Re: Eastside Heavy Rule - How to Practically Apply Query
The
primary reason (like 98%) is because I can do it MUCH sooner than I could with
a camera.. I have a closeby ridge that blocks the Sun from hitting the scope
early in the afternoon.. (17 deg in the SW, 0 deg at 290 deg azimuth).. In the
Winter especially (Northern Hemisphere / California)
I am doing this with the Sun at least 10 degrees above the horizon (or more)
and the sky is quite bright..
The
secondary reason is my crap Laptop, which takes awhile after opening to be
useful for imaging. It has a hard time running my small camera (ASI178MC or MM)
at full resolution at the speed needed in broad daylight.. (I have often that
of trading my 12” SCT for a decent laptop for this very reason – SF
Bay Area only!! ).. It works just fine for the slow frame rate of DSO’s
and beautifully for ROI planetary imaging at high speed..
?
But
yes, I *could* just use the camera if I was starting in a darksky and it would
work all the time for me too..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Stu Beaber
Sent: Saturday, January 30, 2021
10:42 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Eastside Heavy Rule - How to Practically Apply Query
?
Why mess with an eyepiece at all. Just use your camera to begin with. I
use a G11 (Gemini1) with a 10" SCT and 999 times out of a 1000 the object
is in the FOV when I do a "goto". The FOV for my combo is 14x20
arcmin and it works great for the past 18 years. I did do what you do the first
year I did AP but quickly decided it as a waste of time.
?
Yes..
Yes, sort of.. Being a (former)
Carpenter, I use a tape measure and measure between the Toe Saver Washer on the
end of the counterweight shaft and the bottom edge of the lower weight.. *but*
I only do this before initial startup when I am finding the “It balances
here” and “I need to move the weight a half an inch here”..
Then I put it back balanced, power up, and “do my thing”.. For me,
that involves an eyepiece, a GOTO a bright star or planet, switch to a high
power eyepiece, center.. Then I switch to the camera, adjust the weight
slightly, center the target, and synch.. All this occurs before Sunset and
before you can see any stars (by looking up at the sky).. (To do this, you need
to know exactly where the focus point of your eyepieces are, as the contrast of
a target in a bright sky is quite low..).. Then I wait or do other setup things
until it is actually dark..
?
Once it’s dark, if I switch
sides of the pier, I just move the weight “by feel”.. i.e. one hand
feels the counterweight shaft and edge of the weight while the other loosens
the bolt holding the weight and I “feel” how much the weight moves,
tighten the bolt, and carry on..
?
It’s not an exact science and
it depends on the payload.. My G11 is only carrying about 30 pounds so *for me*
it doesn’t matter if it is “barely” or “a lot”
East Heavy.. My Goal is “just enough” so the drive wont be able to
“flop” to the other side of the gear tooth.. With a heavy payload
– like when I get around to mounting my 12” SCT – I will be
*much* more exact.. When I do this, I will make two sticks or rods that can go
between the weight and the toe saver so I can accurately adjust with no light..
?
YMMV, but it works for me and my
tracking is pretty good..
?
Derek
?
?
On Thu, Jan 28,
2021 at 10:54 AM, Derek C Breit wrote:
I move the lower
counterweight up or down the shaft depending on which side of the mount things
are.. *AND* I find where these points are – before ever turning on the
mount – during initial balancing..
?
Doesn’t
take much offset from balanced, just “some”..
Derek
Thanks very much for replying and explaining your approach to this topic. Just
checking I understand correctly - So when the counterweight shaft is on the
eastside you slide the lower weight a little down the shaft from it's
'correctly balanced' position and when the scope is on the eastside you slide
the lower weight up the shaft a little way beyond it's 'correctly balanced'
position. Presumably you use tape or something to mark the shaft for each
position?
Is this method which most use?
Many thanks
Terry [uk]
|
Re: Used GM-8 Guiding Help
Awesome..
Thanks for explaining that, as I like to learn..
?
