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