Mach2GTO counterweight shaft stuck midway #Mach2GTO
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Has anyone ever tried teflon tape on the counterweight shaft threads? I have seen it used a lot in the chemical process industry. The most common use is on tapered pipe threads in stainless to stainless connections, but it is also used a lot on the threads of stainless steel compression fittings to make sure that they don't gall.
Teflon tape will prevent galling, but it will also increase the thickness of the threaded shaft. So, if the threads are a close fit as the Astro-Physics counterweight shafts typically are, then teflon tape could actually make the problem worse. Personally, like Chris Erickson's suggestion to use CLP. It is a little messier, but if you wipe the threads off and reapply it every once in a while, it does a good job. Mike |
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Brian Kaine
Hi Christopher M,
Thank you so much Christopher, but no apology is necessary! I was in no way offended by your remarks. I only intended to convey the fact that some techs do indeed use WD-40 in ways that others might not expect, and that in our lab there were never any detrimental effects from it. Many decisions are made at an institutional level; our people were given the freedom to use their own judgement. As professionals, that is something we both clearly understand! I would also add that our laboratory studied the molecular evolution of extremophilic bacteria, organisms that live in harsh environments such as hot springs and deep sea-floor vents. These critters posed no obvious health concerns; perhaps that was another reason that we had an easier time with bureaucratic decisions. I assume your work is in health care, an entirely different situation. I am glad to hear that Carl received his replacement parts so quickly. I live in Chicago and am less than a two-hour drive away from Astro-Physics. If I order something from them in the morning, I often receive it overnight. Carl's overseas shipment really hustled! Once again Christopher, no apologies are necessary. And I look forward to conversing with you again in the group! Take care, Brian |
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Christopher M
I want to appologise to Brian Kaine and his crew. After rereading my post it looks like I am deriding the Biomed techs he has worked with. That was not my intent at all. All the techs I know do the best they can with what they have and what they find works and doesn't work. I meant to point out that not all labs, especially bio labs, are free to use whatever, especially in the last few decades as regulations tighten up, depending upon what is being dealt with. For the lab I work with, SQuIPP is paramount concern. But I realised that my post came out harsher than that.
Again, my appologies Brian. Christopher |
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Brian Kaine
Carl,
That's great news! All the best, Brian |
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Carl Björk
I just received the replacement insert and shaft. I am impressed it came to my continent so fast.
Perfect fit, the threads are real smooth :-) I'll proceed gluing the insert with Loctite 271 and within 2 days I should be imaging! Well, at least I would be if the weather wasn't compliant to the "new gear" rule :-D Many thanks to George and Daleen, you are the best! Carl |
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Cheng-Yang Tan
If you try graphite lubricant, DON'T use this one: It actually got my CW shaft stuck because I *think* the film is thick enough to cause the threads to bind. And I thought I sprayed a thin film too ... cytan
On Wednesday, August 10, 2022 at 10:52:04 PM CDT, Christopher M <mirfak@...> wrote:
"On the other hand, when used carefully WD40 is marvelous stuff. I was a research scientist in a NASA funded biology lab for nearly twenty years. Our maintenance techs used it on ultracentrifuge spindles and rotor hubs as well as on scintillation counter sample delivery chains. Never had a bit of a problem. And of course, those guys had to know what they were doing. The replacement cost of those instruments was far beyond that of any mount Astro-Physics ever produced." I'm a Biomed Tech in a blood lab for a quarter C now and respectfully and in short, we are only allowed to use the lubricants and cleaners approved by the Mfr on our equipment (centrifuges, processors, extractors, etc). WD-40 is not one of them. The only time we use WD-40 at work is to remove gummy label and tape residue, and then only on some things (I do not respect people who use plain masking tape to hold down power cords), or to sometime free stuck parts. I heartily agree with Christopher E, Woody and others that while WD-40 has a lot of great uses, it is not a "Lubricant" but a "penetrant". It may lubricate in the short term, but once it dries up, it is the opposite of a lubricant. Personally I'm going to try a bit of parrafin wax or other dry lube (graphite?) on the threads of my new CW adapter and CW shaft. |
