Questions for iOptron mount users - advice please

[The Admiral]

I'm a little unsure about setting up my new GEM45, and would appreciate some advice please. I would suspect that the setting up procedure is common to all the later iOptron mounts.

• I set up and tear down for each session so I normally 'clear alignment data' before doing an alignment. I'm assuming that the stored alignment data is no longer pertinent to each new set up. Is this correct?
• Before I perform an alignment I align the mount to the 'zero position' by eye,  and then use the 'set zero position' command on the hand controller. Is this correct?
• What are the commands 'search zero position' and 'goto zero position' used for then? Does 'search zero position' make the mount find its own zero position?

None of these things are explained in detail in the manual (so far as I can see), so any help would be appreciated.

Ian

[The Admiral]

Anyone?

Ian

[Annehouw]

Hello Ian,

As nobody replied, I will give you my (limited) experience with an iEQ30Pro. Maybe, the following link may be of help? Post#9 in this tread: https://www.cloudynights.com/topic/612459-ioptron-cem60-how-to-set-the-zero-point/

1) As for the other questions: After powering down and tear down, the stored alignment certainly is not valid anymore as the orientation of the mount in all three axis will be different.

2)  Correct. I am primarily an imager. I pole align, point the cw shaft downwards and set the zero position to that position. (I have learned that on my Ieq30Pro, it will disable tracking if I do not set a zero position). To get accurate pointing for visual use you need to do the alignment steps. Again, as I am an imager, I just point the scope somewhere, do a platesolve and after that go to my target (I use goto++ in APT, which does that in a recursive way: goto, platesolve, measure the distance from target, goto, platesolve etc. How crucial an absolute correct zero position is if you want to do the manual alignment process, I do not know.

3) See the link above. 

 

Anne

 

[Davey-T]

On my old iEQ45 I select go to zero position and let it wander off to where it thinks zero is then using hand controller rotate it so the spirit level is level ( don't know if new models still have a level built in ) then loosen clutches and set it to home position up / north.

Dave

[The Admiral]

3 hours ago, Annehouw said:

I am primarily an imager.

Thanks very much for your input and link Anne. Me too, but I don't have a camera which has an accessible image (it's a mirrorless camera), so I can't plate solve. I have taken to doing a 3-star align before slewing to my chosen target.

This part of #9 of the link, is basically what I do.

"2) Level the tripod, point counterweights down and DEC veritcal using a level if you wish.  The enter ""set zero to current position".  This will now be the new zero position."

 

2 hours ago, Davey-T said:

don't know if new models still have a level built in

It has a level but only on the base of the mount. Hmm, interesting routine you do.

Ian

[Davey-T]

2 hours ago, The Admiral said:

It has a level but only on the base of the mount. Hmm, interesting routine you do.

Mines got a level attached to the RA axis that rotates with it.

Dave

[PaulE54]

I use my CEM40 for imaging. So I don't set or clear alignment points, I just plate solve. I'd agree with all the points above. I'd also add in answer to your third point that I use the "goto zero position" at the end of each night before I pack up. You either have to do this, or "set zero position" at the start of each night with the mount physically in the zero position. 

What you MUST NOT do, which is also not explained except very indirectly in the manual, is to turn the mount off with it not in zero position, return it to zero by unlocking both axes & physically moving the mount, and then start imaging on the next night without performing a set zero. The mount remembers where it was when unpowered. Life will get very confusing. You will give yourself a nasty scare. 🙂

Paul

[The Admiral]

4 hours ago, PaulE54 said:

I use my CEM40 for imaging. So I don't set or clear alignment points, I just plate solve. I'd agree with all the points above. I'd also add in answer to your third point that I use the "goto zero position" at the end of each night before I pack up. You either have to do this, or "set zero position" at the start of each night with the mount physically in the zero position. 

