New DDM60 owner noob question on initial AutoSlew setup

[AnakChan]

I (not so recently) acquired an ASA DDM60 Std and Berlebach Planet tripod setup back in Nov and only now have made an attempt to set it up properly. I live in the Southern Hemisphere.

Using the ASA AutoSlew manual, I'm good with the Servo Setup and Balance. But the next part I'm stuck with which I need help with are :-

1) GPS dongle - Device Manager doesn't complain, but doesn't seem to pick up any satellites. So can I can ignore the GPS dongle but just :-
   a) input my latitude/longitude manually. What about the elevation? Is it in metric of imperial?
   b) my NUC is connected to my home WiFi so I can time sync with the my ISP's NTP server. Is that good enough? I don't see a date/time in Autoslew and assume if my PC's date/time/TZ is correct, that's good enough?

2) Homefind - I set my scope to point to zenith and my CW bar pointing to West. It seems to set it correctly (at least the DEC, the reading on the RA OTOH looks off), but I save that Park1 position anyway (but I don't Set new Homeposition as I've not done any PA, nor actual star position sync - which is the next problem #).

3) I use the virtual keypad to roughly point to a star, then I go to CdC select that same star in the planetarium. I then go ahead and sync in CdC.

However after that whenever I use the virtual keypad to move the mount (especially in the N/S) it seems to be in reverse! The E/W movements on the other hand seem correct.

For some reason the alignment seems to think I’m in the Northern Hemisphere with the DEC values increasing instead of decreasing when I try to point the scope to SCP.

The RA is sidereally tracking the correct direction for the Southern Hemisphere however.

Can anyone please provide some guidance on the issues I’m having?

thanks in advance.

[Corpze]

What GPS are you using?

I have made several videos on how to making sky model and sequences etc. On my Youtube channel: https://youtube.com/c/ExoPhotography1

Maybe one of those will help

 

Regards / Daniel

[AnakChan]

Daniel,

Thank you for your response! Yes I do watch your YT videos, thank you for making them. I watched your PID tuning which is where I'm fine with the Servo Setup and the Balance. It's after that for the alignment is where I have an issue, which I believe is due to me being in the southern hemisphere. My DDM60 Std has relative encoders only and there's the HomeFind is where I run into hiccups. So I'm way behind PA, sky modelling, sequences, etc.

I bought the DDM60 off another ASA Forum member here and it's 11-12 years old. There's no info on the GPS USB stick except for the word GPS. I'm assuming it's ublox 5. I couldn't find the ublox 5 drivers, so I installed the UBX-GNSS-CDC-ACM v1.2.0.8 driver instead which put on the ublox 6 driver instead into COM6 (which from Device Manager seems fine - but I don't seem to receive any satellites). 

Cheers,

Sean

 

[Corpze]

Regarding the GPS - Try downloading Ublox GPS software, i needed to coldstart my GPS with that software once before autoslew recognized my ublox.

 

is your settings of where your CW-shaft is pointing correct?

[AnakChan]

I do believe I have the right drivers downloaded although I can't seem to find a uBlox 5 driver specifically. I couldn't find any other ublox GPS application to test whether the drivers are working. However per my original Q1, even if I can't get the GPS working, I can input in my location manually but :-

1) the sea level elevation, I don't know if it's asking in imperial or metrics
2) no where to manually input date/time/TZ, but I'm assuming AutoSlew could just read that off my PC's system time (I'm connected to the internet so I should be pulling the time from the NTP server)

As for where my CW-shaft is pointing, yes it's correctly pointing to the West since I'm in the Southern Hemisphere as per the AutoSlew manual.  When I click on HomeFind button which then moves the RA/Dec to find the reference mark which it reports success.

a) Comparing to my planetarium software, the Dec at zenith seems close enough to what is reported on AutoSlew, but the RA seems way off.
b) moving the mount with the virtual keypad, pressing N(orth), the mount seems to move toward S(outh) - the Dec numbers also seem to increase/decrease in the opposite direction to what I expect it to. e.g. the Dec is pointing to zenith, I press S, the scope starts to move towards "northwards" toward the celestial equator, but the Dec numbers drop moving toward -90deg. If I press N, the scope starts to move toward the SCP, but the Dec numbers start to decrease toward celestial equator.

Pressing E(ast) & W(est) however, seems to moving toward the correct direction. Also if I leave the mount alone (Sidereal tracking), it's rotating toward the correction direction for the Southern Hemisphere.

[MarkS]

You should set New Home Position on the zenith as soon as homefind has completed. This is important, and you can change it later if you wish.  You should only need to do this once.

The GPS can be tricky - however it is worth getting it functioning as the mount will then know which hemisphere it is in, and the ini files will be set up automatically.

I have found that using a 1 or 2 metre long heavily shielded cable between the GPS unit and the computer helped me. I just connected the GPS via the cable and took the laptop to a clear place in the yard and waited for the software to register 4 or more satellies. If it didn't I would move to another place and try until I did get a reading. Even then I found it needed a clear sky.

Then with Sequence open as well as Autoslew, ensure the readings have transferred to Current Location and Hardware settings panel, Apply AND Save. You only have to do this once. The altitude is in metres, but you don't need to worry about inaccuracy of this reading - it's really not critical.

When you fire up the system, you may get a notice asking if you want to change hemisphere. This should fix your problem - assuming all else is correct......

Hope this helps.

Mark

 

Edited March 29, 2022 by MarkS

[AnakChan]

Hi Mark,

Thanks for replying. If you're referring to :-
a) this part of the documentation (Saving Park Position 1), yes I do do that.

b) or did you mean set new Homeposition? I hadn't set Homeposition yet 

 

I've only done (a), but I haven't tried (b) yet as I came across an old post that set new Homeposition is only after I've Polar Aligned or have a good pointing model.

Should I just do (b) first? Then from there, go through a more accurate PA routine, then set a Homeposition again?

[MarkS]

Yes - I have not bothered with a) for a long time.

Mark

[AnakChan]

Hi Mark,

Unfortunately no joy. Even setting new HomePosition, after pointing to Zenith (counterweight points west), and going through the HomeFind routine, and setting new HomePosition, the zenith RA/Dec are actually correct. However moving the mount in the Dec direction (N/S), the scope moves to the opposite to N/S, and the Dec numbers on AutoSlew is counting up/down in the opposite direction of where it should be (i.e. Autoslew would have SCP at some Dec +xx:yy value).

I switched on Advanced option and found a way to sync the time from internet (without GPS) however to no avail. This is something really fundamental in the sync alignment that I'm just missing.

Sean

[MarkS]

Maybe you should organise a remote session with Wolfgang Promper at ASA Support. He can check your system and diagnose software problems on line.

Mark

 

 

[AnakChan]

Big thx to @ColinR, the issue is now resolved. So whilst I had pointed my CW to the west, it seems I also need to Define the Zenith Park Position to select West. The other missing instruction for Southern Hemisphere owners would be to use the Synch in the Galaxy submenu (after centering to an object, naturally) and in that Synch, it’ll also ask for where the CW is pointed to. Both of these seem to then have the mount registered in the correct orientation/alignment and thereafter, the mount limits and general GOTO are correct.

It would be good to have the AutoSlew manual updated to include either of the above for the initial setup. Just having the CW pointed toward the west and scope at zenith for HomeFind is not enough, the Zenith Park Position E/W orientation needs to be updated too.

Cheers to all who’ve helped me with this.
Sean