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CEM60 vibration

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#26 NorbertG

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Posted 09 December 2017 - 02:12 PM

I had a similar effect with my CEM60 in the beginning. I had a self made adapter mounted on a EQ6 tripod. It was made if 20mm aluminum, and I used it with an even heavier mount before. So I just drilled the two holes for the CEM60 adapation and the result was a very poor performance in terms of vibrations in both directions. Just by chance I found that the 20mm disk was not perfectly flat. Even if I fixed the two screws with brute force (replacing the Nylon washers by metal ones before), the whole mount could move slightly back and forth, especially in zero position it was easy to see. Since the mount is center balanced (although not perfectly) it can oscillate between the two endpositions. I didn´t follow up the issue since I received the Berlebach Planet, which doesn´t show any issue like that.

But the design with the two bolts to fix the base seems to be generally a weak point, same as for the two screws that fix the altitude setting. Doing polar alignment with the polemaster shows how sensitive the position is according to the torque you apply to these four screws. Tightening the screws is the most demanding part of the polar alignment.If it can move so easily it is rather likely it can oscillate. 

 

cheers 

Norbert

 

 

   


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#27 adastranova

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Posted 09 December 2017 - 11:16 PM

What you are seeing every few minutes is probably the resonance frequency effect of a periodic error.

Try to shorter the threaded rods of your rat cage and see what happens as I suggested before. I bet you will be amazed....

It would be a good thing to fill the remaining thread with nuts, so they will be more solid, which will Change the res. freq. as well.

The whole rat cage construction is a mostly unnecessary thing anyway. If it is absolutely needed for positioning the mount, keep the rods as short as possible. For levelling it is not absolutely necessary, because EQ mounts do not need a perfect levelling. Direct mounting the head on the pier if possible is a far better option. 

 

Levelling is nice for a mobile set up to have a starting point for further adjustment, but that is about it.

 

Edit:

4" diameter steel pipe is not a solid construction for a pier anyway, even if it is thick walled.

An extra solution to dramatically change the res. freg. may be the use of a thick plywood plate between the pier and the upper mounting plate.

Thanks. My leveling plates are  5/8 in. aluminum, the discs were easy to find online. Very thick plywood is not easy to find, I think i have only seen about 1 in. max at the lumber stores. My post is is probably 5 degrees off vertical, so the rat cage was needed. If I change the post perhaps i could do better. All is now under several inches of snow, so it may be a while to prove these changes out. Going from pier to tripod is next. All good info. Many thanks to all.


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#28 adastranova

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Posted 10 December 2017 - 02:17 AM

Just for an example.
I have a pier with a diameter of 219 mm and a height of 1.5 meters.
If I apply a horizontal force of 1 kg to the top of the pier, the top of the pier will deviate by 0.002 mm. This corresponds to a deviation of 0.3 "arcsec.
If your pier has a diameter of 4 inches thick steel pipe (diameter 101 mm and wall thickness 5 mm), then the force of 1 kg will tip its top by 0.023 mm.
This corresponds to a deviation of 3.4 arcsec and this is already a lot.

 

Ranger 4 - thanks for the idea of the plywood plate. I will do it myself.

I suppose with mount and scope much of the mass is top heavy and could flex the structure underneath. Much to think about for a new pier.



#29 Waldemar

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Posted 10 December 2017 - 07:15 AM

This works great! :http://www.bigfootsystems.com/

Simple,fast and rigid...

 

If you cannot open the link, just google bigfoot systems


Edited by Waldemar, 10 December 2017 - 07:20 AM.


#30 dvalid

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Posted 11 December 2017 - 10:22 AM

 

However, this setup seems to have some vibration issues I am trying to figure out. In the daylight I noticed that just touching to scope seems to make it wobble for quite a few seconds. My permanent pier is anchored into the ground with a 6 foot piece of railroad track surrounded by concrete. The pier is inside a 6x8 foot SkyShed with roll off roof. So the pier base is super solid and mostly shielded from minor wind gusts. When using the Luminos 23 mm eyepiece that was included the visual image is pretty good. However, the slightest tap makes a star wobble around in circles and doesn't completely disappear for over ten seconds.

