wanted: tube rings/dovetail bar for 8" newt.

[AlexN]

As the title says...

Pm me with any offers, cheers.

[Screwdriverone]

Hee hee, COME ON EQ6!

Then there will be no more "DOB POWER" :(

Chris

[AlexN]

:D thats the plan.... its ordered and should be here in 1 - 1.5 weeks

[Screwdriverone]

Yay!,

no more field rotation and longer tracking.

Chris

[acropolite]

Alex, FWIW MyAstroshop has tube rings for the SW600 (http://www.myastroshop.com.au/products/details.asp?id=MAS-035) (8" OTA) They will bolt directly on to the dovetail, whether your SW dob is the same diameter or not I'm not sure of.

[Ian Robinson]

Not all 8" OTA have tubes of the same outside diameter , you should specify the actual measured outside diameter of your tube , else you might buy tube rings that wont fit.

[AlexN]

I'll measure it shortly... I //think// its 230mm or there abouts..

[acropolite]

Alex, if you'd like to measure it exactly I can measure my SW600 and see if they're the same diameter.

[AlexN]

235mm tube diameter...

thanks Phil.

[acropolite]

It's a bit hard to get an exact measurement, at the ends where the cast flange is, it's around 235mm (OD) but I'm guessing the tube itself is closer to 230. The Sw600 mirror is different from the dob (SW680). The 680 is an F5.9 F/L 1200mm, 203mm mirror according to the spec, the SW600 F5 1000mm F/L 200mm mirror. The rings at MAS are advertised as 235mm so they should fit. Might be worth giving Steve Massey at MAS a call and asking if there is any variation in the OTA diameters between the various models, his phone number is listed on the site and he usually answers his phone.

[madtuna]

what is the length of the dovetail you need?

[AlexN]

Phil, the measurement was 237 on cast flange. I measured the flange difference to the tube by measuring the step up. it was 1mm (perhaps 1.1mm) resulting in my 235mm final measurement of tube diameter.

Steve. Im unsure how long it will have to be.. someone with more experiance could probably tell me... my tube is 1110mm long. I suppose somewhere around 300mm for the dovetail.. but Im open to options..

[leinad]

I got the SW 235mm rings from MyAstroshop for my 8" Dob and dovetail bar and they fit perfect. On the EQ6 'Dobinator', I can loosen the rings easily and twist or move the mount. :thumbsup:

The Dobsonian I have: http://www.skywatchertelescope.net/swtinc/product.php?id=51&class1=1&class2=106

[AlexN]

cool, same dob as mine... :) Just wondering, how long is your dovetail bar?

[madtuna]

how long is your dovetail bar?

[leinad]

30cm at moment. I have a 43cm losmandy bar also, which I may use. Im not sure if it would be better, havnt tried it yet.
Pics here that Tandem showed are the same ones
http://www.iceinspace.com.au/forum/showthread.php?t=30396

[madtuna]

oops! GMTA Alex..sorry

[Tandum]

Yep 235mm rings and a 30cm bar work for me.

[AlexN]

235mm rings ordered, and Steve has helped me out with a dovetail bar (Thanks once again mate.)

EQ6 should be in my hands within 2 weeks... ITCHING FOR IT!!

[Tandum]

You'll find balance will be a problem east to west cos the focuser and finder are on one side of the tube. I've just rebalanced and have the focuser and finder forming a V on the top of the scope. I sudo ran it this arvo and it didn't miss a beat. With the guide scope peeking through between them, I can no longer see into the finder scope easily so I've just ordered a right angle finder scope. Open that wallet, you have only just started :)

[AlexN]

hahh.. I use a red dot finder, that eliminates some of the excess weight off to one side..

I noted in the pics of your setup, you've got an extension on your counterweights. Do you think that will be necessary with the EQ6 for me?

[Tandum]

I had 3 weights to balance the 8" dob and the I just won that battle. The more I added to the the scope the more I lost the balance battle. Hence the extension arm. The problem isn't the weight, it's the height of it with stuff pilled on top. Leverage. I can't see the eq6 being any different.

[AlexN]

mmm... I intend to mount my guidescope side by side with the 8", and its a fair bit smaller than your 80mm refractor too.. hopefully i'll get away with it..

[Bloodbean]

AlexN,

I'm going down a similar route to you (8" but with HEQ5Pro) and just curious on the size of your guidescope?

Cheers!

Troy

[AlexN]

I've bought an Orion ST80 guide scope.. its tiny compared to most refractors of the same aperture, and weighs around 1kg

Cost is minimal too... $219 at bintel is what I paid.. from info I've recieved from others the SPC900NC has no problems focusing with a barlow and works great as a guidecam in said scope.