>>
I've never used PEC yet, but it's on my to do list, as if I actually had a list! Only 15 things at a time! ha? ??
that would be first on my list of things to do to improve any PE in your mount
i know there's a few different approaches to this: hardware folks tend to focus on the hardware components, software folks (like me) tend to focus on the software components
The reason I go with software first is because it's often easier to implement, easier to refine, and if you F it up completely, easy to back out of
Brian
On Wed, Jan 1, 2020 at 1:55 PM glnth < IDEAL18@...> wrote: Anthony Q
The gear box, I was hoping it would take out some of the spike at 7.5x?? I'll find out
I would like to know what the worm drive spike in the beginning is from. But I'm hoping it might be from putting to much pressure on the bearings.( Form not wanting it to move).? I think I fixed that at least.
I'm waiting on bearings for the worm. Some were making a very rough movement especially in the beginning and if I put side pressure from a belleville washer. (Michael sent me some pdf's on some of the ways they have been tweaking things).? It just got rougher like something was inside. Only some of the bearings are real bad, but is this normal?
I've never used PEC yet, but it's on my to do list, as if I actually had a list! Only 15 things at a time! ha? ??
Glen? ??
-- Brian?
Brian Valente portfolio
|
Anthony Q
The gear box, I was hoping it would take out some of the spike at 7.5x?? I'll find out
I would like to know what the worm drive spike in the beginning is from. But I'm hoping it might be from putting to much pressure on the bearings.( Form not wanting it to move).? I think I fixed that at least.
I'm waiting on bearings for the worm. Some were making a very rough movement especially in the beginning and if I put side pressure from a belleville washer. (Michael sent me some pdf's on some of the ways they have been tweaking things).? It just got rougher like something was inside. Only some of the bearings are real bad, but is this normal?
I've never used PEC yet, but it's on my to do list, as if I actually had a list! Only 15 things at a time! ha? ??
Glen? ??
|
Re: G11 survival kit - Oldham Coupler
I spent ~42 years in the heavy side of the Industrial Electrical field. Every machine I worked with where shaft to shaft coupling was done, flexible couplings where used.
Even with very heavy machinery, roller chain coupler's were used (Multiple hundreds of Horsepower applications) And Machinists aligned these.
Couplers allow for ease of disassembly, but they also take up things like flexing due to torque loads, temperature variations and stress that could shorten the drive's life.
Often, it is just better to let things run the way they were engineered, and have been proven over countless hours of use.
When you solid couple something, the stresses must be compensated for elsewhere. Like breaking things. Or rubber mounted feet.
But, if you would like to reinvent the wheel, .
|
Re: Almost a new owner - Safety Limits..
I can run everything outside, from inside, as if I was sitting at that
station.
***
Don¡¯t
do that until you have set the Safety Limits properly or you can drive the
scope into the mount or tripod.. Not a big deal, unless the limits aren¡¯t set
and no one has mentioned them yet, so..
?
Derek
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of sonnyedmonds@...
Sent: Wednesday, January 01, 2020
10:41 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Almost a new owner....
?
Thank You Brian!
Not visual at all, really. I got into this sport to do imaging of Nebula,
specifically.
So although coming at it from a budget point of view, I bought my initial gear
with Astrophotography as my first aim. I do have a "beginners set" of
eyepieces, two Barlow's, and viewed Saturn and it's rings my first summer.
Spectacular, BTW.
I'm in Saugus,
but originally grew up in Encino. So I sometimes refer to myself as "The
Encino Man" ;^) I took a very long road to land
here in Saugus, CA.
I'll have to learn about Gemini, and how the Losmandy starts up, connects, and
gets running. I use to mount my telescope and connect my cables (all bundled),
then power up, open my programs (PHD2, Infinity, AFF2 focuser, NexRemote
(virtual hand controller), and Stellarium). Usually Stellarium connected
automatically through the Celestron Virtual remote.
I suspect Stellarium will just need to connect through the ASCOM or Gemini 2.
(Not too sure about the pathways my Windows computer takes, but I do get there.
LOL)
I'm betting Scott Losmandy has these things all figured out being as he has
been at this near forever.
I kind of got lost mining down about the Gemini 2 on the Losmandy site. Looks
to be very straight forward and very well explained. Just have to do a step-by-step
for initial start (Cold Start). I was going to ask about cold start, warm
start, but I think I have that figured out now. Thanks to you mentioning it,
and my curiosity and trying to find the answer myself.
I'll be pouring over those and taking notes so I can avoid my usual trial and
error, error, error....
Thanks Brian!
A coupling program called connects my two computers so I can run everything outside, from inside,
as if I was sitting at that station. Once I got it all working, it's been
great!
And I have a Micro USB card mounted in an auxiliary slot that I store my
imaging to. That works great because I can pop the card out, mount it to an
adapter and put it in a slot of my tower computer to process.
|
Re: Almost a new owner....
Hi!
You might want to have a look at Ekos/Indi, nicely packaged in
the Stellarmate for instance:
This is what I use for my G11. Only this.
Best,
Magnus
toggle quoted message
Show quoted text
Oh no, I plan to delete anything about Celestron from my Mount
Computer, I refer to it as my Baby Dell. I think I might wait
until the new GM811G is here and working. Or hopefully, somebody
runs through a quick set-up with me at Losmandy and I bring it
home working.
My indoor tower is also a Dell. In the 1990's I took to building
my own computers. But in the wee-side of the 2000's I just started
buying ready-made computers when needed. So far, been very happy
with Dell Brand boxes-of-rocks.
I hope to Flush Celestron from the bathroom of my heart. ;^) I'm
expecting the Losmandy to be my "forever mount".