 

When using a 15 mm eyepiece, there seems to be a lot of distortion. Star images seem like they are always oscillating in all directions to some degree. Every minute or two brights stars seem to increase in size for a few seconds and then shrink, like a larger vibration pattern which then dampens, perhaps due to wind or atmosphere? Carefully balancing payload and counterweight and using the mirror locks reduced this somewhat but I still am not satisfied. Even turning off the scope does not appear to resolve the problem. Have not even attempted imaging yet.

 

I have exactly the same problem with my 1100HD OTA. I've tried iOptron 48" Pier and 2" tripod, with/without pads, added the counterweight to reduce moment arm - result is the same. 

 

I keep primary mirror locked and focusing with FLI PDF, but still, after every correction the mount awfully wobbles for several seconds. I have to use AO unit for guiding to get decent results..

 

On the other hand CEM60 works flawlessly with my other setup - FSQ106. Maybe 60 pounds is way overestimated for the mount? Well, I know, this capacity is for visual use only, but it seems the mount could hardly handle even 30 pounds of payload.

 

Honestly, before I'll move to a better pier, want to be sure that the problem is pier/tripod and not the mount itself.

 

David


Edited by dvalid, 11 December 2017 - 03:16 PM.

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#31 adastranova

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Posted 12 December 2017 - 01:02 AM

 

 

However, this setup seems to have some vibration issues I am trying to figure out. In the daylight I noticed that just touching to scope seems to make it wobble for quite a few seconds. My permanent pier is anchored into the ground with a 6 foot piece of railroad track surrounded by concrete. The pier is inside a 6x8 foot SkyShed with roll off roof. So the pier base is super solid and mostly shielded from minor wind gusts. When using the Luminos 23 mm eyepiece that was included the visual image is pretty good. However, the slightest tap makes a star wobble around in circles and doesn't completely disappear for over ten seconds.

 

When using a 15 mm eyepiece, there seems to be a lot of distortion. Star images seem like they are always oscillating in all directions to some degree. Every minute or two brights stars seem to increase in size for a few seconds and then shrink, like a larger vibration pattern which then dampens, perhaps due to wind or atmosphere? Carefully balancing payload and counterweight and using the mirror locks reduced this somewhat but I still am not satisfied. Even turning off the scope does not appear to resolve the problem. Have not even attempted imaging yet.

 

I have exactly the same problem with my 1100HD OTA. I've tried iOptron 48" Pier and 2" tripod, with/without pads, added the counterweight to reduce moment arm - result is the same. 

 

I keep primary mirror locked and focusing with FLI PDF, but still, after every correction the mount awfully wobbles for several seconds. I have to use AO unit for guiding to get decent results..

 

On the other hand CEM60 works flawlessly with my other setup - FSQ106. Maybe 60 pounds is way overestimated for the mount? Well, I know, this capacity is for visual use only, but it seems the mount could hardly handle even 30 pounds of payload.

 

Honestly, before I'll move to a better pier, want to be sure that the problem is pier/tripod and not the mount itself.

 

David

 

Just today I put the Ioptron Mini-pier on top of my old Meade LX200 tripod and mounted the CEM60 and 925 EdgeHD on top, all inside the house. There is still some wobble with the tap test but it seems a little better than my pier. Won't have a chance to take this outside soon with bitter winter weather coming to eastern PA. Really need some observing time to make any final determinations. The CEM60 may have a limit on the payload which is less than advertised, esp. for astrophotography. 

 

Now looking for some pier alternatives, as it seems my 4" pipe was less than ideal for stability.

 

Thanks.


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#32 adastranova

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Posted 20 December 2017 - 12:39 AM

Hi Folks,

 

My CEM60 vibration issues are continuing. Was outside tonight with the 925 EdgeHD, Mini-Pier, and LX200 tripod mentioned above and in the grass. The vibration issues were just the same as when all was on my steel pier inside my roll off observatory. The star gyrates around with the slightest disturbance from touching the focuser knob or a light touch of the cheek to the eyepiece. The slightest draft of wind makes the image shake around, even without dew shield. I am confident all was tightened down and secure.

