#1  
Old 17-09-2012, 09:00 AM
baileys2611's Avatar
baileys2611 (Simon Bailey)
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Join Date: May 2012
Location: Murrumbateman
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Party on 15th September

Hi All,

I thought I might share some recent not so good experiences, but good lessons to learn from. I'm a beginner (aren't we all) but am a little more experienced than an absolute beginner, so this might come in handy for anyone with the same equipment, or perhaps people can offer some suggestions for me to ponder on equipment and technique.

On 15 September, I invited some friends around to gaze at the stars with me at my property in Murrumbateman. Perfect night, -1 forecast, no moon, no cloud, excellent conditions; So I hiked the BBQ, outdoor heater and some seats and a table out on top of my in-ground water tank. I've added a picture for viewing pleasure.

I started setting up around 13:00 and finished probably close to 17:00, ready to align my scopes. For the evening I used an 8" Meade LX200R GPS, a William Optics GT-81 mounted on an HEQ5 Pro and a Celestron 9.25" XLT mounted on an Ioptron IEQ45. You can see the three of them individually and a "group shot" in the pictures. All of them were connected to their own laptop, using Ascom and EQMOD, with Cartes Du Ceil, Stellarium and Meade's Astro-star suite for the Meade.

I started off aligning the Meade. I can't say enough about how well these scopes perform, it self-levelled, found home, took the GPS coordinates and aligned pertty much perfectly on the first and second guide-stars. After that I sent it to 47 Tucanae and it was a tiny way off, so slewed to the correct spot, told the software to sync the scope and it spotted perfectly for the rest of the evening. This scope was a great addition to the party as it was so easy to use the handset in combination with the software to get a guided tour of that night's best (according to Meade). Sure, while the optics on a 8" aren't the same as the C9.25, it was great to give guests a tour and some good views.

After I synced the Meade I went on the WO GT-81. I must be doing something wrong with it. I put an eye-piece directly in to the focuser (a WO 26") and could not achieve focus. I came close to it at the end of the travel for the focuser, but couldn't get anywhere near prime focus. The stars were large round blobs and not anywhere near resolving. I spent some time with different eye-pieces and didn't use a 90" upright or any assisting 45" prism so I wonder if that's what is causing the problem? Anyway, that scope was unfortunately not used for the night because it couldn't see anything!! As an aside, I'm quite proud that I was able to point to HEQ5 Pro in the right direction of the south celestial pole without using the polar scope in the mount. According to the software (and that's no perfect guide, I know), I was only a few degreed off the pole

Lastly, the Celestron 9.25" was an amazing view. The optics on that are excellent. Stars and Nebula had visibly more contrast than the Meade, the views were stunning. I didn't bother to align the IEQ45 with the handset, just used to software to sync on target after finding 47 Tucanae and then Alpha-Crux and from that point on it worked well. I did encounter one problem though. The Celstron with my William Optics Ferrari Zenith-Star used as a finder weighs a total of 14.5kg. The Mount's supposed weight ability is 20kg of instruments. I used 10kg of counterweights and could not obtain balance (obviously) in one axis. The Dec axis was ok, but the other was not, should that matter so much? Only when it went close to the point that the scope outweighed the counterweights, the whole axis tipped suddenly and made this terrible grinding noise. I was next to it when that happened and my reflexes are good, so I stopped any damage to the OTA, but am wondering if anyone else has had that happen before? I righted the mount, reset the axis to zero position and started again and luckily it worked afterwards, but that same thing happened once again - this time I was ready for it so I supported it at that point and did not let it fall. I'm hoping that this is just a balance problem. I've ordered an extension bar from the US, which is on it's way but if it's something to do with the worm gears in the mount itself I'll be a little dark as I bought it second hand from these forums.

So, something to be aware of if it's a balance issue is that apparently, 5kg of weight is enough to cause the scope to slip it's gears. If it's not balance then what could possibly cause that? A burred threat on the worm drive to begin with?

So, that aside, as long as I manually controlled the scope it worked well. It still tracked nicely but I had to watch it to make sure it didn't tip again. The Meade was perfect and the WO GT-81 was blurry and a disappointment.

Any suggestions or comments welcome!
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  #2  
Old 18-09-2012, 08:17 PM
allan gould's Avatar
allan gould
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Location: Brisbane
Posts: 4,481
Any WO refractor needs a diagonal to achieve focus and the Celestron 9.25 is grossly out of balance and you were lucky not to have hit the scope on the mount or far worse to both scope and mount. Take the zenith star scope off as a finder as it just weighs too much and use a proper finder scope. You will also need an other counter weight for the Celestron to balance on the ioptron mount. You were lucky not to strip the gears or get the scope to hit the mount and mess up the optics. If you set up each system properly then they will work brilliantly but if you ignore the fundamentals you are heading for trouble.
Just my 2 cents
Allan
Quote:
Originally Posted by baileys2611 View Post
Hi All,

I thought I might share some recent not so good experiences, but good lessons to learn from. I'm a beginner (aren't we all) but am a little more experienced than an absolute beginner, so this might come in handy for anyone with the same equipment, or perhaps people can offer some suggestions for me to ponder on equipment and technique.

On 15 September, I invited some friends around to gaze at the stars with me at my property in Murrumbateman. Perfect night, -1 forecast, no moon, no cloud, excellent conditions; So I hiked the BBQ, outdoor heater and some seats and a table out on top of my in-ground water tank. I've added a picture for viewing pleasure.

