Heq5 goto a little inaccurate

[Phil Fargaze]

I was wondering if any of you clever people had any suggestions for me.

I have polar aligned, checked the ra,dec,date and time inputs, levelled the mount, and start from home position.

But.....I have found that when I have done a 3 star alignment the goto can be more than a degree out. I checked the skywatcher web site and there was a suggestion to make the first alignment star near to the meridian as possible. I didn`t do this the other night but would it produce the sort of error I am getting?

Also, I centered it on Castor, did a re-alignment on that star by pressing esc for 2 sec then did the short hop to Pollux and it was out by a degree or so . Any suggestions gratefully received.

[Breakintheclouds]

Phil,

I'm not sure how useful this will be, but I've found that certain sets of alignment stars just work better than others. Every now and again I'll find a perfect set of three and enjoy excellent alignment, until they move too much and I have to start again! For example, I seem to recall back in Autumn that Vega and Deneb plus anything the other side of the meridian used to give a really good starting point; other sets weren't as good.

I once saw some sort of system for finding these groups, but alas can't remember where I saw it. For now, perhaps a bit of trial and error? If you're a degree off, try some other alignment stars and see how you get on with those?

[Phil Fargaze]

Ok. I will experiment with my alignment stars for a start.

Just a thought, after I had parked the scope and turned off I had loosened the lock nuts and moved the ota about. When I went to use it the next time I simply put it back to what looked like a good park position and did the usual alignment. I don`t know if this would have an effect. I might try not starting from the park position to see if that helps.

[Breakintheclouds]

Phil,

I always start my HEQ5 from an approximate park position, having moved things around by hand during set up (e.g., when balancing the scope). I've not found that to be an issue.

Ian

[Phil Fargaze]

Well, I gave it another go earlier this evening and got it to work really well. After a couple of attempts, I ended up on aligning with Caph 1st, Capella 2nd, and Castor 3rd. I did a slew to M35 and it appeared in the eyepiece So I chose to goto NGC2392 (Eskimo Nebula) for a more serious test and there it was went for Mars and it was all good. I carried on touring about the Auriga clusters until the old fingers called it a night in the -1 temp.

[Breakintheclouds]

Good news! It's a relief to find that there's nothing wrong with the mount.

[ZOG]

I don't know about the SW goto but the celestron give you a choice of alignment stars on one side of the meridian and then recommends that you add another 3 calibration stars on the other side of the meridian for optimal performance.

[Phil Fargaze]

I noticed that the synscan handset (ver 3.25) gives an option to turn on or off auto select for aligmnent stars, so this might do the same as the celestron.