PDA

View Full Version here: : First Light (with pics): EQ6 + 12" Newt


iceman
29-01-2007, 09:40 AM
Hi all

Last night I was finally able to get a first light with my new (second hand) EQ6 + 12" GSO newt. I used the EQ6 with my 10" newt at IISAC2007, and it went well, but hadn't had a chance to use the 12" yet.

I started early yesterday evening, aligning the mount South (including 12° magnetic deviation to the East), so using a digital compass, set it facing 168° and levelled the mount. Once I put the EQ6 head on, the bubble level on the mount indicated it wasn't level!? Don't know why, I left though, and trusted that the tripod was level so the mount should be as well.

Getting the 12" in the rings and balanced was fairly painless.. I need to use 20kg (!) of counterweights to balance the tube, but it seemed nicely balanced afterwards and swung around freely.

Collimating the scope took ages, because a) it was an unfamiliar scope, b) the collimation screws need a screwdriver instead of a hand, c) the centre spot ring on the mirror is a bit too small, d) it's a long way from the eyepiece to the back of the scope ;)

Has anyone replaced the collimation screws on the 12" newts with something that can be done by hand? If so, what/where/how much?

I plugged the fan in and left it running, and went to bed. Got up at midnight to tackle drift aligning, and hopefully image Saturn.

I had no intentions of trying to do any goto or 2-star alignments, I just set tracking to sidereal and used the finderscope to get Saturn in the eyepiece. I noticed some drifting in the eyepiece, but thought I'd try with the CCD just to see if I could get away with only minor adjustments while imaging. I fairly quickly got the image on the CCD (with a bit of luck, I think) using the 5x powermate with the DMK. The first thing I noticed was the increased image scale that the 12" gives over the 10" - exactly the reason why I got the 12" :)

Saturn was drifting way too quickly to image, so I started tackling drift alignment. With no knowledge of how to do it properly, I tried adjusting the latitude and the longitude (azimuth) knobs on the mount, but they didn't make much difference. I now couldn't get Saturn back in the CCD, so ignored that and used the 12.5mm illuminated reticle.

Eventually I found that by physically moving the tripod back to the West (much trial and error), so it pretty much pointed back at South 180°, the drift was almost completely gone.. so a couple of questions arise:

- Why was it drifting when pointing at 168°? If it helps, I think it was drifting in DEC (I had to press "up" on the hand controller to get it back to centre).

- Is there any better knobs for the longitude/azimuth adjustment? With the weight on the mount, it's extremely difficult to tighten it up to make adjustments. My fingers were very sore!

- Is there any better knobs for the latitude adjustment? With the weight on the mount, it's extremely difficult to tighten it up to make adjustments.

- Would a barlow work with the illuminated reticle? The 12.5mm is probably not accurate enough for the long focal length I need.

- Can you get a longer (or not curly) cord between the mount and the hand controller? It doesn't stretch far enough (easily) and wants to keep slinging back when I rest it on the table next to the laptop.

- Can you get a longer (or not curly) cord between the Orion Accufocus unit and the hand controller? It's no-where near long enough when the top of the scope is 2.5m off the ground and the laptop table is 1m off the ground.

- I need new rings, that more easily allow me to rotate the OTA while maintaining balance. The straps are ok, but I reckon they're too dangerous. The eyepiece and RA finder were almost pointing down at times, and made it incredible difficult to get Saturn back in the FOV. Can anyone recommend where I can source some rings that suit a 12" newt? (I can measure the OD tonight unless someone knows it).


Once i'd eliminated most of the drift, I tried putting the CCD back in, but just couldn't get Saturn in the FOV with the 5x powermate. I finally gave up and put in the 2x barlow and got it on the screen easy enough. The seenig just wasn't good enough to do any imaging, and after 2 hours of tackling aligning I gave up, packed up and went to bed.

The weight didn't seem to be too much of an issue, and there didn't seem to be too much (more) vibration when I touched the scope. The Orion Accufocus worked pretty well. I need an illuminated finder like I have on my 10".

All in all, a frustrating night but I learnt a fair bit. No images through the scope yet.. that's the next step (after drift aligning), so I can evaluate the quality of the images compared to my 10", ease of use, vibrations/dampening, image scale/resolution, etc.. that will all help me decide whether to keep the 12" or the 10" (and sell the other).

At the moment it just doesn't feel "comfortable", like it does with my 10".. The 10" is a tube i've had for over 2 years and I know how it works, what it's capable of, it has the good focuser, the temperature sensors, easier to collimate, etc. I'll need to get to the same level of comfort with the 12" before I can properly decide.