 

You know I bought this mount to do some imaging, and I am not even satisfied with visual. As I am past the 30 days after purchase, I am concerned about what financial loss I may have incurred here. I plan to call Ioptron in the morning to see what can be worked out but am not hopeful.

 

Reading old posts here it seems that many have experienced this same problem over the past several years. Others seem satisfied. There is some repair sheet floating around online about tightening the RA bearing housing, but I am not even sure this would solve the problem. The mount seems to act like a seismograph, picking up any minor disturbance.

 

Frustrated and exhausted with my options at this point.

 

Thanks to all with their previous suggestions.


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#33 Whuppy

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Posted 20 December 2017 - 12:26 PM

Alrighty, here's my take, lose the mini pier. Mount it to the tripod as solid as possible and lower the tripod as much as possible. I use my CEM60 on an AVX tripod and it's rock solid. Here's a link to the DIY thread I started clearly showing my tripod, adapter plate and my CEM60 with my ES102CF and camera. Just throwing this out there because to me, the pier adapter seems like it could be a source of problems. Here's the link...

https://www.cloudyni...d/?fromsearch=1

#34 dvalid

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Posted 20 December 2017 - 12:51 PM

This problem was discussed many times here. It is very hard to convince people, who has not experienced this kind of wobble, that it's not related to the tripod. 

 

"It's not a matter of the tripod (it's on the stock iOptron tripod; not the beefiest, but that's not the issue).

This isn't micro-vibration; this is pendulum-like swinging of the entire scope/CW assembly around the RA gears.  You can see it swinging; you don't need to be looking through an eyepiece."

 

"No, my wobbling had nothing to do with the tripod.  I bought an aftermarket spreader/battery holder, and the tripod is solid enough with that.  You can watch the RA assembly move every time you touch the scope.  That movement is relative to the mount head and tripod, not relative just to the ground; the RA assembly is acting like a pendulum, with lots of play in the worm."

 

 

https://www.cloudyni...= cem60 wobble

 

This thread is from 2014. It seems nothing has changed since then..

 

David

 

 

 


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#35 adastranova

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Posted 20 December 2017 - 10:01 PM

This problem was discussed many times here. It is very hard to convince people, who has not experienced this kind of wobble, that it's not related to the tripod. 

 

"It's not a matter of the tripod (it's on the stock iOptron tripod; not the beefiest, but that's not the issue).

This isn't micro-vibration; this is pendulum-like swinging of the entire scope/CW assembly around the RA gears.  You can see it swinging; you don't need to be looking through an eyepiece."

 

"No, my wobbling had nothing to do with the tripod.  I bought an aftermarket spreader/battery holder, and the tripod is solid enough with that.  You can watch the RA assembly move every time you touch the scope.  That movement is relative to the mount head and tripod, not relative just to the ground; the RA assembly is acting like a pendulum, with lots of play in the worm."

 

 

https://www.cloudyni...= cem60 wobble

 

This thread is from 2014. It seems nothing has changed since then..

 

David

Yes. Thanks. I saw this thread after buying the mount and doing some searching. You would think in 3 years they would have made some changes. They got back to me today and I had to answers some questions about whether I had tightened the knobs, rebalanced the load, etc. which is is the first thing any dummy would try. Finally I got an RMA number from them. I have already spent 5 nights, and about 40-50 hours trying to twiddle all things on the outside of the mount, while viewing and during the day without success. We'll see what they find at their shop. Never before had this trouble with any astro equipment brand new.



#36 adastranova

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Posted 20 December 2017 - 10:08 PM

Alrighty, here's my take, lose the mini pier. Mount it to the tripod as solid as possible and lower the tripod as much as possible. I use my CEM60 on an AVX tripod and it's rock solid. Here's a link to the DIY thread I started clearly showing my tripod, adapter plate and my CEM60 with my ES102CF and camera. Just throwing this out there because to me, the pier adapter seems like it could be a source of problems. Here's the link...

https://www.cloudyni...d/?fromsearch=1

That may be another option thanks. I bought the Mini-pier as my old pier inside my observatory was a few inches short, after changing setups. It seems the folks who are satisfied with the CEM60 are mainly using long and narrow refractors, while those like myself who have reported issues are using short and wide Schmidt-Cassegrains. An aerodynamic issue perhaps, bigger profile catching more wind?


