Torque spec for the screw that holds the clutch assembly together

[michael8554]

"Tighten it down really tight and it won't impact motion, and also Don't over tighten it or it won't move."

No.

One or the other depending on the design, which I don't know.

Bearings like this are seated by pressure on the outer race.

With a suitably sized socket resting on the outer race.

Then a hydraulic press, or careful hammering.

Or a long bolt and nut through the socket and bearing and mount, drawing the bearing in by tightening the nut.

A Nylok locknut should work when finally assembling.

Michael

 

 

[rpdayton]

29 minutes ago, AstroKeith said:

which means the gears on the other side are not meshed correctly which will seriously damage them.

I think that is the answer to my question right there, assuming the bearing isn't seated properly like most have suggested - It's been this way since we got it (5 years ago at this point) and I have tried literally hundreds of alignments since then.  To be fair, it may not be a full 5 years; I went through about 6 months of tech support emails after we got it before I finally just said screw it and took it apart, when I saw the loose nut, so more like 4 and a half years since I first actually saw it was loose.

But either way I'm thinking based on the replies to the pictures after this long it is probably going to need more than just a new nut.   I'm not too worried about replacing the bearing, Timken is one of our customers... I'm sure I could talk them into a freebie.

But at this point, I've sank more money into it getting eyepieces and adapters and collimators and so on...  I'm not interested in finding and replacing gears as well, and undoubtedly the drive motor won't be far behind.

I was hoping just getting the nut tightened down correctly would allow it to work better, but it sounds like this bearing may be causing more issues than it's worth.  This may just be posted as a curb alert at this point. 

Sorry, this is just really disappointing. I end up in a sour mood every time I get it out, this time is no exception.  Anybody in SW Ohio want a scope to use for spare parts lol?!

[rpdayton]

Apologies all. I know you are all trying to help; I shouldn't post when I'm frustrated.  This thing has been disappointing since we first got it; it's a little upsetting to think I need to keep putting time and money into it just to (hopefully) get it working. Until I find the next thing that needs fixed or replaced.

Maybe I'm just hangry!

[Cosmic Geoff]

As I said, I have not dismantled one of these so I don't know what this is supposed to look like. Did you get the mount from new? If not, one suspects that somebody has been in there and messed with it. 

If others say the nut should be Nyloc, then get one - it does not need to be special so long as it has the right thread.

If you have engineering skills, it might be a good idea to strip the mount down and then figure how it is supposed to work.

Rather than sell the mount for parts ☹️ it might be smarter to buy a SLT mount that somebody else is selling for parts, and swap (or copy) the relevant subassembly.

[Ricochet]

21 minutes ago, rpdayton said:

Apologies all. I know you are all trying to help; I shouldn't post when I'm frustrated.  This thing has been disappointing since we first got it; it's a little upsetting to think I need to keep putting time and money into it just to (hopefully) get it working. Until I find the next thing that needs fixed or replaced.

Maybe I'm just hangry!

I don’t think you’ve got anything to apologise for, this is all on Celestron. Assuming you bought it new, they should have examined and replaced the mount when you contacted them. Did they ever see a photo like you’ve shown us? I doubt they will do anything after this time but I would still be inclined to go back to them and say this is the fault that has existed since purchase, here are all the support emails from that time, what will you do about it?

[rpdayton]

21 minutes ago, Cosmic Geoff said:

Did you get the mount from new?

it might be smarter to buy a SLT mount that somebody else is selling for parts,

Yes, we bought it from Celestron as a christmas present for our son.

I'm not going to buy more parts for it. After all the crap we've purchased for it trying to get it to work, I really can't see spending any more money on it. Like I mentioned before, replacing the bearing will likely reveal that the gears need replaced, and then who knows maybe the drive motor as well. I don't know where it will end.  Our son is at college and hasn't shown any interest in it after the first 6 months he had it; I only get it out from time to time thinking it would be nice to get it working, but if I have to spend any more on it I think we'll just get a cheap refractor scope like I had as a kid... at least those can be manually pointd at the thing you want to look at and can be focused without pivoting toward the ground!

Again - apologies for being grumpy about this; I really should not post when I'm frustrated.

