How acurate is your "goto" ?

[toryglen-boy (Duncan)]

I have recently aquired a HEQ5 Pro mount in very good condition from another forum member (thanks Daniel you where very helpful!) i no the polar alignment isnt exact, but for observational use its pretty good, but i am finding out that the "goto" on it is woefully inaccurate, i know its probably caused by me messing around with the mount, and i know there is nothing wrong with the equipment, it just doesnt seem that acurate at all !!

I am using an Orion ED80 with a Meade 26mm plossl, the scope is only F7 (F7.5?) so it should be a wide-ish FOV, but its usually out by quite a bit

Can anyone recommend any tips for getting the best out of the HEQ5 Pro mount?

thanks

[madwayne (Wayne)]

Hi Duncan

Are you doing a three star alignment? And making sure one of three is on the opposite side of the meridian to the other two? Your first alignment star will usually be well off (outside the FOV your finder, or it was when I tried it with my EQ6) but the next two should be pretty close. The aim is to draw a big triangle around the part of the sky your are viewing/imaging - if you knew this my apologies for pointing it out.

Also, you bought the mount from someone on the forum, is he in Canberra by any chance or do you need to adjust the lattitude on the side of the mount?

I've made these suggestions on the assumption you are entering lattitude and longtitude correctly as well as the date in the correct format on the hand controller.

That's all for now please report back .

Wayne

[toryglen-boy (Duncan)]

Originally Posted by madwayne

Hi Duncan

Are you doing a three star alignment? And making sure one of three is on the opposite side of the meridian to the other two? Your first alignment star will usually be well off (outside the FOV your finder, or it was when I tried it with my EQ6) but the next two should be pretty close. The aim is to draw a big triangle around the part of the sky your are viewing/imaging - if you knew this my apologies for pointing it out.

Also, you bought the mount from someone on the forum, is he in Canberra by any chance or do you need to adjust the lattitude on the side of the mount?

I've made these suggestions on the assumption you are entering lattitude and longtitude correctly as well as the date in the correct format on the hand controller.

That's all for now please report back .

Wayne

Hi Wayne

Yeah i knew what it was trying to do, and yeah the first star is usually way out, and the other two, not so bad. I got the mount, leveled it (checked all over with a spirit level) and set the angle of the tilt with a digital inclinometer so i know its pretty good. Alignment has been set with a digital compass pointing to the pole rather than magnetic, although i have a compass and have worked out the amount of degrees its out from the pole, and i have covered as much as i can.

I suppose drift alligning of the pole would help, to get it as accurate as poss.

does anyone have any general advice on this mount?

thanks

[Terry B]

My EQ6 with the hand controller would be within 20arcmins with any slew. With the EQMOD it is within 10arcmins always.
Polar alignment needs to be reasonable.
Can you use the polar scope?
If you can get it close with your inclinometer and compas you should be able to find the 4star asterism that is used on the polar scope. This is plenty accurate for visual use.

[mozzie (Peter)]

different scope and setup but my meade 2 star align the first star is within the 2 deg ring on my telrad and the second is in the eyepiece it tracks perfectly all night and centre of eyepiece so they are very accurate make shore the tripod legs are tight and on solid ground any movement and it all fails you may have to train your drives and make shore the backlash is correct this can cause it to drift it works fine but they can easliy go pear shaped if something is not right since ive permently piered mine its never been a prob
mozzie

[toryglen-boy (Duncan)]

Originally Posted by Terry B

My EQ6 with the hand controller would be within 20arcmins with any slew. With the EQMOD it is within 10arcmins always.
Polar alignment needs to be reasonable.
Can you use the polar scope?
If you can get it close with your inclinometer and compas you should be able to find the 4star asterism that is used on the polar scope. This is plenty accurate for visual use.

Due to trees, and buildings the pole is invisible from my location 365 days a year

i am sure with perserverance, i will get on top of it

[Robert9 (Robert)]

With my Nexstar I can get an object into the field of my 8mm Hyperion (mags = 180 x) from a swing of more than 180 degrees. I found a lot depended on backlash compensation and during the inital alignment, approaching the alignment stars in the same directions (altaz) as the goto.

[gmbfilter (Geoff)]

I have a HEQ5Pro
I set it to magnetic South with a compass
Level by eye, almost always do only 2 star align.Then it's "up up and away"
Its distance to initial alignment stars seems random and I don't worry anymore.
I would waste heaps of time fussing about with my initial polar alignment.
Drift alignment is a different issue.
Most errors are me aligning on wrong star.
I take the first 2 stars that come up in menu (unless they are behind my Hill)

[toryglen-boy (Duncan)]

Originally Posted by gmbfilter

I have a HEQ5Pro
I set it to magnetic South with a compass
Level by eye, almost always do only 2 star align.Then it's "up up and away"
Its distance to initial alignment stars seems random and I don't worry anymore.
I would waste heaps of time fussing about with my initial polar alignment.
Drift alignment is a different issue.
Most errors are me aligning on wrong star.
I take the first 2 stars that come up in menu (unless they are behind my Hill)

Thanks for that, but how accurate is the goto?

[pmrid (Peter)]

I noted that you aligned on magnetic south. Whoops! You need true south of course. And depending where you are the divergence can be quite significant. I'm in an area of 11 degree variation. You shoulod correct that immediately and then go back and do your go-to system's alignments.
Peter

[toryglen-boy (Duncan)]

Originally Posted by pmrid

I noted that you aligned on magnetic south. Whoops! You need true south of course. And depending where you are the divergence can be quite significant. I'm in an area of 11 degree variation. You shoulod correct that immediately and then go back and do your go-to system's alignments.
Peter

Who is aligned with magnetic South?

