On Tue, May 4, 2021 at 10:47 AM, Pete wrote:
@Les Niles,??
My mount currently does not have "wavy washers."? It has true Belleville washers which Brian says are not supported by Losmandy.? I have therefore ordered a pair of Losmandy wavy washers?
They were so cheap that it was silly not to buy them.? Thanks for your input.? It swung my decision.
Pete
Coincidentally, I just picked up a digital setting circle kit for my G-11. ?The instructions for installing it refer to the springy thingy as a "curved washer" and in the diagram it looks like a Belleville, not a wavy washer. ?(It's one of the pieces that's supposed already be on the mount, not part of the DSC kit.) ?I don't know when Losmandy sold this kit, but apparently at some point in the past they did use something like what you found on your mount. ? -Les 
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Re: Still some DEC issues
TVC does not affect RA in any way
If your DEC movements seem to be impacting RA, it sounds to me like a calibration issue in PHD
If you can post your guidelogs that include a clean calibration, GA run, and then 15-20 minutes of uninterrupted guiding, that would be super helpful
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Re: Still some DEC issues
Tripod is Losmandy HD.
I have not tried locking the blocks yet.
The grease on the worm looks to be the same as the grease on the axis shaft that lubes the needle bearing - a light brown color.
I don't want to change the grease unless I can completely remove the old grease.? Can the axis be taken apart to clean the ring gear all the way around?
The sticktion is either worm-to-ring gear, or the bearings of the axis.
I am using NINA for the capture program, which also have settings for dither size, timeout, etc.? I need the dither to be at least several pixels because that seems to be the splotchiness or fixed point noise in my sensor.? Sometimes this bad behavior happens even 30 seconds after a dither move, so it's not really feasible to set a dither timeout that long.
I was able to reduce the RA spikes a little by lowering the TVC value down to 7.? I don't know how fast the Gemini moves the gears for TVC, but maybe even at a setting of 10 there is occasional "gear banging".? In my first post, I said that I got these spikes even with TVC =0, but I was using a higher PHD backlash compensation setting then.? I dunno, maybe I have to lower the guide speed to below 0.5x to make the gears move slower?
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Thanks for he tips Brian V!
I was asking for some explanation for something else and Brian asked for my PHD2 logs. He made a couple of recommendations about PPEC settings, and tonight I set a new personal best for guiding my G11 G2.
Thanks Brian!
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Re: Mount sales must be doing great, glad I already ordered!
Right now new orders are 10-12 weeks estimated lead time.
for existing orders, many of them at the longer end of the estimate are getting ready for shipment. We are shipping out orders every day.?
Tanya's doing her best to respond to everyone, but she also is in charge of the packaging and shipping, so she tends to focus her efforts there.?
FYI we've already hired and are onboarding new staff, but it takes time to bring them up
My personal suggestion (not a losmandy recommendation) is to plan for the mount arrival only when you get the official notification.?
Brian
Hello Jason,
You should be very close now from what I have read. It is hard to wait but it will be worth it. Maybe Brian, will chime in here with a better ETA.?
HAPPY SKIES TO YOU AND KEEP LOOKING UP Deric
Sent from my Galaxy Tab A
-------- Original message --------
Date: 5/6/21 5:38 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] Mount sales must be doing great, glad I already ordered!
Does anyone have an idea of current new mount lead times? I ordered a GM811G on March 11th, so tomorrow is 8 weeks. My emails have gone unanswered and the number goes to a voicemail, so I figure they're hard at work, which is good.? But, I am interested
in getting some idea because of travel plans and upcoming outreach events.? Thanks,
Jason
-- Brian?
Brian Valente portfolio
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Re: Mount sales must be doing great, glad I already ordered!
Sunday will be 9 weeks (Ordered March 7th)? I've been calling and adding more stuff to my order as I wait.? Waiting is expensive, I keep thinking of more little parts, knobs and stuff I should get right away.? You do save money ordering things with the mount, they deduct the difference in price because they don't have to use the original part. Anyway,? a little birdie told me I SHOULD get a call by the end of next week. Then the wait, I estimate 1 week to ship halfway across the US.? I know it will be worth the wait!? With my current mount, I've never seen a PHD2 graph that doesn't look like a magnitude 9 earthquake. :)?
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Re: Mount sales must be doing great, glad I already ordered!
Hello Jason,
You should be very close now from what I have read. It is hard to wait but it will be worth it. Maybe Brian, will chime in here with a better ETA.?
HAPPY SKIES TO YOU AND KEEP LOOKING UP Deric
Sent from my Galaxy Tab A
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Show quoted text
-------- Original message --------
From: Jason Close <jason@...>
Date: 5/6/21 5:38 PM (GMT-06:00)
Subject: Re: [Losmandy_users_io] Mount sales must be doing great, glad I already ordered!
