开云体育

I have just been looking at Jupiter and Saturn for the first time through my
TV101/G11 combination. At medium power (x100) a vibration of the image was
obvious. The vibration frequency seemed to be close to that of the ticking
from the RA motor and decreased markedly with the drive off, though did not
disappear completely (obviously seeing was effecting the image as well).
Before I tear the RA drive apart, does anyone have any views as to what in
particular I should be concerned with.

Adam Stephens
adamstephens@...

Were the clutches tighten down when you noticed the vibration?
I have noticed vibration also, but tightening the clutches dampens
it out on my G-11.

Rockett Crawford

----------------------------------------------------------------------------

Capella's Observatory (CCD Imaging)



Adam Stephens wrote:

Hi Adam

I have seen this on a GM8 and a G11. The source *is* cogging of the RA
stepper, but resonances in the mount can augment it mightily. There is
a web site discussing disassembly of the motor can and realigning the
poles, I was unable to get the motor assembly out of the can ( and I
also can't find the site now - anyone else? ).

A few folks on saa noted their setup was weight and balance sensitive.
I would get the jitters at 150+ power with a C9.25 mounted and
balanced, the C9.25 carried a telrad and 50mm finder. I switched to a
dual plate saddle, have the C9.25 ( with Telrad on top ) on one side
and an 80mm short fl finder on the other. When balanced perfectly, it
vibrates above 250 power. When I make it slightly "east heavy" I can
get to around 400x no problem.

Good luck! -David

Hi Guys:

stepper, but resonances in the mount can augment it mightily. There is
a web site discussing disassembly of the motor can and realigning the
poles, I was unable to get the motor assembly out of the can

A word of warning here:

I attempted this and ended up trashing the motor. Had to buy a new one
from Losmandy. I would advise against Rene's procedure unless you are
completely comfortable with your mechanical skills. I wish Rene had a
disclaimer on his site, he made it sound *a lot* easier than it is.
He's probably much better with his hands than I am - or he has the right
tools.

--Dave O'Toole
odave@...
www.concentric.net/~odave

I agree Dave, once I saw I was having trouble getting the poles out of
the can, I chickened out.

IMLE, attacking the resonance by adjustment of weight / balance is a
lot easier to implement, and seemed to do the trick for a few people,
including myself.

-David

Adam,

I have just been looking at Jupiter and Saturn for the first time through my TV101/G11 combination. At medium power (x100) a vibration of the image was obvious. The vibration frequency seemed to be close to that of the ticking from the RA motor <<<<<

Could it be, the TV is just to light for the system. I am wondering if
there is not enough weight on the G11 to "hold" things in place. I have
a GM8 with an 8in SCT and do not get the vibration you speak of.

Also, what is the mount sitting on, solid ground?? Try some rubber under
the feet of the mount.

No offense, but disassembling the mount head should not be the first
step to controlling a problem. Look for the simple solutions first.

Take care,
Gregory david Stempel
FIREFRAME

I encountered the same problem with my 4" apo and didn't think about lack
of weight atop the mount. Good suggestion!

I did find that backing off the worm from the worm wheel a small amount
greatly reduced the amount of vibration.

Others have told of putting a thin piece of rubber between the motor
assemblies and the mount.

Paul Sterngold

--- Gregory David Stempel <fyrframe@...> wrote:

Adam,

I have just been looking at Jupiter and Saturn for the first time

through my TV101/G11 combination. At medium power (x100) a vibration of
the image was obvious. The vibration frequency seemed to be close to
that of the ticking from the RA motor <<<<<

Could it be, the TV is just to light for the system. I am wondering if
there is not enough weight on the G11 to "hold" things in place. I have
a GM8 with an 8in SCT and do not get the vibration you speak of.

Also, what is the mount sitting on, solid ground?? Try some rubber under
the feet of the mount.

No offense, but disassembling the mount head should not be the first
step to controlling a problem. Look for the simple solutions first.

Take care,
Gregory david Stempel
FIREFRAME

__________________________________________________
Do You Yahoo!?
Send instant messages & get email alerts with Yahoo! Messenger.

Paul,

Others have told of putting a thin piece of rubber between the motor

assemblies and the mount.<<<<

That sounds promising. Similar to putting the rubber pads under the feet
of the tripods I assume.

Take care,
Gregory david Stempel
FIREFRAME