Let me emphasize in a pinned comment that this video is not for bashing on CEM mounts. In fact - as my previous CEM related video showed (th-cam.com/video/sl_1xzLS29w/w-d-xo.html) - I really like these iOptron mounts. I was probably just experiencing bad luck. That my mount was waiting all that time for my camera to return from a repair (did I mention bad luck already?) probably didn't help either.
Thanks Matrin for your video. One question though, would moving the problematic belt from the RA motor/belt setup to the DEC side not create problem on the DEC side?
@@dnranjit Yes it did. But as the DEC direction is barely moving during tracking, this is hardly an issue. By now I have replaced that belt with a brand new one.
I feel you as a CEM25P user for 3 years now. It started out horribly - always guided perfectly fine in RA, but my DEC was close to unguidable due to backlash. I did surgery on it a couple of times, first only the belt, then the gear meshing. The belt alone helped a bit, I was able to guide unidirectional quite decently in DEC, but I wasn’t perfectly content, so I fixed the meshing, took me an hour and I was so afraid to mess it up. In the end, it was worth it - I can guide in both directions in DEC now, backlash is down to 1000ms which is pretty good for a 950€ mount (what I paid for it 3 years ago). My guiding is at 0.5-0.8” normally in total, depending on if I’m close to the zenith or not. If seeing is atrocious, it might go up to 1”, but still good results imo. I’m convinced I could have never reached that with the HEQ5, plus it is quieter, and most important, lighter, also was cheaper back then. I’m so content with that tiny thing now, I run around 6.5-7kg on it, I’d say, on an imaging scale of 1.1”, but I also did lower with success. I still crave a bigger mount, mainly because I want a smaller image scale and a bigger scope, but I don’t know a single mount who can achieve guiding like that with a pricetag and a weight like that, same applies for the other CEM mounts. Yeah, the meshing / belt might need fixing with those if you’re unlucky, but at least for the cem25p it was pretty easy. In fact I love it so much now that I won’t ever sell it, even when I plan to get a higher payload mount - dual rigs it is then, it is too good now to not use. It’s plug and forget now with a small refractor and tiny pixels, as long as there’s no cloud fucking up the guiding, I have ZERO pics that need to go after a night imaging. I even did narrowband images up to 5 mins, could probably easily go higher. My next one will be iOptron as well :D
I had two CEM40's until recently. I have replaced the star of this video with a ZWO AM5. It is very similar in performance to the CEM40, but much more easy to use / setup. A video on it is still in production. It is going painfully slow.
That is awesome. I hope you will have it fixed in no-time and enjoy this mount! I ended up getting new belts from iOptron (through my favorite Astro gear shop in the Netherlands)
I've never had to open my Celestron mounts (CGX and AVX), and was always worried that I might have to someday. This video has reduce my concern from a Bortle 8 to a 4. Thanks!
In case there is no warranty left, it doesn’t mind opening things up to see if you can solve issues. I was unsure what to find when starting to record myself tinkering away. The original footage is over an hour long (plus lost footage when my phone and camera had run out of storage, while I tinkered on).
Brilliant stuff! I have been experiencing a similar noise from y CEM40g from 2022, and it’s been deteriorating in RA while tracking/guiding. Have belts on order and fingers crossed on getting this resolved! Many thanks as this absolutely helps. Cheers, Aayush
Thanks. That is the point of my videos. Every time I hit a roadblock in my astrophotography journey I am convinced that the solutions I find, will be somehow valuable to others as well.
Great job there Martin glad you have your mount back up & running, I have to admit I were thinking it was a damaged worm drive by the clicking but thank goodness it wasn't that. I'm thinking about getting an old Celestron CGE pro up & running as I cannot afford a big hefty mount for the observatory. There's a guy called Chad Gray who makes a complete onstep kit which basically junks all the Celestron electronics & motors & replaces it with new motors with belt drives etc. Maybe I'll start on that project next year. Good to see Dylan offering his advice to lol, clear skies.