Edited by adastranova, 20 December 2017 - 10:09 PM.


#37 dvalid

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Posted 20 December 2017 - 10:12 PM

 

This problem was discussed many times here. It is very hard to convince people, who has not experienced this kind of wobble, that it's not related to the tripod. 

 

"It's not a matter of the tripod (it's on the stock iOptron tripod; not the beefiest, but that's not the issue).

This isn't micro-vibration; this is pendulum-like swinging of the entire scope/CW assembly around the RA gears.  You can see it swinging; you don't need to be looking through an eyepiece."

 

"No, my wobbling had nothing to do with the tripod.  I bought an aftermarket spreader/battery holder, and the tripod is solid enough with that.  You can watch the RA assembly move every time you touch the scope.  That movement is relative to the mount head and tripod, not relative just to the ground; the RA assembly is acting like a pendulum, with lots of play in the worm."

 

 

https://www.cloudyni...= cem60 wobble

 

This thread is from 2014. It seems nothing has changed since then..

 

David

Yes. Thanks. I saw this thread after buying the mount and doing some searching. You would think in 3 years they would have made some changes. They got back to me today and I had to answers some questions about whether I had tightened the knobs, rebalanced the load, etc. which is is the first thing any dummy would try. Finally I got an RMA number from them. I have already spent 5 nights, and about 40-50 hours trying to twiddle all things on the outside of the mount, while viewing and during the day without success. We'll see what they find at their shop. Never before had this trouble with any astro equipment brand new.

 

Would eagerly wait If they'll manage to solve the problem. Please keep us updated.

 

Regards,

 

David



#38 dvalid

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Posted 20 December 2017 - 10:16 PM

 

Alrighty, here's my take, lose the mini pier. Mount it to the tripod as solid as possible and lower the tripod as much as possible. I use my CEM60 on an AVX tripod and it's rock solid. Here's a link to the DIY thread I started clearly showing my tripod, adapter plate and my CEM60 with my ES102CF and camera. Just throwing this out there because to me, the pier adapter seems like it could be a source of problems. Here's the link...

https://www.cloudyni...d/?fromsearch=1

That may be another option thanks. I bought the Mini-pier as my old pier inside my observatory was a few inches short, after changing setups. It seems the folks who are satisfied with the CEM60 are mainly using long and narrow refractors, while those like myself who have reported issues are using short and wide Schmidt-Cassegrains. An aerodynamic issue perhaps, bigger profile catching more wind?

 

I tested the mount with RC8" scope couple of days ago. The vibration is still there. The only setup CEM60 holds nicely is the FSQ106 refractor.



#39 adastranova

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Posted 21 December 2017 - 01:49 AM

 

 

This problem was discussed many times here. It is very hard to convince people, who has not experienced this kind of wobble, that it's not related to the tripod. 

 

"It's not a matter of the tripod (it's on the stock iOptron tripod; not the beefiest, but that's not the issue).

This isn't micro-vibration; this is pendulum-like swinging of the entire scope/CW assembly around the RA gears.  You can see it swinging; you don't need to be looking through an eyepiece."

 

"No, my wobbling had nothing to do with the tripod.  I bought an aftermarket spreader/battery holder, and the tripod is solid enough with that.  You can watch the RA assembly move every time you touch the scope.  That movement is relative to the mount head and tripod, not relative just to the ground; the RA assembly is acting like a pendulum, with lots of play in the worm."

 

 

https://www.cloudyni...= cem60 wobble

 

This thread is from 2014. It seems nothing has changed since then..

 

David

Yes. Thanks. I saw this thread after buying the mount and doing some searching. You would think in 3 years they would have made some changes. They got back to me today and I had to answers some questions about whether I had tightened the knobs, rebalanced the load, etc. which is is the first thing any dummy would try. Finally I got an RMA number from them. I have already spent 5 nights, and about 40-50 hours trying to twiddle all things on the outside of the mount, while viewing and during the day without success. We'll see what they find at their shop. Never before had this trouble with any astro equipment brand new.

