Lesvedome Dome control and Eqmod report 10 deg difference and doesn't hold sync

Sequence Generator Equipment Compatibility
1

I am using the Lesvedome Dome software and a EQ6 mount together.

I have set the Dome Diameter,sensor size and number of holes in the Lesvedome software and i can position the slot quite accurately around the dome just using the dome software and goto’s. In SGP I have the same Diameter and the rest of the details, (Gem Offset,etc) in the Slave Settings Of SGP.

I have tried connecting using both the Lesvedome driver and Ascom for dome control and get the following result…

After slewing to a star the dome usually positions the slot quite close to being centered over the scope, however there is a 10 deg Azimuth difference between the reported position of the dome, in SGP, to the mount.

A few times the slot was not centered, so i disconnected the dome from the mount in SGP, jogged the dome to center over the scope, synced the dome, in SGP, to the reported Azimuth mount position and as soon as i reconnected the dome to follow the scope, the dome moved back to the old position. As if it didn’t care about the new sync point but was just using the mount AZ position

The only way i could stop the dome moving away from the new “jogged” position was to trick it by syncing with the original AZ position . Only then would the dome stay centered over the scope and not move.

I have checked my Time and coordinates in the Planetarium program and Eqmod and they match

Has anyone experienced this, Not sure why there is 10 deg difference but more interested in why when re-syncing, the dome wants to go back to the old position and not stay put

Thanks Geoff

2

Unless you have an Alt/Az mount the Azimuth of the dome and the azimuth of your mount will rarely ever be the same when the mount is correctly tracking.

I would double check the slaving parameters in SGP and make sure they’re accurate as well as making sure the dome azimuth is correct (should be 0 when the slit is pointed north). Have you previously slaved your dome to your mount using other software?

Thanks,
Jared

3

Jared, thanks for the reply.

No i have only connected the dome and mount using SGP.

I can slew to south 180 deg and slot is quite close to that point, which is pleasing. I believe the Lesvedome and SGP Slave settings are very close, as after a few slews the scope still points quite close to the center of the slot and they both track together.

If the dome and mount star stay matched up then happy days, just curious why a 10 deg difference.

Cheers Geoff

4

I guess I don’t understand what you mean about the 10 degree difference. There’s really only one area where you can guarantee that the azimuth of the scope and dome will be nearly the same and that is when the scope is pointed due north in the counterweight down position. Every place else there will be some offset between the dome and telescope azimuth because of the gem offset distance.

Thanks,
Jared