Now
if can just answer the question I have (on a different topic) I’ll be golden
for awhile.. I’ll tyr and find the answer online, but I might (OK Probably) ask
it anyway.. :-))
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Chip Louie
Sent: Saturday, January 30, 2021
10:09 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Derek,
The worms use a miniature ball bearing because this type of bearing can be used
to carry both radial and axial loads. Needle roller bearings are only really
used to carry a radial load. Losmandy uses two kinds of cylindrical roller
bearings each designed and located to carry loads in the direction for the
bearing design used.?
--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
|
Re: Eastside Heavy Rule - How to Practically Apply Query
Why mess with an eyepiece at all. Just use your camera to begin with. I use a G11 (Gemini1) with a 10" SCT and 999 times out of a 1000 the object is in the FOV when I do a "goto". The FOV for my combo is 14x20 arcmin and it works great for the past 18 years. I did do what you do the first year I did AP but quickly decided it as a waste of time.
Stu
Yes..
Yes,
sort of.. Being a (former) Carpenter, I use a tape measure and measure between
the Toe Saver Washer on the end of the counterweight shaft and the bottom edge
of the lower weight.. *but* I only do this before initial startup when I am
finding the “It balances here” and “I need to move the weight
a half an inch here”.. Then I put it back balanced, power up, and “do
my thing”.. For me, that involves an eyepiece, a GOTO a bright star or
planet, switch to a high power eyepiece, center.. Then I switch to the camera, adjust
the weight slightly, center the target, and synch.. All this occurs before
Sunset and before you can see any stars (by looking up at the sky).. (To do
this, you need to know exactly where the focus point of your eyepieces are, as
the contrast of a target in a bright sky is quite low..).. Then I wait or do
other setup things until it is actually dark..
?
Once
it’s dark, if I switch sides of the pier, I just move the weight “by
feel”.. i.e. one hand feels the counterweight shaft and edge of the
weight while the other loosens the bolt holding the weight and I “feel”
how much the weight moves, tighten the bolt, and carry on..
?
It’s
not an exact science and it depends on the payload.. My G11 is only carrying
about 30 pounds so *for me* it doesn’t matter if it is “barely”
or “a lot” East Heavy.. My Goal is “just enough” so the
drive wont be able to “flop” to the other side of the gear tooth.. With
a heavy payload – like when I get around to mounting my 12” SCT –
I will be *much* more exact.. When I do this, I will make two sticks or rods
that can go between the weight and the toe saver so I can accurately adjust
with no light..
?
YMMV,
but it works for me and my tracking is pretty good..
?
Derek
?
?
On Thu, Jan 28, 2021 at 10:54 AM, Derek C Breit wrote:
I move the lower counterweight up or down the shaft
depending on which side of the mount things are.. *AND* I find where these
points are – before ever turning on the mount – during initial balancing..
?
Doesn’t take much offset from balanced, just
“some”..
Derek
Thanks very much for replying and explaining your approach to this topic. Just
checking I understand correctly - So when the counterweight shaft is on the
eastside you slide the lower weight a little down the shaft from it's
'correctly balanced' position and when the scope is on the eastside you slide
the lower weight up the shaft a little way beyond it's 'correctly balanced'
position. Presumably you use tape or something to mark the shaft for each
position?
Is this method which most use?
Many thanks
Terry [uk]
|
Re: Used GM-8 Guiding Help
Derek,
The worms use a miniature ball bearing because this type of bearing can be used to carry both radial and axial loads. Needle roller bearings are only really used to carry a radial load. Losmandy uses two kinds of cylindrical roller bearings each designed and located to carry loads in the direction for the bearing design used.?
--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
|
Re: Eastside Heavy Rule - How to Practically Apply Query
Yes..
