Author Topic: Orion Starseeker IV w/120st  (Read 1431 times)

Daniel Johnson

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Orion Starseeker IV w/120st
« on: December 30, 2017, 05:46:15 PM »
Okay gang, need your input please. I recently acquired an Orion120st refractor. I upgraded with a GSO dual speed focuser and a 2" star diagonal for casual observation.

l'm looking at the Starseeker IV GoTo mount. Has anyone combined the two and had good luck with the compatibility? I'm concerned with the weight of the OTA (8.6 lbs according to Orion specs) and if the length of the OTA will clear when at zenith. I personally think it weighs more that's 8.6 lbs after adding the dovetail, rings, upgrading the star diagonal, and lens.

Thanks in advance.

Mike



Brian Ross

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Re: Orion Starseeker IV w/120st
« Reply #1 on: January 08, 2018, 03:58:19 PM »
I owned a 120ST for a long time, and kind of regret selling it. During that time I mounted it on a Star Seeker-IV, which came with my 127 Mak. I also used a 150 Mak on it, and don't know why Orion would sell this as a combo. It was fine with the 127. The 120ST Actually was better than the 150 Mak on it, for visual of course. BUT...... I also have a couple of older Celestron Alt-Az GT mounts, and these handled the 120ST and other refractors quite well! And I still have and use them, especially for my 80ED and 100ED. Very stable if you put them on a decent Tripod.

frosperloacatch

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Re: Orion Starseeker IV w/120st
« Reply #2 on: January 09, 2018, 02:30:11 AM »
I think the Star Seeker 4 mount may be marginal for the 120ST, particularly with the rings and rail bar. I used a 127 Mak on the mount and it was just OK (8 - 9 lbs) but I wouldn't go any heavier. This type of Goto mount is rated at about 8 pounds max I think. The 120ST also has a longer moment arm and this would tend to aggravate the situation even more. When I had a 120ST, I used it on an old EQ3 and that worked fine, however, no goto!

Frank

dustsungline

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Re: Orion Starseeker IV w/120st
« Reply #3 on: January 10, 2018, 09:52:46 AM »
It sounds like you had good luck with the combo. I wasn’t sure of the weight limits on the mount and motors would handle the OTA weight.
Were you able to acheive zenith clearance between the scope and the mount base?

James Scaturro

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Re: Orion Starseeker IV w/120st
« Reply #4 on: January 11, 2018, 09:48:46 AM »
Quote
I think the Star Seeker 4 mount may be marginal for the 120ST, particularly with the rings and rail bar. I used a 127 Mak on the mount and it was just OK (8 - 9 lbs) but I wouldn't go any heavier. This type of Goto mount is rated at about 8 pounds max I think. The 120ST also has a longer moment arm and this would tend to aggravate the situation even more. When I had a 120ST, I used it on an old EQ3 and that worked fine, however, no goto!

Frank

Thanks Frank. I looked up the specs of the Orion Starseeker IV Mount and they state it can handle up to 13lbs. I just have a weird vibe concerning compatibility.

Jacob Cota

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Re: Orion Starseeker IV w/120st
« Reply #5 on: January 12, 2018, 11:23:37 PM »
I had a StarseekerlV, it should handle your 120, I had a c8 on mine, weight about 12lbs. And yes you should be able to reach Zenith. Just keep in mind that point all the weight of the scope will be over to one side, so there could be some shaking or even some instability.
2 years ago I had four of them sent to me, they were all plagued with bugs. Namely poor adjusted azimuth clutches. I gave up on them.
Hopefully they got that issue fixed

Tommy Evans

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Re: Orion Starseeker IV w/120st
« Reply #6 on: January 13, 2018, 12:58:05 AM »
I have a Sky Watcher Light Chariot mount (which looks to be essentially the same as the Celestron SLT and the Orion Star Seeker 4). I've used it with the 120ST. It works okay, especially at lower magnifications. One thing to watch for (at least with mine) is that as the mount is used the bolt that connects the dovetail base to the mount tends to loosen, allowing the mount to slip a bit in altitude (elevation)...especially when focusing. I have to tighten mine up now and then. When traveling on with the mount I always bring a socket wrench with me just in case. Other than that, it's a fine highly portable mount if you keep the payload to around 10 pounds or less.