I was afraid somehow my worm or RA gear developed a defect as I had my gear engaged all those months I was waiting for my camera to return. I now have my mount stored with the clutches open. Hence the rubber bands you see at the start. Luckily that was not the case and it was ‘just’ a worn belt.
I have the same sounds coming from my new CEM70 after using it just 30 minutes or a little more. Guide graph shows a spike at intervals which leads me to think I may have the same issue as you had in this mount. I am going to check it out. Thank you !!
If it is a brand new mount, I think it is a good idea to also inform your supplier. This wear and tear is a bit weird for a brand new mount IMHO. Mine developed the issue after 2 years.
Looks like mission successful with the round stars at the end. Interestingly my CEM60 has started making a clicking noise when it slews although at this stage I haven't seen an issue with the stars but I'm beginning to wonder of my belt might need replacing.
I first noticed it in my stars. They turned into squiggly worms... In the morning my mount is in home position, and the only slew I am at the mount was at polar alignment. Didn't notice it then.
@@KopLamp I bought just in case one of the original belts breaks, not had chance to use one yet but I did change the bearings on the RA & DEC worms whilst the belts were off I checked and same size. New ones had same part number so shouldn’t be an issue either
Thanks for that brilliant video! Even though it is already a few days old I will still try to get any answer. Do you know what is the length of the belts? B76MXL belts are available in different lengths.
Really? Hmm I thought it had a predefined size. The 76 refers to the amount of teeth. The MXL refers to the shape of those teeth. So the two together should equate to a certain length. The width however is something you get to choose. For the iOptron mount pick the 6mm width version.
@KopLamp Hey! I just saw it's a stupid display on AliExpress. You are right the length is defined by the number of teeth. I ordered some with the same marking like it is visible in the video. I also ordered 6mm wide. Let's see how long the 10 belts will last. 😂 10 was the smallest package that I could get. 50 or a 100 might have been a few belts too many. 🤣 I hope my 2020 CEM40 (I have the G config without Guider) can be opened as easy as yours.
@@astrofromhome I think all CEM40's should have a similar motor mounting. It is the plugs and wiring that differs from model to model. You could look up my video on all different iterations I found: th-cam.com/video/sl_1xzLS29w/w-d-xo.html
Hi Martin. I hope you can help. I’ve disassembled my CEM40, but I’m stuck at the step where you missed the recording!! 😅 Can you please clarify how did you remove the saddle? I’m trying to open the DEC axis cover, as I have a bad grinding noise in my DEC axis, which grew louder when I tensioned the DEC belt. If you have the time, have a look at the video I uploaded today to TH-cam. I removed the plate covering the wires, and the four bolts anchoring the saddle, but I was still not able to remove the saddle? What am I missing? P..S. I have the same first version CEM40 like yours. Many thanks Ossi
That is strange. The saddle is only attached to the mount by those four bolts. Be careful though as pulling too hard on it might become a problem when it does come loose suddenly. You might damage those wires.
I don’t know. This time it was just wear which was easily fixable. I’ve read about other mount brands that need complete dismantling and tuning with gear replacement kits if you want to get good results, because the off the shelf units are mediocre. When the on/off switch broke, the shop (and ultimately iOptron) was quick in saving the day to get me a replacement board.
@@KopLamp That's good to hear. I have been thinking of getting the CEM40 or the GEM45. Can't really seem to make up my mind. People seem to love or hate the iOptron mounts lol
As always people with one brand will burn the competitors brand to the ground. Think Apple / Android. Or in our world ASIAIR / NINA. There is always a list of pro and cons to take into consideration and those differ per person. Don’t listen to haters or lovers too much.
Let me emphasize in a pinned comment that this video is not for bashing on CEM mounts. In fact - as my previous CEM related video showed (th-cam.com/video/sl_1xzLS29w/w-d-xo.html) - I really like these iOptron mounts. I was probably just experiencing bad luck. That my mount was waiting all that time for my camera to return from a repair (did I mention bad luck already?) probably didn't help either.
Thanks Matrin for your video. One question though, would moving the problematic belt from the RA motor/belt setup to the DEC side not create problem on the DEC side?