Yes,
sort of.. Being a (former) Carpenter, I use a tape measure and measure between
the Toe Saver Washer on the end of the counterweight shaft and the bottom edge
of the lower weight.. *but* I only do this before initial startup when I am
finding the “It balances here” and “I need to move the weight
a half an inch here”.. Then I put it back balanced, power up, and “do
my thing”.. For me, that involves an eyepiece, a GOTO a bright star or
planet, switch to a high power eyepiece, center.. Then I switch to the camera, adjust
the weight slightly, center the target, and synch.. All this occurs before
Sunset and before you can see any stars (by looking up at the sky).. (To do
this, you need to know exactly where the focus point of your eyepieces are, as
the contrast of a target in a bright sky is quite low..).. Then I wait or do
other setup things until it is actually dark..
?
Once
it’s dark, if I switch sides of the pier, I just move the weight “by
feel”.. i.e. one hand feels the counterweight shaft and edge of the
weight while the other loosens the bolt holding the weight and I “feel”
how much the weight moves, tighten the bolt, and carry on..
?
It’s
not an exact science and it depends on the payload.. My G11 is only carrying
about 30 pounds so *for me* it doesn’t matter if it is “barely”
or “a lot” East Heavy.. My Goal is “just enough” so the
drive wont be able to “flop” to the other side of the gear tooth.. With
a heavy payload – like when I get around to mounting my 12” SCT –
I will be *much* more exact.. When I do this, I will make two sticks or rods
that can go between the weight and the toe saver so I can accurately adjust
with no light..
?
YMMV,
but it works for me and my tracking is pretty good..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Terry Pullen via groups.io
Sent: Saturday, January 30, 2021
6:04 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Eastside Heavy Rule - How to Practically Apply Query
?
On Thu, Jan 28, 2021 at 10:54 AM, Derek C Breit wrote:
I move the lower counterweight up or down the shaft
depending on which side of the mount things are.. *AND* I find where these
points are – before ever turning on the mount – during initial balancing..
?
Doesn’t take much offset from balanced, just
“some”..
Derek
Thanks very much for replying and explaining your approach to this topic. Just
checking I understand correctly - So when the counterweight shaft is on the
eastside you slide the lower weight a little down the shaft from it's
'correctly balanced' position and when the scope is on the eastside you slide
the lower weight up the shaft a little way beyond it's 'correctly balanced'
position. Presumably you use tape or something to mark the shaft for each
position?
Is this method which most use?
Many thanks
Terry [uk]
|
East side weighting cord vs preloading both worm bearings...is there a difference?
Hi gang,
Several really nice contributions have raised the question: ? How can one get better performance of the RA (that is, reduce periodic error and improve "unguided tracking" duration)?
Many people use a weighted cord wrapped around the RA axis, so the torque on the RA axis tugs the ring gear (aka worm wheel) counterclockwise (viewing the RA from the front as if looking down the polar scope shaft ).? ?The weight?must hang off to the East? if you are operating in the Northern (but West if you are in the Southern) hemisphere.? The weight must always push the worm toward the Oldham coupler.??
That torque on the ring gear pushes it's left thread sides against the worm right thread sides, pushing the worm to the left.? On a G11 or GM8 that compresses the worm bearing closest to the gearbox, compresses the Oldham coupler, and (on a plastic stock gearbox) can push the gearbox drive shaft slightly outward.??
This is pretty easy to do, and requires no effort other than buying some flexible cord or maybe wire, and hanging a weight off the East side of the RA axis.? It must hang off the East if you are operating in the Northern (but West if you are in the Southern) hemisphere, otherwise all those compression effects I note above reverse and become loosened.??
The only thing that weighted cord will not do is compress the right "far" worm bearing.? That bearing will be loosened (axially).? (If you have a Belleville spring pushing that far bearing toward the worm, then that bearing is also compressed by the spring. )?
Does it matter if one bearing is compressed and the other one is not compressed???
Please read this nice write-up by a bearing industry expert about getting the most performance from a ball bearing system:
So the question is: do you?consider an?Astronomical mount to be a case where "Preload is critical in most high-precision and high-speed applications, particularly where rotational and positional accuracy is required."
You already know my answer.? It is probably the most critical application if you are doing high focal length astro-photography.??
