Orion deluxe OAG

[Jfinis]

Hi All,
Does anyone have any suggestions/process on how I can get an Orion Deluxe OAG setup read manual tried and failed
I spent the last two nights trying to get OAG focused to no avail, getting ready to smash it with a hammer.
I've read lots of info on the net tried some of the suggestions but nothing seems to work.
No matter what I do I'm unable to see any objects to focus on, this evening tried with the moon and no go
Equipment:- WO FLT 110 + P-flat68 Flatterner, QHY9 Mono with FW

Please help

Jim :mad2:

[Tandum]

I use one on a qhy9 mono with starlight wheel and I have the long extension plus the short extension tube in between the QHY5 and the OAG, I removed that thin top bit and I have the middle sized extension tube between the wheel and the OAG. What guide camera do you have?

If you have the OAG in front of the flattener then add the length of the flattener minus the middle sized tube to the distance between the guide camera and the OAG. However, I think that would make that stalk too long to be stable, you'll probably get flex in there.

I'll get a photo tomorrow.

[gregbradley]

I bought a MMOAG ages ago and tried to install it a few years ago. I could not get it to focus so put it aside.

Later on I tried again and still no focus. I read the net wondering what was the problem.

I eventually got it to work.

Firstly the trick with these things is that if they are out of focus even slightly the stars disappear without a trace giving you no clue as to where you are with regard to focus. That's what makes them so hard to focus.

The next point is the distance from the pickoff prism to the guide camera chip has to be the same as the distance to the imaging camera chip.

So work out what the distance is from the pickoff prism to your imaging chip (not the front of the camera - to the surface of the chip).

Now measure where that distance ends up for the guide camera. It now gives you an idea of where the focal point is.

With the MMOAG Don Goldman also sells a negative lens for the guide camera to help achieve focus with some setups. Not sure about the Orion.

The MMOAG came with 2 types of focusers to hold the guide camera.

But the main point here is assuming your pickoff prism is acutally in the stream of light that you won't see much in your guide camera unless you are probably something like 5mm or less from focus.

I hope this helps.

Greg.

[Logieberra]

Jim, you're not alone. I've got one too and yet to reach focus with the guide camera...

Reading with interest....

Logie.

[Tandum]

Here's a couple of pics of what I ended up with here. The qhy5 has the 1.25" nose removed and it screws directly to the t-threaded tubes.

As I remember on initial setup I pointed it to M8 or a similar heavy starfield, focused the qhy9 and then looked into the guider stalk with a hand held eyepiece and rotated it until I saw a star in the FOV. I then moved the eyepiece in and out to find the approx focus point. Then I put on the guider camera and started messing with distances till I had focus on it. Done.

I also pulled the thing completely apart as it was so sloppy. I put a strip of mylar sheet between the inner and outer tubes that rotate around each other and that made it a lot more stable. Before I did that I found you could get a star on the guider but when you tightened up the lock screw the star would move out of view.

Once you get all that right, you might find the prism intrudes into the light path as per the attached flat. I tried lifting the prism a bit but found that made it a lot harder to locate a star in the guider so I just live with it.

[jenchris]

Right - this is one I've mastered! I had a helluva time getting it to focus but now I can do it quite quickly if it is altered.

First off, make sure the prism is set up right.
Mine was off kilter so badly that it wasn't even looking through the objective lens properly.
I stripped the thing down and adjusted the prism bearings so that it swung without catching and swung squarely - it was badly set up and jammed so the adjuster was not operating properly.

Do some paper calculations and adding up - the thin lock ring is about 5.5mm the thinnest adjuster is 7mm the slide adjustment is 5mm so you have infinite adjustments to ensure focus is possible. The measurement to both sensors should be the same length from the prism back face.

When you put the thing onto the focuser take off the camera and look through the hole - centring your eye - you should be able to see a light shone at the other end (or daylight if you're sensible enough to set it up in daylight!)

By far the best way of setting up initially is to get the arithmetic right giving yourself a good chance of adjustment on the slide for rough perfection.