I started setting up around 13:00 and finished probably close to 17:00, ready to align my scopes. For the evening I used an 8" Meade LX200R GPS, a William Optics GT-81 mounted on an HEQ5 Pro and a Celestron 9.25" XLT mounted on an Ioptron IEQ45. You can see the three of them individually and a "group shot" in the pictures. All of them were connected to their own laptop, using Ascom and EQMOD, with Cartes Du Ceil, Stellarium and Meade's Astro-star suite for the Meade.

I started off aligning the Meade. I can't say enough about how well these scopes perform, it self-levelled, found home, took the GPS coordinates and aligned pertty much perfectly on the first and second guide-stars. After that I sent it to 47 Tucanae and it was a tiny way off, so slewed to the correct spot, told the software to sync the scope and it spotted perfectly for the rest of the evening. This scope was a great addition to the party as it was so easy to use the handset in combination with the software to get a guided tour of that night's best (according to Meade). Sure, while the optics on a 8" aren't the same as the C9.25, it was great to give guests a tour and some good views.

After I synced the Meade I went on the WO GT-81. I must be doing something wrong with it. I put an eye-piece directly in to the focuser (a WO 26") and could not achieve focus. I came close to it at the end of the travel for the focuser, but couldn't get anywhere near prime focus. The stars were large round blobs and not anywhere near resolving. I spent some time with different eye-pieces and didn't use a 90" upright or any assisting 45" prism so I wonder if that's what is causing the problem? Anyway, that scope was unfortunately not used for the night because it couldn't see anything!! As an aside, I'm quite proud that I was able to point to HEQ5 Pro in the right direction of the south celestial pole without using the polar scope in the mount. According to the software (and that's no perfect guide, I know), I was only a few degreed off the pole

Lastly, the Celestron 9.25" was an amazing view. The optics on that are excellent. Stars and Nebula had visibly more contrast than the Meade, the views were stunning. I didn't bother to align the IEQ45 with the handset, just used to software to sync on target after finding 47 Tucanae and then Alpha-Crux and from that point on it worked well. I did encounter one problem though. The Celstron with my William Optics Ferrari Zenith-Star used as a finder weighs a total of 14.5kg. The Mount's supposed weight ability is 20kg of instruments. I used 10kg of counterweights and could not obtain balance (obviously) in one axis. The Dec axis was ok, but the other was not, should that matter so much? Only when it went close to the point that the scope outweighed the counterweights, the whole axis tipped suddenly and made this terrible grinding noise. I was next to it when that happened and my reflexes are good, so I stopped any damage to the OTA, but am wondering if anyone else has had that happen before? I righted the mount, reset the axis to zero position and started again and luckily it worked afterwards, but that same thing happened once again - this time I was ready for it so I supported it at that point and did not let it fall. I'm hoping that this is just a balance problem. I've ordered an extension bar from the US, which is on it's way but if it's something to do with the worm gears in the mount itself I'll be a little dark as I bought it second hand from these forums.

So, something to be aware of if it's a balance issue is that apparently, 5kg of weight is enough to cause the scope to slip it's gears. If it's not balance then what could possibly cause that? A burred threat on the worm drive to begin with?

So, that aside, as long as I manually controlled the scope it worked well. It still tracked nicely but I had to watch it to make sure it didn't tip again. The Meade was perfect and the WO GT-81 was blurry and a disappointment.

Any suggestions or comments welcome!
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  #3  
Old 18-09-2012, 08:36 PM
baileys2611's Avatar
baileys2611 (Simon Bailey)
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Thanks Allan, yes - point taken, it was a poor set up. I guess then that my plan of putting a side by side set up on the mount would mean it needs even more counterweights, which also means it needs to take into account the added weight from that, reducing the instrument load capacity by whatever additional weight is used to counterweight the OTA.

Hmm...I may need to look at something more suited to my end goal and approach it slowly I think.
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Old 19-09-2012, 09:05 AM
brian nordstrom (As avatar)
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Location: Perth WA
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Ouch !!!! a grinding noise from your IEQ45 , I have one of these mounts and did a similar thing a while ago , in a moment of brain fade , as I was taking it outside I took the counter weights off before the OTA ..,, yea it took off and made the same " Grinding " noise . OUCH!!!.
My quick reflaxes saved the OTA from any damage as well....
It caused no damage as I found out that the worm gear is spring loaded onto the ring gear and that realesed and made that horrible noise , I think its designed to do this , saves damage to either gear ... Yes !
Good observing report , I enjoyed reading it .
Brian.
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  #5  
Old 19-09-2012, 09:53 AM
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baileys2611 (Simon Bailey)
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Thanks Brian,

I'm still learning a lot about this. I'm all about the journey though

I did open up the mount and check the drives in a fit of fear after Allan's comment. Could not see any damage so I'm very pleased to hear you say you had the same experience and had no damage also.

I'm going to look for another counterweight anyway, I still want to push ahead with my side by side set up. Thing is, I don't see them for sale anywhere. Is it a case of finding somewhere that sells these things generically?

Simon.
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  #6  
Old 19-09-2012, 11:01 AM
brian nordstrom (As avatar)
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Bintel sells generic wieghts , check them out .
Brian.
Quote:
Originally Posted by baileys2611 View Post
Thanks Brian,

I'm still learning a lot about this. I'm all about the journey though

I did open up the mount and check the drives in a fit of fear after Allan's comment. Could not see any damage so I'm very pleased to hear you say you had the same experience and had no damage also.

I'm going to look for another counterweight anyway, I still want to push ahead with my side by side set up. Thing is, I don't see them for sale anywhere. Is it a case of finding somewhere that sells these things generically?

Simon.
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  #7  
Old 19-09-2012, 11:14 AM
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baileys2611 (Simon Bailey)
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Good one! Got it.
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