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Old 16-11-2007, 04:17 PM
Terran
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Big problems with a new 12" dob

Hi everyone , I'm new here (first post) and bought my first telescope last week - a 12" Bintel Dob. I've had nothing but problems with it ever since though, and was wondering if anyone here could give me some good advice with collimation and the state of my mirrors.

The problems started when buying it from Bintel - I recieved a phone call from Bintel a while after ordering it because they got the credit card number wrong. I was told that it would arrive the next day, but it arrived 2 days later instead. After putting the mount together (ran into problems there too due to there being mistakes on the instructions and parts list), the telescope wouldn't fit! After a couple of hours of trying to figure it out, I called up Bintel and found that they had given me the wrong mount. I was told I would recieve the new mount the next day. It took another 2 days. I put it all together, take off the cover on the front end and look inside. I found the secondary mirror covered in dust, and the edge of the plastic box connected to it covered in what looked like saw dust of plastic shavings wich might also be what the secondary mirror itself is covered in. The primary mirror was in worse shape. It had even more dust, a couple of small solid objects on its surface (maybe deep scratches), and a few scratches, one being about 4cm long. The back of the primary mirror also had a mark where it had been chipped on its edge. This is the way it was on delivery. It was the very first time the insides were exposed since they collimated it at the shop.

I finally get to use it, and did a test on the moon. I was very dissapointed in what I saw. Barely any craters were visible, it was a big distorted blur. The telescope was supposed to be collimated at the shop, but it was far from collimated. I had to try collimating it myself with the laser collimator I bought. The laser was supposed to come with instructions, but the only collimating instructions I could find was in the basic instruction manual. It was very confusing and the drawings in the manual were nothing like my telescope. After trying to figure it out for a while, the best I could come up with was to do it on my own by using common sense, and put the collimating laser into the focuser, then adjust the 3 screws on the secondary mirror to aim it in the small centre ring of the primary mirror. Then I adjusted the primary mirror screws to make the laser shine right back into the centre of the collimator. After that I could see the moon clearly, though certainly not as clear as it could be. I also spotted jupiter, which was only a tiny blob. After changing to the 2x barlow and 9mm eyepiece, it was still a very small blob, but just big enough to notice the main cloud bands. I had to adjust the focuser to a pinpoint in order to get enough detail to see those clouds, it was very prone to blurring. The next night, I managed to see the orion nebula, but couldnt get anything else. The orion nebula was about as bright as a weak smudge on the eye piece. If it wasnt for the fact that it moved with the stars, I would have dismissed it as such. I could only just make out some of its cloud shapes. Below are a couple of pictures of the mirrors. It was hard to get a good picture of the dirt on the primary mirror, but if you look at the secondary mirror, the primary is much worse than that and looks like sand paper when a torch is shined onto its surface. You can see some of the solid material (or scratches) and part of the large scratch near the top around the torch light reflection, can't see most of the dark markings though which is on the lower half.

http://img520.imageshack.us/img520/6...ymirrorfb6.jpg (20kb)
http://img119.imageshack.us/img119/9...ymirrorvv2.jpg (37kb)

All night and day, I tried again to collimate it, even looking online for guides but they are all pretty much the same and jibberish to me, because they explain things that dont apply to this telescope, missing the most important information and referring to multiple things under the same name (for example the screw, the mirror, and the excessive use of abbreviations that have multiple meanings that have absolutely nothing to do with anything). The guides all say to do this or that, but the actual effect of such actions is nothing like what the guides say.

There are 2 ways I can allign the mirrors, and neither make much difference to what I see through an eyepiece...

Manual Allignment - Focuser ring alligned to the middle of the dark spot in the centre. Can't get it exact without a sight tube or something. The laser says it's far from the centre of the primary mirror, and shines back into the wall the telescope is pointed at.
Laser Allignment - Puts everything way out of position, but the laser does point to the centre of the primary mirror and back to itself. I think the laser might not be showing centre properly, because when I spin it in the focuser, the allignment moves in a cirle.

