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iexos-100 slewing is sticky #iEXOS-100


Yorksman
 

I find that short distance slews with the scope pointing high in the sky nice and smooth but if asked to slew say from M31 in the northern sky to Jupiter in the southern sky, as the mount approaches its target nearer to the horizon, it sticks, makes a noise and then continue. It does this two or three times and then when it finally comes to rest, it is way off target. Going back to the Park position, it is also away from its original position. Have tried altering the clutches, though I don't tighten them much. It's a brand new mount, only two or three weeks old and hardly used. Any suggestions as to what might be causing this?


Wes Mcdonald
 

You are binding.  Make sure the balance is good.   Might need to adjust your worm/wheel mesh 

Wes

On Sun, Jul 26, 2020 at 6:51 PM Yorksman <harry@...> wrote:
I find that short distance slews with the scope pointing high in the sky
nice and smooth but if asked to slew say from M31 in the northern sky to
Jupiter in the southern sky, as the mount approaches its target nearer
to the horizon, it sticks, makes a noise and then continue. It does this
two or three times and then when it finally comes to rest, it is way off
target. Going back to the Park position, it is also away from its
original position. Have tried altering the clutches, though I don't
tighten them much. It's a brand new mount, only two or three weeks old
and hardly used. Any suggestions as to what might be causing this?





--
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


Yorksman
 

Thanks. I didn't realise balance was so critically sensitive but already a big improvement. Just a slight amount of binding now but it is very much improved. I'm reluctant to open the motor housing up given that it is a brand new mount. Not too sure what to do with a worm/wheel mesh anyway.


On 27/07/2020 01:54, Wes Mcdonald wrote:
You are binding.  Make sure the balance is good.   Might need to adjust your worm/wheel mesh 

Wes

On Sun, Jul 26, 2020 at 6:51 PM Yorksman <harry@...> wrote:
I find that short distance slews with the scope pointing high in the sky
nice and smooth but if asked to slew say from M31 in the northern sky to
Jupiter in the southern sky, as the mount approaches its target nearer
to the horizon, it sticks, makes a noise and then continue. It does this
two or three times and then when it finally comes to rest, it is way off
target. Going back to the Park position, it is also away from its
original position. Have tried altering the clutches, though I don't
tighten them much. It's a brand new mount, only two or three weeks old
and hardly used. Any suggestions as to what might be causing this?





--
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
 

Yorksman

There is video from ES that shows how to adjust the mesh for the iexos.  


This will show you how.  Also in the files section of the mounts subgroup you will find a tuning document by Robert Hoskins for the exos2.  While it is for that mount it will give you a sense for what you are trying to achieve.

Generally ES is fine with you adjusting your mesh without wacking your warranty.

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


Yorksman
 

Wes,

Thanks, that is really very helpful and looks straightforward enough. I'm usuaally reluctant because sometimes thingslike springs pop out and I don't know in what order to put things back. But this is OK.

yorksman

On 27/07/2020 13:21, Wes Mcdonald wrote:
Yorksman

There is video from ES that shows how to adjust the mesh for the iexos.  


This will show you how.  Also in the files section of the mounts subgroup you will find a tuning document by Robert Hoskins for the exos2.  While it is for that mount it will give you a sense for what you are trying to achieve.

Generally ES is fine with you adjusting your mesh without wacking your warranty.

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
 

I ran into the same issue. Balance is a critical issue for the iExos100 that requires a LOT more attention than for my C14 and 127mm refractors on much larger Orion mounts. The problem is that a DSLR+ Flattener or a diagonal plus 2" eyepiece and possibly a barlow is a significant fraction of the weight of the whole telescope.  Changing from visual to photographic mode, or even changing from a high power to low power eyepiece or adding a Barlow upsets the balance. I can do these changes with impunity with a C14 and there is enough extra horsepower in the drive mechanism that I can get by.  I did not appreciate that for a small scope, balance changes are more significant and motors are much weaker.

I ran into the problem when I did a 2star alignment with an eyepiece, and then switched to a camera. I think the only solution for the iExos100 is to do the 2star alignment using the finder scope with the exact photographic optical train in place and the camera pre-focused.  I bought my iExos100 + 80mm F/6 refractor to have a portable rig for solar eclipses.  I worry that the metal cell of my solar filter will be enough weight to upset the balance.  The only solution I can think is to add a Velcro weight on my telescope tube when using the solar filter.


Yorksman
 

Thanks. Good point, well made. I am beginning to appreciate that. Having read the post, I tried changing the eyepiece and was surprised at the difference it made. As you ay, smaller motors need need more attention because they work within stricter limit.

On 27/07/2020 15:49, Joe Izen wrote:

I ran into the same issue. Balance is a critical issue for the iExos100 that requires a LOT more attention than for my C14 and 127mm refractors on much larger Orion mounts. The problem is that a DSLR+ Flattener or a diagonal plus 2" eyepiece and possibly a barlow is a significant fraction of the weight of the whole telescope.  Changing from visual to photographic mode, or even changing from a high power to low power eyepiece or adding a Barlow upsets the balance. I can do these changes with impunity with a C14 and there is enough extra horsepower in the drive mechanism that I can get by.  I did not appreciate that for a small scope, balance changes are more significant and motors are much weaker.

I ran into the problem when I did a 2star alignment with an eyepiece, and then switched to a camera. I think the only solution for the iExos100 is to do the 2star alignment using the finder scope with the exact photographic optical train in place and the camera pre-focused.  I bought my iExos100 + 80mm F/6 refractor to have a portable rig for solar eclipses.  I worry that the metal cell of my solar filter will be enough weight to upset the balance.  The only solution I can think is to add a Velcro weight on my telescope tube when using the solar filter.



Luke
 

You could use a flip mirror diagonal, I think it might solve your balancing issue. What do you think. Luc

--
Mounts:       ES PMC-Eight G11 - upgraded with OPWB on both RA and DEC
                     EXOS-2 GT PMC-EIGHT
Scopes:       Televue NP127IS with HSM20 and focuser boss II - Questar field model 3.5 - Takahashi FC76 classic MC Starbase Tokyo edition - Takahashi FOA60Q - Zeiss telementor - Lomo Astele 150mm
Cameras:     ZWO ASI071 PRO
                     ZWO ASI 290
Misc:            Televue 0.8 X  Focal Reducer - ZWO ASIAIR-PRO
Eyepieces:  Pentax - Masuyama - Televue - Takahashi - Vixen
Software:     Starry night PRO 8  - Nebulosity - Topaz studio - Sharp cap


Yorksman
 

Thanks for you suggestion. Now that I have realised that balaance is so critical it is much better behaved. I simply didn't realise that small differences had such a great effect so I am now testing balance much more thoroughly. Fingers crossed that it stays like this.


Wes Mcdonald
 

The 100 has the same motors as does the exos2.  The torque is the same.  It’s ability to handle of balance loads is probably the same.  If anything it will be better at it if the scopes are smaller.

Start with a well balanced tube with representative loads and you should be fine when you change things.  Clearly if you put in a 3 pound Barlow in place of an 8oz small eyepiece things are gonna get a bit crazy. 

We’d

--
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