I did try SGP back when it was new, but found it quite resistant
to understanding. So it got flushed.
I don't know anything about NINA, yet, but I'm going looking for
it. I'm not so much into complete night automation as of yet. I
guess like my typing, I'm a visual, hunt and pecker sort of object
imager. Often as I was doing my old alignment I would look in
Stellarium for nearby objects at the last star, then slew to them
for a session. Usually setting up PHD2 at that time, and dialing
in my focus. I'd leave the mount fully operational and collecting
images. Then retire inside and connect with Vnc to continue. After
the first target was as much as I desired, I'd find another object
and continue.
In fact, I'd be imaging with the mount computer displayed on one
display, and browsing around in Stellarium for my next victim.
I still need to learn plate solving. I was miserable when I
attempted it before. And Multiple Target Scheduling didn't work
for me either. But I am willing to try and try again. As long as I
can get things working initially.
|
Sonny,
I have gotten new disks from Michael and they seem to have a lot more friction then what I had.
I haven't been able to get the mount out yet, but I think they will solve that problem.
I kind of agree with you about Getting out and doing it. But I have this thing about trying to make it as close as I can. I think it might be OCD?
Glen??
??
|
Re: G11 survival kit - Oldham Coupler
It is my view that you must try and
adjust out as much (ideally all) of the Oldham
coupler movement other than pure rotation.??
***
Michael
also elaborates on lining up the motor so everything is in a straight line..
?
QUESTION..
Why not just replace the Oldham entirely with
a solid coupler.. I would happily be the test bed for a solid coupler if I
could find a couple.. (and I bring this up now, because when I place my order
for a custom rail and other small parts in the near term, I plan on buying a
couple new couplers.. Unless I could find solid coupler replacements..)
?
Derek
|
No.
But if you take one to a Lowe's, or a Home Depot, they usually have a thread matching card or device and you can >carefully< try your screw and find the right thread and pitch.
Ask for help if you need to, but remember, the help you get may know less than you do and might screw up your screw.
And that you don't wanna do.
|
Re: Almost a new owner....
This shift to a Losmandy Mount may be much smoother than I imagined.
***
Uh-oh..
You just *had* to say that..
?
I
have a coworker who just LOVES to say ¡°we¡¯re almost finished!¡±..
Invariably we *are* done, after finishing what was left to do and redoing the
half we thought we had done.. ¡°Just stop saying we¡¯re almost
finished until we are actually putting the tools away!¡±
?
Your
¡°shift¡± will be vastly easier than my shift from 15 years with a
fork mount (LX200 Classic) to my G11 w Gemini II about 30 months ago!! If I didn¡¯t
live close enough to be able to wave wads of cash and beg and grovel to have
Michael Herman pay me a visit, I would have given up.. :-)) 100% User Error
while trying to learn an equatorial mount that decidedly didn¡¯t want to do
things my way..
?
:-))
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of sonnyedmonds@...
Sent: Wednesday, January 01, 2020
8:33 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Almost a new owner....
?
Thank You Paul. I'm not a Raspberry pie user, but appreciate your
reply. Thanks!
Thank You for the short list, Chip.
Looks like the only thing for me to add is the Gemini ASCOM driver (maybe. It
may already be onboard)
All the rest I have and have been using. Except the ASCOM controller.
I would imagine the ASCOM handset (virtual) will just need getting use to for
me. But shouldn't be any problem.
This shift to a Losmandy Mount may be much smoother than I imagined.
|
Re: Almost a new owner....
Oh no, I plan to delete anything about Celestron from my Mount Computer, I refer to it as my Baby Dell. I think I might wait until the new GM811G is here and working. Or hopefully, somebody runs through a quick set-up with me at Losmandy and I bring it home working.
My indoor tower is also a Dell. In the 1990's I took to building my own computers. But in the wee-side of the 2000's I just started buying ready-made computers when needed. So far, been very happy with Dell Brand boxes-of-rocks.
I hope to Flush Celestron from the bathroom of my heart. ;^) I'm expecting the Losmandy to be my "forever mount".
I did try SGP back when it was new, but found it quite resistant to understanding. So it got flushed.
I don't know anything about NINA, yet, but I'm going looking for it. I'm not so much into complete night automation as of yet. I guess like my typing, I'm a visual, hunt and pecker sort of object imager. Often as I was doing my old alignment I would look in Stellarium for nearby objects at the last star, then slew to them for a session. Usually setting up PHD2 at that time, and dialing in my focus. I'd leave the mount fully operational and collecting images. Then retire inside and connect with Vnc to continue. After the first target was as much as I desired, I'd find another object and continue.
In fact, I'd be imaging with the mount computer displayed on one display, and browsing around in Stellarium for my next victim.
I still need to learn plate solving. I was miserable when I attempted it before. And Multiple Target Scheduling didn't work for me either. But I am willing to try and try again. As long as I can get things working initially.
|
Thank you Brian, Will add those to my list.
Sent from my Galaxy Tab A
toggle quoted message
Show quoted text
-------- Original message --------
From: Brian Valente <bvalente@...>
Date: 1/1/20 12:26 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] G11 survival kit
Hi Deric -?
Michael's post is pretty comprehensive to have your mount run for the next century
my simpler list for the next few years is:
spare batteries for the Gemini
spare motor cables for RA and DEC (they don't often go bad but they can)
complete set of allen wrenches
that's about it for me
Brian
|
Thank you Michael, always informative. I brought in the New Year out under the stars with the G11 it worked like a charm especially after I remembered to place the minus sign in the time zone settng.
