Go Back   IceInSpace > Equipment > Equipment Discussions

Reply
 
Thread Tools Rating: Thread Rating: 25 votes, 4.84 average.
  #101  
Old 12-01-2009, 07:51 PM
GrahamL's Avatar
GrahamL
pro lumen

GrahamL is offline
 
Join Date: Jun 2006
Location: ballina
Posts: 3,068
Thanks for the great info gary.

Quote:
Refrain from fastening the far end solidly to the side of the rocker
So its just sitting over the screw?... Is to allow any movement of the alt encoder to be transfered to movent in the tangent arm rather than
placeing undo strain on the encoder itself ?

I think I'll use nylon bush like on your az bolts .. can It be bought and easily fitted .. I hope to get a couple of mounting options turned up on the old mans lathe later this week.

cheers graham
Reply With Quote
  #102  
Old 12-01-2009, 09:16 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Quote:
Originally Posted by nightstalker View Post
So its just sitting over the screw?... Is to allow any movement of the alt encoder to be transfered to movent in the tangent arm rather than
placeing undo strain on the encoder itself ?
Indeed, just let it slide over the shoulder of the shoulder screw.
That way there won't be enable sideways force imparted to the encoder
should the encoder not be exactly centered or if the bearings aren't
perfectly circular.

Quote:
I think I'll use nylon bush like on your az bolts .. can It be bought and easily fitted .. I hope to get a couple of mounting options turned up on the old mans lathe later this week.
Rather than use a sleeve, do you have sufficient clearance for the edge of
the optical tube to pass over the encoder if the head of the Az pivot bolt
were above the inside base of the rocker? If so, consider drilling and tapping
a hole in the side of the bolt to accept a socket head set screw. Then hold the
encoder shaft in place by tightening up the set screw with an approriate size hex
key.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
wildcard@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #103  
Old 12-01-2009, 11:06 PM
GrahamL's Avatar
GrahamL
pro lumen

GrahamL is offline
 
Join Date: Jun 2006
Location: ballina
Posts: 3,068
Sorry gary I seemed to have confused things .. my az bolt is one of yours and fitted to the base now (pics last page)..my alt mount was the one i was thinking of slipping in a nylon bush ..I might figure something to come of the top of the mirror box like you mention as I'm not happy with that little bracket I've made .. the axis is right down in that corner of the bearing .. which is a real ..pita.
Reply With Quote
  #104  
Old 13-01-2009, 09:54 AM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Arrow Bushes

Quote:
Originally Posted by nightstalker View Post
Sorry gary I seemed to have confused things .. my az bolt is one of yours and fitted to the base now (pics last page)..my alt mount was the one i was thinking of slipping in a nylon bush
Hi Graham,

No, it wasn't you. I am on the same page now. When you said 'bush' you really
meant bush and not the sleeve inside the bolt.

OK. There are a few ways one can go here. You could use an off-the-shelf
bronze bush. They come in a variety of I.D./O.D & length combinations with
and without flanges. You could use an off-the-shelf polymetric material
bush from someone like Vesco Plastics.
You could use a bush made of any number of other materials, including
acetal, from someone like Miniature Bearings.
Or you could get some appropriate O.D. acetal rod and turn it yourself.
I'd recommend you start by looking at the bushes at Miniature Bearings Australia
who are up in Qld and you can purchase from one-off online.

Quote:
..I might figure something to come of the top of the mirror box like you mention as I'm not happy with that little bracket I've made .. the axis is right down in that corner of the bearing .. which is a real ..pita.
That segment on the trunnion, that is currently to the left of your bracket in the photo,
does get in the way a little, doesn't it?

If it wasn't for that segment, ideally you could have a bracket similar to the
one you have but allow the bracket to slide back and forth across the
top of the cross member and then mill a vertical slot in the bracket for the encoder shaft
to allow the encoder to move up and down. This is the opposite way around
to what I suggested before, but the previous suggestion was based on you didn't
do anything to that segment.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
wildcard@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

Last edited by gary; 16-01-2009 at 11:32 AM.
Reply With Quote
  #105  
Old 15-01-2009, 09:00 PM
Dave47tuc's Avatar
Dave47tuc (David)
IIS member 65

Dave47tuc is offline
 
Join Date: Dec 2004
Location: Mornington peninsula. Victoria.
Posts: 1,658
Very happy to have my AN on order and due next week.