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Christopher M
"On the other hand, when used carefully
WD40 is marvelous stuff. I was a research scientist in a NASA funded biology lab for nearly twenty years. Our maintenance techs used it on ultracentrifuge spindles and rotor hubs as well as on scintillation counter sample delivery chains. Never had a bit of a problem. And of course, those guys had to know what they were doing. The replacement cost of those instruments was far beyond that of any mount Astro-Physics ever produced." I'm a Biomed Tech in a blood lab for a quarter C now and respectfully and in short, we are only allowed to use the lubricants and cleaners approved by the Mfr on our equipment (centrifuges, processors, extractors, etc). WD-40 is not one of them. The only time we use WD-40 at work is to remove gummy label and tape residue, and then only on some things (I do not respect people who use plain masking tape to hold down power cords), or to sometime free stuck parts. I heartily agree with Christopher E, Woody and others that while WD-40 has a lot of great uses, it is not a "Lubricant" but a "penetrant". It may lubricate in the short term, but once it dries up, it is the opposite of a lubricant. Personally I'm going to try a bit of parrafin wax or other dry lube (graphite?) on the threads of my new CW adapter and CW shaft. |
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Harley Davidson
Indeed I do use it Fernando. Works great. As long as there isn't
heavy dirt on the car though. For bugs I spray directly on them and
let it set for up to a minute. Then wipe right off with microfiber
cloths. I use it in between using "Glide" by Nanoskin Car Care
Products.
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tony On 8/10/2022 12:28 PM, fernandorivera3
via groups.io wrote:
Tony- furniture spray wax applied on your car? |
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fernandorivera3
Tony- furniture spray wax applied on your car?
Does it look like a haze after an application? Even if it does I suppose it's easy to buff out. Fernando |
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Harley Davidson
I use furniture spray wax on the threads every now and then. I keep
it in my car as I use it to clean the inside and even bugs on the
front of the cars bumper and hood. I let it set a minute or two on
the threads and then wipe the threads off. I bet you could also use
car wax although I've never tried it.
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tony On 8/9/2022 5:42 AM, Christopher
Erickson wrote:
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Cheng-Yang Tan
HI Carl, I'm not a mechanical engineer so, I'm probably using the incorrect terms like cross threading. I think the correct terms should be seizing or galling. After reading quite a bit of info and talking to the engineers and techs who work with me, seizure or galling of stainless steel on stainless steel will happen because surprisingly, it is considered soft:
Any deformation of the stainless steel can cause seizing/galling. So even if the counterweight shaft was perfectly made and you're careful threading, it can still happen because of deformation. One solution is to use a harder steel or different material for the insert so that galling is prevented. My engineer colleague suggested silicon bronze for the insert, but other materials can work as well. cytan
On Tuesday, August 9, 2022 at 05:09:19 PM CDT, Carl Björk <carl.bjork@...> wrote:
Hi Tan, ( <-- I hope I got this right :') ) |
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Carl Björk
The fact that the screwing went fine first then resisting then fine again and repeating this pattern is not consistent with cross threading. On Wed, Aug 10, 2022 at 12:23 AM, M Hambrick wrote: I agree with Cytan that a bronze insert would be ideal, but I also agree that stainless is better than aluminum. All it takes is one slipup with the aluminum threads and they are toast. |
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fernandorivera3
I have an AP 1200 GTO from July 2009 delivery & a few months ago I replaced it's original counterweight shaft adapter for the brand new one with the stainless steel insert.
Of course when I threaded in my original counterweight shaft into the brand new adapter, after a few turns the thing got stuck on the insert threads. I'm glad I was able to separate the two as this actually happened immediately before taking off to a favorite dark sky site for the 1st time in a long while <thanks to Covid 19 concerns regarding long distance trips>. Anyways if this problem of the shaft seizing up against the stainless steel insert happens again [especially if it becomes a repeating issue] then at the very least I still am holding on to my old school adapter, just in case... Fernando |
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I agree with Cytan that a bronze insert would be ideal, but I also agree that stainless is better than aluminum. All it takes is one slipup with the aluminum threads and they are toast.
