Dome Control Help

[steppenwolf]

7 hours ago, alcol620 said:

Me again. A quick question. When you had your Pulsar Dome installed, did you have the pier offset to the south or was fixed it in the center of the dome? I read somewhere that there needs to be a small amount of offset to cater for the EQ mount.

Hi Alec,

I don't have a deliberate pier offset as it just isn't necessary as the Pulsar shutter opens past the zenith. If you have a really large aperture telescope, then it may be more of an issue but my 100mm and 150mm refractors are fine with a centre mounted pier - I am a bit of a nerd when it comes to 'symmetry'

[alcol620]

Thanks Steve.

If it is good enough for you it is certainly good enough for me. Thanks for responding. Mixing concrete Wednesday!

Regards

Alec

[steppenwolf]

Quote

Mixing concrete Wednesday!

That is always an exciting start point as you know the project is really under way!

[alcol620]

On 7/28/2016 at 17:38, steppenwolf said:

I use POTH to control both my mount and Dome and all works very well. You only enter the figures into POTH, not into any other interface.

This diagram may help you:-

Hi Steve

Presumably the only data to be measured and input are those not yellowed in your table? Also, the figures look to be to the nearest mm with measurements not being taken on flat surfaces, it looks difficult to be this accurate? Dome is in place but yet to be switched on!

[steppenwolf]

The figures in yellow are calculated from input that you supply.

27 minutes ago, alcol620 said:

Also, the figures look to be to the nearest mm with measurements not being taken on flat surfaces, it looks difficult to be this accurate?

Yes, I am a little geeky here, you do NOT need to be millimetre perfect!

I have sent you a PM - I hope it helps.

[alcol620]

13 minutes ago, steppenwolf said:

The figures in yellow are calculated from input that you supply.

Yes, I am a little geeky here, you do NOT need to be millimetre perfect!

I have sent you a PM - I hope it helps.

Many thanks Steve. PM received and printed. One last question - for now! presumably different figure for "g" axis offset will change for different scopes?

regards and thanks

Alec

[steppenwolf]

7 minutes ago, alcol620 said:

Many thanks Steve. PM received and printed. One last question - for now! presumably different figure for "g" axis offset will change for different scopes?

Exactly so!

[alcol620]

Thanks Steve

[petevasey]

Hi, Guys,

I recently motorised my dome, just a simple control system using timers.  See:

http://www.madpc.co.uk/~peterv/astroplover/equipnbits/ObservatoryDrive.htm

Works ok when imaging in the South, but as you know the dome slot position and required movement is very different when imaging in the North, particularly if near the Pole (this for northern hemisphere of course).  So I'm toying with going further.  I came across 'Lesvedome' which looks like a very reasonably priced solution, using the inexpensive Velleman board and a couple of relays and IR sensors.  I'd make my own sensor wheel, and don't intend to motorise the shutter.  But I'm a bit confused as to how to enter the GEM axis offset into POTH - do you have to change the sign depending on which side of the mount the telescope is lying when starting a session, or is this automatically allowed for by the interface of POTH with the telescope control system - my mount uses LX200/Autostar standard, and can start imaging on the 'wrong' side of the meridian without doing a meridian flip.

Cheers,

Peter.