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Old 30-10-2015, 07:47 AM
cfranks (Charles)
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FLT132 collimation

Has anyone performed a collimation of an FLT132? Hints on how to remove the Dew Shield and how to adjust the lens cell (if possible) would be greatly appreciated. Image below shows why!
Thanks
Charles
Image not stretched, sorry. I'll get it replaced.
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  #2  
Old 30-10-2015, 07:55 AM
cfranks (Charles)
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It should be visible now.
C
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Old 30-10-2015, 09:44 AM
glend (Glen)
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Is your focuser centred? Before you adjust the objective make sure your focuser and objectve are aligned. A laser in the focuser should hit the exact centre of the objective. You can make a target out of paper and tape it over the front.
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Old 30-10-2015, 09:59 AM
SkyWatch (Dean)
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Unfortunately as far as I know you have to send Williams scopes back to the factory for collimation. Certainly the case with the Megrez line where there are no collimation screws in the objective cell. (I had to send one back twice!)
It is a very good idea to check the focuser first!

Good luck.

Dean
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Old 30-10-2015, 10:18 AM
loc46south (Geoffrey)
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Hi - if the scope is new I would shoot that pic off to Williams for their comment. It looks very much like pinched optics - the cell screws could be to tight.

Cheers
Geof
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Old 30-10-2015, 08:59 PM
cfranks (Charles)
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Thanks for the replies. I will try the focuser centring, it's an after market FeatherTouch but I fitted it, albeit with a coupler made by FT for the Williams, very soon after purchasing it. The scope is about 6 years old and to my recollection, has been like this from the start although I wasn't smart enough to recognise the distortion in the early days. I think I accept that I have to send it back so I'll make some enquiries with Williams.
Thanks again.
Charles
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Old 31-10-2015, 09:50 AM
SkyWatch (Dean)
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Hi Charles,
I found Williams to be very helpful- initially I went through Lee Andrews (where I purchased the scope from), but then Williams direct.
Good luck!

- Dean
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Old 31-10-2015, 11:37 AM
casstony
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There are no collimation screws on the flt132 objective. The dew shield is removed by first unscrewing the gold ring at the rear of the shield, then the objective may be unscrewed from the tube.

Some of the early flt132's reputedly suffered pinching/astigmatism in cold temperatures as the aluminium cell shrank against the lenses. The cell material was changed to steel in 2013. Also some poor quality objectives made it through QC around 2008/09.

I bought one of these dodgy scopes which displayed obvious astigmatism (flip-flopping ovals either side of focus) and spherical aberration (bright outer ring on the extrafocal rings/star test) and WO let me upgrade to a new objective for US$300.

Yours may or may not be bad scope, don't want to cause unnecessary worry, but I thought my experience might be of interest.
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Old 01-11-2015, 08:24 AM
cfranks (Charles)
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Thanks again for the replies. I sent an email to Williams asking for price etc for them to collimate and I'll await their reply. That was interesting, Tony, as mine was bought ~ 2008/2009, before Williams came out with their digital focuser. I can't check more accurately as I disposed of all the images from that time because of poor quality.
I tested the centring with my Glatter laser and the dot (on the wall) was within 1 - 2 mm of the centre so it can be improved a little but I doubt if it would cause my problem. I rotated the OTA to check this but of course, if the tube is not round, the test wouldn't be very accurate.

Charles
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Old 05-11-2015, 10:39 AM
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Have you tried a short Cheshire eyepiece , skywatchers supplied them with their 6". achromatic refractors .When the Reflections at each optical surface aligned the objective was collimated. It would be an easy way to check.
Philip
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Old 06-11-2015, 08:58 AM
cfranks (Charles)
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Thanks Sash.
I've tried the full set of collimation eyepieces, Glatter Laser, Tak scope etc. and I think Casstony has the right idea. The stellar distortion does suggest pinched optics. I asked Williams for suggestions and when I told them the purchase date and supplier, they just told me to send the lens cell back to them. Quote to fix + return freight is $US240 so, not bad at all. I'll send it off next week when go down to Adelaide.
Thanks for all the help.
Charles
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Old 29-12-2015, 09:33 PM
cfranks (Charles)
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I just heard back from WO. They said some parts inside my lens are damaged and unfortunately those parts cannot be replaced. The scope has always been treated like a precision item and never even bumped so I will never know where the damage came from. They offered me a current lens assembly with a steel cell for US$860, inc freight for both new and old. I hope this one will fix my problems.
Thanks again for the help.
Charles
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Old 30-12-2015, 10:26 AM
SkyWatch (Dean)
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Sorry to hear about that Charles, but it sounds like they are giving you a good price for the new lens assembly.
Hope all goes well!
- Dean
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Old 31-12-2015, 12:16 PM
casstony
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Quote:
Originally Posted by cfranks View Post
I just heard back from WO. They said some parts inside my lens are damaged and unfortunately those parts cannot be replaced. The scope has always been treated like a precision item and never even bumped so I will never know where the damage came from.
Assuming nobody has ever tried to adjust the objective then it's likely been faulty from new - it is from the era of dodgy flt132's.
Anyway your new objective should be excellent.
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Old 31-12-2015, 07:50 PM
Alchemy (Clive)
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The front objective has some grub screws that align the lenses, given that I had the same issue, it was overcome by trial and error of adjusting them, it's possible ( as mine did) it has a slight pinch and too much pressure. As said I did my own and succeeded in fixing it, of note the tiniest adjustment makes a huge difference.