Either way, the view I get is very dissapointing. My last collimation attempt ended up with having both the laser and manual allignment fairly close to each other. Below is a picture of how it looks through the focuser, but moving it around since I collimated it might have moved it out of position a tiny bit. I want it perfectly alligned, and I don't even mind if it takes hours to do, just knowing HOW to do it is the problem.

http://img119.imageshack.us/img119/1...imationto2.jpg (30kb)


My questions are...

1. . Is the magnification I'm getting what it should be? Should Jupiter be a small blob even with a 9mm and 2x barlow? Will buying another eyepiece be the right choice?

2. Is a faint smudge view of Orion what I should expect? I can't see anything else and for a telescope like this, I expected MUCH more.

3. What should I do about this mirror damage and contamination? How serious is it? I can see my own reflection clearly by looking at it, but with a torch I can see that it's covered in dust. Maybe this is the reason why I can't see much from the telescope. Bintel told me when I ordered it that I shouldn't try to clean it myself. I don't want to send it back again if I can help it. I've gone through enough nonsense with it already.

4. How do I actually collimate the telescope? (without buying more accessories). All the guides I've seen (including here) just dont make any sense to me. The view they describe is not the view I see, and the screws they say to turn do something different on mine. The only collimation tool I have is a laser collimator and the battery sets only lasted an hour each so ive gone through all my batteries now. I might be able to get a few minutes out of the batteries if I'm lucky.


It looks like they have given me an old display model. It's dirty and damaged, and all I can really see so far is the Moon, Jupiter and a faint Orion. I can't see anything else with it and might as well be using cheap binoculars. It is of such poor quality that I can put on the dust cover and remove the small peep hole, and I get almost the same quality image as I do with the cover off.

I'm thinking about getting a refund or dumping this junk at the tip . I apologize for my frustration, it's just that I've invested a lot of time, effort and money into this and it's driving me up the wall. But even if I get it exchanged for a new one, I still have no idea how to do collimation properly. If I do figure it out, I'll probably write a guide myself and fill in all the important blanks that the others missed. As far as I can tell (and I'm sure I'm wrong somewhere), you collimate with a laser by doing this...

1. Loosen all 4 screws on the secondary mirror. Looking through the focuser, hold the secondary mirror capsule (without touching the mirror of course) and tighten up the big middle screw into a position where the secondary mirror is centred to the focuser. If you need to move the secondary mirror up/down the tube, you will need to tighten/loosen the 3 small screws a bit as well.

2. Put the laser into the focuser and tighten up/tape the laser so that it sits in the middle without wobbling. let the laser opening face the back of the telescope

3. Adjust the 3 small screws so that the red dot reflects into the middle of the primary mirror where the small ring is. You need to look down the tube to do this, and be careful not to let the laser reflect into your eyes.

4. Loosen the screws on the primary mirror, and tighten then up while watching the laser opening. The screws will move the red dot around, and you need to adjust it so that the red dot reflects back into the middle of the collimating laser where the light comes out.

I've been majorly let down by Bintel. If it was an honest mistake, even a few, I wouldn't mind. But this is rediculous, even worse than DELL.
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Old 16-11-2007, 04:37 PM
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hickny (Peter)
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Disappointment

Terran,

How disappointing for you. The best suggestion I can make regarding the collimation is to visit Andys Shot Glass http://www.andysshotglass.com/Collimating.html
the video really helped me.

Have you spoken to Bintel I understand that they offer a good after sales service however never having dealt with them I cannot say for certain.

Keep trying.

Peter
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Old 16-11-2007, 04:40 PM
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janoskiss (Steve H)
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Hi Terran, welcome to IIS!
Could you summarise the problems? (in 100 words or less say ) you'll get more response.
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Old 16-11-2007, 04:45 PM
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Hi

Seems to me two major problems:
1. Issues with telescope--tell Bintel. If the condition is as you've described then I'm sure they will deal with it (frustrating as it might be)
2. Not understanding your scope/collimation--user error I doubt it'd be useful to attempt collimation anyway with damage and dirt on your scope though. See 1.