 

[rpdayton]

22 minutes ago, Ricochet said:

I would still be inclined to go back to them and say this is the fault that has existed since purchase,

I told them about it 4-6 months after we bought it, both tech support and then in a review on their site.  This was back when every question to them was answered with "Don't adjust anything, alignments are hard and the instructions are very difficult to understand, just keep practicing util you get it."

They never asked for pictures; it didn't sound like they thought the loose nut was a problem.  I don't remember what the warranty on it was, but it certainly is long since passed. I just assumed it was a lack of practing or getting it set up accurately on my part; but the more I saw pictures that other people are getting with theirs I started asking on reddit (downvotes cause I can't figure out how to align) and twitter (a few people gave me instructions on how to align) and ultimately on here.

I appreciate the assistance, I really do, but yelling at them after this long doesn't really appeal to me. 

[rpdayton]

For completeness.. 6 years ago, not 5.  I was looking through the emails back and forth from tech support.  We bought it in late 2017, the tickets spanned the end of the year.  I've been writing this thinking we *bought* it in 2018, but that was the most recent time I contacted them.  My bad.

[Cosmic Geoff]

2 hours ago, rpdayton said:

Like I mentioned before, replacing the bearing will likely reveal that the gears need replaced, and then who knows maybe the drive motor as well. I don't know where it will end. 

Sir, you are clearly a pessimist. 🙂  If you bought a faulty mount for a few dollars, you would probably find it had faulty electrics (which seems to be the most common problem - I had to reprogram the firmware in my SLT twice)  and perfect mechanical parts, so you'd just have to swap some circuit boards over to get a good mount.  My SLT has worked OK for over 8 years asides for the firmware becoming corrupted a couple of times.

But it's up to you. Clearly these mounts don't cost much to manufacture - just look at what little is inside - two motor-gearbox assemblies (identical), a circuit board or two and some wires.

[rpdayton]

1 hour ago, Cosmic Geoff said:

Sir, you are clearly a pessimist. If you bought a faulty mount for a few dollars...

Please understand...  I didn't buy a faulty mount for a few dollars. I bought a $700 telescope.  This was a huge expense when we bought it, but it was for our son and wanted to get him something better than the $50 refractor scope I had as a kid.   He lost interest in it after the first 6 months.

When it wouldn't align, I relied on celestron's tech support to troubleshoot the cause.

"Make sure the tube is level before aligning."  Okay, there's a bubble level on the tube, I assume that's close enough. But to confirm, bought a dovetail adapter to hold a machine level we use at work.  Absurdly accurate to a few microns per meter. "You don't need to make it THAT level. Just use the bubble level on the tripod."  Okay, but I DID make it that level, and it didn't solve the problem.  Isn't that still a valid result?  Nope, you need to practice aligning because the instructions are real hard to follow.

"Use a 20mm eyepiece to align with, not the 25mm or 9mm that came with it."  Bought a 20mm eyepiece, complete with reticle.

"Make sure the power supply is good."  Bought a new 12v power supply.

"Make sure the tube is balanced."  Fair point.  Out of the box, it was very tail heavy and would insist on drifting upward at the slightest touch, or if slewing too fast.  Spent an evening finding the balance point with every combination of hardware I could imagine... single eyepieces, eyepieces in the 2x barlow, camera+adapter, a zoom lens we got. This was before I found the loose nut.  Now, I can pretty much get it at 3oz or less tail heavy without much trouble.  It starts to drift upward at about 6 oz, depending on how tight I make the nut.  No expense, just another disappointing trial because that didn't solve the problem.

"Might need collimated."  Bought 2 collimators; wasn't sure if the first one was accurate, so got a higher quality one next.

I also confirmed time zones, lat and lon, time to within a second... Updated the firmware (tricky in a non-windows house lol) I'm sure I'm leaving a few steps out.  By this time I was getting suggestions on another forum that his since disappeared, so had also moved the mirror all the way in (had to re-set all the balance points) and all the way out (had to reset the balance points,) considered buying a bluetoothe adapter... that's when we stopped wanting to keep spending money on it.  

During all of this, I'm spending 2-3 nights a week outside for 3 and 4 hours, making zero progress.

Found this screw loose.  Told celestron.

