Dual RASA 8 rig - nearly there

[gorann]

Finally I got my first two images with the rig. The first night I aimed at LBN603 and to be safe I had one laptop for each camera and a third running the mount and PHD2. But in the morning I found that one of my laptops had probably decided to do a Windows update so I only got about three hours from one of them (first image below) - still better than none so an unforseen advantage of a dual rig. The second night I had all laptops in airplane mode and got 2 + 2 hours on LBN438 (second image below). I could have got a bit more if I had done a flip but I prioritized sleep. Still 4 hours gets me rather deep with these light buckets. Stars were not perfect in the corners but could be fixed reasonably well with processing. I suspect that like @ollypenrice found just rotating the cameras could affect this and I may try some of that first, or just live with it.

By the way, I noticed no problems with flexure.

Cheers, Göran

Edited September 5, 2021 by gorann

[Tomatobro]

I run some free software called "Caffeine" which simulates keypresses of a key that no longer exists and it seems to be very effective in stopping shutdowns.

When running it puts a small coffee pot icon in the task bar.

[gorann]

10 minutes ago, Tomatobro said:

I run some free software called "Caffeine" which simulates keypresses of a key that no longer exists and it seems to be very effective in stopping shutdowns.

When running it puts a small coffee pot icon in the task bar.

Very clever, I may try that if airplane mode does not help. I do have the computers set to never turn off when on a charger and that seems to work. In this case it had not gone to sleep but had rebooted (so I had to type in my password) which makes me suspect a forced update.

[Sp@ce_d]

I have mine set to only allow updates during daylight hours 

[ollypenrice]

Those are great images. I'm very much looking forward to doing some of these dusties with our setup. The reflection nebulosity in the first one is particularly attractive.

Olly

[gorann]

9 minutes ago, ollypenrice said:

Those are great images. I'm very much looking forward to doing some of these dusties with our setup. The reflection nebulosity in the first one is particularly attractive.

Olly

Thanks a lot Olly, much appreciated as allways. I agree that the first image is a bit more attractive and shining than the second one, but I who can blame a nebula for beeing at bit dull if you have a magnitude of 16 and a surface brightness only 23😉.

[gorann]

Just for the record. Here are two more images caught with the rig. No flex issues as far as I can tell. The first one (part of Sh2-126 with LBN437) is only 2x1 hours before clounds stopped me, so a double rig was probably essential to give a decent S/N ratio. The second one is 2x3 hours. 6 hours help for faint IFN (MBM54 with the galaxy NGC7497 in the background).

Cheers

Göran

[gorann]

And here is the setup from last night waiting for clouds to go away. I have one laptop for each camera (including the piggy back) and one running the mount (Cartes du Ciels and PHD2). All to reduce the chance of total computer/USB failure.

[ollypenrice]

That's very convincing indeed!

Olly

[gorann]

2 minutes ago, ollypenrice said:

That's very convincing indeed!

Olly

Thanks Olly!

[AKB]

On 23/08/2021 at 13:54, gorann said:

It is this one: I do not know of any other brand making such adjustable saddles.

https://www.firstlightoptics.com/misc/jtd-dual-rig-telescope-alignment-saddle.html

I just bought one of these myself.  It’s built like a tank.  The specs say it’s rated to 9kg, but that must be just notional.  I take it that your RASA plus scope plus focuser plus… actually comes in at quite a bit more than that?

I’m trying to decide whether to put the Esprit 120 or the C9.25 with Hyperstar on it. 
 

Tony

[tooth_dr]

45 minutes ago, AKB said:

I just bought one of these myself.  It’s built like a tank.  The specs say it’s rated to 9kg, but that must be just notional.  I take it that your RASA plus scope plus focuser plus… actually comes in at quite a bit more than that?

I’m trying to decide whether to put the Esprit 120 or the C9.25 with Hyperstar on it. 
 

Tony

Tony

Not sure if it is the way I've set mine up but I've seen some flexure with my APM 105/650 and EFW/camera etc where stars are slightly elongated in one direction in 5 minute subs.

[gorann]

1 hour ago, AKB said:

I just bought one of these myself.  It’s built like a tank.  The specs say it’s rated to 9kg, but that must be just notional.  I take it that your RASA plus scope plus focuser plus… actually comes in at quite a bit more than that?

I’m trying to decide whether to put the Esprit 120 or the C9.25 with Hyperstar on it. 
 

Tony

Yes Tony, that JTD holder has worked fine for my dual RASA rig. No flex noticed but the FL of 400mm is forgiving and I tighten the holder quite hard. Here is a recent example from the rig.

Cheers

Göran

 

[AKB]

3 hours ago, gorann said:

Yes Tony, that JTD holder has worked fine for my dual RASA rig. No flex noticed but the FL of 400mm is forgiving

 

4 hours ago, tooth_dr said:

I've seen some flexure with my APM 105/650

Thanks both.   I’ll put the 120 and guider on the fixed  clamp and the wide angle hyperstar (which has some mirror flop anyway) on the JTD.