Sent from my Galaxy Tab A
toggle quoted message
Show quoted text
-------- Original message --------
From: Michael Herman <mherman346@...>
Date: 1/1/20 12:12 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] G11 survival kit
Very good question!
(Oh oh... Another lightning rod question... off the deep end I go.? Apologies again!? My first blunder of 2020!)
... survival...and maintenance...
Firstly: The G11 mounts have been tested by Periodic Error ("PE") tests to get to as low as about 0.9 arcsec RMS.? Those used the new version "high precision brass" worm (these vary individually) and also
had some slight mount mods (added a Belleville spring washer under the far end worm bearing).? Stock G11 mounts vary.? The stock Titan used to be stated to have PE below 2 arcsec, and that has twice the ring gear size of the G11.? That would translate to about
4 arcsec on a G11 (G11 has no stated PE spec).?
So the basic mount design is capable of fabulous performance.? I think all G11 units should get under 2 arcsec RMS if properly tuned up. I'll talk about the issues below.? ?
_____
Your question about "survival" then has to do with how to make adjustments, how to recognize what adjustments to make, and other maintenance issues that might some day arise.? Here is a list of common issues
this group has encountered, though frankly many folks have never had any issues at all.?
Your sensitivity to issues really depends on what optical equipment you are using... could be a light short refractor or long 65lb Newtonian... or a long FL SCT.? So here goes....?
______
Tools:
To adjust the drive gears, required from time to time, you should have these tools:
1. US fractional sized hex key ("Allen") wrenches.? Get two types:
? ? ?a.? straight end (use these if you have straight-on access)
? ? ?b. ball end (these allow you to get to bolts where you have no straight-on access).? That occurs for the critical large bolts below the worm blocks mounting flange (on the GM8, those bolts are accessible at an angle, on the G11, it's tight
from straight on)
2. Good lubricants for the needle bearings.??
? ?a. WD-40
? ?b. A lubricant recommend by many is the Superlube type with teflon.? ?
________
Maintenance:
_______
Gemini units:
The Gemini units have an internal "coin" battery, nominally 3 volts.? Keep a spare of the required size battery for replacement, about once per year or 2 years.??
Preventing Gemini damage:
To prevent internal corrosion, protect the unit from weather (i.e. rain!) and to protect it from electrical shock (like lightning), just unplug it's power and comm lines when you are done using it.? I find it's ok to
keep the motor cables plugged in if the system is enclosed or totally covered up.
*** Label your motor cables and motor and Gemini connections ***?
The connectors on the motor cables are round ("DIN") and have 6 pins and a "detent" metal notch.? But the pins are rather equally distributed around in a circle.? And the notch is not very deep. It has been know to happen
that an owner forced a motor cable into the socket when it was mis-rotated.? ?If you were to mistakenly rotate the motor connection you will damage either the Gemini or the motor...costly repairs or costly replacement.?
Easiest to use a label-maker and keep the connections very clear.? Also the DEC cable is longer than the RA cable, because the cable must travel around with the mount head.??
_______
Mount head parts:
Pertains to?non-tucked motor type drives:??older G11 and all GM8 type designs (DEC axis of GM811):
Of course, don't drop the mount head(!) and when transporting, be sure to protect the motor end that is only attached to the gearbox, if your G(11 or M811 or M8) if it is exposed. The newer tucked motor design protects the motor and gearbox
by metal flanges. The plastic gearbox cases have been known to break.? The gearboxes do not break under normal operation.?
You can force grease into the internal plastic gears from the motor shaft side, but these gearboxes do not come apart.? ?Of course, over decades, the plastic becomes brittle and can break down.??
Therefore, some folks recommend having a spare gearbox! (About
$35?from Losmandy). That's inexpensive insurance.
(On the strsight-out motor version, people have replaced the plastic gearbox with a metal precision one.? McLennan has a model that can be made to fit ...needs some handiwork to fit one in.? I've done this on one GM811, and plan to do that on
a G11 and CG11, but those are still working great with the plastic gearboxes.)
_____
AZ hold down bolts
You will be using the AZ and Elevation adjusters to polar align your RA axis.? (Strongly advised to drift align... and the PHD2 software has a nice feature for this.) There are two side hold down, T handle top AZ bolts that clamp the mount vertical
rotation axis.??
I find the mount gets too slack when I loosen my 2 bolts.? So I add in Belleville spring washers to adjustably take up the slack.? Adding these also needs slightly longer bolts.? Contact me off line if you want these parts.? I have caps in Red,
Yellow, Black.? I find the colored ones help me in near darkness.? See attached photo of this mod.?
_______
All G11, and GM8 and GM811 (and Titan)
Clutch disks issues and options:
The clutch disks are plastic donut shaped pads, and they gently couple the driven bottom plate (driven by the worm gear) to the upper plate (holding the scope if DEC or holding the DEC axis if RA).? These plastic stock pads were designed to
slip, so that an observer could easily push the scope to see something desired, and then gently grab to be again driven by the RA worm clock drive.? But in our age of 8 deep sky imaging, or the real world of bumps, a slippery clutch is a troublesome hazard.?
So...let's talk about the clutches...
The clutch pads can wear out...but should not.? They fail (slipping, won't hold position) because oils eventually creep on to the flat surfaces from the lubricated bearings.? Once oils creep into that area of the flat clutch pad, capillary action
pulls the oils across the whole surface.? They are cleanable.? You can rather easily (no scope or counter weights!) undo and bag the rear clutch knob and it's flat needle bearings, and flat race washers, and lift off the axis shaft. Then de-grease the clutch
metal faces, and clean the plastic clutch pad. The clutch pad and mating surfaces might come clean with just isopropyl alcohol.?