Anyway thanks for reading my ramblings, and if you know any of the answers to my questions I'd be most grateful. :)

Some images below.

matt
29-01-2007, 09:52 AM
Now, that's a cannon!!!:lol:

First of all. Ignore the bubble in the mount head. It's useless and doesn't help.

Secondly, you will need that 12 degree offset for your polar alignment.

But you'll probably also need to ignore setting your latitiude on the scale on your mount, since they are also not as accurate as they should be. Mine is out 6 degrees on my SkyWatcher EQ6:scared:

Use your inclinometer and fine tune from there.

You will, however, need to go between a star fairly high up approaching the northern meridian and one low in the east or west close to 0 degrees dec to tweak your alignment.

There are plenty of good sites for how to do this, but I really enjoyed a drift align simulator which has already been posted here at IIS.

If I can find it, i'll post it.

Good luck

gbeal
29-01-2007, 09:55 AM
Hi Mike,
welcome to the world of newts on GEMs, frustrating is a word that springs to mind. Most of your questions relate directly to the EQ6, and I have no idea what to suggest.
A couple of thoughts though. The "rings" look like decent half rings, and I wonder about getting a strap (stainless or similar) made that afixes better, rather than what appears to be fabric type webbing. I am sure I have seen commercial rings like this, half shell, and spring strap over the top, hinged on one side, and turn-buckled on the other.
No idea why the drift occured has me, but the facts speak for themselves.
You "aligned" the tripod I presume first, as this is what you say, and then fitted the head proper. I would tend to align the head only, and do this with the azimuth in the centre area, so as to allow adjustment east and west. Leveling the tripod top I would do without the head though. All this is foreign to me as I leave my base set up. Maybe when you used the compass you had it near ferous metal from the top of the tripod, and this affected the reading?? Try it in daulight, sit the tripod up, walk the compass to it, and see if the reading changes. Now you will understand why I have to do a "compass swing" every now and then, it is called deviation.
If the dec needed adjustment, and assuming Saturn was near the meridian, then the azimuth was at fault. If the object drifts north, then the mount is facing too far east, etc. This info is actually written in K3 help too, if you forget it. Maybe try again, during daylight, and see what gives.
Lastly. If I was looking to use that setup for a length of time, I would be getting someone to fabricate a very short stubby pier, about 100mm longer than the length need to clear the bottom of the tube at the zenith. My 10" uses a pier (in-built) that is about 600mm tall, and that is more than enough. If the pier is not permenant, make one like my roling pier, I can send a few pictures if it helps. That way all can be left on the pier, mount, batteries etc, and simply wheeled out, with another trip to fetch the OTA.
Gary

matt
29-01-2007, 10:05 AM
Here you go, Mike.

I found this really easy to understand and learn from.

It's like a PC astro game!!!!

http://www.petesastrophotography.com/index.html?mainframe=/tutorial.html&tutormain=/tutorial/polaralignment.html

make sure you scroll down and use the guiding simulator

wavelandscott
29-01-2007, 10:41 AM
In the words of another poster in another thread...that is one "smooth" set-up.

Hope you get the bugs worked out and enjoy it!

OneOfOne
29-01-2007, 11:50 AM
Definitely pretty smoooooth to me too...

With a cannon on the top like that, it looks like it is ready to topple over any minute if not for the big lump of glass on the bottom.

Now you just have to add all the associated wires and other bells and whistles and it will start looking just like Bird's!

ving
29-01-2007, 12:20 PM
1 cords: cords can be made to just about any length you want i am guessing. a 5 meter cord was made for me using one of those blue computer networky cables. i assume the same can be done for the focuser.

2: you can shave a little weight off your scope by ditching teh alt bearings mike :)

chunkylad
29-01-2007, 01:11 PM
Great looking setup Mike!!!

I have been considering an EQ6 for a while, but always thought, from others' advice (!) that they weren't up to it. I see from yours however, that they are!

Keep us informed as you iron out the bugs.

Cheers

Dave W

Striker
29-01-2007, 01:34 PM
Hi Mike,

Nice to see you moving on to an EQ mount.

12" looks too big for the mount but with the work you can do with your platform set up I wouldn't be surprised if you make this work.

All the best mate.

sejanus
29-01-2007, 02:25 PM
lol at the pictures, makes my 8" look like a finder :lol:

sheeny
29-01-2007, 04:36 PM
Sounds like a perfectly normal first night of drift aligning. My diagnosis is that you are perfectly normal and healthy:lol: .

