Dovetail too long, need a variable dovetail?

[whzzz28 (Nathan)]

I just received my HEQ5 Pro and Meade 80mm refractor.
The Meade is a shot tube design (480mm) and comes with an L dovetail bracket.
Least to say, it isn't very stable (as i suspected). So i am trying to mount it with tube rings, and boy is it anything but straight forward!

Problem 1:
I bought 90mm Skywatcher tube rings... to go with my Skywatcher HEQ5... which includes a Skywatcher dovetail bar. According to the skywatcher site, the rings are compatible with the mount/dovetail.
Trying to attach them and they just seem wrong. The steel is very big so it does not "slot" into the grooves of the dovetail. As seen here: http://core-au.net/astro/IMGP0032.jpg
As a result the bolt is too short so i can not attach the ring to the dovetail. As seen here: http://core-au.net/astro/IMGP0033.jpg
There is some thread too attach it with, but not enough to make me feel that it is secure.
Ok not the end of the world, i have some longer bolts outside. Found some that fit and attached the rings to the dovetail - although the dovetail sits on top of the grooves along the edges, it is still pretty solid. Moving on...

Problem 2:
The scope is too short to fit inside the tube rings. There is only one place on the dovetail bar to put the tubes (only two holes for mounting) so i can't adjust it.
The distance between the two tube rings needs to be ~30mm less for it to fit. Clearly seen here: http://core-au.net/astro/IMGP0034.jpg

Maybe i am doing something wrong but it just does not seem to fit, not even close.
Now i am looking for a dovetail that will fit (more money!).
Something like this possibly: http://www.bintel.com.au/Accessories...oductview.aspx

Skywatcher do seem to produce a variable dovetail, but i cant find it for sale anywhere in Australia, or anywhere that ships to Australia
http://ca.skywatcher.com/_english/03...il.php?sid=210

So does anyone know of an Australian store that sells variable dovetails or something else that will allow me to use the tube rings with this scope?

Maybe i am doing it wrong, in which case please let me know the errors of my way.

Cheers.

[Tandum (Robin)]

That is how they go, the base of the rings sit ontop of those 2 ridges. Take that split washer out and that bolt will probably be long enough. The 2 allen screws then screw up to tension it.

There are 2 sizes in dovetail bars, short and long, 200mm and 330mm. Sounds like you have a long one. Ron at sirius optics at springwood might have a short bar in stock. Give him a ring tomorrow. If he has one, take the scope and rings there to make sure it all works. Not sure what they cost.

[Ross G]

Hi Nathan,

Also check out the William Optics short and long dovetail bars.

Andrews communications in Sydney have them.


Ross.

[whzzz28 (Nathan)]

Ended up taking a drill to it.
Got everything mounted now.

Still waiting on my QHY5 and DSLR to turn up, and then i am at the mercy of the rain.

Thanks for the suggestions too.