Topics

Exos2 Something majorly wrong #EXOS2

Trevor B
 

Hello everyone.  First time posting here.

I'm thinking something has happened to the RA on my mount.   I was out tonight trying to work on setting up my guiding correctly and things were going nice and smooth until I slewed the mount to another part of the sky when I finished my calibration.

I did notice a little noise coming from the mount as I slewed from near the celestial equator back to the Capella area in the north/northwest.  And when I started guiding again the RA was off the charts in PHD2.   In fact the RA never even had a line in the graph and when I stopped the guiding  it was at 28.84" on the RA.  

At this point, I parked the mount and shut everything down..  That's when I noticed that the RA was extremely stiff and not moving freely like it normally does.

After the mount was inside for a while I looked at it again and it's still super stiff.

I'm up in Alberta, Canada and I'm wondering who do I talk to about possible sending this mount in for warranty if its needed?  

AstroObsessed
 

This happened to mine as well, had to send it back twice. Haven’t used it since I got it back but will be trying it out soon. 

If you open a support ticket on the Explore Scientific website they’ll take care of it.

On Sat, Oct 12, 2019 at 4:44 AM Trevor B <tjb0666@...> wrote:
Hello everyone.  First time posting here.

I'm thinking something has happened to the RA on my mount.   I was out tonight trying to work on setting up my guiding correctly and things were going nice and smooth until I slewed the mount to another part of the sky when I finished my calibration.

I did notice a little noise coming from the mount as I slewed from near the celestial equator back to the Capella area in the north/northwest.  And when I started guiding again the RA was off the charts in PHD2.   In fact the RA never even had a line in the graph and when I stopped the guiding  it was at 28.84" on the RA.  

At this point, I parked the mount and shut everything down..  That's when I noticed that the RA was extremely stiff and not moving freely like it normally does.

After the mount was inside for a while I looked at it again and it's still super stiff.

I'm up in Alberta, Canada and I'm wondering who do I talk to about possible sending this mount in for warranty if its needed?  

--
Thank you, Samuel Amos

--
Samuel

Newmarket, ON, Canada

Mount: ES EXOS2 W/ PMC8

Scope: Orion 8" Astrograph

Cameras: Canon T3i, ZWO ASI120MM Mini, RisingCam IMX224

 

 

Trevor,
 
Another Ontarian here... :-)
 
The problem you describe with PHD2 just sounds like gear binding.  That's an easy DIY adjustment, if you're comfortable with that.  
 
As Samuel said, ES customer service is very helpful. I've done this as well. Just open a case online, and then give them a call to discuss. 
 
If you're up for a DIY adjustment, or just want see what would be involved in one, have a look at my tuning notes:
 
https://espmc-eight.groups.io/g/MOUNTS/files/EXOS2PMC8_TuningNotes_v1.pdf
 
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Trevor B
 

Thanks very much for the replies.  Will me doing an adjustment or inspection myself void the warranty?  

I downloaded your guide Robert, it's very well written and likes quite easy to tackle.  I think I might at least open it to inspect it to see if anything got damaged.

Before the RA tightened up it actually had a little bit of play.  With the RA clutch locked you it would a little but left to right.

My dec backlash also isnt the best as when PHD2 makes south steps, it always comes up with little to no movement and the star barely moved on the screen, but north steps are always decent.

I seen tour notes about the tripod leg and I'm glad I'm not the only one. Before this happened last night I was actually going to get in touch with them about a replacement tripod as mine is like you said, about an inch further out than the other 2 legs.

Trevor B
 
Edited

Also Robert, I see you mention making sure you remember the position of the pulley and belt in the gears.  Why is that exactly ?

Jerry Hubbell - Explore Scientific VP Engineering
 

On Sat, Oct 12, 2019 at 11:53 AM, Trevor B wrote:
Will me doing an adjustment or inspection myself void the warranty?  
Hi Trevor,

Explore Scientific supports our customer's efforts to maintain their equipment and provide help in that regard.  Additionally, we support and enthusiastically recommend that the user community shares information on how to best use and maintain your equipment. The warranty will not be voided by you maintaining your equipment. We provide warranty coverage based on workmanship and defects from the factory. We do not provide a warranty on unauthorized repairs. Here is the text of our warranty (Full Warranty page) https://explorescientificusa.com/pages/warranty-1

"This warranty is not valid in cases where the product has been abused or mishandled or where unauthorized repairs have been attempted or performed. EXPLORE SCIENTIFIC specifically disclaims special, indirect, or consequential damages or lost profits, which may result from a breach of this warranty. Any implied warranties that cannot be disclaimed are hereby limited to a term of one year from the date of purchase by the original retail purchaser."
 