The clutch disk can be replaced by a new plastic one, but the problem will eventually recurr.? I make up a special clutch disk that resists water and oils, and has a higher friction than the slippery stock
clutch disks.? If you are planning to image, these replacement pads will help protect against bumps and also reduce the rear knob force needed to lock the axes in position.??
_______
Degreasing and re-lubing the bearings:
When replacing the clutch disks, this is a great time to re-lube all the internal needle bearings.? The needles are very thin hardened steel rods, and they are supposed to be oiled or greased to work properly. The needles should be free to revolve.
When you pull out the 1.25 inch axis shaft, you can reach in to touch the top needle bearing rollers. See if they are moving easily or are gummed up.??
?If (when) old lubricant loses its fluid light oil part, it can congeal into a gummy tar, and the axis will not rotate freely.? There is a very strong toxic auto parts cleaner called Berryman B-12 that will totally de-grease the internal bearings...just
stuff a rag into the bottom of the shaft opening, and spray in this de-greaser solvent.? Of course, use protective?gear (air mask and rubber gloves, etc) and do this outside.? Once cleaned out if old grease, you
must re-lube those internal cylindrical needle bearings.??
If you don't want to de-grease, try WD-40 to free up the needle bearings.? Then add in a Superlube or perhaps a lithium based grease.??
(Superlube makes several formulations. There is a general purpose PTFE gease that says "< 2%" separation and there is a dielectric grease that has 0% separation (also acts as a vacuum grease).? Both are good from -45F to very high temperature.?
I'm not sure which is best for lubing the G11 needle bearings...)
______
The Oldham coupler.
There is a special mechanical coupler called an Oldham coupler.??
On the strsight-out drive, that critically links the gearbox drive output to the worm gear drive shaft.? On the Tucked Motor version, the coupler attaches the inner transfer gear shaft to the worm drive shaft.??
The metal ends are held on their metal shafts with tiny setscrews, and these can work loose over time and temperature.? When one end gets loose, the drive will either have a time lag, or spin without driving anything.??
Each metal end has an attached polished metal rod. The rods insert into perpendicular grooves on the two sides of a molded plastic center part.?
It is a rare but known problem that the 2 tiny allen-head setscrews in the metal Oldham ends can work loose. Then the Oldham coupler might either fully spin, or partly spin.? When that happens, you will have a large time lag (hysteresis) when
you reverse axis direction (or the motor spins and the axis does not move!).? Always check both of the Oldham coupler ends grip first when you have time-Iags in your RA or DEC drive.??
The metal rods on each metal end of the Oldham coupler can slide in it's plastic center part groove.? The rods can also pivot. This ingenious coupler design allows a drive shaft (the gearbox) to be offset and at an angle to the worm driven shaft...it
will still drive 360 degrees at the same rotation time!?
But...just rotating at perfect 4 minute 360 degree intervals is not good enough for precise Astro imaging!? The rotation has to have the same drive speed throughout the 360 degree rotation.? So beware: you don't want the coupler ends to either
pivot, or to slide!? If those mechanical movements occur, the worm will have either a slight glitch? or periodic error !? You will see these on?your Astro image!? And in a frequency ("FFT") evaluation, the error
from the Oldham coupler will look like it's at the worm period (looks like a bad worm) or at 2x the worm speed (half the period)...looks like a worm with a secondary harmonic.? It's all possibly from a misaligned Oldham coupler.? People have tried other coupler
designs (Ruland) but none work as well as a properly aligned Oldham coupler.??
So it is important to look at the Oldham coupler behavior as you fast-slew the motor.?
Note: On the older straight-out motor design, you can easily see and adjust the Oldham coupler.? On the newer tucked motor design, the Oldham coupler is totally hidden under the worm drive, so it's impossible to get to.? You'd have to consult
Losmandy on how to adjust or fix that case. Probably you'd have to remove the worm drive entirely to get to the coupler hidden inside. That's like the strsight-out OPW design where the Oldham coupler is inside the drive housing.?
If you can observe the coupler in action, you will see if the Oldham coupler parts are totally lined up or not.? It is my view that you must try and adjust out as much (ideally all) of the Oldham coupler movement other than pure rotation.??
How can you do that?? The worm is fixed because it is forced fairly tight against the ring gear that is driving the axis.? So the only way (on a straight out drive) you can adjust the Oldham coupler is at the gearbox, where it is mounted.? If
that gearbox does not have enough manouver room, you have to enlarge or slot? it's mounting holes to get the optimal position.? (On the tucked motor version you would adjust the inner transfer gear position, though I did not see how to do that on the unit
I examined.? It is probably lined up by design at the factory. )
_________
Adjusting the worm gear spacing:
The only critical gear spacing was originally thought to be the worm to ring gear spacing.? On newer drives (Spring Loaded Worm), this is automatically done by a spring mechanism.? On the older straight-out drives, you had to adjust this spacing
by hand.? The adjustment provided was to loosen the two bottom worm block bolt fasteners, then nudge the worm into the ring gear, then tighten down the worm blocks again.??
_____
Improving worm and bearing performance...
Even with the worm gear tight to the ring gear, sometimes there still remained a wiggle in the drive....? many people worked to trace this down.?
Finally, it was recognized that the wiggle was coming from a problem that can occur: worm side to side movement.? That is, the worm is only confined by the two blocks on either side, holding the worm bearings (R4ZZ type).? If the blocks are
not pressed together at assembly, or loosen up over time and temperature, the worm can move laterally in the gap.? That gap shows up as a time lag in reversing direction, thus can affect autoguiding.??
