JumboFlex
sage
Reged: 01/20/09
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Slewing Noise
#3148216 - 06/06/09 01:26 AM
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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.
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rmollise
Postmaster
   
Reged: 07/06/07
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Re: Slewing Noise
[Re: JumboFlex]
#3148583 - 06/06/09 09:25 AM
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Quote:
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.
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Nick Lloyd
He asked for it
   
Reged: 10/24/06
Loc: cincinnati
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Re: Slewing Noise
[Re: rmollise]
#3148587 - 06/06/09 09:28 AM
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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.
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hudson_yak
Carpal Tunnel
Reged: 11/15/07
Loc: Hyde Park, NY, USA
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Re: Slewing Noise
[Re: JumboFlex]
#3148610 - 06/06/09 09:47 AM
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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
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ibase
Vendor Affilliate
   
Reged: 03/20/08
Loc: Manila, Philippines 121*E 14*N
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Re: Slewing Noise
[Re: hudson_yak]
#3148660 - 06/06/09 10:35 AM
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Music to my ears
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ccs_hello
Postmaster
   
Reged: 07/03/04
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Re: Slewing Noise
[Re: hudson_yak]
#3148930 - 06/06/09 01:32 PM
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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
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hudson_yak
Carpal Tunnel
Reged: 11/15/07
Loc: Hyde Park, NY, USA
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Re: Slewing Noise
[Re: ccs_hello]
#3149111 - 06/06/09 03:20 PM
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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
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rmollise
Postmaster
   
Reged: 07/06/07
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Re: Slewing Noise
[Re: Nick Lloyd]
#3149486 - 06/06/09 08:14 PM
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Quote:
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...
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rmollise
Postmaster
   
Reged: 07/06/07
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Re: Slewing Noise
[Re: ibase]
#3149487 - 06/06/09 08:14 PM
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Quote:
Music to my ears
Right ON!
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Nick Lloyd
He asked for it
   
Reged: 10/24/06
Loc: cincinnati
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Re: Slewing Noise
[Re: rmollise]
#3150001 - 06/07/09 07:49 AM
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Quietest? Try a Giro mount.
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Chris Curran
scholastic sledgehammer
   
Reged: 06/14/05
Loc: Brandon, FL
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Re: Slewing Noise
[Re: Nick Lloyd]
#3150008 - 06/07/09 07:59 AM
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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...
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Qkslvr
Pooh-Bah
Reged: 06/23/06
Loc: NE Ohio, US
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Re: Slewing Noise
[Re: Chris Curran]
#3153648 - 06/09/09 09:28 AM
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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?
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Lane
Post Laureate
Reged: 11/19/07
Loc: Frisco, Texas
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Re: Slewing Noise
[Re: Qkslvr]
#3153818 - 06/09/09 11:14 AM
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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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