I want to make it clear that normal mount gear train adjustments are considered an "authorized" repair under the terms of this warranty.
But, the warranty is only valid if you have registered your product within 60 days of purchase.


This means that we maybe could consider any adjustment on equipment that has not been registered as "unauthorized", but we have not taken that stance in the instances I am familiar with over the past couple of years. In fact, we bend over backwards to help our customers get the full benefit of their warranty, even covering instances where people have bought their mounts second-hand from third parties. 


Suffice it to say, I would strongly suggest that anyone that has not registered their equipment do so at your earliest convenience. Here is the product registration page: https://explorescientificusa.com/apps/product-registration

 
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

Trevor B
 

Thanks for chiming in Jerry and thanks for the info.  I also registered my mount within the first few weeks of purchasing.  

I'm going to start taking things apart later this evening.   Kind of excited to see its inner workings, just wasnt planning on doing it so soon haha   Hopefully everyhting is in tact.

I'll report back if I see anything abnormal.

Thanks again 

 

Just caution, and as a bit of a before-image benchmark.  

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

 

Re: the tripod leg...  Regarding Jerry's point about modifications, you might ask about that if you call ES CS and see what they say.  
If you saw my notes, you know that the field mods to fix it aren't hard, but one of them does involve putting file to metal. 
I never did think to try switching the legs around, so no idea if that helps or not. 

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Trevor B
 

Robert, 

I think I'm going to take permanent marker and just make a little mark on the edge of the pulley where it lines up with a specific mark on the belt to be safe.

Thanks again,  I'll be home later tonight and I'm going to get in a little further. I took the gear housing off before I left this morning and thats where I left it. 

Will update later.

 

Trevor,

I wasn't trying to convey that the stop-and-take-a-picture step had any functional use - just something that would be a reference for the reader if they wanted that.
Any given belt tooth should be able to engage any given pulley tooth, so mark if you like, but if the marks don't line up when you're done, it's ok.


--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Trevor B
 

Well that was alot less frightening than I thought it was going to be lol  Everything came apart easily.

I ended up wiping all the grease off the worm gear and partially on the RA gear so I could get a good look at the teeth.  Nothing appears to be damaged as far as i can see.

As for the worm gear, I wouldnt say it spins smoothly like say a roller bearing would in your fingers.  Maybe it's just a little too tight as I cant get it to free wheel and when I turn the gear slowly, it feels catchy. I wouldn't say crunchy per se, but kind of ?

As for using low temperature greases, is there any particular greases that should be used and any that should be avoided? 

Alberta winter is like 7 months long so alot of my time is going to be in temps around maybe 0c and -15c.  

Robert, I can't thank you enough for making this guide. Its absolutely spot on and very easy to follow.  I seriously thought something broke the RA axis went from having a bit of physical movement to hard like a rock.

 

Trevor,
 
Glad the doc was helpful!  :-)
 
Sticky/catching worm blocks aren't unusual. While a bad bearing is a possibility, I and a few other folks have had good luck by simply adjusting it - the factory adjustment was squeezing the bearings too hard.  H/T to Wes for that one - he had good luck with one of his worm blocks and passed the tip along.  I'd replaced a sticky block (ES has replacements) not long before and so I had a known-bad block sitting idle.  Tried it, and voila!  I was able to reproduce the solution.   
 
See Section 7.3 of the doc for coverage on worm bearing adjustment and the infamous 'middle capscrew'.  
 
When adjusting the worm block, do be careful with the loctite, both the grade used, and not getting it on the bearings.  
 