That article goes on to say:
?Spring preloading is simple, inexpensive, and should be a designer’s first consideration. Coil springs or wave spring washers are most commonly used, but a variety of spring types are available. The spring is used to press the races together, or apart. Spring preloading provides a relatively constant preload because it is less sensitive to differential thermal expansion and can accommodate misalignment. Spring preload is what a Belleville spring washer will do for both worm bearings at the same time...and all the worm drive components (Oldham coupler parts too) pushing them toward the gearbox end.?
But installing a Belleville spring is a bit of work (getting out the old bearing by heating the aluminum block works), and slight cost (new $12 each bearings and a $1 spring) , and polishing down the far bearing OD so it will slide, lubed, with the spring behind it.??
And the Belleville spring approach will not keep the ring gear teeth always on the East side (West side if in the S hemisphere) of the worm threads.? Maybe the SLW spring keeps the teeth centered into both sides of the ring gear teeth and the worm teeth.? Maybe (if the SLW spring is backed off by it's smaller bolt to reduce it's friction) then you still need a weighted cord?? The SLW does nothing to address the worm bearing axial pre-compression question.??
Maybe you need both things?? I've not tried that trick on the RA.?? Have fun thinking about these topics and trying your own experiments.? If you are happily imaging and happy with your tracking and autoguiding...keep enjoying yourself!? If driven toward further goals then think about some improvement options.
There is a great story in the (1000 and 1) Arabian Nights stories...the story of Prince Agib.? Maybe read that tale first!!! Here is a good link to the story.
Now...are these palaces the beautiful heavens we seek to photograph? Who are the 10 men?? That's another good riddle for you!
Very best of luck and health, clear skies (and easy available vaccines...) Michael
|
Re: Making the most of cloudy winter nights with a new mount and scope
Have you looked at the KStars/EKOS/INDI suite on the Mac?? EKOS has a polar alignment routine that I use (on Linux).? It is also the only astro capture software that I use.
|
Re: Eastside Heavy Rule - How to Practically Apply Query
I've always used the weight on a string 'trick' for my non-SLW G11 which always east-biases no matter where the scope is pointing.? Multiple references if you search past posts.
Keith
|
Re: Eastside Heavy Rule - How to Practically Apply Query
On Thu, Jan 28, 2021 at 10:54 AM, Derek C Breit wrote:
I move the lower counterweight up or down the shaft depending on which side of the mount things are.. *AND* I find where these points are – before ever turning on the mount – during initial balancing..
?
Doesn’t take much offset from balanced, just “some”..
Derek Thanks very much for replying and explaining your approach to this topic. Just checking I understand correctly - So when the counterweight shaft is on the eastside you slide the lower weight a little down the shaft from it's 'correctly balanced' position and when the scope is on the eastside you slide the lower weight up the shaft a little way beyond it's 'correctly balanced' position. Presumably you use tape or something to mark the shaft for each position? Is this method which most use? Many thanks Terry [uk]
|
Re: Used GM-8 Guiding Help
Awesome..
Thanks, Michael..
?
Derek
?
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Michael Herman
Sent: Friday, January 29, 2021
12:20 PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
To answer...some history of the RA drive evolution...
The earliest design uses 2 separate worm blocks, a short Oldham coupler, and the gearbox bolted to the mounting
flange.??
It was recognized that the worm blocks could pinch a ball in one of the
bearings resulting in an erratic Periodic Error (PE).? Owners found
improvement by using a metal straightedge or bracket to line up the bearing
blocks.??
The Ovision company in France
came up with their one piece worm block that put the bearings, worm, and a Belleville spring washer
at the end to keep the worm bearings under compression as they are designed for
best performance and lowest "rumble".? That still left the
gearbox bolted to the mounting flange and used the same short Oldham
coupler.
The earliest version Losmandy OPW was a "long" version.?
It offered the chdncevfir excellent PE behavior.? It contained 3 worm
bearings, and was the one I bought for my G11 upgrade.? That is why it
appeared in my drawings on "Improving the PE..."