Reported loose screw to celestron in a review.

No answer from celestron. (Review is still up, too.)

Now it sounds like it needs a new bearing.

Also sounds like the gears might be borked as well.

I'm guessing the motor is probably going to need replaced, if the bearing is bad and not seated right, then I'm sure that puts a horrible load on the motor.

It never ends with this, and I'm honestly just disgusted with the thought of putting more time and money into it.

I'm not trying to be rude, I honestly was having kinda good luck with just keeping the nut snug, but this is just another expense that will likely reveal yet another thing to replace... I'm really just done at this point.

Thank you again for your help, sorry if the answer I was asking for isn't one I'm wanting to hear.

[Cosmic Geoff]

15 hours ago, rpdayton said:

Like I mentioned before, replacing the bearing will likely reveal that the gears need replaced, and then who knows maybe the drive motor as well. I don't know where it will end. 

Your discouragement is noted. Seems that you have been a victim of a syndrome we have seen before here, where, for whatever reason, the seller develops a particular opinion of the situation and fobs off the hapless buyer with cut-and-paste advice. 

Others should note that the best response in this situation may be on the lines of: This is faulty. Replace it under warranty or refund me or you will hear from my lawyer. 

[StevieDvd]

Based on your comment on leaving it out on the street, then my reponsse would be to try getting the bearing back in place (if it does not look completely ruined) and see if it works. If it's just for visual use and the goto/alignments are near enough then perhaps it will do for a while.  Other than that if a new bearing is only a few dollars you could try that or sell it for spares/repairs.

 

[rpdayton]

Thanks again everyone for looking at this and confirming my suspicion that the loose nut was the problem all along.  And/or a messed-up bearing.

I notified celestron, included a link to this thread, they can do whatever they want with that info.  I would think they'd add a page to their tech-support flow chart that says "if a nut is loose it might cause alignment issues" but my guess is they'll ignore it and just keep telling people "alignments are hard. keep practicing." Whatever.  I'm done with it and with them.

Happy stargazing all.

[doublevodka]

On 21/09/2023 at 15:04, rpdayton said:

Sorry for sporadic responses; I'm in training at work this week, so bouncing back and forth between this forum and our latest cadcam system.

Suggestions I'm receiving:

Tighten it down really tight and it won't impact motion, and also Don't over tighten it or it won't move.

Currently it is just finger tight against the race, and it is already making it harder to move in Alt. I can go a little tighter by hand and it becomes very difficult to move the alt axis. I think if I actually put a wrench on it it will sieze up the entire assembly.  When I first found the loose nut, I gave it about a quarter turn past where it is now, and it became very difficult to move in alt, atleast 2 lbs at the end of the tube.  I tried it tightened down to about 1 lb, and had better luck, but it didn't last long.  (Last time I balanced the tube in the dovetail with the nut appx as tight as it is now, it will move in alt with about 6oz at either end of the tube.)

 

The bearing needs to be seated differently. I'm a little nervous about banging on it even with a piece of wood, it seems like as delicate as it is that would cause some damage if not extremely careful.  Followed by, I can't get it to move any deeper just squeezing it by hand; it feels like it seats pretty securely where it is.  If I need to completely disassemble it, would it be better to use a shoulder screw that has a diameter close to the ID of the bearing, and try drawing it in using a nut?  Just a thought; I know I asked for help and shouldn't dismiss any suggestions, but I'm nervous about damaging anything.

 

Someone (@doublevodka) posted a picture showing a similar mount with a nyloc nut instead of the one that mine has; is there a specific nut that is used for this, or is something from home depot good enough?  And also, several replies suggesting using loctite instead of a locknut; is that a common fix for this?  Again - I just want to make sure I'm not causing any damage going through this.  Loctite seems like a good way to make a bad situation even worse.

I know there have been many posts since this, I'd urge you not to give up hope though. You are closer than you think to resolving it, so hopefully I can be clear enough below to get you up and going 🤞 it will be a very minor spend, maybe none at all if you are a bit of a hoarder like the rest of us 😂

Firstly to to bearing, totally appreciate you not wanting to hit it with a hammer. Remove the nut and the altitude assembly should slide out the other side, you then need a bolt long enough to slide right through, a couple of washers and a suitable nut. Put the bolt through from the altitude assembly side with a large washer installed to spread the load, then add another large washer at the bearing end, then the nut (doesn't need to be a nyloc at this point and probably easier if it isn't). Tighten slowly and the bearing should level out and push into it's correct place.