@@dnranjit Yes it did. But as the DEC direction is barely moving during tracking, this is hardly an issue.
By now I have replaced that belt with a brand new one.
I feel you as a CEM25P user for 3 years now. It started out horribly - always guided perfectly fine in RA, but my DEC was close to unguidable due to backlash. I did surgery on it a couple of times, first only the belt, then the gear meshing. The belt alone helped a bit, I was able to guide unidirectional quite decently in DEC, but I wasn’t perfectly content, so I fixed the meshing, took me an hour and I was so afraid to mess it up. In the end, it was worth it - I can guide in both directions in DEC now, backlash is down to 1000ms which is pretty good for a 950€ mount (what I paid for it 3 years ago). My guiding is at 0.5-0.8” normally in total, depending on if I’m close to the zenith or not. If seeing is atrocious, it might go up to 1”, but still good results imo. I’m convinced I could have never reached that with the HEQ5, plus it is quieter, and most important, lighter, also was cheaper back then. I’m so content with that tiny thing now, I run around 6.5-7kg on it, I’d say, on an imaging scale of 1.1”, but I also did lower with success. I still crave a bigger mount, mainly because I want a smaller image scale and a bigger scope, but I don’t know a single mount who can achieve guiding like that with a pricetag and a weight like that, same applies for the other CEM mounts. Yeah, the meshing / belt might need fixing with those if you’re unlucky, but at least for the cem25p it was pretty easy. In fact I love it so much now that I won’t ever sell it, even when I plan to get a higher payload mount - dual rigs it is then, it is too good now to not use. It’s plug and forget now with a small refractor and tiny pixels, as long as there’s no cloud fucking up the guiding, I have ZERO pics that need to go after a night imaging. I even did narrowband images up to 5 mins, could probably easily go higher. My next one will be iOptron as well :D
I had two CEM40's until recently. I have replaced the star of this video with a ZWO AM5. It is very similar in performance to the CEM40, but much more easy to use / setup. A video on it is still in production. It is going painfully slow.
You are a life saver, got a new/used one and it's having this exact issue, was so disappointed but now I have a solution!
That is awesome. I hope you will have it fixed in no-time and enjoy this mount! I ended up getting new belts from iOptron (through my favorite Astro gear shop in the Netherlands)
Very timely video Martin. I just recently developed those huge periodic spikes in my RA out of nowhere. So I'll be checking my belts asap. Thanks.
I've never had to open my Celestron mounts (CGX and AVX), and was always worried that I might have to someday. This video has reduce my concern from a Bortle 8 to a 4. Thanks!
In case there is no warranty left, it doesn’t mind opening things up to see if you can solve issues. I was unsure what to find when starting to record myself tinkering away.
The original footage is over an hour long (plus lost footage when my phone and camera had run out of storage, while I tinkered on).
Brilliant stuff! I have been experiencing a similar noise from y CEM40g from 2022, and it’s been deteriorating in RA while tracking/guiding. Have belts on order and fingers crossed on getting this resolved! Many thanks as this absolutely helps.
Cheers,
Aayush
Great to hear! I hope it will solve the issue as it did with mine.
thanks for the video, most informative
Thanks. That is the point of my videos. Every time I hit a roadblock in my astrophotography journey I am convinced that the solutions I find, will be somehow valuable to others as well.
Great job there Martin glad you have your mount back up & running, I have to admit I were thinking it was a damaged worm drive by the clicking but thank goodness it wasn't that. I'm thinking about getting an old Celestron CGE pro up & running as I cannot afford a big hefty mount for the observatory. There's a guy called Chad Gray who makes a complete onstep kit which basically junks all the Celestron electronics & motors & replaces it with new motors with belt drives etc. Maybe I'll start on that project next year.
Good to see Dylan offering his advice to lol, clear skies.
I was afraid somehow my worm or RA gear developed a defect as I had my gear engaged all those months I was waiting for my camera to return. I now have my mount stored with the clutches open. Hence the rubber bands you see at the start.