As to the setscrew, I had passed that to ES as a proposed engineering change, and Alex agreed to implement - but I would have no idea when the factory might actually react, and then there's the inventory pipeline.  No idea if ES has the setscrew replacement available as a part, but in any case, McMaster-Carr does ship to Canada and my few orders were quick and painless.  The setscrew is just odd enough that you are unlikely to find metric + stainless + long on the retail shelves - I tried. The problem I found was that if the factory capscrew head sits proud of the block (and it surely will), then it acts as a fulcrum against the motor and the motor wants to tip as you tighten it, rather than stay straight. Very difficult to detect the problem, as you almost can't see the point of contact.  It's buried deep and requires a flashlight to be held at just the right angle to see.  The mount will operate ok with the factory capscrew, but you may not to be able to optimize by getting the belt straight.
 
See Section 8 of the doc for coverage on winter grease. The LiquiMoly + MnS2 has been ok - I think it's basically a winter-rated ball joint grease.  Lots of vigorous debate over on CloudyNights about the best grease for mounts. One that seems to come up fairly often is Super Lube with PTFE (NOT the one with silicone).  My factory gear grease was white, so I expect it must have been a Lithium.  
 
Worm drives basically wipe the gear they mesh with, so a bit of 'cling' is good, and don't be surprised if the grease needs to be refreshed periodically.
 
Something to bear in mind for winter service lubrication, though... 
The axis motion with locks-on is completely different than with locks-off.  The ring gear fits over a central axis casting.  When the lock is on, the ring gear is pressed hard against that casting, and that enables gear motion to be transmitted to the axis and your scope for tracking and slewing.  When the lock is off, the ring gear just slides around the axis and gear motion is not transmitted, so you can balance your scope.  
 
The factory grease on my mount internals was very sticky stuff and not what was on the exposed gears. I have no idea how it behaves in your kind of cold.  Might be fine, might not, and the only way you can change it is a full disassembly, which probably should be avoided.  If there's a problem with the internal grease in the cold, it'll show up when you go to balance your mount, and you can work around that by figuring out your balance point indoors, before you set your scope out to cool.
 
- Bob
  
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Jennifer Shelly
 

Trevor:

The crunchiness you are describing is likely caused by the worm bearings being dirty, not enough lube, or the worm retainer/locking nut is a little too tight.  My guess it is the worm retainer/locking nut. First try to slightly loosen the locking nut with your fingers.  Then check if the worm spins freely.  If the crunchiness is gone then you need to make sure the adjustment did not introduce worm slop (side-side play).  You can check this by trying to move the worm from side-to-side. If you detect any movement then tighten the locking nut very slightly and recheck if the worm spins freely and check for slop again.  This is a very iterative process, so keep repeating until satisfied.  

If loosening the locking nut does not help let me know and I will walk you through adjusting the retainer.  The retainer is behind the thin lock nut which is located on the opposite side of the worm gear.  Do not use any wrenches or screw drivers when making this adjustment.  Please note the worm retainer is made out of aluminum with two slots and the metal is very soft, so please do not proceed until you have been given further instruction.

As far as the lube I have used SuperLube Synthetic Multi-Purpose Grease.  It is important that you do not mix lubricants.  If you switch you must clean all existing grease with degreaser before using a new type of grease.  ES might be able to chime in and let us know what grease is used at the factory.  All I know is that it is super sticky.

Sincerely,

Jennifer Shelly
AstroPorch, VA

Mounts
: ES PMC-8 G-11, ES PMC-8 EXOS-2
Scopes: ES ED127 FCD-100, ES Levy Comet Hunter, ES N208CF, Meade APO 70 MM Astrograph, QHY Mini Guide Scope
Cameras: QHY168C, ZWO ASI183MC-P, ZWO ASI183MM, Nikon D5600
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance
Imaging Software:  APT, BYN, SharpCap Pro, ASICap
Processing Software: PixInsight, Lightroom, Premiere Elements

Trevor B
 
Edited

Robert,

If I do adjust the block I'll be sure to use green loctite, the weakest of the bunch. I've used blue on a few things before and that may be overkill for this application and easier to get off after the fact if there needs to be another adjustment down the road.

My lock screw does in fact have the cap head so I'll be ordering the cap screw in the near future.

As for grease, I'm defintely not going to tear down the rest of the mount at this point.  

Since I've wiped the majority of the grease off, is it ok to use a different grease on the worm and ring gear or should I be putting the same type on?  If thate the case I'll email ES and find out exactly what the factory grease is and track it down

I was reading a few forums and they said that if you change grease, everything should be done with the same stuff and not to have 2 different greases on various components.  So just greasing the ring and worm gear with a different grease would be a bad idea?

