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Alt-Az mount choice for ST120

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#1 Tim C

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Posted 23 October 2013 - 07:43 PM

Hi,

I just bought an Orion ST120 F5 refractor and need a mount. I was able to use it on a shaky camera tripod the other night long enough to know I like the OTA (17mm ethos was very nice). The OTA with rings, eyepiece weighs around 12lbs I think.

I don't ever plan to use it over about 70x (35 Pan, 17mm Ethos, 9mm ES100) with 17mm ethos probably getting the most use. I plan to use this as my airline portable scope and carry it on and check the mount so mount weight is important with those 50lb limits. I also want good stability, as much height as possible, and I'm 99% sure I want geared slo-mo cables.

Here are the ones I'm leaning to:

Vixen Star Guy $399, weight 18 lbs
Vixen Porta II $279, weight 15 lbs
ES Twilight I $299, weight 16.7 lbs

I like the Vixens and the way the head attaches to the tripod. Looks easy to screw off and fold up with no slightly annoying dangling rod on an e-clip like the twilight has. Based on my reading, I would guess at the stability in this order (best to worst) 1) Star Guy 2) ES Twilight (because of the legs) and 3) Porta II.

Anyone compared these 3 with a similar OTA? I guess my specific question is, will I notice an appreciable difference in stability with the Star Guy over the other two? There is a $$ cost and a weight cost with the Star Guy but I do like the looks of that one.

Thanks for your input!

Tim

#2 brokenwave

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Posted 23 October 2013 - 07:55 PM

My choice would be ES Twilight.
The Vixen Star guy 2nd.
(Vixen Starguy is a PortaII with a Hal tripod and a better tray.
A PortaII on another HD tripod is fine also. But more costly.
I've used ES TwilightI and a PortaII and found the Twilight to handle a 102mm and larger scope better.
The ES tripod is sturdier for anything larger than a 102mm scope.

#3 Tim C

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Posted 23 October 2013 - 08:31 PM

Thanks Brokenwave. Looks like you've confirmed my guess that the ES is probably more stable than the regular Porta. I'm wondering if the better star guy tripod would make that big of a difference so that it' even a notch better than the ES?

#4 Locoman

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Posted 23 October 2013 - 08:32 PM

Here is the ST120 on my StarGuy. I don't have the ST120 anymore (sometimes regret selling it) but it was very stable on the StarGuy. I would think the regular Porta ll would handle the ST120 but maybe someone else can chime in on it because I'm sure someone has tried it. The StarGuy is not a light mount to carry around. I have the Orion VersaGo ll with the aluminum tripod and it feels a lot lighter than the StarGuy. The Porta ll would be easier to travel with. I really like the StarGuy a lot. The Hal 130 tripod is heavy duty and the mount head screws off easily. I've used my SLT mount, and my VersaGo mount on the StarGuy tripod with great results.

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#5 brokenwave

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Posted 23 October 2013 - 10:26 PM

I saw the Star guy tripod (Hal) compared to the std one and it was much sturdier. For the price difference I feel the ES Twilight to be better.
My brother was going to upgrade to the HAL tripod for his PortaII but bought the ES mount and is very happy with it. I used it and like it a lot.

#6 core

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Posted 24 October 2013 - 01:51 AM

Tim,

You've listed ES Twilight I - in which case I'd really avoid it; there's a thread a while back about the cast metal arm fracturing, and using one in a store setup, I found the movement and controls rougher than the Portamount. Another option would be to get Porta Mount head alone, and get a tall Oberwerk tripod (~65" height to tripod top) in their blemish section ($125+shipping) - I think you'll be quite pleased. You should then contact Manny Miles over here at CN and get him to make a panhandle and eyepiece tray (customize how may 2" holes you'd like) for the mount! I have a ED103SWT on this setup, and it's about as comfortable as I'd like it to be - the main issue being the long moment arm of the OTA. The shorter ST120 should be a breeze on it. The only thing to watch out for is that the tripod comes with a 3/8" stud, and iirc Porta II is M10 ...

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#7 Locoman

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Posted 24 October 2013 - 05:43 AM

Is the ES Twilight l azimuth control cable adjustable to be out of the way of the scope when higher in altitude? I used to own an AZ3 and the azimuth control cable got in the way of the scope the higher I went in altitude and it was annoying.

#8 Tim C

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Posted 24 October 2013 - 06:23 AM

Thanks Locoman. Appreciate the picture! That looks like a great combo. The weight difference between the StarGuy and Porta II is supposedly only 3 pounds which doesn't sound like much but it must be enough to make a difference. Your comments about it being harder to travel with would sway me against it since this is supposed to be a set-up I can take on airplane trips.

Here is the ST120 on my StarGuy. I don't have the ST120 anymore (sometimes regret selling it) but it was very stable on the StarGuy. I would think the regular Porta ll would handle the ST120 but maybe someone else can chime in on it because I'm sure someone has tried it. The StarGuy is not a light mount to carry around. I have the Orion VersaGo ll with the aluminum tripod and it feels a lot lighter than the StarGuy. The Porta ll would be easier to travel with. I really like the StarGuy a lot. The Hal 130 tripod is heavy duty and the mount head screws off easily. I've used my SLT mount, and my VersaGo mount on the StarGuy tripod with great results.