Good luck
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Old 16-11-2007, 04:54 PM
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astronut (John)
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Hi Terran,
If there is ANY issue with your scope give Bintel a chance to put it right. They are a very reputable company.
To get a good grip on collimating go to www.andysshotglass.com there is a great video that shows you how to collimate.
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Old 16-11-2007, 04:56 PM
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cookie8 (Vincent)
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Hi Terran
I can understand your frustration.Collimation can be a pain but only a small price to pay for a Dob. I purchased a deluxe laser collimator but it is only useful when the laser beam is coming out dead straight. So you need to collimate the collimator first. Follow this link to find out how:
http://www.iceinspace.com.au/forum/s...ad.php?t=25321
I found an old film canister with a small hole in the centre in the EP holder is a good enough collimation tool.
Good luck
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Old 16-11-2007, 05:02 PM
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HI Terran,

BINTEL have a well-earned reputation for delivering terrific after-sales service (many other Aussie vendors do too). Give them a call again and tell 'em about the problem (s). I'd be pretty confident that they will address it quick-smart.

Don't expect too much from Jupiter at this time -- remember it is virtually around the other side of the solar-system and low in the sky so you are looking through a lot of (moving) air.

Hope it all works out.

Best,

Les D
Contributing Editor
AS&T
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Old 16-11-2007, 06:07 PM
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acropolite (Phil)
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Ditto what the others have said, seeing you're in Sydney take the beastie back from whence it came and get the helpful staff to look at your problems.
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Old 16-11-2007, 08:31 PM
Terran
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Thank you for all the replies guys. I plan to call Bintel tomorrow morning. The reason I decided on getting a Bintel scope was because of the positive feedback I've heard from their customers. I'm willing to give them another chance, but I'll still have to re-pack everything for the second time and it might be a good idea if I can find a way to take it down to the store and pick up more collimation tools as well. It's a 2 hour drive each way. This has been such a hassle.

Collimation - I think the problem I have is in the alignment of the focuser to the secondary mirror. If you look at the "ring" of my focuser inside the dark spot in the middle, it's only slightly misaligned in comparison to the other parts. No guide I know of even mentions this, not even Andy's. Below is an example of what the focuser ring can look like. Alligning the dark circle in the middle does not allign the focuser.

http://img248.imageshack.us/img248/5590/focuseria1.jpg

I'll try again later to play around with the focuser alignment to see if I can figure out what I'm doing wrong. The reason I can't properly align anything past that early step is because for each step afterwards, every other screw I turn will warp all the other allignments out of position. It doesnt really matter for now until I get these mirrors sorted out. If I end up taking it down to the store, I'll be sure to ask them about it.

Cookie, I took a look at that "collimating the collimator" thing. My collimator definately needs to be adjusted and it explains a lot of things, but I'm not too sure if I understand it right. Is the picture below how to do it, while spinning the collimator on the nails and adjusting it until it doesn't do a circle as you spin?

http://img409.imageshack.us/img409/9...imationkz7.jpg

Jupiter - So the size I'm seeing it is acurate then? Would it be a good idea to get another eyepiece with more magnification or would it be too distorted to see? The atmospheric interference hasn't really been affecting the view much, but there is a lot of light around at night.
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Old 17-11-2007, 11:44 AM
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While you're at Bintel, try getting (as if you haven't already spent enough, right?) a combination sight tube/Cheshire collimating eyepiece. NOT that I'm an expert, but I believe these are good for beginners and don't need collimation themselves (or batteries!).

In fact, I'm sure they would throw one in to make up for some of the quality controls issues you seem to be facing
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Old 17-11-2007, 12:05 PM
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cookie8 (Vincent)
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collimation

Yes Terran
Assuming the nails and the piece of wood are rock solid and doesn't move.
The further away the more accurate the collimation will be. Mark the position of the laser dot on the paper, then rotate 90 degree and mark again and rotate and mark and so on. You might need a second person to help. Trial and error with the 2 knobs until the red dot stay put no matter how you rotate and you're done. Note: you might want to get more batteries. They don't last long.
Cheers. Hope things only get better from now on.
Cookie8

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Old 18-11-2007, 12:40 PM
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Hi Terran, and welcome, Your frustration is obvious, and very understandable, you have been given good advice, so I won't attempt to add more, except this...

