Re: 1600gto dec gears "singing"


Thanks Howard--I will be in contact on Wednesday.  Happy eclipsing!

John Collins


On 8/18/2017 3:53 PM, Howard howard@... [ap-gto] wrote:

Hi John,


If the sound is coming from the RA axis, I would loosen the gear mesh a tiny amount.  Remember that backlash is NOT an issue in RA, unless it has reached a ridiculous level.  RA is always driven, so the backlash effects from direction reversal don’t come into play.  It is more important to have smooth, effortless operation for good tracking.

If the sound seems to be in declination, we can work on it after the eclipse break.  AP will be closed Monday and Tuesday, but I’ll be back on Wednesday, and George will join me on Thursday or Friday.


Mag. 7 Skies!


Howard Hedlund

Astro-Physics, Inc.

Phone: 815-282-1513

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From: ap-gto@... [mailto:ap-gto@...]
Sent: Friday, August 18, 2017 9:42 PM
To: ap-gto@...
Subject: [ap-gto] 1600gto dec gears "singing"




I've just done the prescribed gear mesh adjustments on my 1600GTO mount
which is about 3 years old. After storage and some shipping shakeups,
there was sone backlash. The adjustments worked fine from a backlash
perspective, but my dec axis has developed a metallic singing sound
which I expect is the worm gear resonating(?) maybe.......

Since the ringing only occurs in the final 20 degrees as the scope lays
down into park4, I thought it might be a balance issue, however, as I
apply more or less weight by hand, the sound does not change. I've
obviously adjusted this noise into existence...I'm wondering if this a
known issue and if there is guidance available to an adjustment that
satisfies the backlash needs AND doesn't create unusual noises. In my
limited experience, shrieking and howling gear trains are not a good

many thanks

John Collins


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