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coenie777

Re-greasing NEQ6

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I replaced all bearings on my NEQ6 and it makes a huge difference. The bearings that were there from the factory were consumed after a little over a year of use. Being Swedish, SKF came to my mind and I found exact replacement bearings from their catalog. The difference in quality is enormous... SKF bearings do not corrode in a year as the originals had.

As for re-greasing, the quality of the grease the factory puts in there is definitely questionable. There is grease and then there is grease, the latter preferred. I asked the guys who sold me the bearings what I should use. One interesting property is how the grease behaves over changes in temperature, and I ended up getting a small tube of Barium grease - at £35! The grease the factory had used was well distributed, yet the bearings corroded. That says a bit about the grease.

The NEQ6 is a low cost mount, and as such it is subject to imperfections and lack of quality control. Among the six or seven ones I have seen, the differences in feel and performance have been signifficant. The basic design - copied from Takahashi and Vixen - is good, and there is no reason why a simple tweak session should not make the mount excellent and on par with many almost premium mounts. But in original configuration it is what it is; a product spaced out randomly over the quality spectrum...

So, my advice is to give it a going over. If you search the forum you will find my post with the bearing part numbers from SKF. Any high quality (and expensive - these things are no free lunches) grease will do, be it Lithium, Barium or straight marine application.

My national pride invites you to read about SKF on Wikipedia: https://en.wikipedia.org/wiki/SKF

All the best,

Per

Hi Per

Same idea for the Heq5 (syntrek), do you think ? Mine's never performed as well as I think it should - even with a belt mod. It's about 18 months old, only had light use and never been outside. I've partially stripped it down before but not considered changing bearings etc.

Louise

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Well, I'm another sceptic on much of this stripping and rebuilding of EQ sixes. If you take most things apart and put them together carefully you are likely to get an improvement. I've had quite a few carefully rebuilt EQ sixes visit and I've never seen any of them do much that mine don't do, quite honestly. And mine are totally bog standard, old and hard worked. We pulled one out of a box a couple of years ago, set it up for Franck M106, put our TEC on it, aligned it via the polar scope only, and Franck knocked out a great set of data on the Owl. It's now back in its box. These bearings rotate at just under one revolution per day. Ahem, lets's not get excited. I suppose of chunk of corrosion could affect the response to guiding but think about the rotation speed of one RPD. I'm sceptical. I might be entirely incorrect but I put this stuff in the same back corner of my mind as I put five tonne blobs of concrete to hold piers in place. Internet mythology. I think that what matters is the accuracy of the worm and wheel mesh and precious little else.

Olly

Edited by ollypenrice
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Well, I'm another sceptic on much of this stripping and rebuilding of EQ sixes. If you take most things apart and put them together carefully you are likely to get an improvement. I've had quite a few carefully rebuilt EQ sixes visit and I've never seen any of them do much that mine don't do, quite honestly. And mine are totally bog standard, old and hard worked. We pulled one out of a box a couple of years ago, set it up for Franck M106, put our TEC on it, aligned it via the polar scope only, and Franck knocked out a great set of data on the Owl. It's now back in its box. These bearings rotate at just under one revolution per day. Ahem, lets's not get excited. I suppose of chunk of corrosion could affect the response to guiding but think about the rotation speed of one RPD. I'm sceptical. I might be entirely incorrect but I put this stuff in the same back corner of my mind as I put five tonne blobs of concrete to hold piers in place. Internet mythology. I think that what matters is the accuracy of the worm and wheel mesh and precious little else.

Olly

Hi Olly

In my limited mount experience the fine mechanical adjustments of the heq5, at least, are fiddly and not very positive. Perhaps less than optimum adjustments are the source of tracking/guiding problems?

Louise

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Im sticking with the old maxim - "if it aint broke, dont fix it"

Yeah, but if things aren't right, you have to try and fix it!

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Maybe Im one of the lucky ones then. Mine is 2nd hand, bog standard and its never given me any trouble (touch wood!).

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Well, I'm another sceptic on much of this stripping and rebuilding of EQ sixes. If you take most things apart and put them together carefully you are likely to get an improvement. I've had quite a few carefully rebuilt EQ sixes visit and I've never seen any of them do much that mine don't do, quite honestly. And mine are totally bog standard, old and hard worked. We pulled one out of a box a couple of years ago, set it up for Franck M106, put our TEC on it, aligned it via the polar scope only, and Franck knocked out a great set of data on the Owl. It's now back in its box. These bearings rotate at just under one revolution per day. Ahem, lets's not get excited. I suppose of chunk of corrosion could affect the response to guiding but think about the rotation speed of one RPD. I'm sceptical. I might be entirely incorrect but I put this stuff in the same back corner of my mind as I put five tonne blobs of concrete to hold piers in place. Internet mythology. I think that what matters is the accuracy of the worm and wheel mesh and precious little else.

