31 replies to this topic

[elstargazer12]

CHAS

 

Yeah, maybe the CG-5 I had really belongs in the bottom tier... it probably does just based on machining quality, but it's more stable than the other mounts down in that tier because it's just bigger. Also, I bought that CG-5 with hard-earned high schooler dollars, and it was my first better-than-department-store mount. Maybe I'm a little biased about it. 

[Astrojensen]

 

- The Vixen Polaris. Significant slop around the axles. But of course, it's by far the cheapest of the Vixens, so it makes sense (although Takahashi is an exception see above).

My Vixen RC-125M on a Polaris mount:

 

 

This is one of the smoothest mounts I've ever used. There is zero backlash or dead play in the slow motions. Everything moves with silky, buttery smooth motions. 

 

I think it's very sensitive to correct adjustment of the worms. I also have an EQ-3 mount, which is partially a clone of the Polaris, and I had to take it apart and readjust the gears twice, before it would work properly. Now it's very smooth, but adjustment was very time-consuming and finicky. I think the same could be true of the Polaris. 

 

 

Clear skies!

Thomas, Denmark

[CHASLX200]

CHAS

 

Yeah, maybe the CG-5 I had really belongs in the bottom tier... it probably does just based on machining quality, but it's more stable than the other mounts down in that tier because it's just bigger. Also, I bought that CG-5 with hard-earned high schooler dollars, and it was my first better-than-department-store mount. Maybe I'm a little biased about it. 

Mine had tar for grease and the small metal tripod. They got better in 2000 with the much bigger tripods.

[CHASLX200]

My Vixen RC-125M on a Polaris mount:

 

 

This is one of the smoothest mounts I've ever used. There is zero backlash or dead play in the slow motions. Everything moves with silky, buttery smooth motions. 

 

I think it's very sensitive to correct adjustment of the worms. I also have an EQ-3 mount, which is partially a clone of the Polaris, and I had to take it apart and readjust the gears twice, before it would work properly. Now it's very smooth, but adjustment was very time-consuming and finicky. I think the same could be true of the Polaris. 

 

 

Clear skies!

Thomas, Denmark

Vixen had it down pat.

[deSitter]

My Vixen RC-125M on a Polaris mount:

 

 

This is one of the smoothest mounts I've ever used. There is zero backlash or dead play in the slow motions. Everything moves with silky, buttery smooth motions. 

 

I think it's very sensitive to correct adjustment of the worms. I also have an EQ-3 mount, which is partially a clone of the Polaris, and I had to take it apart and readjust the gears twice, before it would work properly. Now it's very smooth, but adjustment was very time-consuming and finicky. I think the same could be true of the Polaris. 

 

 

Clear skies!

Thomas, Denmark

It is indeed very similar. My EQ3-2 was found on the curbside! Free! It has NO backlash - I mean none - in either axis. Fully loaded, I can easily spin both worms with 2 fingers. When i first got it, both axes were practically seized. It had been assembled that way I think. No wonder it was put out. The machining in these mounts is usually good, but the assembly is often slipshod, with e.g. an altitude scale that is 10 degrees out of adjustment - and glued on.

 

-drl

Edited by deSitter, 26 January 2025 - 03:50 PM.

[Astrojensen]

 

 

Ok, now to rank these mounts into five tiers:

 

Tier 1 (OMG I can't believe the maker bothered to do this and I feel a little guilty I paid so little for it)

I know what you're talking about. My Zeiss 1b mount from 1989 falls into that category. The RA drive has crazy low PE. One guy in Germany measured his, and it was around 3.5" in the ten minute rotation period of the worm gear. And his mount was from the 1960'ies! Mine seems to be just as accurate. If I'm careful with the polar alignment, I can take hundreds of 30-second exposures at an image scale of 1.35"/pixel and almost every frame has perfectly round stars. Without guiding.  

 

I bought mine used for $300... 

 

 

 

Clear skies!

Thomas, Denmark

[Kasmos]

I don't get it.

There's too many variables to make comparisions.

What's high end or low end?

It would be better to just ask if mount A or B is good for a particular size OTA.