Now, in daylight, find a distance horizon. With camera and imager set up in the machine and spooling on the guiding machinery (PHD) and live view on the imager. Adjust focus on the imager to get your horizon focused as a line across the image.
Now you can concentrate on the OAG camera - slide the camera and tube in and out locking off each time to let it settle - it's a dim image and very large compared to the imager. Eventually you should be able to get the line of the horizon focused as a line across your OAG camera.
The rest can be done at night by adjusting the locking ring for the best focus.
Like all things, the first time is thehardest - it took me hours to find the image - now I can do it in seconds -
If you're setting up PHD at night, set up the OAG camera (I use an SSAG QHY5 equivalent) on about 2.5 seconds and make sure you do a set of darks for it

[Jfinis]

Thank you all for the suggestions although I've already tried most of the suggestions with no success I may need to look at the prism alignment
I'm reluctant to touch the prism seems a very fiddly area

Has anyone measured how far into the light train the prism is, something tells me that the prism does not protrude into the light path far enough

The guiding camera is an Orion SS Autoguider, I can confirm that the camera works I can insert into the Orion short tube scope which I still have mounted on the WO 110 and it works fine.

I'm going to give it another go during the day today and hope that I can get close enough to at least see a smudge

I'll report on what I've found wish me luck

Cheers
Jim

[jenchris]

Here's a pic I just took of the guider prism in its proper alignment
so you can compare.
The prism can be slid further in or out (you don;t want it out) by loosening the tiny allen scres (the key is supplied with the guider)
There's also a tiny lock screw in the lock ring
If you remove the barrel from the main ring, you'll see the prism mount

[Jfinis]

Hi All,
Well after wasting 3 good nights on the long weekend I'm just about ready to give it a drop kick
I sent the email below to the supplier but no reply, not even a peep

"After waiting for a week for the weather to clear up so I can try out the Orion Deluxe OAG.
Well what a disappointment it has been I wasted 3 good imaging nights on the long weekend, I tried/read/tried and tried to bring the OAG into focus to no avail to top it all off last evening I got really frustrated and removed the SS Starshoot autoguider and attached it to the 80 mm Orion short tube I have attached to the main WO 110 scope and decided to take some long 15 min images.

At the end of the night when I parked the scope I heard this almighty bang on to the floor when I turned on the light to see what happened I noticed that the OAG had come apart and dropped to the floor, the barrel that holds the prism stayed behind attached to the OAG body, but the part with the 2 lock screws and the prism adjusting screw came apart and onto the floor, lucky I didn’t have the autoguider on the OAG at the time, no damage occurred to the parts that fell down but I had a hell of a time finding the small rod that fits under the adjusting prism screw, eventually I did find it.

I then worked out how to assemble the unit again and made sure that the 2 allen keys, which lock the unit that has the( 2 Thumb lock screws and the prism adjustment screw) together to the barrel that holds the prism were tightened correctly, these couldn’t have been tightened correctly in the first place and unless the OAG was pulled apart I would not have noticed that these held it all together, I noticed earlier that the unit wasn’t tightening with the 2 thumb lock screws, I was going to look at this the next day.

I would send the unit back for a refund but due to the many configurations to try to get the unit to focus most of the adapters have been scratched, I would still like to have another go at getting it setup to at least get focus let alone get a star in the FOW.
I’ve tried most of the suggestions on the net, not sure if you have any further suggestions on how to get the unit to focus
Are you able to tell me whether the unit is suitable on refractors someone told me that they’re not

I would appreciate your feedback and please don’t take this has a whinge just stating the facts"


Waiting for the weather to fine up to give it another try
Ayone have any thoughts or would like a cheap OAG


Regards
Jim :mad2:

[Paul Haese]

That's not much fun Jim. OAG's can be very tricky to sort out. I spent the better part of a month to get mine sorted. What I found instructive was to get the guide camera in focus first before anything else. This is just to test that the prism is in the right depth and that there is no impediment to focus. Then you at least know what is going on there. Then measure this distance from an arbitary point and then get the main imager in focus. Once again measure that from the same point. This will give you an idea of how much extension you will need to get the guide camera in focus.