As for your predicament Carl, I am glad to hear that Astro-Physics is working on a solution. Maybe I was looking at it wrong, or the angle of the camera distorted the view, but it looked in the picture that you sent like the shaft was cross threaded. Mike |
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Carl Björk
Hi Tan, ( <-- I hope I got this right :') ) |
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Cheng-Yang Tan
Hi Carl, The mechanical engineers and techs that I work with have extensive knowledge of stainless steel. We work with stainless steel everyday because it is used for high vacuum. Stainless steel bolts and nuts seize easily unless we use "never seez" compound which is a mess. Instead we prefer to silver plate all the stainless steel fastening hardware to prevent seizure. Anyway, I had started a thread about this problem a year ago and got some info about how to mitigate this problem. See this link: Anyway, I agree that having an insert is a good idea, but a change of material will certainly lessen or eliminate the cross threading problem. cytan
On Tuesday, August 9, 2022 at 04:29:59 PM CDT, Carl Björk <carl.bjork@...> wrote:
Hi, Looking forward to share great things with my Mach2 ;-P |
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Carl Björk
Hi, Looking forward to share great things with my Mach2 ;-P |
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Brian Kaine
Hi Woody,
That may be true; I've never experimented that way. On the other hand, when used carefully WD40 is marvelous stuff. I was a research scientist in a NASA funded biology lab for nearly twenty years. Our maintenance techs used it on ultracentrifuge spindles and rotor hubs as well as on scintillation counter sample delivery chains. Never had a bit of a problem. And of course, those guys had to know what they were doing. The replacement cost of those instruments was far beyond that of any mount Astro-Physics ever produced. Of course I would never suggest using it on delicate electronics or optical surfaces; that's nonsense. But on the threads of a counterweight shaft; absolutely. All the best, Brian |
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Woody Schlom
Here’s a fun thing to do with the original WD-40 that will prevent you from ever using it again on delicate things or locks – or anything other than what it was originally designed for – rust prevention on U.S. Naval ships.
Find an old metal tool (preferably a bit rusted) – hammer or screwdriver for example. Spray some original WD-40 onto a rag and wipe the tool. Lots of rust should come off. Wipe it again until the tool is nice and wet and shiny. Hang the tool up where nothing is touching it. Leave it for a month or so in a hot garage.
After a month or so, examine the tool again. If it’s been warm enough, I think you’ll find that the WD-40 is now a SOLID coating – just like varnish. That tool will never rust any more – but think about what would have happened if that now hard varnish coating was inside a lock – or clock – or mount?
And yes, I do use it to coat old rusting tools and machinery. And it works super well.
Woody
From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Bill Long
Sent: Tuesday, August 9, 2022 2:55 AM To: main@ap-gto.groups.io Subject: Re: [ap-gto] Mach2GTO counterweight shaft stuck midway
Agree with Chris here.
Spit is probably better than WD40. From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Christopher Erickson <christopher.k.erickson@...>
NEVER use WD-40 on ANY part of a telescope or mount. It is a PENETRANT, NOT a lubricant. It penetrates into everything. It dissolves and ruins real lubricants, it can ruin optical coatings, it can ruin circuit boards, and it can actually accelerate corrosion.
A drop of LUBRICANT in counterweight shaft threads is good. Cleaning dirty, contaminated threads with a toothbrush is good. And doing both is even more goodness. LOL.
Using a [slightly oily] rag to clean shaft threads before assembly might do the trick as well. Place rag around threads, grab rag and threads and then "unscrew" the threads from the rag and your hand.
If your threads are really dirty with something that is really stuck to them, a metal brush and some Break-Free CLP might be required. Followed by the old "unscrew from an oily rag" trick. (Nod to Don Adams.)
Currently my favorite lubricant is Break-Free CLP (the older brown formula over the newer blue formula) but there are lots of good lubes out there for various applications.
On Mon, Aug 8, 2022, 11:18 AM Brian Valente <bvalente@...> wrote:
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fernandorivera3
I agree with Cytan 💯%
Fernando |
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