Moreover, the bearings performance is improved when the bearing is under axial compression.? There is no provision for consistent compression in the stock design.? Earlier mounts like the Meade LXD-55 used a heavy brass bolt to drive the worm
axis...but that had no bearing.? So I recommend on older straight out drives to install a R4 size Belleville spring washer.? I have a PDF describing how to do that, but it is not a stock feature.??
I think that ends my list of maintenance and improvements and tools and issues to look for.? ?I'll attach some photos and notes of the newer Tucked Motor and Spring Loaded Worm systems below.??
Have fun with your new mount... !
Michael
Photos:
Older CG11 worm showing how it drives the large ring gear.? The Oldham coupler is visible at the far end of the worm, with the gearbox.?
The AZ hold down bolts go totally slack when you loosen the T handle to do polar (drift) alignment. I find better performance by adding Belleville spring washers under the T handle.? I make the bolts longer and with color caps to be easier to
find in near darkness.??
The clutch pad goes at the far end if the 1.25 inch drive shaft.? This photo shows a replacement clutch pad in place. The original pads are milk white.??
This is the Spring Loaded Worm spring mechanism.? The big radial spring pushes the worm down into the ring gear. For this to work properly, the worm must be able to pivot on the left side mounting bolt (not shown in this picture), and the right
side hold down bolt must allow the pivoting.? If the bolt pressing the radial spring down is driving too tight, the worm can get stuck (too much friction), so the spring bolt must be loosened up.? The smaller bolt on the left of the spring, when driven in,
lifts the worm away from the ring gear.??
This photo shows the two transfer gears of the Tucked Motor drive.? These should have no gap. You adjust the space between these gears by adjusting the gearbox position.? The gearbox is attached to the back of the bottom transfer gear, in this
photo.??
What spare parts do I need to stock up on to keep the G11 going??
|
Re: static electricity shock
Ron
wrote-
¡ static electricity.
So am I to worry?, not enough power to cause harm right?
***
My
last ¡°POOF¡± went like this..
?
I
do lunar and minor planet occultations.. Involved is a Video Time Inserter and,
in my case, a 32¡± TV (with a tube).. TV is on AC and is powered up.. At a
convenient waist high I attach the cables to the back of the time inserter..
Good shielded cables, such as Monster.. I go to the TV and place the time
inserter on top, with the cables hanging down across the TV as the video cable
needs to be plugged into the front panel jack.. When I go to do that, the hair
on my arm feels the static on the TV tube, there is a mini crack of lightning
out of the speakers, and the time inserter no longer inserts time.. The static
blew up the video titler chip.. POOF.. All because I passed the video cable
near the front of the TV.. Now I run the cables around the sides of the TV
after I have wiped down the screen to discharge the static..
?
This
is an extreme case, but static is static.. Build up enough of it and bad things
will happen..
?
Derek
?
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Rappnron via Groups.Io
Sent: Monday, December 30, 2019
7:29 PM
To: [email protected]
Subject: [Losmandy_users_io]
static electricity shock
?
bottom line ...? do I need to and/or how do I ground the mount ?
Out here in the wild west we get offshore "Santa Ana " winds and the humidity drops
real low. Then when I touch the mount or my metal bodied ZWO camera I might get
a shock of static electricity.
So am I to worry?, not enough power to cause harm right?
Im using a 110v power ( guess this ground doesnt matter as Im getting shocked)
and? imaging on a wooden rooftop deck under a ROR so presumably the mount
is a floating insulated ground?
I have clamped a copper wire to one of the leg mount screws and connected to a
nearby metal vent pipe
But perhaps I should ground myself to the vent pipe?
How best to ground the mount?
Will this help ?
Ron
|
Re: Almost a new owner....
imaging, got it.
Regarding imaging, you won't need that NexRemote, as the already has that built in as a feature. (I don't know of anyone using NexRemote with losmandy, but that could be just me)
you might?consider using something like sequence generator pro or NINA, which provide complete night automation. things have really picked up in this area, and not only is this software and it's components really inexpensive (NINA if free actually), they do all the jobs really well, including mount control, slewing and centering, plate solve, focusing, image acquisition, multiple target scheduling etc.
If you have a small computer attached to the telescope and can just remote in to it (remote desktop, anydesk, teamviewer, etc.) that is ideal.?
re: location, I am just on the border of encino and sherman oaks. I was just up at saugus volunteering?around that terrible high school shooting event (we do therapy dog work) but it seems like a really lovely town
Thank You Brian!
Not visual at all, really. I got into this sport to do imaging of Nebula, specifically.
So although coming at it from a budget point of view, I bought my initial gear with Astrophotography as my first aim. I do have a "beginners set" of eyepieces, two Barlow's, and viewed Saturn and it's rings my first summer. Spectacular, BTW.
I'm in Saugus, but originally grew up in Encino. So I sometimes refer to myself as "The Encino Man" ;^) I took a very long road to land here in Saugus, CA.
I'll have to learn about Gemini, and how the Losmandy starts up, connects, and gets running. I use to mount my telescope and connect my cables (all bundled), then power up, open my programs (PHD2, Infinity, AFF2 focuser, NexRemote (virtual hand controller), and Stellarium). Usually Stellarium connected automatically through the Celestron Virtual remote.
I suspect Stellarium will just need to connect through the ASCOM or Gemini 2. (Not too sure about the pathways my Windows computer takes, but I do get there. LOL)
I'm betting Scott Losmandy has these things all figured out being as he has been at this near forever.