So if it's the same as mine it's doable...... What have you got too lose ?
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Old 25-01-2016, 09:35 AM
cfranks (Charles)
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The FLT132 lens saga continues.
Having paid for the new lens, WO then suggested that they retain the old lens for one of their specialists to look at it and see if they could do something with it!! They sent the new lens via UPS who promptly stuck it in the mail in Melbourne. It was packed pretty well, multiple layers of bubble wrap around the cell and then in a small, well made wooden box. The whole then in a reasonably sturdy cardboard box with plenty of styrene foam. Someone, in its travels, must have dropped it from a fair height because the glass lens now rattles in its cell! Underneath the retaining ring is a ring with 3 'feet' that butt against the lens and hold it in place. Those feet have been pushed out of place by 0.8mm as measured with a feeler guage and the lens block can move back & forth by that amount.
WO say that it was perfect when it left them and asked me to adjust the retaining ring to get rid of the rattle but it is glued in place by a black paint or loctite and is absolutely immovable. I have to return it obviously but since it was a D.O.A, not a Warranty thing, we are arguing about who pays the return freight!! I certainly don't want to give it to AP. Trouble is, they have my old lens and can easily send it back with no further work on it if I get too stroppy. Bugga!
Of course, 3 or 4 days reply time to my emails adds a bit more frustration.
Charles
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Old 25-01-2016, 01:39 PM
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Exfso (Peter)
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This sounds like it could develop into a real crap fight. I had Tak stuff going back and forth, and if anything went amiss, they were excellent about it. Reckon WO should take a leaf out of their book. If it is packed right and properly protected, it should not be damaged by anything short of crushing.
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Old 26-01-2016, 08:09 AM
SkyWatch (Dean)
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Sorry to hear this Charles: what a pain! If they get stroppy maybe you could quietly mention that a lot of people are following your saga and maybe they would like to get some good PR by doing the right thing... They aren't doing their cause any good at the moment.

Seriously though, I agree with Exfso: if there is a rattle then either it wasn't packed properly or it was dodgy when it left the factory. There is no other possibility really. If the outer packing isn't damaged then it really is WO's responsibility to fix it and pay the freight. They can take it up with the freight company if they want, but it shouldn't be your problem.

Good luck!

- Dean
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Old 26-01-2016, 09:16 AM
casstony
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When I sent a dodgy FLT132 objective to WO I made my own packaging out of closed cell foam from the packaging used for a CPC11 scope. I used a bread knife to carve appropriate shapes for the cell leaving space so nothing could press on the glass - ended up being a 12" cube. They sent a new objective back in my packaging and it arrived in good shape.

Perhaps ask WO to ensure there are minimum two inches thickness of bubble wrap on all sides of the objective next time? They are responsible for getting it to you in good shape IMO.

On another note, the new objective I got from WO is close to Tak quality; very much like a TSA120 with another 10mm aperture and slightly faster f/ratio, leaving the colour correction extending less towards the extremes of the spectrum (as observed out of focus) but still no false colour in focus.

So when you finally reach the end of the saga you should have a nice scope, something positive to look forward to. Just keep pushing, but politeness and persistence are key to achieving the desired result I think.
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Old 26-01-2016, 10:11 AM
casstony
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Quote:
Originally Posted by cfranks View Post
The FLT132 lens saga continues.
Having paid for the new lens, WO then suggested that they retain the old lens for one of their specialists to look at it and see if they could do something with it!!
If they can't do anything with it, ask to get the old lens back if you have that option. Wolfgang over at astro-foren demonstrated how to repair an objective from that era by disassembling it and rearranging the spacers. A number of objectives at that time were sent out with good glass but incorrect spacing resulting in strong SA. If your old lens had an extrafocal pattern showing dull central rings with a bright outer ring this may have been part of the problem.

I would have liked to get my old lens back to have a play but it wasn't offered. WO did give me a very good upgrade deal though.
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