Then reinsert the altitude assembly and reattach the now nyloc nut, bear in mind that the assembly is not designed to be moved by hand, it's designed the moved by the motors, so power on, try moving with the controller rinse and repeat. It's going to be a little more than finger tight as it's a nyloc, but effectively it's just holding the alt assembly in place so doesn't need to be crazy tight, really sorry I can't be more specific.

As for the Celestron side of support, I really appreciate your frustration, have worked in IT for many years so that means dealing with equally frustrating service/tech departments regularly, it is rarely a fun experience to put it politely, thankfully online communities like this exist to fill in the gaps 👍

[rpdayton]

Jesus. 

$50 for a motor, and needs to have a new control board for it for another $150 (so why not sell them as a set if you have to get both?)

And that's just the alt. Hopefully the az drive isn't in the same condition. 

And no price for the bearing, (pretty sure I could get one though)

No price for the gears, (no idea where to even look for those if not celestron)

And that's just them sending the parts directly to me.

 

Nope.

 

Lesson learned. 

Maybe banging on it with a hammer would be a good way to work out some frustrations though.

Unbelievable. 

[LandyJon]

I've watched this thread with sympathy hoping you got it solved.

I've read some very good advice diagnosing your primary issue to be a mal-seated bearing and incorrect nut and solutions to remedy it with little to no cost.

I've seen recent replies and thought oh maybe he's getting somewhere, let's see ... oh he seems to be ranting at the people trying to help him.

Doublevodka has explained how to press the bearing in with a long bolt and washers or a socket as michael8554 suggested last week.

Is the motor dead ?

Is the control board dead ?

Are the gears knackered ?

Is the AZ axis loose with a mal-seated bearing and a loose nut ?

If you want to rant at Celestron support, I'm sure they've got plenty social media to vent your frustrations at.

If you want community support, you've been given it, come back when you've tried it and it worked and you're in a happy place again 🙂

If it doesn't work, come back and ask what the next step would be, or just take a hammer to it and move on with your life.

No offence but that last rant didn't even look like you'd read doublevodkas reply, it certainly gave no thanks for it, I guess courtesy is a commodity these days.

[rpdayton]

You are correct,  I did read his reply but ignored it,  I had just been given the news from celestron that it will be an additional $200 in parts, not even the parts I need at this point, just the parts that are likely also in need of replacing... because of the 6 years of use with a loose nut that is not just a loose nut, but a poorly assembled bearing. It is more than upsetting at this point, and I apologize for my outburst. 

I was able to knock the bearing out to try seating it correctly. There is a small lip in part of the bore, the bearing had been driven in at an angles,  likely by being inserted crooked. The aluminum deformed to match the bearing, so it wasn't able to fit in the right way just by me tightening it up by hand. In hindsight this explains a lot.

I was able to get it straighter, but I can't get it all the way flush without damaging it. It's clearly fighting the 'puckered' metal. The shoulder screw just drops right through now, I was expecting a tighter fit I guess, but it goes right on in.

It is nearly impossible to get the nut tightened 'just right,' I got it close and was going to give it a test, but when I plug in the control it says "No response 17"

This is new, but I think it's been 2 years since I last had it plugged in, so I figured I would go through the troubleshooting steps... updated the firmware, double checked all the connectors. No change.

Who knows.

[rpdayton]

And again,  my apologies. Everything we've done with this since it was new has been "just one more thing" to try and get it working.  It's tiresome and it just sucks that this is what we spent our money on. 

It has turned me into a bitter ******* that gets worked up every time I get it out.

It is not kind of me to ask for help and then bark at those who offered that help. I a m sorry to you all.

[doublevodka]

On 26/09/2023 at 02:31, rpdayton said:

And again,  my apologies. Everything we've done with this since it was new has been "just one more thing" to try and get it working.  It's tiresome and it just sucks that this is what we spent our money on. 