This thread has got many tips for AN users. Should be sticky

Thanks Gary
Reply With Quote
  #106  
Old 15-01-2009, 10:17 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Thumbs up Thank you

Quote:
Originally Posted by Dave47tuc View Post
Very happy to have my AN on order and due next week.

This thread has got many tips for AN users. Should be sticky

Thanks Gary
Thanks David,

And welcome to the extended family of Argo Navis owners.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #107  
Old 16-01-2009, 09:38 AM
iceman's Avatar
iceman (Mike)
Sir Post a Lot!

iceman is offline
 
Join Date: Sep 2004
Location: Gosford, NSW, Australia
Posts: 36,709
For the absolute wealth of information in here for current and future Argo Navis owners, this thread has been made sticky.
Reply With Quote
  #108  
Old 16-01-2009, 11:29 AM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Thank you

Quote:
Originally Posted by iceman View Post
For the absolute wealth of information in here for current and future Argo Navis owners, this thread has been made sticky.
Thanks Mike,

And thank you to the forum members who have posted on this thread.
We look forward to your future posts.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #109  
Old 16-01-2009, 11:30 AM
erick's Avatar
erick (Eric)
Starcatcher

erick is offline
 
Join Date: Dec 2006
Location: Shoalhaven Heads
Posts: 8,469
So my silly thread title lives forever
Reply With Quote
  #110  
Old 20-01-2009, 01:59 PM
Dave47tuc's Avatar
Dave47tuc (David)
IIS member 65

Dave47tuc is offline
 
Join Date: Dec 2004
Location: Mornington peninsula. Victoria.
Posts: 1,658
For GSO Dobs with ASDX (B model) use this thread.
http://www.iceinspace.com.au/forum/s...ad.php?t=40158

Or as Gary has said below the 'B' model.


Last edited by Dave47tuc; 20-01-2009 at 04:26 PM.
Reply With Quote
  #111  
Old 20-01-2009, 03:11 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
GSO Model designations

Quote:
Originally Posted by Dave47tuc View Post
For GSO Dobs with ASDX use this thread.
http://www.iceinspace.com.au/forum/s...ad.php?t=40158

Hi Dave,

Thanks for the post.

To the best of my knowledge, the "ASDX" designation is simply a suffix
added by one of the Sydney based telescope shops. I don't believe it
is an 'official' GSO designation and I could see no reference to it on the GSO
web site.

We simply refer to them as the 'B' models and the previous generation as the
'A' models. Again, the 'A' and 'B' aren't official GSO differentiators, but at least this
designation convention has the advantage of being extensible with future models.

Best Regards

Gary Kopff
Wildcard Innovations Pty Ltd
Reply With Quote
  #112  
Old 24-01-2009, 10:06 AM
Dave47tuc's Avatar
Dave47tuc (David)
IIS member 65

Dave47tuc is offline
 
Join Date: Dec 2004
Location: Mornington peninsula. Victoria.
Posts: 1,658
Hi all,
My Argo Navis arrived yesterday, my second AN I had one on a 10" GSO Dob.
My new scope a Skywatcher Collapsible Dob 12"
The AN makes observing so much better so I had to have one again.

So thanks to the great service Gary brings I have the AN fully fitted on my scope.

Pictures tell the story. Gary it all came together well. Have not used it out under the stars yet. But all tests inside worked perfectly.

I used plumbing pipe fittings. I had to make it at a height good for observing. Then easy break down for transport. Phot's show fully fitted then last one mount ready for transport.

I look froward to many great nights out under the stars again with the Argo Navis.
Attached Thumbnails
Click for full-size image (AN1.JPG)
38.2 KB111 views
Click for full-size image (AN2.JPG)
34.7 KB96 views
Click for full-size image (AN3.JPG)
42.7 KB110 views
Click for full-size image (AN4.JPG)
36.8 KB109 views
Click for full-size image (AN5.JPG)
42.7 KB106 views
Click for full-size image (AN6.JPG)
45.1 KB105 views
Click for full-size image (AN7.JPG)
41.8 KB102 views
Reply With Quote
  #113  
Old 24-01-2009, 01:28 PM
danielsun's Avatar
danielsun
Canon collector

danielsun is offline
 
Join Date: Oct 2005
Location: Taylors Lakes Melb
Posts: 1,964
Well done and I like the new set up there Dave . The Argo Navis is a fantastic device.
I have been getting back into the visual side a bit lately and the Argo makes it even more enjoyable.




