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Any Tricks for alt/az with no slow motion?

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#1 Don Trinko

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Posted 08 March 2010 - 11:55 AM

I just go an Orion dual scope mount. I had it out 2 nights ago at 60x and had minimal problems finding and tracking things at 60x. (C6 with 6x finder)I tried a 2x barlow and lost my object. (Mars) The barlow focused different and quality was not good so next time I'll try switching EP's instead. My bigest problem was moving the scope just a little. I'm sure practice will help but If anyone has any tips to make operation smoother I would appreciat it. Thanks; Don T.

#2 Bugsi

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Posted 08 March 2010 - 03:25 PM

There's always the "lengthen the adjustment lever" trick. If you can extend the handle used to move the scope, then a 1/2" adjustment at the end of the handle will have a smaller axial movement of the scope than a shorter handle.

But in general, those of us that want slo-mo adjustments just buy a mount with slo-mo adjustments. They're not hard to find, and not terribly expensive. A versa-mount or porta-mount goes for less than the price of a premium eyepiece.

#3 Don Trinko

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Posted 08 March 2010 - 03:41 PM

Thanks; That is one posability. Don T.

#4 Lt 26

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Posted 08 March 2010 - 03:58 PM

Don T., when moving the scope in AZ try pulling it towards you instead of moving it away backhand. If you use a handle try to attach it as far forward and to the outside on the head as possible for greater leverage and less force.

Dereck

#5 Don Trinko

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Posted 08 March 2010 - 05:50 PM

Thanks; I will try that. Don T.

#6 Erik D

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Posted 08 March 2010 - 07:09 PM

I don't have experience with the Orion dual scope mount but I use a Giro 2 DX two arm mount for my 6 inch F8 refractor. One side is about 30 lbs with OTA, finder, pair of 7 inch rings and 13 inch Losmandy dovetail. The other side is 12 lbs of counter wt because I have not mounted a 2nd scope.

I found the key to smooth operation is to try for perfect balance fore and aft with a long dovetail plate. Once balanced the OTA seems weightless. Stays at the exact location I point the scope. Works for me up to 300X( with 2X barlow). I keep no tension at all on the altitude knob.

Of course this arrangement works with a single payload only. I would have to rebalance if I change from a 6 mm plossl to a ethos. ;-))

No handle is needed because the scope is in perfect balance. Only finger tip pressure is needed to track. I have my Giro 2 DX on a extra heavy duty tripod with geared center column. I can raise and lower the center column and the scope stays fairly close to the object I am pointing. But I also have a 9X50 RACI finder on the main scope so it's pretty easy to make small corrections if needed.

I much prefer using the Giro type mount than dealing with the stiff slow motion cables on the Oriona AZ 3 mount.

ERik D

#7 Don Trinko

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Posted 08 March 2010 - 07:26 PM

I will have the 2nd scope Wednesday. I did balance the scope but I have trouble moving it a small amount. If I put no tension on the alt it moves very easy and I tend to acidentaly bump it. I have been tightening the axis that I do not intend to move and loosening the one I want to move. It's only been one night so far. I think a little practice should improve things.
thanks; Don T.

#8 Don Trinko

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Posted 08 March 2010 - 07:29 PM

My OTA is abought 10 lbs. The scope I am adding is abought 4 lbs. Perhaps adding weight will make it smoother? Don T.

#9 Erik D

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Posted 08 March 2010 - 08:04 PM

Don,

Adding wt on the opposite side will help Az slewing but will have no effect on altitude operation.

I had a long discussion with someone who was using the Orion dual arm mount lasr year. He said his balanced OTA became unbalanced when he changed elevations. Sometimes take a dive if he tried to change EPs. Turned out he had a 50 mm finder (IIRC) mounted on the center clamp ring. As he tilt the OTA up the load will become unbalanced because the center of gravity shifts towards the rear. If you have similar mounting arrangement it will not work. Slo mo control will be needed.

I purchased two 12 lb counter wts for my Giro 2 for use with my 29.5 lb load. But found one 12 lb counter wt was sufficient for smooth panning so I usually don't take out the 2nd counter wt.

ERik D

#10 Don Trinko

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Posted 08 March 2010 - 09:11 PM

I have a C6 on the one side. It has a 6x30 finder. It apears to balance fine so far. The other side will be a 4.5" Orion 450mmfl. I have a Telrad to put on it.
The C6 weighs around 10 lbs. The 4.5" will weigh abought 4 lbs with EP. the tube on the 4.5 is steel so I can add magnets to help counter ballance top heavy on the other scope if nessisary. Thanks for the information. Don T.