Olly

That could be a handy way to turn your scope into an earthquake detector if you are lucky it might pick up passing cars too.

Alan

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Maybe Im one of the lucky ones then. Mine is 2nd hand, bog standard and its never given me any trouble (touch wood!).

I'm thinking of going downmarket and getting a Star Adventurer imaging kit!

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kalasinman, nothing wrong with Superlube in my view. I guess it holds for grease as it does for mounts, you CAN pay $65 for a tube of what ever or $5 for another tube of what ever. The one does have much more than the other but will I see the difference? Most probably not. If I know what I am looking for though, I will be able to show you so much more differences between the two. The question remains how much of this is the minimum required to do the same job under NORMAL circumstances?

Just an observation around the slow motion of the application and the perceived lower demands from a grease support side. I spoke to a Mechanical Engineer recently and made that remark to him in passing. His view was that the extreme slow motion actually will places higher demands on the lubrication. In a mount moving this slow the gears are under more stress due to the fact that centrifugal forces cannot "alleviate" the contact stresses between the gears due to high speed turning. Our gears sit there engaged and under tension and thus would actually require more protection that a fast spinning gear, albeit that heat will probably then become a factor that they lubrication on the high speed setup will need to also take into account.

But it does not sound to me like "since we only turn one cycle a day" etc etc, we can run the gears on sub minimal lubrication. Thoughts?

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kalasinman, nothing wrong with Superlube in my view. I guess it holds for grease as it does for mounts, you CAN pay $65 for a tube of what ever or $5 for another tube of what ever. The one does have much more than the other but will I see the difference? Most probably not. If I know what I am looking for though, I will be able to show you so much more differences between the two. The question remains how much of this is the minimum required to do the same job under NORMAL circumstances?

Just an observation around the slow motion of the application and the perceived lower demands from a grease support side. I spoke to a Mechanical Engineer recently and made that remark to him in passing. His view was that the extreme slow motion actually will places higher demands on the lubrication. In a mount moving this slow the gears are under more stress due to the fact that centrifugal forces cannot "alleviate" the contact stresses between the gears due to high speed turning. Our gears sit there engaged and under tension and thus would actually require more protection that a fast spinning gear, albeit that heat will probably then become a factor that they lubrication on the high speed setup will need to also take into account.

But it does not sound to me like "since we only turn one cycle a day" etc etc, we can run the gears on sub minimal lubrication. Thoughts?

That's why they use the thick , extreme pressure additive grease in manufacture , not a lighter , 'cleaner' grease ...  :rolleyes:

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Interesting reading this afternoon.. I was trying to find where I had seen that Moly grease is abrasihve properties, without much luck.  But in doing so came across lots of forums discussing grease and its uses in a wide range of applications.  The general consensus was that whereyou have a sliding motion then a thicker grease is more suited compared to roller bearings.  However in each case these were circumstances that were hot, under extreme loads and running at high RPM for long periods of time.  Given the typical useage of an HEQ5 / EQ6 I don't think these proprties really play a part in the mounts lubrication, and the lithium based teflon grease that Astrobaby reffers to is fine.  Just as much as using moly grease would be fine  because the mount will never really get to a point where the individula properties for each grease play a part... unless you gear the mount 1:1 on the drive and spin it up like a helicopter  :)

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Thanks all for sharing your wisdom.

I used astrobaby's great guide throughout the strip and rebuild; it is a has to have in my view for anyone contemplating a rebuild/strip.

I will report back on this thread with the results from an observing session next weekend. Let's hope all was not in vane and the "if it is not broken don't fix it" saying will not be haunting me for the rest of my life :laugh:

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Some good advice on the regreasing of those "yellow metals" the worm gear's crown are made of :

http://www.machinerylubrication.com/Read/28958/ep-additives-effects

Conclusion : EP Grease, yes, but beware of the sulfurs/sulfides...

I suspect those are the ones in 'advanced motor oils' which is why they aren't recommended for use on machinery.

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Yes you're absolutely right. Indeed EP grease with sulfide are those used in high pressure, low speed machineries. Sulfide tends to be converted into sulfurs of the parent metals and there crystalline structure will cause damages to the metals. But this reaction only occurs at high temperatures and this is definitely not the case in our mounts.

Therefore, any EP grease should do the job. But those especially made for low speed / interrupted service would be better, like for example Molykote G-n Plus or G-rapid Plus or without sulphur phosphorous like Molykote L-1146FG.

Edited by Fred_76

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I used the following grease on my mount:

Loctite White Lithium Grease which is made by Henkel I see. Here is the link to the technical chart for this:

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/4EF7A95478A9ED0085257E4300685592/$File/LB%208042-EN.pdf

Any views on its efficacy for the intended use (although it is now too late for me :laugh: )

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