Using a light/torch or any illumination down the tube of the best lens/scope will scare you, and make all the small imperfections in optical systems seem 10 fold.

Leon
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Old 18-11-2007, 02:16 PM
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ballaratdragons (Ken)
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Leon just mentioned what I was going to say.
When you shine a torch on a mirror, it is a horrible sight!!! The torch will show up all manner of dust, fluff, pollen, etc.

But relax, it is fine. We all have that. Even if you washed the mirror, it would look that way in a few days again. The views through fairly dusty mirrors are still stunning.

But scratches are a different matter!!! Not good!
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Old 18-11-2007, 07:11 PM
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I thought I had a scratch on my new primary mirror, It diddn't matter which way I looked at it, I would have put my money on it being a scratch. It turned out to be a hair. I'm hoping for you, hope it turns out the same!

Regarding collimation www.andysshotglass.com is brilliant!

All the best and I hope the frustration subsides soon so you can start enjoying the Heavens like you've set out to do!

Cheers Brad
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Old 19-11-2007, 10:20 AM
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Bintel after Sale Service

Hi Terran,

I feel for you and know exactly how you feel. Personally I don't hold out much hope for you of getting any good response out of Bintel. Excuses and delays or no answers at all, Yes.

Won't bother you with all my details with dealing with Bintel only to say that I purchased my first Instrument from them in March this year and still have nothing reasonable for observing.

Mike Smith from Bintels Sydney hasn't even got the decency to reply to email.

Mind you, I am one step ahead of you and on my second 304mm mirror. With the first one I had similar problems as you. Lousy image, no definition, trouble splitting alpha centauri. After having the optics tested with the result it being not even with 1 wave I returned it and got another one from Roger Davies, Melbourne Store, which turned out to be better on test, 1/3 wave, but has 100reds of extremly fine straight lines across the surface of the mirror, which reduce definition and introduce false colour to any astro image. Absolutely useless for anything astronomical.

After talking to Roger Davies and making him aware of that problem as soon as I found out, as I purchased the Instrument from Bintel Melbourne, and sending an email to Mike Smith Bintel Sydney, of which I am still waiting for a reply after more then 4 weeks I am still without a usuable telescope for which I spend nearly a $1000.

Looks like that after seven month of trying to get what I paid for, and Bintels is advertising, it is now a solicitor and small claims tribunal.
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Old 19-11-2007, 04:07 PM
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Take the scope back to bintel so they can have a look. They are very helpfull and will sort out any manufacturing problems with the scope. Most frustration usually stems down to inexperienced users with collimation ect. See if you can go and join a local astronomy club. They have very experienced members who can help you with your scope for free. The 12 dob collimated correctly and used in reasonably dark skys will show you a wealth of objects. Try looking for the eta nebula,Tuc 47, omega centaurus around the southern sky. These objects through a well collimated 12 inch are stupendus including the orion. Dust ect will always be there on the mirrors ect, but any other damage should be addresed before you keep dragging it out.

Regards Matt.
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Old 19-11-2007, 04:13 PM
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Quote:
Originally Posted by Aster View Post
and sending an email to Mike Smith Bintel Sydney, of which I am still waiting for a reply after more then 4 weeks I am still without a usuable telescope for which I spend nearly a $1000.

Looks like that after seven month of trying to get what I paid for, and Bintels is advertising, it is now a solicitor and small claims tribunal.
Hi Alex

Emails are not a reliable way to deal with serious issues: Bintel may receive hundreds each day and its easy for just one to get lost or overlooked.

Why not just just get on the phone and speak to them in Sydney directly. I've been dealing with Bintel for 20 years and always found them dedicated, and an experienced bunch ( mostly keen amateur astronomers ) and heart always in the right place.

