iandh

Hi Guys,

Many thanks. I have just received some 99.9% isopropyl so I think that i may try with a long soak in soapy water and it that doesn't shift it I'll move on to some diluted isopropyl. I'll keep you posted, hopefully I will find some time this coming week.

Hi Guys,

Whilst setting up for observing tonight, I was checking the scope's collimation using a defocused star, when I noticed something moving. Then when I went to the front of the scope I found a snail crawling across the corrector plate!!!!!@@@@ arghhhh.

This left a trail that was obvious on my defocused star image. So now I have to clean my corrector plate, which I was soon going to need to do anyway. The BIG question is what the hell will get snail/slug slime off my corrector, That slime is one of the hardest things to get off your hands, so I guess it's not going to come off my corrector all that easily.

If anyone has had a similar experience and had success in removing the slime I would greatly appreciate some advice.

This is one of the problems of leaving a scope outside under a scopecoat in a damp old place like the UK, I guess!

Regards

Ian

HI Guys,

From what I can see my CEM60 is working in JNow coordinates, that is when I do a GOTO an object from its database via the hand controller it shows  the objects' coords in JNow epoch and when it is  on the target the displayed coordinates would appear to be in JNow epoch.

Can anyone confirm this and also whether there is a setting in the CEM60 to use J2000 coords.

The reason I ask is that I am trying to find the source of some GOTO errors when using Stellarium -> APT -> CEM60  even  though I have the JNow button enabled in APT which should send the mount coordinates in JNow epoch.

Thanks

Hi Guys,

OK so I think that I might have sussed out what is happening. with the CEM60 GOTOs:

I have just bought an iPolar for polar alignment of the CEM60 and the v2.62 software is not waiting for me to rotate the polar axis during calibration of the centre of rotation. Consequently  my polar alignment  is probably way off as shown following 3-star alignment which was reporting circa 45 minutes of error in both Alt and Az.

Having now read some threads on CN this appears to be well kown as is the workround of covering the polar scope between calibration frames. Pity iOptrom don't tell you this before you buy their product and then waste valuable clear sky time trying to figure it out!

Regards

Ian

Hi Guys,

I have now managed to sort the Zero problem by Searching Zero, removing the four Dec saddle bolts and turning the saddle to face forwards and then tightened all the bolts.

Hi Guys,

Zero Position all resolved now but still not doing accurate GOTOs after a 3-star align!

Hi Guys,

Thank-you all so much for your toughts and ideas.

I finally got hold of a very helpful techie at iOptron who,when I explained what we all thought, told me that all I needed to do was Search Zero and then undo the four saddle retaining bolts and move the saddle through 90 degs so that ihe arrow stamped into the saddle was facing forwards with the saddle parallel to the polar axis. Simple!

Simple it wasn't as the saddle was supposed to simply lift off, which it didn't . I then noticed it was sitting on the Dec shaft slightly cocked over . I eventully managed to get a flat bladed screwdriver between  the saddle and shaft and gently twisted the screwdriver until the saddle released. 

When I  went to re-seat the saddle I noticed  that the guy who did this mod had trapped the red (presumably power) cable between the saddle and Dec shaft. Luckily I noticed this as the pressure had almost pushed the conductor out of the insulation! Once I had re-seated the saddle the Dec Stop then started working as the dec stop screw was  then hitting the Dec Stop in the casting whereas it had been missing it by a couple of millimeters before!

So one issue resolved, many  thanks.

Now trying to get the CEM60 to do accurate GoTos following a 3-Star alignment but I will start a new thread about this problem......

Thanks again everyone.

Hi Guys,

I have a used CEM60 with a Mk1 Hand Control which is new to me.  I have updated it to run all the latest firmwares.

A few nights ago I managed to do a reasonable polar alignment after first SETTING Up the Zero Position. I then saved the zero position .

After a  3-star alignment it did absolutely accurate GOTOs all over the sky so I was really pleased.

However, I have found that if I do a GOTO Zero Position it goes back to the zero position as I set it, but if I do a Search Zero Position it ends up with the dovetail saddle at right angles to the polar axis rather than parallel (as I previously programmed into the Zero Position).

Furthermore , if I escape out of  the Search Zero when it stops, by hitting the Back button on the HC, my Zero Position has been reset to one where the dovetail saddle is again at 90degs to the polar axis., not where I set it. Then when I do a GOTO Zero it ends up at the wrong poition.

Has anyone experienced similar?  If so can you help me please.