I kind of got lost mining down about the Gemini 2 on the Losmandy site. Looks to be very straight forward and very well explained. Just have to do a step-by-step for initial start (Cold Start). I was going to ask about cold start, warm start, but I think I have that figured out now. Thanks to you mentioning it, and my curiosity and trying to find the answer myself.
I'll be pouring over those and taking notes so I can avoid my usual trial and error, error, error....
Thanks Brian!
A coupling program called connects my two computers so I can run everything outside, from inside, as if I was sitting at that station. Once I got it all working, it's been great!
And I have a Micro USB card mounted in an auxiliary slot that I store my imaging to. That works great because I can pop the card out, mount it to an adapter and put it in a slot of my tower computer to process.
-- Brian?
Brian Valente portfolio
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Re: Almost a new owner....
Thank You Brian!
Not visual at all, really. I got into this sport to do imaging of Nebula, specifically.
So although coming at it from a budget point of view, I bought my initial gear with Astrophotography as my first aim. I do have a "beginners set" of eyepieces, two Barlow's, and viewed Saturn and it's rings my first summer. Spectacular, BTW.
I'm in Saugus, but originally grew up in Encino. So I sometimes refer to myself as "The Encino Man" ;^) I took a very long road to land here in Saugus, CA.
I'll have to learn about Gemini, and how the Losmandy starts up, connects, and gets running. I use to mount my telescope and connect my cables (all bundled), then power up, open my programs (PHD2, Infinity, AFF2 focuser, NexRemote (virtual hand controller), and Stellarium). Usually Stellarium connected automatically through the Celestron Virtual remote.
I suspect Stellarium will just need to connect through the ASCOM or Gemini 2. (Not too sure about the pathways my Windows computer takes, but I do get there. LOL)
I'm betting Scott Losmandy has these things all figured out being as he has been at this near forever.
I kind of got lost mining down about the Gemini 2 on the Losmandy site. Looks to be very straight forward and very well explained. Just have to do a step-by-step for initial start (Cold Start). I was going to ask about cold start, warm start, but I think I have that figured out now. Thanks to you mentioning it, and my curiosity and trying to find the answer myself.
I'll be pouring over those and taking notes so I can avoid my usual trial and error, error, error....
Thanks Brian!
A coupling program called connects my two computers so I can run everything outside, from inside, as if I was sitting at that station. Once I got it all working, it's been great!
And I have a Micro USB card mounted in an auxiliary slot that I store my imaging to. That works great because I can pop the card out, mount it to an adapter and put it in a slot of my tower computer to process.
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Hi Deric -?
Michael's post is pretty comprehensive to have your mount run for the next century
my simpler list for the next few years is:
spare batteries for the Gemini
spare motor cables for RA and DEC (they don't often go bad but they can)
complete set of allen wrenches
that's about it for me
Brian
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Very good question!
(Oh oh... Another lightning rod question... off the deep end I go.? Apologies again!? My first blunder of 2020!)
... survival...and maintenance...
Firstly: The G11 mounts have been tested by Periodic Error ("PE") tests to get to as low as about 0.9 arcsec RMS.? Those used the new version "high precision brass" worm (these vary individually) and also had some slight mount mods (added a Belleville spring washer under the far end worm bearing).? Stock G11 mounts vary.? The stock Titan used to be stated to have PE below 2 arcsec, and that has twice the ring gear size of the G11.? That would translate to about 4 arcsec on a G11 (G11 has no stated PE spec).?
So the basic mount design is capable of fabulous performance.? I think all G11 units should get under 2 arcsec RMS if properly tuned up. I'll talk about the issues below.? ?
_____
Your question about "survival" then has to do with how to make adjustments, how to recognize what adjustments to make, and other maintenance issues that might some day arise.? Here is a list of common issues this group has encountered, though frankly many folks have never had any issues at all.?
Your sensitivity to issues really depends on what optical equipment you are using... could be a light short refractor or long 65lb Newtonian... or a long FL SCT.? So here goes....?
______
Tools:
To adjust the drive gears, required from time to time, you should have these tools:
1. US fractional sized hex key ("Allen") wrenches.? Get two types: ? ? ?a.? straight end (use these if you have straight-on access) ? ? ?b. ball end (these allow you to get to bolts where you have no straight-on access).? That occurs for the critical large bolts below the worm blocks mounting flange (on the GM8, those bolts are accessible at an angle, on the G11, it's tight from straight on)
2. Good lubricants for the needle bearings.?? ? ?a. WD-40 ? ?b. A lubricant recommend by many is the Superlube type with teflon.? ? ________
Maintenance: _______
Gemini units:
The Gemini units have an internal "coin" battery, nominally 3 volts.? Keep a spare of the required size battery for replacement, about once per year or 2 years.??
Preventing Gemini damage:
To prevent internal corrosion, protect the unit from weather (i.e. rain!) and to protect it from electrical shock (like lightning), just unplug it's power and comm lines when you are done using it.? I find it's ok to keep the motor cables plugged in if the system is enclosed or totally covered up.
*** Label your motor cables and motor and Gemini connections ***?
The connectors on the motor cables are round ("DIN") and have 6 pins and a "detent" metal notch.? But the pins are rather equally distributed around in a circle.? And the notch is not very deep. It has been know to happen that an owner forced a motor cable into the socket when it was mis-rotated.? ?If you were to mistakenly rotate the motor connection you will damage either the Gemini or the motor...costly repairs or costly replacement.? Easiest to use a label-maker and keep the connections very clear.? Also the DEC cable is longer than the RA cable, because the cable must travel around with the mount head.?? _______
Mount head parts:
Pertains to?non-tucked motor type drives:??older G11 and all GM8 type designs (DEC axis of GM811):
Of course, don't drop the mount head(!) and when transporting, be sure to protect the motor end that is only attached to the gearbox, if your G(11 or M811 or M8) if it is exposed. The newer tucked motor design protects the motor and gearbox by metal flanges. The plastic gearbox cases have been known to break.? The gearboxes do not break under normal operation.?
