Very cold weather tracking problem
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Hi Bob,
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When was the last time you regreased the mount? Grease starts to break down over time, and starts absorbing moisture from the atmosphere. When temperatures fall below freezing, grease becomes harder and can cause binding.?
Regards,
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? ?-Paul
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On Fri, Jan 24, 2025 at 08:50 AM, Robert Kesler wrote:
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开云体育If you adjusted the worm mesh at “room temperature” or even 32F, the worms will bind on the worm wheels at 10F or maybe even at 15-20F. ? You’ll need to adjust the mesh in the cold, not in the comfy warm room! ? D. ? From: [email protected] <[email protected]> On Behalf Of Robert Kesler via groups.io
Sent: 24 January 2025 13:51 To: [email protected] Subject: [Gemini-II_io] Very cold weather tracking problem ? >I tried adjusting the worm gears and still had the same issue which I have never had in the past? 9 years. |
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On Fri, Jan 24, 2025 at 11:09 AM, Robert Kesler wrote:
Bob, if you are going to re-grease the mount, I suggest you use the Losmandy's recommended low-temperature grease: ?/g/Losmandy_users/message/81238
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You can also get the full kit for re-greasing the mount from Losmandy:
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Regards.
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? ?-Paul
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On Fri, Jan 24, 2025 at 08:09 AM, Robert Kesler wrote:
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Only the very cheap, poor excuse for grease known as white lithium grease is really susceptible to breaking down and drying out and turning into the nasty hard powder that gums up precision machinery. Almost any modern fortified grease based on a pure synthetic base oil will not dry out and leave that hard crusty stuff behind to gunk up the works and has a much higher level of lubricity.?
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The lubricant kit Losmandy offers is very solid stuff and will not breakdown much if at all over long periods, stiffen excessively in the cold or run off in the heat.? The Losmandy grease kit is generally thought to be one of the best all in one options.? There are other greases out there that offer higher performance but they would require you to buy research and buy them in quantities you don't need.? So my advice is to go with the kit and be happy in the knowledge it is very good stuff.??
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I also have advised people with the classic Losmandy drivetrain (straight line steppers or servos without spring loaded worms) to put their mounts outside in the cold for a few hours before setting the backlash and to ignore the alarming amount of warm room backlash for maybe going on 9-10 years.? The reason is that aluminum has double the material contraction of steel and brass is somewhere in between.? The basic Losmandy mechanical design will keep contracting as the metal gets colder and vice versa which makes any warm room backlash setting basically disappear in the cold.?
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Whatever you do do not use white lithium grease, it is a poor lubricant for this application. ?
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric - South Pasadena, CA? |
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On Sat, Jan 25, 2025 at 11:14 AM, Robert Kesler wrote:
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Hi Bob,
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I used to be a Doc Clay advocate many moons ago when I bought my first LX200 back in early 1992.? But he changed.? After buying a scope a few years ago that Dr. Clay advertised that he repaired, tuned and was in pristine condition I opened the box to find an 8" LX200 ACF OTA that was trashed and broken.? I emailed Dr. Clay and had to go round and round with him for months and then having to lose a significant percentage of the cost of the scope AND pay the return shipping to him I have put him on my blacklist and tell people to stay away.? It is a very long story and I have all the emails where he accuses me of damaging the scope myself and the emails where he was abusive and in fact sounded like he was mentally ill.? Ultimately I ended up eating not only the cost of shipping both ways and a restocking fee I had also purchased several new accessories which I was now out of luck on unless I could find the same scope at a time they were in high demand used.? It took me two years of looking to find a scope that was in the pristine condition the scope I bought was supposed to be in.? I bought it and it was a great used scope and a smooth transaction just like virtually 100% of my used gear purchases are.? I still love that late model Meade LX200?8" ACF?in Meade Blue Crinkle coat scope today.? I just took it off my side-by-side rig on the G11G to mount the little Takahashi FS-60Q to partner with the fully optioned ASIAIR Plus imaging rig behind an Askar FRA500 which BTW really is an impressive imaging optic.?
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Anyway... the Losmandy website is a mixed bag and it helps to be familiar with the odd way the old information site and new store sites mate.? So here is a link for you to see the official .? Just order it and it will arrive in the mail as if by magic!??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric - South Pasadena, CA? |
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It's more complicated than does it work when very cold or hot.? While an antiseize paste like MP-50 can reduce the chances of metal parts seizing under pressure better than a general purpose lubricant that's not the lubricant profile needed for precision machinery.? For example I don't see Rolex using MP-50 to lubricate their precision watch movements.??
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So because this application is not a drilling rig or high pressure undersea valve in this application there is more to lubricant performance than just having a wide operating temperature range and very high anti-seize characteristics.? In this application, lubricating a precision machine operating at low speeds and moderately light loads only intermittently there are likely other more important characteristics that need to be weighed from any lubricant choices.? ?
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For example how well it actually lubricates, how well it maintains the same starting torque as temperatures vary and how well it maintains viscosity within the normal temperature range for the application.??
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To choose a lubricant for this application a more nuanced look at lubricants is probably needed.? This will be difficult because to really compare MP-50 to almost any other high quality grease for a precision application there is virtually no relevant information in the MP-50? technical data sheet other than operational temperature range and a 4-ball test.??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric - South Pasadena, CA? |
Paul Kanevsky
David C. Partridge
Chip Louie