I liked that design best because the gearbox attached directly to the
OPW housing end, and you could easily line up the worm, the Oldham
coupler parts, and the gearbox.? It was all easy to see all the parts
while it was upside down on your benchtop.? After you assembled the entire
OPW and gearbox and motor, you attached that entire assembly, all lined up, to
the mounting flange.
When you swiveled the entire OPW on the left mounting block pivot bolt,
to engage the worm, the gearbox always stayed aligned...by way of the long OPW
assembly.
That long OPW also required, and Losmandy provided with the sale, a
long Oldham coupler to reach from the worm to
the farther out gearbox.??
These extra parts added expense...longer Oldham
coupler, added bearing, more machining.??
However...Losmandy changed that and went to a less expensive OPW that
is shorter.? The gearbox went back to be bolted to the main mounting
flange.? And the Oldham coupler went back
to the older short version.??
That short version also went back to just 2 worm bearings.
This change to the "short" OPW saved the customer $100.
Unfortunately, you cannot get the older long OPW any more....not made
any more.? Only the short OPW is offered.??
Losmandy then abandoned the "straight out" motor version and
adopted the more compact "tucked motor" version.? And after that
added the Spring Loaded Worm (SLW) mechanism to the right worm block area of
the tucked motor design.??
Hope this answers the history lesson!
?
Ah.. I saw Michael’s image where it
looked like you’d grease them up and put the “cover” and “retainer” back, but
if they / all such bearings we would use in the blocks are “sealed” that’s
great too.. Less for me and my single digit IQ to mess with.. :-))
?
And combining this with another
thought to make a single email, I saw in Michael’s PDF “Improving the PE..” the
image shows three bearings per worm.. Does anyone actually have three bearings
per worm?? Did they ship that way?? Is there a reason to prefer 2 bearings over
three or three over two??
?
Derek
?
?
I worked in the
lubricants business for 30 years and the bearings used in the worm blocks are
sealed and “fill for life” with grease. I don’t think it will be easy to take
these apart and regrease them, and even if you could there is an art to packing
roller bearings with grease (it is easy to overfill them). Given the bearings
are only about $10 each, it is far easier to replace them if there are problems
with them. I also found a source of “premium” R4ZZ bearings in the UK (but the
ABEC value wasn’t specified):
The “premium” bearings from the above company are about ?9 whereas budget
versions of the same bearings are only ?2.30, so they are likely similar to
bearings from Boca Bearings or other suppliers.
I still have some contacts in roller bearings companies like SKF and FAG so
I’ll see if I can find some information on now many balls will be in the
bearings
|
Re: Used GM-8 Guiding Help
Thanks for the history lesson Michael! Chip, wish I recognized that before pulling one apart, it's smoothness is slightly worse now, still better than my existing but I will be sure it goes in the Dec axis! As for needle bearings at the r4-zz size, if I had to guess I'd say it's not something that's standard or available, the width of these bearings is very small, I could be wrong of course. I will keep everyone posted with how the upgrades go shortly, I have family in town so it may be later this weekend. Love all the input from everyone, thanks!
|
Re: Used GM-8 Guiding Help
I
meant “do they make needle bearings that could go in the (two piece) worm
blocks”.. Almost precisely because all the other bearings in the mount
are needle bearings..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Brian Valente
Sent: Friday, January 29, 2021
11:57 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
>>>Do they make these bearings with
rollers instead of balls??
There are such things, called needle bearings. You have some in your
Losmandy mount axes (that's the plural of axis, right?)?
?
Another image! So “we”
really DON’T want to fill all that space up with Superlube?? It looks
like a natural thing to do (which is why I am kept away from the knives..)
?
Do they make these bearings with
rollers instead of balls??
?
Derek
?
?
Update:
I opened up a bearing this morning (the ones from McMaster Carr). It turns out
your suspicions as well as my uncertainty in trusting the CAD drawings is
correct. There are 8 balls and a retainer. FYI yes I did remove the piece of
dog hair before placing the cover back on! :-D
--
|
Re: Used GM-8 Guiding Help
To answer...some history of the RA drive evolution...