 

Would eagerly wait If they'll manage to solve the problem. Please keep us updated.

 

Regards,

 

David

 

Yes. I will. Comments are much appreciated from someone with your experience and talents, your Astrobin images are quite remarkable! I hope to be on your level someday. Cheers.


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#40 adastranova

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Posted 18 February 2018 - 12:09 AM

Hello All,

 

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

 

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.

 

After working on the mount, they never said they found the issue reported, told me they adjusted and replaced components, and then never said the issue was fixed. They just wanted me to take it back and try again. After refusing they tried to jam it back on me, so I asked for a refund, which was denied. Eventually I got my money back by using the consumer protections on my credit card, and not from any direct cooperation from Ioptron. I just decided to cut my losses while I could.

 

You know I really wanted this mount to work as I liked the features, but frankly their tech support was unfriendly and illusive, in my opinion. I never got anybody understandable on the phone, and had to email back and forth on the details.  Obviously I was not the first to report the RA wobble, and I really don't know if they have a fix for it. Something was unsecure inside the mount causing oscillations in the one direction. I was hoping for a fix, as it seems others here are using the CEM60 without this issue.  But tech service is part of ownership, and I had no sense that the problem would ever be resolved. 

 

So anyway, I have used the refund money to buy a Losmandy G11G, which I have set up inside the house for now, waiting for better weather. But my Celestron 925 EdgeHD now shows no sign of uncontrolled oscillations, gyrations, or other unwanted movement. This mount I think I can work with. But several months and other money was wasted trying to turn bad into good, which I won't ever recover. Others had reported vibration problems a few years ago, and my experience was identical. Hope Ioptron tightens up on whatever it is, but I won't be using them again. 

 

Again thanks for the support.


Edited by adastranova, 18 February 2018 - 01:26 AM.

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#41 AntMan1

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Posted 18 February 2018 - 02:04 AM

Hello All,

 

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

 

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.

 

After working on the mount, they never said they found the issue reported, told me they adjusted and replaced components, and then never said the issue was fixed. They just wanted me to take it back and try again. After refusing they tried to jam it back on me, so I asked for a refund, which was denied. Eventually I got my money back by using the consumer protections on my credit card, and not from any direct cooperation from Ioptron. I just decided to cut my losses while I could.

 

You know I really wanted this mount to work as I liked the features, but frankly their tech support was unfriendly and illusive, in my opinion. I never got anybody understandable on the phone, and had to email back and forth on the details.  Obviously I was not the first to report the RA wobble, and I really don't know if they have a fix for it. Something was unsecure inside the mount causing oscillations in the one direction. I was hoping for a fix, as it seems others here are using the CEM60 without this issue.  But tech service is part of ownership, and I had no sense that the problem would ever be resolved. 

 

So anyway, I have used the refund money to buy a Losmandy G11G, which I have set up inside the house for now, waiting for better weather. But my Celestron 925 EdgeHD now shows no sign of uncontrolled oscillations, gyrations, or other unwanted movement. This mount I think I can work with. But several months and other money was wasted trying to turn bad into good, which I won't ever recover. Others had reported vibration problems a few years ago, and my experience was identical. Hope Ioptron tightens up on whatever it is, but I won't be using them again. 

 

Again thanks for the support.

I believe you & many others on here are 100% correct stating the advertised weight limit is way, way off with Ioptron. I had about 14 pounds on a cem25p & it acted like it was overloaded. I am happy you got your money back. Whatever else you buy shake it down before the thirty days is up so its not your problem.


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#42 Waldemar

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Posted 18 February 2018 - 03:19 AM

I do not understand why they did not just replace your mount ???

You would be a very happy customer, making free advertising for them, and they would get a better name and more customers... Now the opposite is happening... they loose customers and get a bad name.

I really can not understand this incredibly customer unfriendly way of dealing with your problem, while most people were quite happy with their products as well as their service. No doubt this will translate in lower sales...

 

I am glad for you, your CC company covered at least part of your losses. Hope you will have a great time with your new mount!


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#43 dvalid

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Posted 18 February 2018 - 08:16 AM

Hello All,

 

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

 

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.