[dugnsuz (Doug)]

Originally Posted by toryglen-boy

Who is aligned with magnetic South?

Not me! True South's the way!!
This basic guide explains it (unfortunately no value for Canberra is given!!!)

http://www.myastroshop.com.au/guides...lign-basic.pdf

Doug

[toryglen-boy (Duncan)]

Originally Posted by dugnsuz

Not me! True South's the way!!
This basic guide explains it (unfortunately no value for Canberra is given!!!)

http://www.myastroshop.com.au/guides...lign-basic.pdf

Doug

Thanks for that fella, maybe he means someone else? i am aligned with true south.

[tempestwizz (Brian)]

Just bear in mind that even if you are perfectly polar aligned. and if the starting point of your alignment is perfectly at the 'home' position of 0.00 Hrs, 90 degrees, should your time setting not also be perfect for your location (E-W), there will be an initial pointing error of 15 arc minutes per minute of entered time inaccuracy.
Also consider that the 'time' you enter is for a time zone, ie same for Sydney or Broken Hill, and a given star will have a different relative RA angle in Sydney as distinct from Broken Hill.
Hence it is quite acceptable that the initial RA pointing angle is out. However, for a given location and accurate input data, that RA pointing error should start out reasonably consistent.
The DEC value should be close regardless of system timing inaccuracies.

HTH,

BC

[dugnsuz (Doug)]

Try this too Duncan...
http://www.iceinspace.com.au/63-499-0-0-1-0.html
...I use similar to set up each time, works well!
Doug

[toryglen-boy (Duncan)]

Originally Posted by tempestwizz

Just bear in mind that even if you are perfectly polar aligned. and if the starting point of your alignment is perfectly at the 'home' position of 0.00 Hrs, 90 degrees, should your time setting not also be perfect for your location (E-W), there will be an initial pointing error of 15 arc minutes per minute of entered time inaccuracy.
Also consider that the 'time' you enter is for a time zone, ie same for Sydney or Broken Hill, and a given star will have a different relative RA angle in Sydney as distinct from Broken Hill.
Hence it is quite acceptable that the initial RA pointing angle is out. However, for a given location and accurate input data, that RA pointing error should start out reasonably consistent.
The DEC value should be close regardless of system timing inaccuracies.

HTH,

BC

LOL

Hey there B, i was wonderin when you wuold show up in this !!

TBH, after using it for a few night, the polar alignment is pretty much spot on, i seen a minimal amount of drift after 10 mins, and it looked pretty good. i do take on board what your saying though, the time entered is from my phone (Tempestwizz very kindly came round to mine last week, and showed me his excellent method of alignment) and is set to be almost exact to the second, from my location

My illuminated reticle and T-ring have just arrived, so i will practice my drift aligment during the course of the full moon, so i can see what i am doing. i guess after realigning again and again, the mount will 'learn' my locale.

after goingt hrough it, i know its user error, and not anything else !!

[pmrid (Peter)]

In answer to the question "Who is aligned to Magnetic South" see the posting reading:

Originally Posted by gmbfilter http://www.iceinspace.com.au/vbiis/i...s/viewpost.gif
I have a HEQ5Pro
I set it to magnetic South with a compass
Level by eye, almost always do only 2 star align.Then it's "up up and away"
Its distance to initial alignment stars seems random and I don't worry anymore.
I would waste heaps of time fussing about with my initial polar alignment.
Drift alignment is a different issue.
Most errors are me aligning on wrong star.

'Nuff said?
Peter
I take the first 2 stars that come up in menu (unless they are behind my Hill)

[toryglen-boy (Duncan)]

Originally Posted by pmrid

In answer to the question "Who is aligned to Magnetic South" see the posting reading:

Originally Posted by gmbfilter http://www.iceinspace.com.au/vbiis/i...s/viewpost.gif
I have a HEQ5Pro
I set it to magnetic South with a compass
Level by eye, almost always do only 2 star align.Then it's "up up and away"
Its distance to initial alignment stars seems random and I don't worry anymore.
I would waste heaps of time fussing about with my initial polar alignment.
Drift alignment is a different issue.
Most errors are me aligning on wrong star.

'Nuff said?
Peter
I take the first 2 stars that come up in menu (unless they are behind my Hill)

so i see....

[gmbfilter (Geoff)]

Originally Posted by gmbfilter

I have a HEQ5Pro
I set it to magnetic South with a compass
Level by eye, almost always do only 2 star align.Then it's "up up and away"
Its distance to initial alignment stars seems random and I don't worry anymore.
I would waste heaps of time fussing about with my initial polar alignment.
Drift alignment is a different issue.
Most errors are me aligning on wrong star.
I take the first 2 stars that come up in menu (unless they are behind my Hill)

Oops I mean true south
Sorry about that!

The go accuracy is fine for me. I have a WO FLT110
everything I look for is neat center of eyepiece

I also use Starry Night Pro 6 to drive the mount, lots
more to see and find.

If accuracy decreases after a couple of hours I just realign

[TJD (Trevor)]

my nexstar 6 se is dead center even at 735x its just you got to set it perfectlywitch is anoying when the power goes out and it resets


but goto scopes are more acurate than the person using them its almost allways user errer