Does anyone have an idea of current new mount lead times? I ordered a GM811G on March 11th, so tomorrow is 8 weeks. My emails have gone unanswered and the number goes to a voicemail, so I figure they're hard at work, which is good.? But, I am interested
in getting some idea because of travel plans and upcoming outreach events.? Thanks,
Jason
|
Re: Mount sales must be doing great, glad I already ordered!
Does anyone have an idea of current new mount lead times? I ordered a GM811G on March 11th, so tomorrow is 8 weeks. My emails have gone unanswered and the number goes to a voicemail, so I figure they're hard at work, which is good.? But, I am interested in getting some idea because of travel plans and upcoming outreach events.? Thanks,
Jason
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Re: Editing posts - please don't
Proofreading
is even older..
?
:-))
?
Derek
?
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From: [email protected] [mailto:[email protected]] On Behalf Of Pete
Sent: Tuesday, May 04, 2021 4:59
PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Editing posts - please don't
?
I have only ever used groups.io as a forum.? Just about the last
thing I want is more emails. The way I use groups.io, each separate forum is
its own channel.??
I make the occasional spellnig erraz when typing.? Sometimes, say a
dropped s when I meant to use a plural, it can completely change a sentence's
meaning.? If I do not catch this prior to posting, I need to edit.
Editing is a part of today's computerized life and has been since the
mid-1980s.
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Re: Still some DEC issues
Alan,
Did you mention what capture software you are using? Please see attached screenshot for the dither settings for SGPro. Here you can change the size of the dither, the number of frames before a dither, and the settling time before imaging resumes. Have you tried manipulating these variables? More dithers result in higher errors, especially if you use after each frame, and your frames are short. It is pretty common for a dither to increase your guiding error for a short period of time, but it should smooth out over time. Have you checked off Fast Recenter after Calibration or Dither in the PHD2 brain guiding settings??
Perhaps your issue is within the various settings, not a stiction effect.
John
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Re: Still some DEC issues
A good puzzle, Alan.
Your mount has spring loaded RA and DEC.? The RA is the G11 type drive and the DEC is the GM8 type.
The RA and DEC are orthogonal.? The only way a vibration from.DEC could affect RA is if a jolt from DEC somehow shook the whole mount.
So: a few questions...
1. What is your tripod type?? If it is lightweight perhaps it could vibrate?
2. Last few emails, it seemed the view was to lock down the worm blocks (as they used to be before the spring loaded mechanism was introduced).? Did you bolt down the RA and DEC worm blocks?? If you didn't I'd suggest you bolt them down tightly on both axes, and skip the looser spring loaded operation to see the effect.??
3. When we spoke, you wanted to keep the same worm to ring gear lube as the factory installed.? It was a semitransparent and lightly red or pink color....I think that's what I saw.? ?I think this is the? ? ? ? Jet-Lube Arctic low temp grease ? that Brian has suggested.? You did not want to take a chance on the CRC brake and caliper grease that I offered.? I wonder if you were to try the thicker CRC lube if it could eliminate the vibration.??
Anyway, that's my suggestion for experiments to try.? ?
Best of luck, Michael
Hello folks,
I have the latest GM811.? A few weeks back, I posted about adjusting the screw to get the backlash as low as possible, mechanically.? When using the mount for long-exposure imaging, there are still some DEC issues that ruin a frame here and there.? I have the clutch pressure set very low.
0) First, I should mention that sometimes when the seeing is good, the guiding is good too at < 0.6 rms and the DEC axis just gives gentle nudges back and forth to the axis and everything is fine.
1) Sometimes a large DEC pulse (when changing direction) will cause a corresponding spike in RA also.? See attached picture.? Here only the northward pulses (approx 1 second worth, if I remember + TVC 10) cause a spike in RA.? (BTW, I also had these spikes with TVC 0) I noticed when running the backlash test in Guiding assistant that the guide star also moves a little in RA when changing DEC direction from N to S.
2) a dither move in DEC seems to "unsettle" the axis, and it seems to misbehave for maybe the next 30 seconds or more.? It's like the axis builds up "sticktion" and then releases it at some random time later.? In the picture, the sticktion amount is about 3 arc-sec.? After several minutes, this sticktion drops down to about 2 arc-s, and maybe if the seeing is good for a long time and I don't do any dithers in DEC, it gets even lower.? It's like the worm needs to move back and forth a few times before settling down for best performance.
So at this moment dither in DEC is unreliable because the later movement will mess up a frame.? I've resorted to dither RA only and then "manual DEC dither" after a sequence of images.
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Re: Editing posts - please don't
I have only ever used groups.io as a forum.? Just about the last thing I want is more emails. The way I use groups.io, each separate forum is its own channel.??
I make the occasional spellnig erraz when typing.? Sometimes, say a dropped s when I meant to use a plural, it can completely change a sentence's meaning.? If I do not catch this prior to posting, I need to edit.
Editing is a part of today's computerized life and has been since the mid-1980s.
|
Brian, I just watched the wavy washer video.? Two things:
1. I expected to see workers from a laundry greeting me by raising their arms in greeting (wavy washers...).
2.? I had no idea the wavy washer went where it does.? I thought it went between the (on order) spacer/slip ring and the rear bearing thrust washer.