The earliest design uses 2 separate worm blocks, a short Oldham coupler, and the gearbox bolted to the mounting flange.??
It was recognized that the worm blocks could pinch a ball in one of the bearings resulting in an erratic Periodic Error (PE).? Owners found improvement by using a metal straightedge or bracket to line up the bearing blocks.??
The Ovision company in France came up with their one piece worm block that put the bearings, worm, and a Belleville spring washer at the end to keep the worm bearings under compression as they are designed for best performance and lowest "rumble".? That still left the gearbox bolted to the mounting flange and used the same short Oldham coupler.
The earliest version Losmandy OPW was a "long" version.? It offered the chdncevfir excellent PE behavior.? It contained 3 worm bearings, and was the one I bought for my G11 upgrade.? That is why it appeared in my drawings on "Improving the PE..."
I liked that design best because the gearbox attached directly to the OPW housing end, and you could easily line up the worm, the Oldham coupler parts, and the gearbox.? It was all easy to see all the parts while it was upside down on your benchtop.? After you assembled the entire OPW and gearbox and motor, you attached that entire assembly, all lined up, to the mounting flange.
When you swiveled the entire OPW on the left mounting block pivot bolt, to engage the worm, the gearbox always stayed aligned...by way of the long OPW assembly.
That long OPW also required, and Losmandy provided with the sale, a long Oldham coupler to reach from the worm to the farther out gearbox.??
These extra parts added expense...longer Oldham coupler, added bearing, more machining.??
However...Losmandy changed that and went to a less expensive OPW that is shorter.? The gearbox went back to be bolted to the main mounting flange.? And the Oldham coupler went back to the older short version.?? That short version also went back to just 2 worm bearings. This change to the "short" OPW saved the customer $100.
Unfortunately, you cannot get the older long OPW any more....not made any more.? Only the short OPW is offered.??
Losmandy then abandoned the "straight out" motor version and adopted the more compact "tucked motor" version.? And after that added the Spring Loaded Worm (SLW) mechanism to the right worm block area of the tucked motor design.??
Hope this answers the history lesson!
Best regards, Michael
Ah..
I saw Michael’s image where it looked like you’d grease them up and
put the “cover” and “retainer” back, but if they / all
such bearings we would use in the blocks are “sealed” that’s
great too.. Less for me and my single digit IQ to mess with.. :-))
?
And
combining this with another thought to make a single email, I saw in Michael’s
PDF “Improving the PE..” the image shows three bearings per worm..
Does anyone actually have three bearings per worm?? Did they ship that way?? Is
there a reason to prefer 2 bearings over three or three over two??
?
Derek
?
?
I worked in the lubricants business for 30 years and the bearings used
in the worm blocks are sealed and “fill for life” with grease. I
don’t think it will be easy to take these apart and regrease them, and
even if you could there is an art to packing roller bearings with grease (it is
easy to overfill them). Given the bearings are only about $10 each, it is far
easier to replace them if there are problems with them. I also found a source
of “premium” R4ZZ bearings in the UK (but the ABEC value wasn’t
specified):
The “premium” bearings from the above company are about ?9 whereas
budget versions of the same bearings are only ?2.30, so they are likely similar
to bearings from Boca Bearings or other suppliers.
I still have some contacts in roller bearings companies like SKF and FAG so
I’ll see if I can find some information on now many balls will be in the
bearings
|
Re: Used GM-8 Guiding Help
>>> Do they make these bearings with rollers instead of balls??
There are such things, called needle bearings. You have some in your Losmandy mount axes (that's the plural of axis, right?)?
Another
image! So “we” really DON’T want to fill all that space up with Superlube?? It
looks like a natural thing to do (which is why I am kept away from the
knives..)
?
Do
they make these bearings with rollers instead of balls??
?
Derek
?
?
Update:
I opened up a bearing this morning (the ones from McMaster Carr). It turns out
your suspicions as well as my uncertainty in trusting the CAD drawings is
correct. There are 8 balls and a retainer. FYI yes I did remove the piece of
dog hair before placing the cover back on! :-D
-- Brian?