I was also reading a bit more on factory greases. Some people have noted that theres reasons for using a sticky grease as it keeps it adhered to the gears.  One guy mentioned that lithium grease shouldn't be used as its thin.  So it should be a thick load bearing grease.

 
Edited

Trevor,
 
<< I'm defintely not going to tear down the rest of the mount at this point.>>   
Good choice!  :-))
 
I'm no lubricant expert.  Mine was already clean (wiped w/WD-40) by virtue of other work I needed to do, and after a bit of research, just threw my hands up and picked a grease with what looked like an appropriate service rating.  It's been fine so far, but if I had things apart for a full adjustment, I might take a second look at SuperLube w/PTFE for the gears.  I have used Teflon lubricants for other things, and it's pretty nice.   
 
There are TONS of strong opinions about lubricants on CN, Stargazers, etc. and I really didn't have the background to evaluate their merits or cautions - but I'm not sure that every last one of them is well-founded.
 
I agree with Jennifer's point about cleaning - there are a bunch of different lubricant and additive technologies out there.  Some might be fine to mix, some not, and we're not going to have any idea which is which.  Safest to clean. 
 
<<So just greasing the ring and worm gear with a different grease would be a bad idea?>>  
Not sure what you mean here.  The ring and worm mesh together, so you'd clean them with whatever, and grease that mesh with a single product.  The fact that the mount's internal lubricant may be different doesn't matter - they don't mix.  On my mount, at least, the factory grease on the internals and the grease on the gears were very different, and that makes sense - they were doing very different jobs.  Don't read anything into my greasing it all with a single product - that's just how it worked out.
 
<<Sticky grease as it keeps it adhered>> 
Well, yes, some sticky will help it resist being wiped off, but the gear action is what it is, so probably all we're really talking about is length of service before needing a touchup.
 
- Bob
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Trevor B
 

Robert,

Sorry was in a rush typing here this morning.   I was confused as to whether I'd gave to regrease the entire mount or I can just do the worm and ring gears if I decided to change grease.  If it's ok to do just the ring and worm gear, then I'm going to clean it with wd40 and then put some of that superlube on them.  Looks like I can get it off amazon.ca for pretty cheap and it contains PTFE.



 

On Sun, Oct 13, 2019 at 05:01 PM, Trevor B wrote:
I'm going to clean it with wd40
Trevor,

Just a damp wipe on the teeth - don't let liquid solvent run inside.  As tenacious as that sticky factory grease inside was, WD-40 (and, I assume, other solvents) cut it very effectively.
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Jennifer Shelly
 

If you are using a cloth to wipe off the grease make sure any fuzzies/lint from the fabric are not trapped in the ring or worm gear's teeth.  There will definitely be a bunch of fine pieces of metal that will need to be removed.  I suggest giving it a thorough cleaning by using toothpicks to clean each tooth one at a time.  It might sound like overkill, but your mount will thank you for it.
--
Sincerely,

Jennifer Shelly
AstroPorch, VA

Mounts
: ES PMC-8 G-11, ES PMC-8 EXOS-2
Scopes: ES ED127 FCD-100, ES Levy Comet Hunter, ES N208CF, Meade APO 70 MM Astrograph, QHY Mini Guide Scope
Cameras: QHY168C, ZWO ASI183MC-P, ZWO ASI183MM, Nikon D5600
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance
Imaging Software:  APT, BYN, SharpCap Pro, ASICap
Processing Software: PixInsight, Lightroom, Premiere Elements

Trevor B
 
Edited

Thanks Robert and Jennifer for the advice.

I order a 3oz tube of super lube multipurpose synthetic grease with PTFE on amazon.  Should be here in the next day or two.  

I'm probably just going to use paper towel with the wd40 as it doesnt really leave much behind. And I'll defintely use toothpicks to clean any debris out.

I even noticed on the worm gear pullet there was some black gunk built up in there so I managed to clean that out already.

I'm trying to hunt down a proper tool to adjust the bearing retainer on the worm gear itself as well.

Currently trying to find something to use for the shims for the worm gear install. I ahve some 1.0mm guitar picks floating around, I may try and use them with some tape to hold them in place.