Thanks for pointing me in the right direction.
Pete
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With the wavy washers and the spacer/slip rings ordered, I shall rebuild my mount and see how well it works in its existing worm and bearing configuration before making changes.? Change one variable at a time and watch its effect.? This will be my motto until I understand this mount.??
I'll upgrade the Gemini-1 firmware to the latest available and see how that goes with ASCOM and indi.? Later I may wish to upgrade to Gemini 2.? I have read good and not so good reports of various features of Gemini 2.? Since I mainly use either ASCOM and more recently indi/KStars//Ekos, I honestly wonder if this particular upgrade is warranted for my installation.? For me a major advantage of Gemini 2 is that it has an RJ45 Ethernet connection and this is my preferred method of connection wherever possible.
Pete
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Thanks, Derek for the suggestion. It works great in keep the declination motor cable from fouling with the clutch knobs. The yogurt tub has been retired from service.
Russ
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Re: Gemini-2 momentarily went haywire
Thanks for your thoughts, Michael. I'm hoping the board is bit less than you are quoting. Desoldering the old encoder chip and soldering in a few dozen 0.5mm(?) connectors sounds like an extreme challenge. Even under a magnifying lens using a super small soldering iron, this will required quite a steady hand. If only I had one of those manufacturing robots :). Just wondering if the old board can be connected to some sort of analyzer to check what this chip is really doing.
Regards,
John
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Hi gang,
The wavy style washers, and the cup-shaped Belleville spring washers, are used commonly in mechanical systems.? Their purpose is to provide a rather constant axial force, vs a force that would change very abruptly and dramatically when temperature changes.? And temperature certainly does change in our outdoor usage.
The cup-shaped Belleville spring can be used in any situation where you want a rather uniform force on the outer circumference on one side of the spring, and a corresponding force in the inner edge of the spring on the other side.
When you want to keep the constant force on the worm bearings, that keeps the balls on their races for lowest bearing rumble, you want to use the Belleville cup shape (R4 sized spring for the R4ZZ bearing size).??
If you want a force that is somewhat uniform on the thrust bearing, you first of all should use a thick spacer on the thrust washer thin race washer.? After the thick spacer disk which is flat you can use either a wavy or a Belleville cup shape washer.? Losmandy used a cup shaped Belleville spring in the CG11 Celestron G11 ...that's what came in my unit.? Later they switched to a wavy style washer.? Once you have the thick aluminum flat spacer on the thin thrust washer race disk, the type of spring washer on the other side cannot matter.
If you were to put the spring right on the thin thrust washer race disk, as the factory prefers, you'd be better off with the wavy washer.? But I can't support that assembly sequence.? I prefer the way Mark Crossley described in his website
Anyway, there are "bigger fish to fry" in the optimization of the performance.? In this case, the used mount was purchased missing a key part.? You just need to buy the part and you will be fine.? You can use the existing cup shaped Belleville or the wavy equivalent.? You want find any difference in practice.
The CG11 came with steel worms.? It came with two separate worm blocks.? If you replace the steel worm on RA with a new brass worm, new R4ZZ ABEC-7 bearings like these? ?
and if you add on an OPW, you will get better RA PE.??
You can have fun all along the way.? The mount is very strong and can support a 12 inch SCT.??
Have fun!
Michael
@Les Niles,??
My mount currently does not have "wavy washers."? It has true Belleville washers which Brian says are not supported by Losmandy.? I have therefore ordered a pair of Losmandy wavy washers?
They were so cheap that it was silly not to buy them.? Thanks for your input.? It swung my decision.
Pete
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Hey P.
That sounds good. Please make sure to check out our wavy washer video on our YouTube channel as well
@Les Niles,??
My mount currently does not have "wavy washers."? It has true Belleville washers which Brian says are not supported by Losmandy.? I have therefore ordered a pair of Losmandy wavy washers?
They were so cheap that it was silly not to buy them.? Thanks for your input.? It swung my decision.
Pete
-- Brian?
Brian Valente portfolio
|
@Les Niles,??
My mount currently does not have "wavy washers."? It has true Belleville washers which Brian says are not supported by Losmandy.? I have therefore ordered a pair of Losmandy wavy washers?
They were so cheap that it was silly not to buy them.? Thanks for your input.? It swung my decision.
Pete
|
Re: Gemini-2 momentarily went haywire
David,
Thanks for the info. Please see attached photo with board label. The chip you mentioned seems like it has a few dozen pins. I am capable on doing some fine soldering, but that many connections so close together would probably be beyond my skill level. Still I might risk it since the other alternative would be buying the whole board. Would you know the chip price offhand?
I have corresponded with Michael before on this and I don't think he does this with the G-2. I have previously checked all the cable socket connections to the PC board and they are solid.
Any further suggestions would be appreciated.
Thanks,
John
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David Malanick
Michael Herman
Pete
Russell Milton