Brian Valente portfolio
|
Re: Used GM-8 Guiding Help
Another
image! So “we” really DON’T want to fill all that space up with Superlube?? It
looks like a natural thing to do (which is why I am kept away from the
knives..)
?
Do
they make these bearings with rollers instead of balls??
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Nick
Sent: Friday, January 29, 2021
6:25 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Update:
I opened up a bearing this morning (the ones from McMaster Carr). It turns out
your suspicions as well as my uncertainty in trusting the CAD drawings is
correct. There are 8 balls and a retainer. FYI yes I did remove the piece of
dog hair before placing the cover back on! :-D
|
Re: Used GM-8 Guiding Help
Ah..
I saw Michael’s image where it looked like you’d grease them up and
put the “cover” and “retainer” back, but if they / all
such bearings we would use in the blocks are “sealed” that’s
great too.. Less for me and my single digit IQ to mess with.. :-))
?
And
combining this with another thought to make a single email, I saw in Michael’s
PDF “Improving the PE..” the image shows three bearings per worm..
Does anyone actually have three bearings per worm?? Did they ship that way?? Is
there a reason to prefer 2 bearings over three or three over two??
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of robert.ian.taylor@...
Sent: Friday, January 29, 2021
4:47 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
I worked in the lubricants business for 30 years and the bearings used
in the worm blocks are sealed and “fill for life” with grease. I
don’t think it will be easy to take these apart and regrease them, and
even if you could there is an art to packing roller bearings with grease (it is
easy to overfill them). Given the bearings are only about $10 each, it is far
easier to replace them if there are problems with them. I also found a source
of “premium” R4ZZ bearings in the UK (but the ABEC value wasn’t
specified):
The “premium” bearings from the above company are about ?9 whereas
budget versions of the same bearings are only ?2.30, so they are likely similar
to bearings from Boca Bearings or other suppliers.
I still have some contacts in roller bearings companies like SKF and FAG so
I’ll see if I can find some information on now many balls will be in the
bearings
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Re: Making the most of cloudy winter nights with a new mount and scope
There's only so much you can do without the sky. But you can admire and practice running your mount.
Just don't mess with it. Don't take it apart to look at the parts. Don't think you can improve it, because you can't.
It is too bad you decided to hobble yourself with stubbornness about your Apple and unwillingness to open your mind to other possibilities. Good luck with that.
Going into my adventure with Astro Imaging, one of my early check points was computer platforms. I was willing to change to Apple if it was a better way. It wasn't. So I stuck with my PC.
Glad I did, because you will find yourself hobbled.
But if you are stubborn, you'll find various work arounds that you might get to work.
Your GM811G will work great in spite of you cutting off your nose to spite your face.
I think Paul gave you the best advice above.
--
SonnyE
(I suggest viewed in full screen)
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Re: Used GM-8 Guiding Help
Huh, you beat me to reply. If anybody read the description of the bearings on the McMaster Carr page for the bearings you would have read that the precision S.S. ABEC 5 and 7 bearings are caged. The number of balls is easy to figure out by looking at the materials and static load, dynamic load and max. RPM. Closer tolerance bearings are rated lower and slower which for this application doesn't matter.?
--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
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Re: 365 covers, condensation, and Wavy Washer standing water..
On Fri, Jan 29, 2021 at 02:05 AM, Paul Homer wrote:
Sonny,
?
You should mention to the CFO that most Astronomy happens at night :)
LOL! Well, her exact words were, "When you are done looking at the stars." But she sez it cost too much to leave outside. So unreasonable! ? -- SonnyE (I suggest viewed in full screen)
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Re: Used GM-8 Guiding Help
Update:
I opened up a bearing this morning (the ones from McMaster Carr). It turns out your suspicions as well as my uncertainty in trusting the CAD drawings is correct. There are 8 balls and a retainer. FYI yes I did remove the piece of dog hair before placing the cover back on! :-D
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Chip Louie
Michael Herman
Richard Beck