How does the DDM 85 find it position after power off?

[maxmirot]

If the mount is powered down without parking, will it still know where it is when powered up?

Or if it  is parked and gets bumped/moved with power off will know it is position?

 

I am trying to understand if when I need to find home.   Also if the scope is moved will it have trouble finding home?

 

I have assumed that these are absolute encoders. 

 

Therefore, autoslew would know a correct position as long as the time was correct and a sync was properly done.

 

 

Max

[RamaSpaceShip]

Hi Max,

 

If the mount is not moved at all after power off, it will know where it is when powered up. But ti can move very easily (gone with the wind) so there is no certainty here.

It is very wise to do a home find at start up, as this is how it gets its reference position.

 

To make sure it will find its home, first point to the zenith, as the home is nearby.

 

Of course, you need to have made a good pointing model and set the home position, for the mount to know the correct position.

 

Bernard

[maxmirot]

If I move the scope 90 degrees will it then still point to zenith ? Or will it be confused and possibly hit the pier?

 

I know if I visually bring the scope to East Zenith and then find home it will be perfect ever time.

 

 Do have to have a web cam to verify its position to be safe if I am working remotely?

 

Thanks

 

Max

[MichiP]

Hi Max,

 

I would really recommend to use a webcam with night vision when using your observatory remotely. A visual check will give you more safety in unclear situation. Such webcams are not very expensive anymore, I'm using a 40€ cam which can be tilted in all directions.

 

Regards,

Michael

[lukepower]

Bernard,

 

these mounts are using relative encoders - as long as the software is running (or probabily the mount's electronics are powered up) they track the movements and know this way their position.

After a power cycle (power off then power on) they suppose that the mount has not moved. If it has, take care as it can hit everywhere. Michael's suggestion of a webcam is a very good one I hit quite a few times the pier or the roof when I got my mount

 

There are other mounts around - and possibly the DDM160 (not sure) which use absolute encoders: They do not loose the position even without power

[maxmirot]

Thanks for answering the question. I though they were absolute encoders. Webcam is no big deal.

 

Max