Randy Ott

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Re: Orion Starseeker IV w/120st
« Reply #7 on: January 15, 2018, 10:56:27 AM »
The azimuth clutches can be tightened without too much trouble.

James Merrill

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Re: Orion Starseeker IV w/120st
« Reply #8 on: January 16, 2018, 11:21:39 PM »
Quote
The azimuth clutches can be tightened without too much trouble.

Any hints as to how you go about that? just in case I have too.

ricoperte

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Re: Orion Starseeker IV w/120st
« Reply #9 on: January 23, 2018, 12:13:10 AM »
Guys, I took a leap of faith and just purchased one. As soon as it gets in, I'll run it through the ringer. I'll keep you posted.

(If it can be broke....I'm the guy for the job.)

climopepvi

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Re: Orion Starseeker IV w/120st
« Reply #10 on: January 23, 2018, 11:19:06 AM »
Don't forget to post pictures and tell us your experience with the mount and scope

Bobby Cruz

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Re: Orion Starseeker IV w/120st
« Reply #11 on: January 25, 2018, 05:31:23 PM »
Wow, they say great minds think alike.... I have had an Orion 120ST for about a year. I am in my 60s and dragging the scope in and out with the heavy EQ mount became a chore, so I too, after some research, I also ordered the Orion Starseeker IV mount, both for the reduction in weight and for goto capability.  I found for $49 more I could order one with the small 113mm reflector, which I didn't really need, but that package also includes the RS232 cable for the mount, and theOrion EZ Finder II reflex sight, which would be an upgrade to the 120ST finder.

johrich

chionewssesu

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Re: Orion Starseeker IV w/120st
« Reply #12 on: January 26, 2018, 03:01:18 AM »
So my Orion Starseeker IV mount with the small reflector arrived.  The mount went together easily and worked fine.  Unfortunately, when I took the small 114mm reflector out of the box, there was a large rattle coming from inside the tube.  The mirror had come loose and as a result was damaged and also damaged the eyepiece mirror. A call to Orion and they promised to ship another scope and I will ship back the damaged one. However, since I bought the mount primarily for my 120ST, this was not a big problem. I should mention, that since I bought the mount with the reflector, there were a number of extra goodies supplied, as well, including the RS-232 cable and AC power supply for the mount, moon filter, barlow, etc, making the extra money spent worth while.

The one thing I did not receive because I ordered the mount with a scope vs just the mount, was the L bracket used for mounting a camera on the mount.

So last night, after watching several YouTube videos and reading the instructions on the mount, I took the Starseeker IV mount outside, leveled it, and put the Orion 120ST on the mount.  I used the 2 star alignment process, using Fomalhaut and Altair to align the mount.  I then selected the Andromeda Galaxy as my first target and the mount moved effortlessly with the 120ST and stopped at Andromeda. The galaxy was within my 25mm eyepiece when the mount stopped and only required a small adjustment to center it.  I then toured several other nebulae, galaxys, Uranus and Neptune using the remote control, each time the scope stopped with the desired object visible in the scope.

So at this point, I am very pleased. Besides the ease of finding objects in the sky, the Starseeker IV mount is considerably lighter then the EQ-3 mount it came with, but the Starseeker seemed very stable while I was using it despite it's much lighter weight. If I had to do it all again, I would buy the OTA separately and just order the Starseeker mount.

So my next test will be to put my Canon SL1 on the 120ST and see if the there is any issue with the mount handling a little extra weight.

johrich

tyrrcencifunc

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Re: Orion Starseeker IV w/120st
« Reply #13 on: February 09, 2018, 08:44:25 AM »
I have several Celestron GT mounts and one SLT mount. The SLT will handle the ST120 fairly well for visual use, but it's a bit shaky. I don't think I'll be hanging a camera on it. Have a Celestron 8SE mount coming soon. That should handle it fine.