Cheers Daniel.
Reply With Quote
  #114  
Old 24-01-2009, 02:19 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Smile Thanks Dave

Quote:
Originally Posted by Dave47tuc View Post
So thanks to the great service Gary brings I have the AN fully fitted on my scope.
Hi Dave,

Thanks for the post and the great pictures!

It's looking good!

Quote:
Pictures tell the story. Gary it all came together well. Have not used it out under the stars yet. But all tests inside worked perfectly.
Excellent! That's what we like to hear!

Quote:
I used plumbing pipe fittings. I had to make it at a height good for observing. Then easy break down for transport.
Love it!

Quote:
I look froward to many great nights out under the stars again with the Argo Navis.
Great stuff! Hope you get some clear skies down there over the long weekend.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #115  
Old 24-01-2009, 02:38 PM
mick pinner's Avatar
mick pinner
Astrolounge

mick pinner is offline
 
Join Date: Feb 2005
Location: monbulk-vic
Posts: 2,010
would there be a noticable advantage in upgrading from 8192 to 10,000 step encoders on a G11? based on accurate polar alignment.
Reply With Quote
  #116  
Old 24-01-2009, 03:37 PM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Telescope Pointing Analysis System - G-11

Quote:
Originally Posted by mick pinner View Post
would there be a noticable advantage in upgrading from 8192 to 10,000 step encoders on a G11? based on accurate polar alignment.
Hi Mick,

Thanks for the post.

When going from 8192 steps on each axis to 10,000 steps on each axis,
there is a potential 49% increase in pointing resolution.

However, because the geometric, eccentric bearing and gravitational flexure
errors within the mount/OTA might be causing pointing error residuals significantly
more dominant than those attributed to encoder resolution alone, the approach
we would recommend would be to perform a TPAS analysis.

TPAS stands for Telescope Pointing Analysis System and it is built-into the
Argo Navis firmware. It is described in the User Manual in the section on
SETUP MNT ERRORS.

After one has performed a star pointing test, TPAS can analyse and potentially
compensate for many of the most common mount errors and can even report
and refine any residual polar-misalignment.

With your G-11, what we would specifically recommend is to initially polar the
scope in the way you prefer, either using a polar alignment scope or drift test.
Then set the SETUP MOUNT menu to the GEM EXACT ALIGN setting.
To assist with the information TPAS can report on polar-misalignment,
check that the time is reasonably accurately set in SETUP DATE/TIME
and that your location has been set in SETUP LOCATION.

Then devote one evening, perhaps during full moon, to do an extended
star pointing test. This might entail sampling the positions of say 50 to 100
stars across the entire sky from zenith to within about 10 degrees of the
horizon. Whilst doing the sampling, one can go into the SETUP MOUNT ERR menu
from time to time and perform an analysis to get some feel as to how things
are progressing. You can even start to put an initial pointing model in place
which then starts improving your pointing performance straight away, easing
the identification of stars during subsequent sampling.

Once you have sampled enough data, one can determine which types
of errors within the mount/OTA are likely to be persistent from session to
session and then save these terms into the unit's non-volatile memory.

The real magic of TPAS is that once you have a model in place, on
a subsequent observing session you can re-synchronize the model on as
few as perhaps two to five stars and your pointing performance will be
as good as it was after the extended star sampling run.

A classic problem with GEM's is non-orthogonality between the Dec axis and
the optical axis. This is because the human operator is responsible
for mounting the OTA onto a dovetail or into the rings and if the OTA is
not 'square' with respect the mount head, the telescope will tend to 'look'
to one side compared to where the mount and the associated encoder
system 'thinks' it is pointing.

You might find this case study of a TPAS analysis done on a G-11
interesting. See http://www.wildcard-innovations.com....573/index.html

The above case study includes links to graphs which are in Scalable
Vector Graphics (SVG) format. These are the most intersting part
of the document. Some new browsers, such as Internet Explorer, support
SVG format natively. If your browser does not, to view SVG content, you will need
to load a free Adobe SVG viewer plugin, which is available for
Windows, Linux and Mac OS-X from http://www.adobe.com/svg/viewer/install/main.html

If one passes the mouse cursor over the sampled data on any of the graphs,
the graphic actually reports the error residual for that data point. So the graphics
are interactive.

The 'before' and 'after' cases are most dramatic. Whereas the raw pointing
performance of this particular telescope was about 13.6 arc minutes Root
Mean Square (RMS), the after case dropped it down to 1.1 arc minutes RMS
with the largest error residual being only 1.9 arc minutes. Given the 8192 step
encoder resolution is about 2.6 arc minutes a step, this is an excellent result.

