300 replies to this topic

[Allan Wade]

[Allan Wade]

[Allan Wade]

[Allan Wade]

[Allan Wade]

[Allan Wade]

[Allan Wade]

[macdonjh]

 

I’ve got two acreages for sale near Coonabarabran, protected night sky area, close to where the OzSky Safari is held. PM me if you’re interested.

 

 

 

I can't afford the whole property.  Would you consider selling just the sky?  I'll pay shipping to the Gulf Coast.  Hurry, I've made a similar offer to another Cloudy Nighter in west Texas, USA.

 

Good looking scope, Allen.

[Mike Lockwood]

Thanks for the photos.  That is quite the eyepiece case!

 

Happy New Year Allan, here's to great observing weather in 2018.

[Don H]

Amazing scope! Thanks for sharing. Seeing it and your observing reports stirs my imagination. One thing though, the fan suspended over the primary is a bit scary...

[Kunama]

Great report Allan, and fantastic pictures. I'll be up to see it in person in March

 

(or maybe before, let me know when you're next heading up).

Edited by Kunama, 29 December 2017 - 04:14 PM.

[Starman1]

Egads, that's a beautiful scope.

And 32" under southern skies?

Simply fantastic.

I'll love to read more remarks as time goes on.

Edited by Starman1, 29 December 2017 - 08:27 PM.

[Allan Wade]

Thanks for the photos.  That is quite the eyepiece case!

 

Happy New Year Allan, here's to great observing weather in 2018.

Yes it’s a gun case full of little weapons.

 

Happy New Year to you too, I look forward to catching up again in 2018.

[Allan Wade]

Amazing scope! Thanks for sharing. Seeing it and your observing reports stirs my imagination. One thing though, the fan suspended over the primary is a bit scary...

I probably thought the same thing about the fan when I first saw the concept some years ago. But it’s an integral part of getting the telescope to perform optimally. For now though, I admit to turning the fan on slowly and keeping an eye on it for a bit to ensure it behaves.

[Allan Wade]

Great report Allan, and fantastic pictures. I'll be up to see it in person in March

 

(or maybe before, let me know when you're next heading up).

Thanks Matt. You know I’m there all the time. I’ll send you a message.

[Allan Wade]

Egads, that's a beautiful scope.

And 30" under southern skies?

Simply fantastic.

I'll love to read more remarks as time goes on.

Thanks Don. You have to stop by the next time you’re in Australia.

[macdonjh]

Thanks for the photos.  That is quite the eyepiece case!

 

Happy New Year Allan, here's to great observing weather in 2018.

 

 

 

Thanks for the photos.  That is quite the eyepiece case!

 

Happy New Year Allan, here's to great observing weather in 2018.

Yes it’s a gun case full of little weapons.

 

Happy New Year to you too, I look forward to catching up again in 2018.

 

I've always thought the idea of a hard-shell rifle case for eye pieces is a cool idea.  I just don't carry enough eye pieces to warrant such a big case.  A pistol case would be too small.  Perhaps a case for an Uzi?

[Mike Lockwood]

The front fan has been used by others for some time, with no failures that I have heard of.

 

I first saw it in Joe Wambo's 32", and since then John Pratte has used it on a number of telescopes.  It is suspended by very strong stainless steel wires or other wire that carry the current to run the fan.

 

The front fan highlights an important point in moderate to large telescope performance - it is best to cool both sides of the mirror as uniformly as possible if you want to achieve the best possible performance.  I prefer a center fan over so-called "boundary-layer" fans because I believe that it cools the mirror in a more radially symmetric manner - i.e., it doesn't cool one side more than another, which can cause temporary astigmatism as the glass shape is warped asymmetrically.  One larger fan is used to cool the rear of the mirror as well, and other fans may be used in various locations to further assist cooling.

 

At 100F, you need all the cooling you can get, so cooling both sides is wise and necessary.

[starzonesteve]

****, Allan, that is one fine looking scope. Enjoy!

 

....ok, just a bit less enthusiastically, let’s go with ‘dogonnit’.

Edited by starzonesteve, 29 December 2017 - 11:35 PM.

[Darren Drake]

So cool! But why are there 2 hand controllers? Is this some option with servocat?

[Allan Wade]

Darren, the wireless hand pad on the UTA is an optional extra. It’s invaluable on the big scope where I can’t obviously reach the wired hand pad on the stalk. To be honest, I don’t think I’ve used the one down on the stalk yet. I control everything through the Nexus or the upper hand pad.

[Symui]

Congrat's on first light and more with your new 32" and thanks so much for this thread and posting all the pictures. 

 

Have you noticed a pointing improvement with the 1.5 million step magnetic encoders?  Also what size secondary did you decide on?   I have a 6" on my 32" F3.6.

 

-Rick

Edited by Symui, 01 January 2018 - 10:27 PM.

[Allan Wade]

Hi Rick. My secondary is 6.5”. I was joking with Mike Lockwood when he made it that it’s bigger than the first two telescopes I started out with.

 

The potential of these new high res encoders is quite great. But it’s a leap forward in the current technology used, and essentially being a prototype it isn’t exactly plug and play. I’m not happy yet with the pointing accuracy in altitude, and I think it stems from the placement of the altitude encoder reader. So I’m going to move the reader to a more ideal location directly under the altitude bearing. Eventually I would like to achieve near perfect pointing accuracy over the entire sky. That may not be possible until it’s permanently mounted in the observatory. 

[glend]

Allan does that encoder accuracy work out to 0,864" per step? If so, why is that precision needed on a visual scope? Are you trying for object centering under very high powered EPs?  I could see some justification in an imaging setup using plate solving, to return to the exact imaging location night after night.

[Allan Wade]

Allan does that encoder accuracy work out to 0,864" per step? If so, why is that precision needed on a visual scope? Are you trying for object centering under very high powered EPs?  I could see some justification in an imaging setup using plate solving, to return to the exact imaging location night after night.

Hi Glen. Looking through my thread and photos of the telescope should suggest to you that I wanted to build something unique, that was a step forward from the current way of building premium dobs.

 

I have been fortunate to use a lot of premium dobs and gauge from that experience how well they point around the sky. If I went down the 32k US Digital encoder path that is the norm for most big dobs, I felt like I was limiting myself to that kind of accuracy. On the whole, that's nothing to sneeze at considering how long the focal length of these big scopes is, but for my telescope I wanted to try and achieve observatory class type pointing. As you mention, that means higher power pointing accuracy across the entire sky.

 

The dob is not at that level yet, but I've had it barely more than a month, and observatory level pointing won't happen until I further refine some components and then actually get it into the observatory.