What you MUST NOT do, which is also not explained except very indirectly in the manual, is to turn the mount off with it not in zero position, return it to zero by unlocking both axes & physically moving the mount, and then start imaging on the next night without performing a set zero. The mount remembers where it was when unpowered. Life will get very confusing. You will give yourself a nasty scare. 🙂

Paul

Thanks for the input, but would I be correct in assuming that you are using a permanent set up, where you can switch off, leave the mount, and then come back and switch on again? When you have to set up and tear down for each session, you end up unlocking the axes after the mount is put back in its case for transport. So re-setting the zero position sounds like the correct thing to do.

Ian

Edited June 10, 2020 by The Admiral

[david_taurus83]

I platesolve with my CEM25 and the setup is left relatively intact and just lifted indoors after but if I was to strip down fully each time I would think resetting the zero (home) position each time would be standard procedure. I assume you are exclusively using the hand controller?

[The Admiral]

1 hour ago, david_taurus83 said:

I assume you are exclusively using the hand controller?

Indeed!

Ian

[PaulE54]

2 hours ago, The Admiral said:

Thanks for the input, but would I be correct in assuming that you are using a permanent set up, where you can switch off, leave the mount, and then come back and switch on again? When you have to set up and tear down for each session, you end up unlocking the axes after the mount is put back in its case for transport. So re-setting the zero position sounds like the correct thing to do.

Ian

No I do actually take it down, and set up for each session. However this is from outside the house to inside and back again, so I don't put the mount in its case. 

My workflow at the end of each night is that I park the mount in zero position. Then I detach all the cables from mount to scope and detach the scope, carry that inside. Then remove tripod spreader and all data and power cables from house to mount.  Then remove counterweights. Finally carry bare mount parked at zero into house. Reverse when setting up. 

But yes, in your case I would reset zero position at the start of each night. 

Clear skies

Paul

[Fegato]

I have a CEM40, purchased fairly recently so still learning. I take in and out in a similar way to Paul, so in theory don't need to reset zero position. But any playing around while switched off does mean you need to do this.

The Search Zero Position function does allow the mount to find the zero position itself, so you don't need to do it by eye. I use this and it appears to work fine. Just make sure the mount is totally level first obviously.

[The Admiral]

29 minutes ago, Fegato said:

The Search Zero Position function does allow the mount to find the zero position itself, so you don't need to do it by eye. I use this and it appears to work fine. Just make sure the mount is totally level first obviously.

I suppose the question that comes to mind is whether it is seeking its 'native zero position' (if such a thing exists), or whether it is returning to the last saved zero position, though I would think that would happen with the command 'goto zero position'. I'll try the search command next time when I eventually get around to using the mount again.

Ian

[The Admiral]

7 hours ago, Fegato said:

The Search Zero Position function does allow the mount to find the zero position itself, so you don't need to do it by eye. I use this and it appears to work fine. Just make sure the mount is totally level first obviously.

I emailed tech support at iOptron today, asking what each command does. I received this speedy response:

"Set zero position: This command set the current position as zero position. It should be executed only if the mount is at true zero position. Usually after a star alignment, and goto zero position.

GoTo zero position: This command should slew the mount to the memorized zero position, or the zero position with newly correction by star alignment. It is useful to check whether zero position is altered in case the motor skipped step (grinding sound).

Search zero position: instead of set the mount at zero position physically, i.e. the telescope point to the Polaris (north), the counterweight shaft point to the ground, one may use the search zero position command to move the mount to zero position physically. The mount has imbedded sensors to find zero position."

I'm not sure that that is entirely clear either. Interesting though that the mount has embedded sensors to find the zero position, I didn't know that before! As Fegato says, but why it isn't obvious from the manual I don't know (unless I've missed it!)

Ian

[PaulE54]

Well you learn something every day! I'll try that "search zero", sounds like it could be useful. Might give me more accurate first slews. 

Cheers

Paul

[The Admiral]

1 hour ago, PaulE54 said:

Well you learn something every day! I'll try that "search zero", sounds like it could be useful. Might give me more accurate first slews. 

Cheers

Paul

Well of course I specifically asked in relation to my GEM45. One would expect that the CEM40 would also have that feature if there is the same command in the handset.

Ian