Home position or not?

[Phil Fargaze]

I was having problems with the goto accuracy of my Heq5, so I now got it on a stable pier and gave it another go last night. Started from home position with 3 star alignment but the mount was about a degree out like it was before. I reparked it and powered up again and chose not to start from the home position, did 3 star alignment and bingo, it was spot on. Mars, Eskimo Nebula, M36-38 were all put in the fov nicely. I am trying to understand why this would be so and should I always not start from the home position?

[decoyp]

Phil,

I dunno ! But mine does the same. I never used to use the home position at all I just powered down after a session and then moved the mount to a convienient storage position using the axis locks. I then found out that you could ask it to park in the home position. So I started doing this but then found as you have, that it's better to say No to restarting from home position at the next session, otherwise it seems to get its knickers in a twist. Sorry I can't help any more than that.

Richard

[Phil Fargaze]

Ok thanks. When this weather gives me a chance I can go out and experiment a bit more.

[adamsp123]

I suppose you could start at the "home position" go to the first star and manually adjust the mount to centre the star and then tell the mount to go to home position which now should be more accurate as a start point, only useful if the mount is permanently positioned and polar aligned.

[Phil Fargaze]

The mount is now nicely set on a pier and polar aligned so I could certainly try that.

[ollypenrice]

I do use the Park Scope-Home Position function on both our EQ6 mounts. I find they are both far more accurate in their first slew when I start from here. Indeed I rarely have to bother to leave the computer screen because the alignment star is on the chip 8 times out of ten. If it isn't then the direction of its glow is often there instead so the finder never gets a look in.

Cone error - misalignment of the OTA with regard to the axes of the mount - is a common cause of difficulty but the EQs can handle it with 3 star alignment, I think.

Olly

[Phil Fargaze]

I havn`t got round to checking for cone error but I do understand that the 3 star alignment can correct for that. I need to study the instruction book a bit more regarding cone error checking though:icon_scratch:.

So if I guess right the park position helps the controller to remember a map of the sky:icon_confused: and if the mount is fixed solid there is a good chance that I can start from the park position. Typical cloud cover is making this a bit of a slow process

[ollypenrice]

So if I guess right the park position helps the controller to remember a map of the sky:icon_confused: and if the mount is fixed solid there is a good chance that I can start from the park position. Typical cloud cover is making this a bit of a slow process

Well, it certainly works for me. I am always vaguely miffed when the need to shoot flats or swap scopes means I lose my park position.

I'm generally running round like a B.A.F. at that stage of the evening anyway so a bit of help from the mount is very welcome.

Olly

[dark knight]

Ditto what Olly and Pete says, works for me too.