Luckily that was not the case and it was ‘just’ a worn belt.
I have the same sounds coming from my new CEM70 after using it just 30 minutes or a little more. Guide graph shows a spike at intervals which leads me to think I may have the same issue as you had in this mount. I am going to check it out. Thank you !!
If it is a brand new mount, I think it is a good idea to also inform your supplier. This wear and tear is a bit weird for a brand new mount IMHO. Mine developed the issue after 2 years.
Looks like mission successful with the round stars at the end. Interestingly my CEM60 has started making a clicking noise when it slews although at this stage I haven't seen an issue with the stars but I'm beginning to wonder of my belt might need replacing.
I first noticed it in my stars. They turned into squiggly worms... In the morning my mount is in home position, and the only slew I am at the mount was at polar alignment. Didn't notice it then.
I bought spare belts for my CEM70EC from Amazon, if you take the part number that's on the belt and do a search on Amazon you will find them
Did they fit correctly? It seemed to me that the most belts sold online are a bit wider (62mm vs 60mm that my CEM40 needs).
@@KopLamp I bought just in case one of the original belts breaks, not had chance to use one yet but I did change the bearings on the RA & DEC worms whilst the belts were off I checked and same size. New ones had same part number so shouldn’t be an issue either
Thanks for that brilliant video! Even though it is already a few days old I will still try to get any answer.
Do you know what is the length of the belts? B76MXL belts are available in different lengths.
Really? Hmm I thought it had a predefined size. The 76 refers to the amount of teeth. The MXL refers to the shape of those teeth. So the two together should equate to a certain length.
The width however is something you get to choose. For the iOptron mount pick the 6mm width version.
@KopLamp Hey! I just saw it's a stupid display on AliExpress. You are right the length is defined by the number of teeth. I ordered some with the same marking like it is visible in the video. I also ordered 6mm wide. Let's see how long the 10 belts will last. 😂 10 was the smallest package that I could get. 50 or a 100 might have been a few belts too many. 🤣
I hope my 2020 CEM40 (I have the G config without Guider) can be opened as easy as yours.
@@astrofromhome I think all CEM40's should have a similar motor mounting. It is the plugs and wiring that differs from model to model. You could look up my video on all different iterations I found: th-cam.com/video/sl_1xzLS29w/w-d-xo.html
Hi Martin. I hope you can help.
I’ve disassembled my CEM40, but I’m stuck at the step where you missed the recording!!
😅
Can you please clarify how did you remove the saddle? I’m trying to open the DEC axis cover, as I have a bad grinding noise in my DEC axis, which grew louder when I tensioned the DEC belt. If you have the time, have a look at the video I uploaded today to TH-cam.
I removed the plate covering the wires, and the four bolts anchoring the saddle, but I was still not able to remove the saddle?
What am I missing?
P..S. I have the same first version CEM40 like yours.
Many thanks
Ossi
That is strange. The saddle is only attached to the mount by those four bolts. Be careful though as pulling too hard on it might become a problem when it does come loose suddenly. You might damage those wires.
LMAO Lab coat and gloves. Your not ok are you? Good video. Found bad power switch in mine.
Are you telling me you never wear a lab coat? ;-)
It is my little hommage to one of my astro-youtube-heroes Dylan O' Donnell.
The iOptrons seem a bit fragile compared to some other mounts, do you think?
I don’t know. This time it was just wear which was easily fixable. I’ve read about other mount brands that need complete dismantling and tuning with gear replacement kits if you want to get good results, because the off the shelf units are mediocre.
When the on/off switch broke, the shop (and ultimately iOptron) was quick in saving the day to get me a replacement board.
@@KopLamp That's good to hear. I have been thinking of getting the CEM40 or the GEM45. Can't really seem to make up my mind. People seem to love or hate the iOptron mounts lol
As always people with one brand will burn the competitors brand to the ground. Think Apple / Android. Or in our world ASIAIR / NINA. There is always a list of pro and cons to take into consideration and those differ per person. Don’t listen to haters or lovers too much.