I can't add much that the guys haven't mentioned already, except the use of a barlow with the illuminated EP is fine for getting your alignment more accurate.

Mike, if you are like me, you will waste a couple of nights drift aligning to start with, but I have no doubt you'll soon get a handle on it. With practice it doesn't take too long at all. For example, at Lostock I think I spent 30 minutes drift aligning, then did a three start align and the goto was accurate to within the FOV of my 10mm EP (203x) for rest of the weekend.

I'll offer a few points as food for thought - some you'll already know I'm sure;) ...

Setup the tripod level and aligned to true south with the compass (watch the magnetic interference as already mentioned!).
Check your azimuth adjustment is about centre before you put the head on just to make sure you've got adjustment both ways.
If you are always using the scope about the same latitude, your altitude adjustments should be pretty minor (you might be able to get away with little or no adjustment depending on the accuracy you need).
To align the reticle for drift aligning, centre the star in the reticle, slew in RA only to the edge of the FOV, then rotate the EP till the reticle hairs are on the star again. Then slew back to centre to check the star stays on the reticle wire.
Make your initial adjustments big. I usually start off adjusting (and slewing in RA (only) to keep the star in the FOV until the star is almost out of the FOV in dec... then I re-centre the star and check drift. Keep doing this till you go too far (i.e. drift is the opposite way). Needless to say, you make smaller adjustments after that!:P I found the biggest time waster when learning to drift align was just making little adjustments. Start big, to get into the ball park first!
Once you've got the azimuth right, do the altitude/latitude or vice versa and then go back and check.
If you need more accuracy, use a barlow to fine tune, and/or learn to use the drift explorer in K3:thumbsup: - it's just the wasp's nipples! I was sure 1ponders was going to write a tutorial on this:D ... I think I even offered to help write the text if he needed the help...:whistle:Al.

[1ponders]
29-01-2007, 05:08 PM
You'll get it Mike. :thumbsup:

I did write most of it Al, including diagrams. That was just before my HDD in my laptop decided to take a dive along with everything on it. I haven't tried to write it up since. There is already one written up but you have to join the Yahoo K3CCDTools group to get the pdf from the files section.

davidpretorius
29-01-2007, 05:45 PM
WOW,

baby bird!!!!

not even going to pretend to offer advice. I will let you make all the mistakes first and then ask you how to do my future setup :D

spudrick
29-01-2007, 05:49 PM
I fitted a set of Primary and secondary "Bob`s Knobs" for the Lightbridge to my 12" GSO.
I bought them direct from USA http://www.bobsknobs.com/Meade/Newt/MLB12.htm
I didn`t get a reply from Bintel when i asked if they stocked them.

iceman
30-01-2007, 05:29 AM
On the scope, or the mount head?


Yep, that's what I'd like to get. Who stocks them for a 12" newt?


1. yeh I have no doubt the cords can be made, I just want to know where I can get them from :)

2. Nah, I've got the dob base still and it's handy to be able to "rest" it in there, or use it as a dob if I don't want to lug the EQ mount out.


Thanks, good advice!


They look good! Do they fit straight in the collimation holes for the normal 12" GSO?

Thanks for all your feedback.. clouds last night (and too tired) so didn't get to try again.

Hopefully be out amongst it soon.

huckabuck
30-01-2007, 07:04 AM
hello iceman, try Orion (telescope.com)for 12" rings. the largest they list on the web sight are 298mm, but, as they sell a 12" eq they can probably set you up with a set. they have fixed me up with many hard to find items on the past.or possibly http://www.meridiantelescopes.com/images/telescoperings/tr120b.htm

matt
30-01-2007, 07:24 AM
Mike

Sit your inclinometer (if it has a flat base) in the mount head saddle, where you'd normally secure your dovetail and rings.:)

Once you adjusted the latitude screws to bring the reading to your local latitude, you can put the scope on and fine tune from there during drift align.

You might be surprised how inaccurate your mount's lat scale is once you've got your actual "real" latitude set from drift aligning.

Mine was out by a full 6 degrees

sejanus
30-01-2007, 08:36 AM
yeah my mount reads 40, when the inclinometer reads 34.

shoddy :(

matt
30-01-2007, 08:53 AM
And don't even think about using the bubble in the mount head for an accurate level.

