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HEQ5 worm adjustment and balancing

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#1 Rhinottw

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Posted 19 August 2019 - 06:48 AM

Hi,

 

So, i have taken apart my HEQ5 following the guide on astro-baby and the guide was great. I have not really used the mount before doing this because it was around 8 years old and a bit stiff. So i just figured to get it done rigt away and then get the lubrication replaced. Everything went fine, the parts look good and it has been re-lubed with white lithium grease.

 

I have been able to get it tracking to around a bit over 1" rms and i am very happy about that. The only thing that seems a bit off to me is that it has to be extremely well balanced. I know balance is importaint, but if it is just slightly off PHD2 will not move the mount at all when calibrating. I will hear the motor move and PHD2 will go through the calibration steps, but the mount is not moving. My total weight mounted is around 8kg or approx 17 pounds. I have used an alt/az eq6 which was much more tolerant of imbalance, but this is also a much sturdier mount with higher load capacity, so not something that can be compared directly.

 

Since i have no reference on this mount my question is if this is normal? I would like to go just slighty off balance in the direction i am guiding to avoid potential oscilation in the RA axis. If it is not normal any idea if i should tighten or loosen the RA worm gear? If i move the gears by hand it moves easily and smooth(perhaps a bit light?), there is zero play in the axis if i try to rock it back and forth.



#2 EFT

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Posted 20 August 2019 - 03:21 AM

I first have to say that if you ever do this again, do not use white lithium grease.  This has been discussed in many other threads and the online guides that recommend using it are wrong.  The next time you have to do maintenance on the mount you will find out why.  Use something like a PTFE-based synthetic grease instead.

 

The RMS that you are getting doesn't seem all that good.  The mount should not have to be "extremely well balanced" in order to work.  In fact, "extremely well balanced" is just what you don't want since it will result in oscillation due to bouncing around in the zone of backlash.  My advice at this point would be to take the mount apart and put it back together again.  Somewhere along the line something went wrong when you were putting things back together most likely.


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#3 Rhinottw

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Posted 20 August 2019 - 06:34 AM

I first have to say that if you ever do this again, do not use white lithium grease.  This has been discussed in many other threads and the online guides that recommend using it are wrong.  The next time you have to do maintenance on the mount you will find out why.  Use something like a PTFE-based synthetic grease instead.

 

The RMS that you are getting doesn't seem all that good.  The mount should not have to be "extremely well balanced" in order to work.  In fact, "extremely well balanced" is just what you don't want since it will result in oscillation due to bouncing around in the zone of backlash.  My advice at this point would be to take the mount apart and put it back together again.  Somewhere along the line something went wrong when you were putting things back together most likely.

Thank you for the reply. I am a bit confused about why to not use white lithum grease, i did think i did a good amound research on this before doing this and the consensus i found was to use this? Of course i found different opinions, but i can see you are a vendor so you must know what you are talking about. What should i use instead specifically? Is there a danger of damaging the mount? I am not afraid to take it apart and re-do the job.


Edited by Rhinottw, 20 August 2019 - 06:43 AM.


#4 EFT

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Posted 20 August 2019 - 12:31 PM

White lithium grease dries out and leaves something like clay behind.  It doesn't do the mount any good at that point and is a mess to clean out.  There is no danger of damaging the mount.  What I use on mounts (and have used for 10 years now) is called Superlube Multipurpose Synthetic Grease which is a Teflon-based synthetic grease.  It works very well in mounts and have a very wide temperature range.  It is readily available in the US but may not be in Denmark.  Similar greases are usually available online if nothing else.  A bike shop may also carry similar greases. 


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#5 Rhinottw

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Posted 20 August 2019 - 01:23 PM

White lithium grease dries out and leaves something like clay behind.  It doesn't do the mount any good at that point and is a mess to clean out.  There is no danger of damaging the mount.  What I use on mounts (and have used for 10 years now) is called Superlube Multipurpose Synthetic Grease which is a Teflon-based synthetic grease.  It works very well in mounts and have a very wide temperature range.  It is readily available in the US but may not be in Denmark.  Similar greases are usually available online if nothing else.  A bike shop may also carry similar greases. 

Cool, thanks a lot for your help.




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