You can force grease into the internal plastic gears from the motor shaft side, but these gearboxes do not come apart.? ?Of course, over decades, the plastic becomes brittle and can break down.??
Therefore, some folks recommend having a spare gearbox! (About $35?from Losmandy). That's inexpensive insurance.
(On the strsight-out motor version, people have replaced the plastic gearbox with a metal precision one.? McLennan has a model that can be made to fit ...needs some handiwork to fit one in.? I've done this on one GM811, and plan to do that on a G11 and CG11, but those are still working great with the plastic gearboxes.)
_____
AZ hold down bolts
You will be using the AZ and Elevation adjusters to polar align your RA axis.? (Strongly advised to drift align... and the PHD2 software has a nice feature for this.) There are two side hold down, T handle top AZ bolts that clamp the mount vertical rotation axis.??
I find the mount gets too slack when I loosen my 2 bolts.? So I add in Belleville spring washers to adjustably take up the slack.? Adding these also needs slightly longer bolts.? Contact me off line if you want these parts.? I have caps in Red, Yellow, Black.? I find the colored ones help me in near darkness.? See attached photo of this mod.?
_______
All G11, and GM8 and GM811 (and Titan)
Clutch disks issues and options:
The clutch disks are plastic donut shaped pads, and they gently couple the driven bottom plate (driven by the worm gear) to the upper plate (holding the scope if DEC or holding the DEC axis if RA).? These plastic stock pads were designed to slip, so that an observer could easily push the scope to see something desired, and then gently grab to be again driven by the RA worm clock drive.? But in our age of 8 deep sky imaging, or the real world of bumps, a slippery clutch is a troublesome hazard.? So...let's talk about the clutches...
The clutch pads can wear out...but should not.? They fail (slipping, won't hold position) because oils eventually creep on to the flat surfaces from the lubricated bearings.? Once oils creep into that area of the flat clutch pad, capillary action pulls the oils across the whole surface.? They are cleanable.? You can rather easily (no scope or counter weights!) undo and bag the rear clutch knob and it's flat needle bearings, and flat race washers, and lift off the axis shaft. Then de-grease the clutch metal faces, and clean the plastic clutch pad. The clutch pad and mating surfaces might come clean with just isopropyl alcohol.?
The clutch disk can be replaced by a new plastic one, but the problem will eventually recurr.? I make up a special clutch disk that resists water and oils, and has a higher friction than the slippery stock clutch disks.? If you are planning to image, these replacement pads will help protect against bumps and also reduce the rear knob force needed to lock the axes in position.??
_______
Degreasing and re-lubing the bearings:
When replacing the clutch disks, this is a great time to re-lube all the internal needle bearings.? The needles are very thin hardened steel rods, and they are supposed to be oiled or greased to work properly. The needles should be free to revolve. When you pull out the 1.25 inch axis shaft, you can reach in to touch the top needle bearing rollers. See if they are moving easily or are gummed up.??
?If (when) old lubricant loses its fluid light oil part, it can congeal into a gummy tar, and the axis will not rotate freely.? There is a very strong toxic auto parts cleaner called Berryman B-12 that will totally de-grease the internal bearings...just stuff a rag into the bottom of the shaft opening, and spray in this de-greaser solvent.? Of course, use protective?gear (air mask and rubber gloves, etc) and do this outside.? Once cleaned out if old grease, you must re-lube those internal cylindrical needle bearings.??
If you don't want to de-grease, try WD-40 to free up the needle bearings.? Then add in a Superlube or perhaps a lithium based grease.??
(Superlube makes several formulations. There is a general purpose PTFE gease that says "< 2%" separation and there is a dielectric grease that has 0% separation (also acts as a vacuum grease).? Both are good from -45F to very high temperature.? I'm not sure which is best for lubing the G11 needle bearings...)
______
The Oldham coupler.
There is a special mechanical coupler called an Oldham coupler.??
On the strsight-out drive, that critically links the gearbox drive output to the worm gear drive shaft.? On the Tucked Motor version, the coupler attaches the inner transfer gear shaft to the worm drive shaft.??
The metal ends are held on their metal shafts with tiny setscrews, and these can work loose over time and temperature.? When one end gets loose, the drive will either have a time lag, or spin without driving anything.??
Each metal end has an attached polished metal rod. The rods insert into perpendicular grooves on the two sides of a molded plastic center part.?
It is a rare but known problem that the 2 tiny allen-head setscrews in the metal Oldham ends can work loose. Then the Oldham coupler might either fully spin, or partly spin.? When that happens, you will have a large time lag (hysteresis) when you reverse axis direction (or the motor spins and the axis does not move!).? Always check both of the Oldham coupler ends grip first when you have time-Iags in your RA or DEC drive.??
The metal rods on each metal end of the Oldham coupler can slide in it's plastic center part groove.? The rods can also pivot. This ingenious coupler design allows a drive shaft (the gearbox) to be offset and at an angle to the worm driven shaft...it will still drive 360 degrees at the same rotation time!?