#11 rg55

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Posted 10 March 2010 - 07:26 PM

Don,

I have that very mount and that very problem. I recently posted on it, and had some respondents who had installed a sort of handle to the scope rings. I think it might even be possible to attach a handle to an unoccupied part of a long dovetail, but this needs study.

My configuration is a C80ED on one side and a 127 Mak on the other. Each/both could have a digital or video camera attached. At least, that was my plan, more for digiscoping than for astronomy. That was one reason I did NOT look at mounts with slow motion controls--I wanted to be able to pan quickly to follow a bird in flight. I haven't been able to reach the magical balance that another poster mentions, where it glides along at pressure from your fingertips. Maybe with more practice?

I'll see if I can find a link to that earlier discussion and post it.

CS,

Richard

#12 rg55

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Posted 10 March 2010 - 07:28 PM

Don, see link below:


http://www.cloudynig...5/o/all/fpart/1

#13 Don Trinko

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Posted 10 March 2010 - 09:08 PM

Thanks; I added a second scope and it has a threaded 1/4-20 hole on both the scope rings. It would be easy to add a handle but unless I am very carefull it would effect the ballance. I think practice will make it doable but probably limit the magnification I can track with easily to abought 150x. Don T.

#14 Erik D

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Posted 10 March 2010 - 11:17 PM

Don,
--I wanted to be able to pan quickly to follow a bird in flight. I haven't been able to reach the magical balance that another poster mentions, where it glides along at pressure from your fingertips. Maybe with more practice?
Richard


I should clarify about my set up with the Giro 2 DX. My 6 inch F8 AP scope is about 5 ft long with dew shield attached and the focuser extended for normal viewing. I estimate I have at least 24 inch of lever arm to make small adjustments by holding and shifting the 2 inch diagonal end. That's why I do not need a handle. If you are mounting a SCT with shorter OTA on a different mount it may not be as smooth.

I have gone as high as 300X with the Giro DX for lunar viewing. My usual magnification for the planets with my 6 inch refractor is ~150 to 220X. Seeing limited, not the mount.

You can see photos of the Giro 2 DX mount in David N's review of Alt Az mounts in the CN review section.
http://www.cloudynig...ry_id=35&pr=2x8

For smooth tracking of flying objects I use Manfrotto 501 or 516 fluid heads with dual pan handles. But that's usually at lower power of 20 to 54X.

My viewing sessions are usually less than 1 hr so I prefer the ease of set up with Alt Az mounts. One mount I found unsatisfactory is the Orion AZ-3 mount. Just not refined enough for my taste. But I guess that's to be expected for low cost mount with slo mo controls AND tripod for ~$150.

ERik D

#15 Lt 26

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Posted 11 March 2010 - 03:22 AM

Don T., you may already be doing this but if not give it a try. When you balance your scope do it at about 45 degrees or close to your viewing angle with the focuser racked out to about where it needs to be an eyepiece in place. With just a little tension you will be surprised at how wide of an arc it will hold. Good luck and keep at it.

Dereck

#16 Don Trinko

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Posted 11 March 2010 - 08:11 AM

Thanks; I thought abought that but forgot all abought it when I balanced! So far balance is not the problem. The problem is me. More practice! This is one of the few hobby's where practice is fun. Thanks; Don T.

#17 Nippon

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Posted 16 March 2010 - 08:26 AM

This will sound silly but it works. I have a TeleVue Alt/Az mount with an 85mm refractor. It has a handle and what I do is press the side of the bridge of my nose against the eyepiece lightly and move my head in unison with the scope as I push or pull on the handle. I have found this greatly increases my ability to control the movement.

#18 dscarpa

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Posted 16 March 2010 - 02:39 PM

I have a WO EZTouch which a lot like the Orion with a IM715 mak on it. I bolted a 11lb counterweight on the opposite without a shaft. I then used the bolt on the weight to attach a spare dovetail plate I have to it. The dovetail works very well as handle. Good weight balance so you use minimal tension on the axis is the key. It's also important that the mount be fairly level.I also have a C9.25 on a Giro and a steel legged SW AZ4 with a WO ZS110 on it at night and a Lunt 60 by day. The Giro needs 2 11 lb counterweights and a shaft to work well with the C9.25. I've used up to 400X power with the C9.25 and IM715 and 300X with the ZS on the alt/az mounts. David






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