On 09/08/2022 at 09:26, michael8554 said:

I don't have a CEM60, but my guess would be:

The mount may have an internal sensor for where Zero is.

Once the mount has done a "Goto Zero Position", you loosen the clutches and position the scope in Zero Position.

Michael

 

Thanks Michael,

Sorry I overlooked your reply earlier.

Yes it seems that the CEM60 requires a Zero alignment whereby the OTA is on top of the polar axis and the counterweight shaft vertically downwards and all ined upthrough the centre of teh polar axis. Apprently it is pretty fussy about this.

Regrads

Ian

Hi Guys,

I am trying to tame a new to me CEM60.

I actually managed to get it to do its first GOTO last night 🙂 I only one star aligned on Vega so did not push my luck too far so only dida GOTO M57!!!

However, I assume that to start with, one needs to set the scope in the Zero position with the OTA pointing at Polaris and the counterweight shaft vertically downwards. So I did this and set this as my Zero position on the handset. I then slewed away from Zero and did a "GOTO Zero Position" which appeared to work fine. However, when I did a "Find Zero Position" it ended up with the counter weight shaft vertically downwards as I had set it, but the OTA saddle was at a rightangle to the polar axis.

Can anyone explain this for  me please. I am running with the attached firmware. 

Hi Guys,

I have now found what appear to be the CEM60 mounting studs and locking nuts. The guy I bought the mount off had left them in  the pier mounting plate that I am not currently using as I am using the iOptron 2" tripod for field trips.

Interestingly, the 8mm x 50mm stainless steel bolts that I bought from Screwfix are non magnetic and therefore do not affect the in-built compass whereas the iOptron studs are mildly magnetic and therefore appear to affect the compass slightly. I assume this is due to the different qualities of stainless.

Thanks for your help.

Hi Michael,

Not if all you want is a quick glimpse but if you want to zoom in on a Sunspot and show a few people while telling the what they are looking at, it's best if the  Sun doesn't keep sliding out of view, which  therefore requires a reasonably accurate alignment I'm afraid.

Same goes for particular crater features on the Moon!

Regards

Ian

Hi,

Has anybody used the solar system align function on a CEM60?

Yesterday I was trying to align my CEM60 mount well enough to do some solar and lunar observing in the afternoon. I tried observing without anything more  than doing a single star align and accepting the coordinates that the scope slewed to. However, this was not good enough and the targets very quickly drifted out of FOV.

Then I thought that I would try Solar System align and use the Moon as the calibration object. However, I was only offered Mercury in the list of objects to align to.

From this, do I assume  that one only gets offered something that should be visible at the time, AND that one CAN'T align to the Moon?

Regards

Ian

Hi,

Yes those are  the bolts I was referring to, thanks. 
The originals are actually studs with a short unthreaded section in the middle for the Az. adjustment bolts to bear down on.  They have a threaded top that  then takes a top hat "Nut" with holes in that is tightened with the locking bar that is stored on the mount.

I have now sourced some M8 x 50mm stainless steel bolts from Screwfix that work quite well thanks. They needed to be non-magnetic as they are very close to the in-built compass.

Regards

Ian

Hi Guys,

I recently purchased a second-hand CEM60 mount but it looks like seller did not give me the mounting studs and "nuts".

I have just gone to attach the head to the IOptron tripod and can't.

Does anybody know what thread size the studs should be as it looks like I might have to use ordinary bolts.

Having measured the hole in the mount it looks like the lower thread that fits into the tripod head may be M8, assuming its metric.

Hopefully the top thread is the same.

Thanks 

Hi Guys,

I have an old (2004) Celesctron Nexstar 11"

I have been refurbishing it and used it last week for the first tme in about 3 months

The first time I powered it up everything went well until one axis stopped driving and I got a motor error message (or something similar)

Rebooted and calibrated on Deneb and Altair and then performed an All Sky Align and got the best ever GOTO accuracy I have ever had!

I then hybernated the scope at the end of the evening.

Tonight I was looking forward to some actual observing but when I woke the scope and checked the GOTO accuracy on Altair and Deneb it all appeared fine until I suddenly saw "Transmit Data" on the handset and could not get any response. I tried the normal things like power off/on but nothing made any difference.

I have read  that this may be caused by the handset being stuck in programming mode so I downloaded the latest version of HC Update and tried to install it on my Win10 laptop. NO CHANCE just get a message saying that its not allowed to run on my version of Windows!

Does anyone know what is the latest version of Windows that will run HC Update and MC Update come to that?

Thanks