But...just rotating at perfect 4 minute 360 degree intervals is not good enough for precise Astro imaging!? The rotation has to have the same drive speed throughout the 360 degree rotation.? So beware: you don't want the coupler ends to either pivot, or to slide!? If those mechanical movements occur, the worm will have either a slight glitch? or periodic error !? You will see these on?your Astro image!? And in a frequency ("FFT") evaluation, the error from the Oldham coupler will look like it's at the worm period (looks like a bad worm) or at 2x the worm speed (half the period)...looks like a worm with a secondary harmonic.? It's all possibly from a misaligned Oldham coupler.? People have tried other coupler designs (Ruland) but none work as well as a properly aligned Oldham coupler.??
So it is important to look at the Oldham coupler behavior as you fast-slew the motor.?
Note: On the older straight-out motor design, you can easily see and adjust the Oldham coupler.? On the newer tucked motor design, the Oldham coupler is totally hidden under the worm drive, so it's impossible to get to.? You'd have to consult Losmandy on how to adjust or fix that case. Probably you'd have to remove the worm drive entirely to get to the coupler hidden inside. That's like the strsight-out OPW design where the Oldham coupler is inside the drive housing.?
If you can observe the coupler in action, you will see if the Oldham coupler parts are totally lined up or not.? It is my view that you must try and adjust out as much (ideally all) of the Oldham coupler movement other than pure rotation.??
How can you do that?? The worm is fixed because it is forced fairly tight against the ring gear that is driving the axis.? So the only way (on a straight out drive) you can adjust the Oldham coupler is at the gearbox, where it is mounted.? If that gearbox does not have enough manouver room, you have to enlarge or slot? it's mounting holes to get the optimal position.? (On the tucked motor version you would adjust the inner transfer gear position, though I did not see how to do that on the unit I examined.? It is probably lined up by design at the factory. ) _________
Adjusting the worm gear spacing:
The only critical gear spacing was originally thought to be the worm to ring gear spacing.? On newer drives (Spring Loaded Worm), this is automatically done by a spring mechanism.? On the older straight-out drives, you had to adjust this spacing by hand.? The adjustment provided was to loosen the two bottom worm block bolt fasteners, then nudge the worm into the ring gear, then tighten down the worm blocks again.?? _____
Improving worm and bearing performance...
Even with the worm gear tight to the ring gear, sometimes there still remained a wiggle in the drive....? many people worked to trace this down.?
Finally, it was recognized that the wiggle was coming from a problem that can occur: worm side to side movement.? That is, the worm is only confined by the two blocks on either side, holding the worm bearings (R4ZZ type).? If the blocks are not pressed together at assembly, or loosen up over time and temperature, the worm can move laterally in the gap.? That gap shows up as a time lag in reversing direction, thus can affect autoguiding.??
Moreover, the bearings performance is improved when the bearing is under axial compression.? There is no provision for consistent compression in the stock design.? Earlier mounts like the Meade LXD-55 used a heavy brass bolt to drive the worm axis...but that had no bearing.? So I recommend on older straight out drives to install a R4 size Belleville spring washer.? I have a PDF describing how to do that, but it is not a stock feature.??
I think that ends my list of maintenance and improvements and tools and issues to look for.? ?I'll attach some photos and notes of the newer Tucked Motor and Spring Loaded Worm systems below.??
Have fun with your new mount... !
Michael
Photos:
Older CG11 worm showing how it drives the large ring gear.? The Oldham coupler is visible at the far end of the worm, with the gearbox.?
The AZ hold down bolts go totally slack when you loosen the T handle to do polar (drift) alignment. I find better performance by adding Belleville spring washers under the T handle.? I make the bolts longer and with color caps to be easier to find in near darkness.??
The clutch pad goes at the far end if the 1.25 inch drive shaft.? This photo shows a replacement clutch pad in place. The original pads are milk white.??
This is the Spring Loaded Worm spring mechanism.? The big radial spring pushes the worm down into the ring gear. For this to work properly, the worm must be able to pivot on the left side mounting bolt (not shown in this picture), and the right side hold down bolt must allow the pivoting.? If the bolt pressing the radial spring down is driving too tight, the worm can get stuck (too much friction), so the spring bolt must be loosened up.? The smaller bolt on the left of the spring, when driven in, lifts the worm away from the ring gear.??
This photo shows the two transfer gears of the Tucked Motor drive.? These should have no gap. You adjust the space between these gears by adjusting the gearbox position.? The gearbox is attached to the back of the bottom transfer gear, in this photo.??
What spare parts do I need to stock up on to keep the G11 going??
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I filed those tabs off to remove the gearbox binding as well. Several different gear boxes exhibited the same binding. I am not sure how you and I are the only people in the world to have noticed this, but we might be.
If you add a belleville washer to you RA bearing, (search this forum and documents for details...), that 3.15x hump in your PEMPro graph should move to 3.0x and then you can smooth it out using PEC from PEMPro to the mount.
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Re: Almost a new owner....
Thank You Paul. I'm not a Raspberry pie user, but appreciate your reply. Thanks!
Thank You for the short list, Chip.
Looks like the only thing for me to add is the Gemini ASCOM driver (maybe. It may already be onboard)
All the rest I have and have been using. Except the ASCOM controller.
I would imagine the ASCOM handset (virtual) will just need getting use to for me. But shouldn't be any problem.
This shift to a Losmandy Mount may be much smoother than I imagined.
Oh, and my main imaging camera is an Atik Infinity OSC and yep, ASCOM. As is my Orion guide scope and camera for guiding.
Edit in: I realized my ASCOM was outdated, so updated it on both computers. Downloaded Gemini ASCOM Driver. Stellarium is currant version. Downloaded Stellarium Scope. And checked PHD2 is the latest.
Thank You for the help! Now then... where is my new mount?
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What spare parts do I need to stock up on to keep the G11 going??
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Michael Herman