It has turned me into a bitter ******* that gets worked up every time I get it out.

It is not kind of me to ask for help and then bark at those who offered that help. I a m sorry to you all.

No problem at all, totally appreciate the frustration, especially with the significant investment at the outset and the lack of aftercare from Celestron.

Parts are expensive, there's no getting around that unfortunately, I was in a similar place with a Nexstar 4SE mount that wouldn't power on a while back, but I managed to diagnose a switch issue and bodge together a fix.

Assuming the optical tube assembly is ok, there are options though, the used market is pretty good for SLT mounts or even others for example a Skywatcher AZ-GTi if you really want to get back into the hobby

I'm not sure where in the world you are, assuming US because of $ but here are some links to classified ads that may help if you want to go down that route https://astrobackyard.com/astronomy-classifieds/ may cost around the same as the parts, but at least you'd have something from another astronomer that is known working and that can be worth its weight in gold

There are other options like pipe mounts and dobsonian mounts that are also popular in the US and can be built cheaply if you want to avoid complications and electronics too.

Best of luck in whichever route you take 👍

 

[rpdayton]

Thanks for the info; I never considered mixing and matching mounts and tubes.

I'll check it out.

I was also given a link to a 'build-your-own-dobs' site last night.  I guess I didn't realize how easy it would be to just get a completely different tripod/mount.  My weekly 'duh' moment I suppose.

[doublevodka]

16 hours ago, rpdayton said:

Thanks for the info; I never considered mixing and matching mounts and tubes.

I'll check it out.

I was also given a link to a 'build-your-own-dobs' site last night.  I guess I didn't realize how easy it would be to just get a completely different tripod/mount.  My weekly 'duh' moment I suppose.

I've got a weird selection of scopes that I use on my AZ-GTI, the original skymax 127 that came with is, an Orion Starblast 4.5 that I've added rings and a dovetail to, a Celestron 102 GT (that one is very rarely, it's really too long for the mount) and a Helios short tube 120 refractor. As my wife says, too many telescopes 😂

There are loads of options for mounting, your scope will have a standard Vixen dovetail bolted to the tube I suspect, so an alt az mount would be best, there are many, many options 👍

Edited September 28, 2023 by doublevodka

[rpdayton]

18 hours ago, doublevodka said:

There are loads of options for mounting,

Thank you.  After 6 years, I still feel like a complete novice at this whole activity/hobby.; I've never gotten comfortable enough using this one to even begin exploring options. I've got about 6 months before next year's eclipse; we're smack in the middle of totality.  Maybe by then we'll get something!

[Bugdozer]

On 19/09/2023 at 20:28, rpdayton said:

Most of the time it would miss it by >30° in Alt, often times it wouldn't even end in the correct hemisphere of the sky.  I gave up trying to goto specific stars almost immediately, as it will rarely goto even one of the alignment stars it just aligned to.  I started using the moon only as a sanity check... if the moon's high in the east, and the scope points at the ground after a goto, my assumption is that it isn't going to the correct location.  In hindsight, I assumed it would be able to find the moon's location very easily; I will stick to stars. (That would also explain celestron's tech support telling me to absolutely not use planets for alignment even though the manual says that's acceptable.)  My second reason for choosing it is to easily ensure it would track an object after a successful alignment, but that is something I've never been able to get working.

OK this might be a very off the wall suggestion, but I actually got caught out with this on my Celestron go-to... Are you entering the date in American format? Mine requires that. Otherwise it gets confused either just a little bit, or a huge amount. What you describe here sounds like it might be the same problem, rather than the screw. 

[doublevodka]

15 hours ago, rpdayton said:

Thank you.  After 6 years, I still feel like a complete novice at this whole activity/hobby.; I've never gotten comfortable enough using this one to even begin exploring options. I've got about 6 months before next year's eclipse; we're smack in the middle of totality.  Maybe by then we'll get something!

You're not the only one, I think many of us feel the same no matter how much experience, SGL has been an absolute godsend for me, learned so much from this forum. And now I know you are definitely in the states by the eclipse 😂

As an absolute minimum, you need to get some eclipse glasses, if you do get a mount etc then a white light filter would be good too - https://www.firstlightoptics.com/solar-filters/page/0/