Bresser Messier AR152s cracked objective lens collimation/retaining ring

[NGC 1502]

Well, I have taken the plunge, and I didn't go over my target price

I'll send some pictures once I've taken delivery.

Wish me luck...

Well done and hope the repair goes well, nothing like a session in the shed to sort something........bliss.......

Regards, Ed.

[Joves]

Nice one, Joe. I reckon, if you can get it sorted, you've done pretty darn well. I mean, what can be bought for 50 pound these days??

[badhex]

Thanks all again for your help.

I'm looking forward to a new project Spoke to Bresser also about spares, but they don't have anything at the moment. They said to get back in touch in a few weeks, so maybe there's a chance of a proper fix!

Joe

[badhex]

Well, I have taken delivery. It's in worse shape than the guy let on - which is not really cool, but I'm not too stressed as most of the damage is all easily repairable.

The one thing which is really not okay is that there is a chip on the edge of the objective lens and something liquid looking plus dust, etc. between the two elements. In fact, I think it's more than possible that it has been taken apart before. I hope that the construction is such that it can be disassembled and cleaned up, and that the chip on the outside edge of the lens will not cause too much of an issue. I asked the guy specifically if there was damage to the lens as well and he maintained that there was none!

Additionally, the part which screws onto the focuser (and in turn accepting 2" EPs or a 2" > 1.25" adaptor) is missing. He reckons that he will send me this on but it won't be until next month!! Oh well, it will give me time to work on it. I'm concerned about whingeing too much at him until he sends on the missing part.

I'm not going to lie, I'm not super happy about the whole thing but you pays your money and you takes your chance, I suppose!

I'll send on some pictures when I get home.

[John]

Sorry that it's not turned out as described Joe, especially as you specifically asked the question about damage to the objective lens and had a clear reply that there was none 

The objective lens elements can be removed from the holding cell, taken apart and cleaned reasonably easily if some care is taken. The chip probably won't be a problem to the optical performance.

So all is not lost ! 

[JamesF]

If the chip does affect performance and is small you could probably just reduce the aperture slightly with a mask?

James

[badhex]

Hopefully it will be salvageable. The chip is on the outside edge, doesn't appear to be on the optical surface... Fingers crossed...

[badhex]

As promised, here are the pictures. As you can see there are several quite blatant cracks which couldn't really have been done during transit. One of the knobs on the focuser also appears to be loose but this is relatively easy to fix.

I've taken close ups of the cell crack which I am now thinking Might be fixable with JB Weld - epoxy reinforced with steel particles, which can then be filed, smoothed and painted. If there's enough purchase I may be able to pin it also.

I've also tried to take a picture of the chip on the edge of the lens but it's not really clear without taking it out to the cell which leads me to my next problem! The two lenses in the cell have holding grubs which come out okay, but the actual retaining ring which screws in and holds it all together seems reluctant to move (possibly due to the bash it has received) and the lenses themselves are now moving freely.

I am worried about using wd40 to free up the ring in case it takes some coating off the lenses. Anyone have any ideas about what I could use?

[Peter Drew]

A chip on the lens edge that size will have no effect on the performance, just black it out with some blackboard paint. I have used objectives with many times that size of chip with no ill effect. You may well need a lens "spanner" to remove the retaining ring safely, it can be done by tapping one of the slots with a hardwood or plastic drift but you need to know what you are doing. 

[badhex]

Hmm, thanks Peter. I saw that the design of the two holes was similar to some (much) smaller security bits I have for normal screwdrivers, which did make me wonder if there were such a tool. My other thoughts were on gripping the whole thing in a rubber/soft vice and gently tapping a screw driver inserted into the hole. There is some damage/wear on the the two holes which was what led me to believe that the thing has been opened before.

Some sort of lubricant on the threads would not go amiss, but I am concerned about getting it on the lenses.

[JamesF]

Euwww.  That's some ugly damage not to have bothered to mention  It looks like it has been delivered by Parcelforce.

James

[badhex]

Ha, irony was that it WAS delivered by Parcelforce... I'm not going to tell you what it was wrapped in, I nearly had a heart attack when it was delivered Still, I can't see that this was damaged in transit as at least one of the cracks is on the plastic INSIDE the dew shield. 

Once I've got the missing bits I'm going to whinge at the guy, although at this stage I'm committed to do what I can just to make the best of the situation. You were of course correct James in your previous concern about how the damage to the cell happened in the first place.  It obviously was not given the care and attention a scope (even an old fairly cheap Bresser) deserves.

Let's see if I can make up for someone else's bad behaviour...

[JamesF]

Sometimes there's no pleasure in being right  I hope you manage to get it all sorted and working properly again.

James

[badhex]

Thanks all. I@ll admit James that I had that voice in my head too but sometimes you try to pretend it's not there, especially when there's a possible bargain to be had!

[philj]

I agree with Peter, the objective chip is nothing to worry about. I have a Towa 339 80mm with 4 clamshells around the edge and it still performs excellently.

Thats a lot of undisclosed damage but it looks like it can all be sorted.

yep definately raise it with the guy. I reckon this scope has been dropped.

[badhex]

Deffo been dropped. Possibly down the stairs. Twice! I've started repairs at any rate. Will post photos in a new thread tmw.

Thanks all for reading so far...!

[NGC 1502]

Deffo been dropped. Possibly down the stairs. Twice! I've started repairs at any rate. Will post photos in a new thread tmw.

Thanks all for reading so far...!

Hi Joe, following this with interest.

Hope the repair goes well, Ed.

[badhex]

Hi all

I've started a new thread over here for my repairs to avoid this thread getting overly long and picture heavy!

For those that are interested: http://stargazerslounge.com/topic/222396-bresser-messier-ar152s-refurbish-and-repair/

Thanks!

[SnakeyJ]

Hi Joe, a few problems getting these from the phone to the computer as Ubuntu 12.04 does like MTP from the new Z2.     However, finally got these e-mailed over, downloaded and then uploaded to SGL - what a palava!

The back plate to the focuser tube is machined aluminium disk, threaded to fit the draw tube (you'll have this thread measurement) it then has a 2" 30mm extension tube/EP adaptor fitted.     The disk is black anodised and probably 3" thick across the flat.    I'm struggling to unscrew mine, but might try again in the vice later after a little soak in penetrating lube.    There are no visible part numbers on this item and getting something machined with the right internal thread to mate with the the draw tube would be interesting.

Definitely worth chasing the seller up to see if he still has the original part.  

[badhex]

Jake - thanks so much for going to the trouble of getting these pictures for me. I hate MTP, always a pain - I don't get why most phones these days are not just mass storage like they used to be!

Anyway, pictures and description really useful, I figured from what I could see on your original pictures and what's left of my scope that it would be something like the above but knowing more specific details really helps. I've already contacted Bresser to find out about spares, even if they can only provide the plate it will be super useful as I've managed to track down one of those 2" fit compression rings with the M54 thread. Obviously the ideal is that the bloke does have the part but I'm not holding out much hope. I may have to construct something if all else fails.

Either way, I'm getting closer to a fully working scope thanks to help from yourself and other SGLers so you have my gratitude!