Shheeeesshhhhhh!!!!!:lol:

RB
30-01-2007, 09:24 AM
Mike unfortunately I don't have any experience with the EQ6 so can't help you with replacing the longitude/azimuth, latitude adjustment knobs.
Or where to get suitable rings apart from contacting OPT corp in the USA.
I'd highly recommend changing over to rings though as they will hold the OTA and reduce any movement.


Spudrick says that "Bob's Knobs" will fit so give Don a call from Bintel, I've got them on the LX200 and they're fantastic.


Once you get the mount roughly pointing South (inc deviation) you then need to go on to do drift alignment, which takes a while at first but gets easier with practice.
Here's another link to a tutorial:
http://www.andysshotglass.com/DriftAlignment.html


Yes give the barlow a go, should work fine.


Can you give me the details of the connectors for each and I'll see what I can do Mike.
Is the Orion Accufocus unit just a stereo 3.5mm plug at either end?
Should be easy to make one up to the length you want.


Like I said OPT in the USA carry high quality rings of all sizes but it gets expensive.
Again you can try Bintel, I'm sure they can help.

As has been stated, use a good quality spirit level to level the tripod and then put the head on it.

Then use your inclinometer to adjust to the latitude. Put this on the mount before you put your OTA on. This will get you in the "ball park" then drift alignment will get you spot on after that.

And don't forget to call me with the cable details.
:)

ballaratdragons
30-01-2007, 07:19 PM
Mike, I took my accufocus and cable to a local electronics store and the guy there made me a cable on the spot!

He used normal telephone cable (not the curly stuff, the straight stuff :thumbsup: ) and put the right plugs on the ends for me.

Mine is 10m long. The plugs look like telephone plugs but are smaller. They are common, and electronics shops carry them.

All up it cost me $12 :)

Also, great to see you got the 12" on the EQ6. I'm still too scared to put my 12" on my EQ6. I don't wanna break the gears in my mount.

iceman
30-01-2007, 09:12 PM
Thanks Ken, excellent! I'll head to Dick Smith or Jaycar on the weekend.

The EQ6 seems to handle the 12" fairly well. I'm not *too* worried about it now ;)

[1ponders]
30-01-2007, 09:40 PM
Mike, I wouldn't be too concerned with the bubble level. It is helpful to be level but it isn't absolutely essential. It just may take you slightly longer to get your drift alignment right.

ballaratdragons
30-01-2007, 10:27 PM
Mike, see this thread for a solution to your bubble level problem.
http://www.iceinspace.com.au/forum/showthread.php?t=16577

iceman
30-01-2007, 10:32 PM
Yep, got that one Ken! :thumbsup: Bought it last weekend.

iceman
30-01-2007, 11:09 PM
Ken, what is the outer-diameter measurement of the 12" OTA?

Also, what did you end up doing for rings?

EzyStyles
30-01-2007, 11:43 PM
nice setup mike. can't wait to see images coming out of it from you. 1 question i was thinking.. wouldn't that kill the bearing and gears in the long run putting the 12" on the EQ6? i think my setup right now is very close to yours weight wise with my 10" + ED80.

33South
03-02-2007, 04:30 PM
Mike in regards to the alt-az adjusting bolts it is common to replace them with hi-tensile (stainless if possible) steel hex headed bolts. They wont bend and you can use a wrench to turn them.

The threads are both the same M10x1.5 about 100mm long for alt and 40-50mm for az. I got mine with nuts to use for locking, but probably not necessary.

Try Bunnings I think that's where I got mine from.


l

iceman
03-02-2007, 04:32 PM
Thanks Chris, can you post a pic or two?

ving
03-02-2007, 06:11 PM
you can get the bolts in bunnings mike. just take ya screw in and find something the same. :)

iceman
03-02-2007, 06:17 PM
yeh I'm not worried about the bolts, just wanted to see if he had anything fancy on the end :P

ving
03-02-2007, 06:45 PM
what? like a skull and cross-bones? maybe little planets? :P

hehe!

33South
03-02-2007, 07:10 PM
Nothing fancy just regular hex bolts, although I did see a suggestion about using socket head bolts so you use can use an Allen key, but couldn't find any.

Anyway here you are, enjoy.;)

33South
04-02-2007, 08:20 AM
One other thing I just remembered, and that's where the nuts came in handy.

One of the bolts had burr on the thread and some crap in the grooves that needed a bit of extra force to get the nut over it, I had to run the nut up and down several times to remove it.
I suspect the bolts are tougher than the mount material and the burrs or shavings could damage the thread.