RMS is a statistical metric and popular in engineering applications.
When we say a telescope has a raw pointing performance of RMS of
13.6 arc minutes, we are saying, on average, approximately 68% of objects
fell within a radius of 13.6 arc minutes from the center of the eyepiece
(i.e. a diameter of 27.2 arc minutes) and nearly all of them fell within a radius
of three times that, i.e 40.8 arc minutes.

So you can appreciate to get the mount errors down to the point where the
pointing residual effectively becomes encoder resolution limited can be
highly desirable for some users.

So, in a nutshell, rather than investing in the 10,000 step encoder solution,
I recommend you stick for now with the 8192 step encoders and steep yourself
in TPAS. There is a bit to absorb at first, but using the system in practice
is relatively easy once one is familiar with the concepts.

By the way, the techniques employed here are essentially identical to that which
professional practitioners perform on all of the world's largest and most
expensive telescopes and the lexicon - terms like RMS, Non-Perpendicular
Axis Error, etc. - is identical as well.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #117  
Old 25-01-2009, 09:34 AM
GrahamL's Avatar
GrahamL
pro lumen

GrahamL is offline
 
Join Date: Jun 2006
Location: ballina
Posts: 3,068
looks great dave

I see your az encoder is belt driven ? .. Is that by choice or just the way
the hardware is supplied for this type of scope ?

anyway thanks for the post you've prompted me back out to the
garage to keep fiddling with my encoder mounts .
Reply With Quote
  #118  
Old 25-01-2009, 11:48 AM
Dave47tuc's Avatar
Dave47tuc (David)
IIS member 65

Dave47tuc is offline
 
Join Date: Dec 2004
Location: Mornington peninsula. Victoria.
Posts: 1,658
Quote:
Originally Posted by nightstalker View Post
looks great dave

I see your az encoder is belt driven ? .. Is that by choice or just the way
the hardware is supplied for this type of scope ?
.
Thanks Yes it is belt driven. That is how Gary at Wildcard supplied the hardware. I'm sure Gary will have more details why the set up is how it is.
I could not get out last night, but fingers x for tonight. It's very clear at the moment.
Reply With Quote
  #119  
Old 25-01-2009, 11:54 AM
gary
Registered User

gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,215
Arrow Timing belts and pulleys on Argo Navis kits for Synta Sky-Watcher Dobs

Quote:
Originally Posted by nightstalker View Post
I see your az encoder is belt driven ? .. Is that by choice or just the way the hardware is supplied for this type of scope ?
Hi Graham,

For mounts where there is insufficient clearance for the OTA to pass over an encoder
coupled directly into the Az pivot bolts, many of our kits use a pair of industrial timing
pulleys and a timing belt, which creates a lower profile and shifts the encoder
out of the way. The Synta Sky-Watcher 12" Collapsible is such a mount as are the
Meade LightBridge scopes.

Timing pulleys and belts have close to zero backlash and are an ideal solution
in situations such as this.

You can find copies of the installation instructions for the Sky-Watcher Dob
kit on our web site here for the Az axis -
http://www.wildcard-innovations.com....s/synta_az.pdf
and here for the Alt axis -
http://www.wildcard-innovations.com..../synta_alt.pdf

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au
Reply With Quote
  #120  
Old 26-01-2009, 09:57 AM
Dave47tuc's Avatar
Dave47tuc (David)
IIS member 65

Dave47tuc is offline
 
Join Date: Dec 2004
Location: Mornington peninsula. Victoria.
Posts: 1,658
First night out with the AN. I made some small mod's, see photo's.
I changed to a bigger tube size and made it so the wires could go through the tubing.
The only thing i had to re set on the AN was one directional arrow.
At late dusk I set the AN on Procyon then Achernar. Then then AN worked a treat for the next 6 hours. No re align through the night. Observed many many objects, way to many to list.
Very happy with the way the AN has come together.
Attached Thumbnails
Click for full-size image (AN 1.1.JPG)
94.6 KB71 views
Click for full-size image (AN 1.2.JPG)
87.8 KB71 views
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:59 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Meade Australia
Advertisement
Bintel
Advertisement
Celestron Australia
Advertisement
SkyWatcher Australia
Advertisement
Lunatico Astronomical
Advertisement
NexDome Observatories
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement