150mm Tube Rings

[mickw]

I want to use rings on the ETX to mount to the HEQ5 without using the "moulded in" things on the scope.

The 150mm rings I ordered are actually 140mm - Seems Skywatcher have an issue understanding that there should be a difference between 150 and 140 

Nobody seems to list 150mm rings (except the Skywatcher ones)
One option would be to extend the 140s like Tony did the 300s with a 6mm bolt, but the right size would be nice.

Anybody got any ideas ?

[Carole]

Will they not change them if they got it wrong?

Greenwitch:
http://www.green-witch.com/acatalog/Rings.html

Carole

[mickw]

Will they not change them 

Yep that's OK, I've got a refund.

The problem is that according to Pulsar, all the rings marked as 150mm are actually 140mm 
But I'm beginning to suspect I have been told porkies, the Green Witch ad. show the OVL code and both of them say the 150 are indeed 150 - a phone call is in order 

[Carole]

I take it you're going to dismantle the ETX OTA from the Mount.  I'd be interested to see you do this if you haven't done it already - just in case I decide to do the same with mine at some point.

Carole

[mickw]

Already done it  

I've used it on the HEQ5 fitting a dovetail in the bolt holes on the bottom of the ETX, but with the interesting angles the scope goes to on the HEQ5, your spine is likely to snap using it for visual - Hence the need for rings.

The 125 was pretty easy to dismantle, just a few screws and a bit of tugging - I'll try and find the link to directions.

*Found it*
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2107706/Main/2096491

[Fay]

Hope you get them to answer the phone Mick, they are pretty bad at that!

[Mac]

The 125 was pretty easy to dismantle, just a few screws and a bit of tugging -

No hammer?

Might start stripping my lx200 down tomorrow, as the bits should arrive monday

[mickw]

Hope you get them to answer the phone

Nope  
Ordered anyway as they are pretty specific about sizes - we shall see

No hammer?

If the LX is the same as the ETX, remove 2 screws to the rear of both the side plates, spring them apart, slide the tube out the back - Done

[Carole]

If the LX is the same as the ETX, remove 2 screws to the rear of both the side plates, spring them apart, slide the tube out the back - Done

Hmmmm, might be worth thinking about at some point.  Hadn't realised it was as easy as that.

Just measured mine it's 125mm accross, you have got a big one Mick at 150mm.

Carole

[mickw]

you have got a big one Mick

Thank you Carole 

[Carole]

Hee hee, yes I did think about making the comment more specific, but then thought I'd let you all have your bit of fun.

Carole

[Carole]

Have you tried seeing how easy it is to put the ETX OTA back in the meade Mount (should you so desire)? 

I would really like to use the ETX OTA for planetry on my new mount, but also want to keep it "as is" for observing as it's so portable and easy and quick to set up. 

Carole

[mickw]

Just the reverse of the procedure, just needs a bit of fiddling so the side plates line up with the fixing holes.

I would slacken off the alt az locks before dismantling or reassembly so the gears don't get strained

[The Thing]

If it's like the LX90 you then need to do an alignment process (no stars required) to make sure you put the OTA back in square to the forks. That's why on the LX90 the mounting screw holes are slots (assume it's similar on an ETX). The procedure involves lining up on something in the distance and then flipping the tube over 180 degs and rotating the the base 180degs and seeing if the tube still points at the object. There are full instructions somewhere on the web.

[mickw]

The plot thickens...........................

Skywatcher, or their Chinese manufacturer appear to have gone completely off the rails.  Nobody seems to have 150mm tube rings - they have the boxes with 150 on the side but the contents are 140mm   

[Carole]

I am assuming you have got this answer from Green Witch.
You're a bit buggered for DSC then unless you

extend the 140s like Tony did the 300s with a 6mm bolt

assuming you've still got the wrong size rings, or put the ETX back together until you get some rings,

or
Give Ian King a ring on 01892 834004
or
Give Bernard a ring on 020 8763 9953

What a ridiculous situation.  

[mickw]

I can still mount the dovetail to the bolt holes on the ETX, but "visual" can be a bit tricky on a GEM as the eyepiece holder has a tendency to point down and with a lack of circus training, my neck and spine will not adapt to the required angle 

Imaging is not an issue with the visual back thingy - It's just the flexibility that I want to go for.

Might give Ian or Bern a ring later, but if they're flogging the Skywatcher rings as well, they'll probably be in the same boat.

[Carole]

What a pity you didn't do this before Astrofest as you would have had loads of stalls to buy from, there was a bloke who had loads of sizes of Guide rings, I think he makes them, I am sure I got his business card.  If I find it I'll let you know.

Carole

[mickw]

Astroparts ?

He makes lots of other quirky stuff as well.

But he doesn't do tube rings, only guidescope rings 
http://www.astroparts.co.uk/index.htm

[Carole]

Could have been.

[mickw]

Sorted - Sold the ETX and bought a C14 

OK, not strictly true...................
Ordered some 140 rings from Bern which I'll modify and just to ensure the weather stays crap, I've ordered a Baader IR filter for the 350D

Must admit, I've dealt with two dealers over the last couple of months that give great service, answer the phone and answer emails.
Modern Astronomy and Ian King.

Pulsar Optical are cheap - no further comment