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Slewing Noise

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#1 JumboFlex

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Posted 06 June 2009 - 12:26 AM

Anyone ever have someone complain that a mount was making too much noise while it slewed? Other than reducing the slew speed have people done anything to quieten down their GOTO mounts? Or is this generally not a problem?

Thanks.

#2 rmollise

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Posted 06 June 2009 - 08:25 AM

Anyone ever have someone complain that a mount was making too much noise while it slewed? Other than reducing the slew speed have people done anything to quieten down their GOTO mounts? Or is this generally not a problem?

Thanks.


Generally not a problem. Oh, I've had a couple of folks observe that my CG5 sounds like its grindin' a pound of Brazillian Roast at the star party, but that was (mostly) in good fun.

:lol:

#3 Nick Lloyd

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Posted 06 June 2009 - 08:28 AM

Yes I had the same complaint about a Nexstar mount I briefly owned.

I still have this complaint about many of the coffee-grinder mounts on the market.

My solution was selling it.

#4 hudson_yak

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Posted 06 June 2009 - 08:47 AM

Personally I found the noise completely unacceptable for use in the backyard of my little quarter-acre village lot. Not that anyone here would likely complain, but I just don't want to be making that sort of noise out there in the middle of a peaceful night when it's only to participate in a recreational activity.

As to making a mount more quiet, I've never seen any really meaningful fixes for that. Some mounts are quieter than others just by the nature of their design, so the only real improvement you can make is to get one of them (eg. Atlas, EQ6).

Mike

#5 ibase

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Posted 06 June 2009 - 09:35 AM

Music to my ears :)

#6 ccs_hello

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Posted 06 June 2009 - 12:32 PM

General info:

To compare and contrast:

Microstepping stepper based Synscan EQ6 (EQ-G version of the Atlas) has the 180:1 worm and 47:12 (about 4:1) mechanical spur gears. The net gear-down ratio is 705:1.
The fast slew rate is approx. 800x sidereal (motor shaft speed: 392.74 RPM).

DC perm-mag servo motor based LXD75 has the 144:1 worm, 37:35 mechanical spur gears and 50:1 gear box. The net gear-down ratio is 7611:1.
At speed "8" (718x sidereal): motor shaft speed is 3744 RPM.
At speed "9" (approx. 1077x sidereal): motor shaft speed is approx. 5616 RPM.

Clear Skies!

ccs_hello

#7 hudson_yak

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Posted 06 June 2009 - 02:20 PM

I'm sure that's part of it. Another part is where the motors are mounted. My SVP uses similar Synscan hardware, and the RA motion is tolerably quiet. The Dec, though, is not, with the motor mounted out in the open directly to the saddle and radiating sound vibrations into the OTA itself. This is a place where newer Atlas/EQ series mounts have an advantage, I believe.

Meridian flips are especially bad, since there's a lot of Dec motion required.

Mike

#8 rmollise

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Posted 06 June 2009 - 07:14 PM

Yes I had the same complaint about a Nexstar mount I briefly owned.

I still have this complaint about many of the coffee-grinder mounts on the market.

My solution was selling it.


Hmmm...in my experience the NexStars (fork mounts) are some of the QUIETEST scopes in the biz... :shrug:

#9 rmollise

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Posted 06 June 2009 - 07:14 PM

Music to my ears :)


Right ON! :lol:

#10 Nick Lloyd

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Posted 07 June 2009 - 06:49 AM

Quietest? Try a Giro mount. :poke:

#11 Chris Curran

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Posted 07 June 2009 - 06:59 AM

Some folks just like to complain. Offer them a Coke and a smile, then go back to what you were doing before they became louder than your gearing... :)

#12 Qkslvr

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Posted 09 June 2009 - 08:28 AM

While my CG-5 ASGT is kind of loud, I know 10-15' away while I'm standing in an open garage, I have a hard time hearing it. For those that think it's loud, if you're standing 30' away do you still think it's to loud?

#13 Lane

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Posted 09 June 2009 - 10:14 AM

Guy had a Vixen Sphinx at our dark site a few weeks ago. Quiet in the extreme, that thing makes my Sirius seem loud by comparison. But that Starbook sure can kill your night vision.






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