If you don't get it sorted in the next week I will try to come down and help you get it sorted. Once you have this sorted your flexure worries will be gone.:)

[Lester]

Good luck with the OAG Jim, I use the same unit on my 14" SCT and it works a dream. I have not commented, due to your scope being different. If you can do what Paul has instructed that should get you well on the way.

All the best.

[Jfinis]

Thanks Paul, Lester,

As I mentioned just waiting for some good weather to give it another try.

One more question I have a flatterner (P-FLAT 68) in between the scope and the OAG which has pushed my imaging chip well away from the recommended distance, I managed to get a couple of images last Monday night and have noticed quite a bit of star distorsions and vignetting on the outer edges, I guess flats should take care of vignetting would not improve stars, I imagine this is caused by imaging CCD distance to the FF.
Any suggestions??
I could remove the FF and see what it does to the images.

Ahhh if only the weather cooperated to carry out further testing

Regards
Jim

[Paul Haese]

Jim the flattener distance is critical and cannot be moved. Can you put the OAG in front of the flattener? What is the metal back distance of that flattener?

[Jfinis]

Hi Paul,
Putting the OAG before the FF is going to be difficult I think as the FF screws directly into the 4" focuser
I'll have a look tonight and see if I've any adapters that I can use

Thanks for your suggestion

Jim

[Marke]

Maybe look at a thinner OAG and custom spacer if needed , my Mitsuboshi
is 36mm thick and FF is 55 +/- 4mm which leaves a bit of leaway . THe SX filter wheels
also have the option for OAG all in one unit as well.

[Paul Haese]

Precision parts make adapters Jim. You need to keep the FF at the correct distance and that means the OAG should not interfer with that distance.

What is the FF metal back distance Jim?

[Jfinis]

Hi Paul,
I've looked at how I can adapt the OAG in front of the FF and seems too difficult and not sure what effects there will be on the light path.
I would need to get and adapter made to go from the 4" focuser to 42mm on the front of the OAG, then have to go from 42mm out the back of OAG to the front of the 4" FF then back down to 42mm on the FW.
Just doesn't seem feasible so I think I'll try to correct any flexure on the Orion 80mm Short tube, and see how it goes.

Thanks to all for all your help

Jim :thanx:
ps. to answer your question the FF metal back distance is 58mm and chip to lense is 113mm

[Paul Haese]

I would think that the adapters you used from the FF to the camera before (assuming this was setup properly before) would not need to be changed. The only adapters you would need is from the focusor to the OAG and from OAG to the FF. Precision parts can make anything so long as you give them the type of thread. Their work is very good and precise. Just run them up an email and ask them to help you with what is needed.

[TechnoBill]

Hi Jim,
I have an orion steady star and that incorporates pretty much the same off axis guider setup as the deluxe. I initially had some issues on my first night out trying to get it setup using stars. it was a frustrting long night with nothing to show. But what really helped me was a few days later I had a clear night and the moon was up.
Being such a big bright target it was pretty easy to first get the main camera in focus, and then pop an eyepiece into the AOG to see what was going on. It was quite a bit out of focus (and I also spent 5 mins trying to focus a reflection :rofl:) but eventually I got the moon into view in the OAG and could tweak it.
I then added spacers so I could get the main camera into focus as well. Then started moving the scope around to work out where the OAG was in relation to the main camera view. Once I had it worked out, I was able to replace the eyepiece and add the spacers needed to get both cameras into focus.
I found this extra easy with the lodestar autoguder camera. because this camera slides into a 1.25 holder, I could add extra long extension to the AOG, bring the main camera into focus and had abou 6 cm of slide to play with with the OAG. :thumbsup:

Let me know if you need need any other info.
Bill D

[Jfinis]

Hi Bill,
Thanks for the info I'm going to give it another try in the next week and I'll let everyone know how I go at the moment I've gone back to the 80mm Guide scope

Cheers
Jim