the 3mm and 2mm hex keys?

I don't want to go twisting the wrong bolts!

---------------------

Mount: iexos-100 with PMC-8
Scopes: Startravel 102
Camera:  Nikon D7500
Software: Deep Sky Stacker, Siril, Photoshop


Wes Mcdonald
 

You probably need to do the one at 3:49.  And you have to manually rotate the wheel 360 degrees to see where it binds and make the mesh just tight enough.   You will have to find the happy medium where the mesh is as tight as it can be without binding at the two (usually) high points (or one) and is not too lose at the low points.   It’s a balancing act.

The second adjustment is also sometimes necessary if there is end play in the worm.   This allows the work to move back and forth along its axis instead of forcing the wheel to turn.  You can observe this when you turn the wheel pulley by hand to where it is moving the wheel in on direction and then reverse the direction while observing the worm movement. It should not translate along its axis.   If it does then do the dime adjustment.    

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


Joe Izen
 

Wes,
Is there a video that shows how to adjust to reduce/eliminate backlash on the declination axis? The RA video mentions it can be done, but doesn’t show how.
Thanks
Joe

On Dec 11, 2020, at 6:30 AM, Wes Mcdonald via groups.io <wesmcd6@...> wrote:

Your mount bound where the thing stalled.   The mesh of the worm and wheel gear is too tight.  You need to adjust it.   

This video shows how 



Doug Walker
 

Read all the comments. Sometimes the adjustment with the dime can't be done (it's locked in place.) so you loosen the screw on the back and adjust it there.

On 12/11/2020 7:57 AM, Wes Mcdonald wrote:
You probably need to do the one at 3:49.  And you have to manually rotate the wheel 360 degrees to see where it binds and make the mesh just tight enough.   You will have to find the happy medium where the mesh is as tight as it can be without binding at the two (usually) high points (or one) and is not too lose at the low points.   It’s a balancing act.
The second adjustment is also sometimes necessary if there is end play in the worm.   This allows the work to move back and forth along its axis instead of forcing the wheel to turn.  You can observe this when you turn the wheel pulley by hand to where it is moving the wheel in on direction and then reverse the direction while observing the worm movement. It should not translate along its axis.   If it does then do the dime adjustment.
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
--
Explore Scientific iEXOS-100
Canon T1i (no mod)
Canon 18-55mm zoom lens
Canon 75-300mm zoom lens
Astromania 60mm guidescope
ZWO ASI 120MC-S
Lenovo m93 / Win10Pro
NINA, DSS, SiriL, GIMP, Phd2


Don Ivie
 

So when the RA moves east it starts to grind. West is no problem.

Pic shows the position where the grinding starts. How do I "balance" this?


Wes Mcdonald
 

Don

I presume you are balanced in RA?  If you are very west heavy you could be stalling the motors when moving East

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


Don Ivie
 

Yes, perfectly balanced. I also tried with no load. It got better but still grinds rocks around the same position. 


Wes Mcdonald
 

Don

It has bind.  Do the adjustment.  Not backlash but bind.  It should bind when you open it up and turn it by hand.  You can feel it.

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


Don Ivie
 

Is that the part and the end of the video? With the dime?


Wes Mcdonald
 

No. The bind comes from the pressure the worm places on the wheel.  Take a look at Bob Hoskins document in the files section of the main sub group (I think, maybe the mounts).  It addresses adjusting the mesh (and other things) in the exos2.  Read it for the sense of what you are trying to do.   Then apply the disassembly described in the video with the bits that allow you to adjust the mesh pressure.     I am not much help as I have not worked on my iexos, only my exos2.   Others have though and hopefully they will chime in.

This is a commonly done adjustment.   Don’t worry.

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


Wes Mcdonald
 

Joe

No
Video that I know of.   But the principle is the same.  Just tear into it and figure out the screws they move stuff around.   The worm end play (axial movement) adjustment with the dime will be the same.  Be careful with the dime tho. The collet  is aluminum in the exos2 and if it’s the same in the iexos I can tell you it is fragile.   But the usual cause of backlash is the mesh of the worm and wheel.  If you get the worm block removed you can easily assess the end play.   But I would avoid the collet unless it’s really wrong.

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