 

 

I dare express heretical opinion. CEM60 has a design defect - the tiny clamps that hold the whole RA assembly:

cem60clamp.jpg

 

It somehow holds the mount at the beginning, but for people like me, who have to set the latitude before every remote session, the clamp could easily wear out, causing the vibration problems. Just thoughts..


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#44 gotak

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Posted 18 February 2018 - 09:46 AM


Hello All,

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.


I dare express heretical opinion. CEM60 has a design defect - the tiny clamps that hold the whole RA assembly:

cem60clamp.jpg

It somehow holds the mount at the beginning, but for people like me, who have to set the latitude before every remote session, the clamp could easily wear out, causing the vibration problems. Just thoughts..

Is the clamps a spring? If not how would it be part of a vibration issue?

The root cause is likely simple but maybe different for each occurrence.

#45 adastranova

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Posted 19 February 2018 - 12:14 AM

I do not understand why they did not just replace your mount ???

You would be a very happy customer, making free advertising for them, and they would get a better name and more customers... Now the opposite is happening... they loose customers and get a bad name.

I really can not understand this incredibly customer unfriendly way of dealing with your problem, while most people were quite happy with their products as well as their service. No doubt this will translate in lower sales...

 

I am glad for you, your CC company covered at least part of your losses. Hope you will have a great time with your new mount!

Thanks.

 

This forum has been most useful. It's great to connect with people who have experience with all kinds of astronomy hardware and hear of their problems and solutions - otherwise you just have to learn all from your own self experience and those around you.



#46 adastranova

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Posted 19 February 2018 - 12:18 AM

 

Hello All,

 

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

 

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.

 

 

I dare express heretical opinion. CEM60 has a design defect - the tiny clamps that hold the whole RA assembly:

attachicon.gif cem60clamp.jpg

 

It somehow holds the mount at the beginning, but for people like me, who have to set the latitude before every remote session, the clamp could easily wear out, causing the vibration problems. Just thoughts..

 

You know I was thinking these parts could be held together by more than the two clamps, which really can only brace along the width of the clamp. A third locking point may be a better way to secure.



#47 Real14

Real14

    Surveyor 1

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  • Posts: 1719
  • Joined: 22 Aug 2008
  • Loc: San Luis Potosi, Mexico

Posted 19 February 2018 - 06:04 PM

 

Hello All,

 

Just wanted to update everyone who replied earlier and tried to help. The mount went back to Ioptron and I never got any satisfactory answers. You know, it's not the mount, it must be your site; not the mount, it must be your pier; it's not the mount, it must be your tripod. Anyone see a pattern?

 

Moving from pier to tripod was the big tell; there should have been some difference, but the severe RA wobble remained. At some point before I sent the mount back, Ioptron offered me a worksheet on how to tighten up on the RA worm gear bearing seats, which I did not try as opening up hardware on a new mount didn't seem kosher to me, plus any damage would then be my fault. The fact there is a worksheet would indicate they have seen this issue before and tried to come up with a fix. The link to these instructions now has seemed to have disappeared from their website.

 

 

I dare express heretical opinion. CEM60 has a design defect - the tiny clamps that hold the whole RA assembly:

attachicon.gif cem60clamp.jpg

 

It somehow holds the mount at the beginning, but for people like me, who have to set the latitude before every remote session, the clamp could easily wear out, causing the vibration problems. Just thoughts..

 

Hi,

 

From yoru point of view a non clamping clamp can be the cause for vibrations. OK the clamp can wear out, no doubts about it but before that steel clamp shows a sign of wear out, the first thing showing a wear would be the surface on which it is pressing as that part is a foundry piece and that could be a 100% Aluminum body or perhaps even a Magnesium/Aluminum alloy and those foundry parts are always softer than Steel.

 

Now in order to check if the clamp does not do its job anymore get a thin strip of aluminum of a can, maybe 2mm wide and a few centimeters long. Bend it straight and push it into the space between the front part of the clamp and the non movable support for the head assembly (green arrow). If you can stick it through with ease then the clamp is doing its job. Of course,first take it off and clean that part well. 