Look out for a PM from me about the old days at AOS

Mark
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Old 19-11-2007, 10:41 PM
Terran
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I took the telescope to Bintel today. They had a look at the mirror and it turns out the scratches must have been hairs and a lot of dust etc on it that they cleaned up, but weren't concerned about. The mirror did have some of the front edges slightly chipped away, which they told me was common and wouldn't interfere with the view. They collimated it and told me that I couldn't collimate my laser without some special factory mill tool or something like that. So they kept it and said I would be sent another one when they get new stock on December 3rd. I wanted to buy an air blower to help clear my eye pieces but they were out of stock. I did manage to get a 12mm eye piece which they recommended at my request for advice on which new eyepiece I should get, and a sight tube (Orion Collimating Eyepiece).

Taking it home, I took extreme caution not to risk bumping it out of collimation. They told me that I will need to use the moon filter because the view will be so bright now that it is collim... ahhh, re-collimated, supposedly anyway. I dared to try it first without the filter, and found the view exactly the same as it was before. I put on the filter and it was darker and dull, similar to cloud cover. The filter is supposed to help you see more detail, but it did the opposite. I looked into the focuser to check the collimation, and surprise surprise, it wasn't done properly! It was closer than before, but still not right. Using my new sight tube, it was easier to pinpoint how far it was out.

The mirror should be getting the light, and the only reason I can come up with why I don't see anything is because of the collimation. There are automatic lights around from the unit complex I live in, but I can't see how they could interfere with the view this much. They told me I should be able to see structures everywhere, but I can't see anything. Just a few more white dots than the finderscope. It was windy tonight, but I don't see how that could affect things either, because my view of the moon and jupiter had almost no waviness at all. I even managed to see 3 of jupiters moons shining nearby as pixel sized white dots. At first I thought they were the reflection of something onto the eyepiece. The Orion nebula is only just there now with a tiny spot of illumination, but the stars in the area are more clear.

The Bintel crew were easy to talk to and did seem like their hearts were in the right place. They explained some things to me and tried to help, but here I am still with 2 failed collimation attempts and an expensive telescope that doesn't do anything .

I'm sorry to trouble you guys with all these problems, and thank you for your time trying to help. I just don't know what else to do with it and I'm thinking of just packing it in and giving up. Below is a picture of my current collimation. Could someone please tell me if that is an acceptable allignment, and what I should expect to see with it in its currrent state? Note that even though the collimation is closer, the focuser ring is way off no matter how collimated it is. Also, does the collimation need to be exact, like a magnifying glass burning paper? For example - you get nothing until you get it almost perfectly right.

http://img513.imageshack.us/img513/6905/2ndtryye8.jpg
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Old 19-11-2007, 10:59 PM
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ballaratdragons (Ken)
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Terran,

you can knock a reflector out of collimation just by carrying it outside!

Other times you can take it down a bumpy road on the back seat of the car and it will still be collimated when you plonk it down.

But take heart, collimation becomes very quick and easy after a few goes at it.

It's pretty hard to tell collimation from a photo, so I can't comment on yours. Don't worry if the 2ndry mirror doesn't look exactly centred. It's not meant to be. It needs to be a fraction off centre to work correctly.

Pity you can't get someone in here to pop around and see you. Usually 10 mins in person solves problems that can take weeks to sort out in a Forum.
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Old 19-11-2007, 11:32 PM
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erick (Eric)
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Terran, this has been very frustrating for you, but I'm sure you will get there. If the Bintel guys have gone over the scope, I'm sure it can be made to work. A Bintel 12" dob is a great instrument. As Ken says, what you really need is a helpful IISer to drop round and work on it with you. Alternatively, can you pack it all up and go to the next observing night up your way?

http://www.iceinspace.com.au/forum/s...ad.php?t=26002

If you send a personal message to some of those attending, I'm sure they could arrange to help you set up, collimate and get the very best out of your scope that evening.

I'm suspecting that you have fairly bright skies where you are trying to set up to observe and that won't be helping - I suspect your eyes are not dark adapting if you have this lighting all around and that makes it hard to pick up the images of nebula (eg. Orion) that the scope is trying to deliver.

Keep going. It is worth it.

Eric
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