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Vixen Porta Mount Question

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#1 armond

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Posted 19 February 2011 - 11:09 AM

I absolutely love my PORTA however when I put some of the heavier 2" eyepiece on it, it sways downwards. I guess the mount is not really meant to handle big loads.

Has anyone ever found a way to add a counterweight system? I looked around online and couldn't find any 3rd party companies that made modifications.

#2 Binojunky

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Posted 19 February 2011 - 11:31 AM

You could move the scope forwards a touch if its being used with rings or take the small allen key kept under the rubber cover and adjust the axis tension via the small allen set screw in the hole just in the side by the slow motion handle, just a small touch is all you need till it stays put,read the instruction book it tells you how to do it, Dave.

#3 Manny Myles

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Posted 19 February 2011 - 12:15 PM

Here is a photo of a counter weight system I built for a fellow CN'r
When you get to a certain elevation if the bar was straight out from the scope would be useless.
The way this was designed so when the scope was pointed higher the CWs would still work.
Bad part was the scope could not be pointed below a certain elevation.
There was 1, 2 &3 pound weights on the bar, with each one being able to be removed or slid fore and aft.
m2

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#4 Manny Myles

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Posted 19 February 2011 - 12:24 PM

In this shot you can see the CW right below the scope, its works to a certain degree then does not affect the counter balance the way it should be.
m2

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#5 Manny Myles

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Posted 19 February 2011 - 12:26 PM

Here is a shot of my CWs below the scope where the weight is supposed to be, in the above shot the user said the weight so close did no good.
m2

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#6 Manny Myles

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Posted 19 February 2011 - 12:34 PM

Here you can see the issue with the loss of horizon when putting the CW bar on the bracket.
m2

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#7 armond

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Posted 19 February 2011 - 01:45 PM

Just curious, what if you put the scope reversed on the mount. would you still have the same problem?

#8 Midnight Dan

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Posted 19 February 2011 - 02:55 PM

If you have a steel tube on the scope, these magnetic weights might help:
http://www.scopestuff.com/ss_mwt1.htm

JMI sells counterweights for the 8SE that just attach to the dovetail. You should be able to use this on your scope if your dovetail is long enough to protrude out the front of the mount a bit. If not, a longer dovetail rail would help:
http://www.jimsmobil... Counterweights

-Dan

#9 armond

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Posted 19 February 2011 - 03:57 PM

Thanks!

Appreciate the help everyone! :)

#10 Ira

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Posted 19 February 2011 - 06:03 PM

I use mine with a 4" achromat, 2" diagonal, and 2" eyepieces, alternating with 1.25" eyepieces, with no difficulty whatsoever. I also don't bother to balance the tube in its saddle. Never had a single problem. I would say you should try tightening the friction on the altitude axis.

/Ira

#11 DaveE

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Posted 19 February 2011 - 07:43 PM

I use mine with a 4" achromat, 2" diagonal, and 2" eyepieces, alternating with 1.25" eyepieces, with no difficulty whatsoever. I also don't bother to balance the tube in its saddle. Never had a single problem. I would say you should try tightening the friction on the altitude axis.

/Ira


What is the total weight of all that, and the length of the tube?

Dave






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