 

Now let us assume the clamp is not clamping. What could that mean that the head is not held sideways on the lower support, but in order that the movable part on the lower fixed support vibrates would mean you really need a continuous sideways movement in order to lift it up on one side and then on the other. From where would that force come ? unless you push it with your fingers ... the stepper motors stepping with I do not know how many few steps per minute. How can the rotor of a stepper motor cause so much vibration in order to mothe whole enchilada on his seating ?

 

The case that having on the head assembly eg. 50 pounds of gear makes it impossible for the whole enchilada to dance from side to side.

 

Image taken from dvalid post # 43

 

 

cem60clamp.jpg



#48 JakeJ

JakeJ

    Mercury-Atlas

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  • Posts: 2659
  • Joined: 31 Aug 2004

Posted 19 February 2018 - 06:12 PM

Glad you got your refund, albeit without any help from Ioptron.

 

All the problems with these I read about here, I would never put my hard earned $$ down for one.



#49 AntMan1

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    Viking 1

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  • Posts: 619
  • Joined: 17 Sep 2007
  • Loc: NY

Posted 19 February 2018 - 06:18 PM

Glad you got your refund, albeit without any help from Ioptron.

 

All the problems with these I read about here, I would never put my hard earned $$ down for one.

This is the 1 thing Ioptron should give a crap about but apparently they don't and it is going to byte them hard. Hope they know how to read this forum.


  • JakeJ, GooglyEyes and adastranova like this

#50 dvalid

dvalid

    Ranger 4

  • -----
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  • Joined: 02 Apr 2014
  • Loc: Georgia

Posted 19 February 2018 - 07:01 PM

Hi,

 

 

 

From yoru point of view a non clamping clamp can be the cause for vibrations. OK the clamp can wear out, no doubts about it but before that steel clamp shows a sign of wear out, the first thing showing a wear would be the surface on which it is pressing as that part is a foundry piece and that could be a 100% Aluminum body or perhaps even a Magnesium/Aluminum alloy and those foundry parts are always softer than Steel.

 

Now in order to check if the clamp does not do its job anymore get a thin strip of aluminum of a can, maybe 2mm wide and a few centimeters long. Bend it straight and push it into the space between the front part of the clamp and the non movable support for the head assembly (green arrow). If you can stick it through with ease then the clamp is doing its job. Of course,first take it off and clean that part well. 

 

Now let us assume the clamp is not clamping. What could that mean that the head is not held sideways on the lower support, but in order that the movable part on the lower fixed support vibrates would mean you really need a continuous sideways movement in order to lift it up on one side and then on the other. From where would that force come ? unless you push it with your fingers ... the stepper motors stepping with I do not know how many few steps per minute. How can the rotor of a stepper motor cause so much vibration in order to mothe whole enchilada on his seating ?

 

The case that having on the head assembly eg. 50 pounds of gear makes it impossible for the whole enchilada to dance from side to side.

 

Image taken from dvalid post # 43

 

 

attachicon.gif cem60clamp.jpg

 

'Now in order to check if the clamp does not do its job anymore get a thin strip of aluminum of a can, maybe 2mm wide and a few centimeters long. Bend it straight and push it into the space between the front part of the clamp and the non movable support for the head assembly (green arrow). If you can stick it through with ease then the clamp is doing its job. Of course,first take it off and clean that part well.'

 

That's what I did some time ago. It feels more rigid, didn't test with the actual load yet though.

 

https://www.cloudyni...nent/?p=8328737

 

'Now let us assume the clamp is not clamping. What could that mean that the head is not held sideways on the lower support, but in order that the movable part on the lower fixed support vibrates would mean you really need a continuous sideways movement in order to lift it up on one side and then on the other. From where would that force come ? unless you push it with your fingers ... the stepper motors stepping with I do not know how many few steps per minute. How can the rotor of a stepper motor cause so much vibration in order to mothe whole enchilada on his seating ? The case that having on the head assembly eg. 50 pounds of gear makes it impossible for the whole enchilada to dance from side to side'.

 

Rainer, I did not get this point, are you questioning existence of the vibration phenomena  in general? 

 

David


Edited by dvalid, 19 February 2018 - 07:02 PM.



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