#9 Tim C

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Posted 24 October 2013 - 06:28 AM

Thanks Peter. Maybe get the regular porta with the lighter weight tripod for airline travel and something like the oberwerk for use around the house (where it will be used most often actually). That tripod looks beefy but also a little to heavy and long for a suitcase.

I'm still considering the ES. Hopefully that issue was an isolated one. I still like the way the porta head attaches better though.



Tim,

You've listed ES Twilight I - in which case I'd really avoid it; there's a thread a while back about the cast metal arm fracturing, and using one in a store setup, I found the movement and controls rougher than the Portamount. Another option would be to get Porta Mount head alone, and get a tall Oberwerk tripod (~65" height to tripod top) in their blemish section ($125+shipping) - I think you'll be quite pleased. You should then contact Manny Miles over here at CN and get him to make a panhandle and eyepiece tray (customize how may 2" holes you'd like) for the mount! I have a ED103SWT on this setup, and it's about as comfortable as I'd like it to be - the main issue being the long moment arm of the OTA. The shorter ST120 should be a breeze on it. The only thing to watch out for is that the tripod comes with a 3/8" stud, and iirc Porta II is M10 ...



#10 Tim C

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Posted 24 October 2013 - 06:29 AM

I probably need to upgrade the focuser on the st120 too. The stock one is hard to turn and introduces more vibration. That might make a lighter weight tripod like the porta II or ES more viable.

#11 core

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Posted 24 October 2013 - 08:58 AM

Okay, that whole part about being airline portable went right past over my head :grin:

I've air traveled with some of the scope tripods before, and at times in order to reduce bulk (no weight), had to disassemble the legs in order to 'pack flat', do-able but I'd prefer not to (possibility of missing parts/tools, the hassle, etc). I've mated the Porta head with a photo tripod as well, and it has worked quite well. Setup below is on a Giottos 9371 (road trip pic though). Manfrotto 475B is much beefier (used <$200?), has a nice center crank column, and both can be made much taller than stock scope tripods. Porta head is 3lb, the 475B list as 9.5lb - so a total of 13lb, less than the options you've listed, packs easier, and should work fine at <100x. A couple more suggestions:

* Check out TONGKW post here on CN, he has a very nice mod of the Porta that makes it really compact, requires some machining though.

* I had a ST100 (Celestron 100mm f/5) on air travel before, UA DwarfStar head with handle and ep tray, and aforementioned Giottos tripod - worked out real well even w/o slo-mo. You will probably have to go with a slightly larger head though.

* I've been considering trying out DSV mounts as well for travel.

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#12 Binojunky

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Posted 24 October 2013 - 12:23 PM

When I had mine it was used on an Orion Versago, also sold under the Skywatcher name, mine had the standard aluminum legs, it handled it fine,DA.

#13 Tim C

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Posted 24 October 2013 - 06:08 PM

thanks for the great info Peter! Those mods from TONGKW are very nice. I'm still leaning towards the Vixen StarGuy but I think a good option would be to use a good camera tripod when I take it on flights if I can't fit the starguy mount into a suitcase. Anyone know how long it is folded up with the head removed?

I could see some use for the HAL130 tripod in other applications as well. Also, I may want to add encoders to the porta at some point. not sure if anyone has a kit for the ES mount yet.

#14 brokenwave

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Posted 24 October 2013 - 06:55 PM

The one advantage of the PortaII is you can add the encoders later. Using it with a decent HD tripod is the key.
We askes Scott Roberts (of ES in July at SCAE at OPT) about the bad casting problem they had with the Twilight and he said it was corrected,
that is why you couldn't buy a Twilight I for awhile this year.
Either way as long as you get one with a more stable tripod you would be fine with either.
But as this thread progresses you may urged to up your choice to a Astro Physics mount. LOL :bigshock:

#15 Tim C

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Posted 06 November 2013 - 07:01 PM

Well, I wound up following Peter's advice and got the Oberwerk tall tripod with the Vixen head. It's one of the "blem" ones but I'll be darned if I can find the blem. My iphone picture doesn't do it justice. It's really a very nice looking tripod. I am very happy this tripod - the ST is very solid on it and the height is great! I just tried it with the highest power EP I plan to use with this fast achro (9mm ES100) and dampening time is very acceptable (~2 seconds or less). In fact, I'm now rethinking the need to add a 2 speed crayford focuser. Might replace the plastic focus wheels though.

I also picked up a used bogen tripod (3036 which is now the 475) for a very reasonable price on a-mart for travel mode. It hasn't arrived yet. Since I'm using two tripods with 3/8" studs I decided to make my own adapter out of maple and it it works great. It's a very solid connection. I'll attach some pictures of it as well.

Thanks for all the great advice!

Edit: ok, I did find the "blems" on a couple of the legs. Looks like places where knots were in the wood. They are on the inside of the legs and not noticeable at all unless you go look the legs up and down at close range. Very minor and doesn't detract from the looks at all in my opinion.

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#16 Tim C

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Posted 06 November 2013 - 07:03 PM

Here is a pic of the adapter I made (prior to finishing it black)

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#17 Tim C

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Posted 06 November 2013 - 07:03 PM

Here is the other side that attaches to the porta head showing the recessed t-nut I used.

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