NEQ6PRO R/A setting circle puzzle

[coldlegs]

Every now and then I lose my park position and the scope ends up in an odd position and the next day I would do the horizontal level/6hr business and then reset the r/a setting circle which would be out. Always thought it was out because it caught on a burr or something.
However last night when it happened I took a close look and found the r/a setting circle was exactly on “0”. This seems to imply both the r/a setting circle and associated encoder have moved relative to the correct scope position. Is this possible??
One other thing bothers me. If I loosen of the Dec latch and move the dovetail mount it feels like I'm moving a stepper motor. I can feel significant tiny jumps. Maybe I'm getting paranoid! It seems nice and smooth when the scope and weights are on.
I'm getting a bad feeling it will have to be torn apart. Any ideas?
Cheers
Stephen

[bmitchell82]

Mine is smooth as a babys Kazoo, The RA setting circle moves! even if you tighten the crappers out of it! If you jump onto the resources part of my web page i have a full guide to set up the EQ6 in there i document how to mark your mount so you will never loose your home position. Mine has been like that for the past 3 years and it is repeatable.

As for pulling your mount down do not be afraid it is actually quite easy and the results are well worth the quietness, smoothness and proformance increase! In saying that if your not adept at fiddling mechanical things stay well clear!

[alistairsam]

That's a nice write up Brendan,
Slightly off track, does the EQ6 use optical encoders or does it just count the steps to determine position?

[bmitchell82]

I believe that they are tick count as there isn't a optical encoder in sight.

[bojan]

This may be caused by hard particles in your bearings... and/or retaining ring tightened too much, which may cause stepper motor to skip (as Brendan commented already, EQ6 doesn't have encoders.. and if the stepper skips a step, processor has no way of knowing where the mount points to)
Definitely, you need to dismantle DEC axis and give it a good cleaning/adjustment.

[RobF]

Why the heck they don't put home markings on the mount for at least RA is a mystery to me. There's no way to reliably set it up to a "home" position otherwise (without a level I guess). Good tip Brendan.

[bmitchell82]

I dunno why they do it either, :) theres a lot of why's in amoungst the EQ6 hahahaha.

I used to set mine with the setting circles but after i figured that they where moving thats why i used the level to level it out then just put physical markings between the two parts. I have always got my home position like that and it is reliable!

As Bojan said when you release the clutches or the mount turns off, thats it you have to start from scratch again, this is why i do not use the EQ6Dir because if your lappy turns off so does the mount. At least with the hand paddle the mount stays on and happy!

I think for every new EQ6 you should pull them down and make sure everything is right, as they are a cheaply made GEM its also good to learn how to do it so that if something goes astray you know exactly what to do, this is invaluable when your 400km from anywhere and something skips a beat.!

In my tool box for this very reason i have everything needed to pull down the mount and completely regrease it, everything to completely dismantle the 10" and put it back together and perfectly align it. I think its just good practice :D

[bojan]

Stephen, you can find a bit more on EQ6 setting circles if you have a look here, we discussed them earlier:
http://www.iceinspace.com.au/forum/showthread.php?t=34823&highlight=setting+circles
http://www.iceinspace.com.au/forum/showthread.php?t=80197&highlight=setting+circles
http://www.iceinspace.com.au/forum/showthread.php?t=53560&highlight=setting+circles
It is important to remember that historically RA circle is essentially the Hour Angle circle.. but not quite as far as EQ6 is concerned. Here, it is meant to show RA, but this works only if tracking is ON all the time and provided the moving to another object is ALWAYS done manually, not with the help of the motors (slewing).
More details on this is available here:
http://en.wikipedia.org/wiki/Hour_angle
http://en.wikipedia.org/wiki/Spherical_astronomy
http://en.wikipedia.org/wiki/Setting_circles

[coldlegs]

Thanks for the info folks. I've ordered a hypertune kit plus some main bearings just in case. Should be here by Xmas. Guess what I'm doing boxing day??
Cheers
Stephen

[bojan]

That (changing bearings) may be an overkill ..
According to this doc below, new bearings are not really needed.
http://f1.grp.yahoofs.com/v1/ANfZThM...comparison.pdf (http://f1.grp.yahoofs.com/v1/ANfZThMHx-sg6kv8foXdfud1EYETRahG7hueGPaAYKHVN gzl2KHTPX7OLXa9P_q3K8nL3OlNLzYBnVoq V1rsWsdg_BAO1os9/Hardware%20Tinkerers/PE-bearings-comparison.pdf)
(in case the link doesn't work, try this: http://tech.groups.yahoo.com/group/E...e%20Tinkerers/ (http://tech.groups.yahoo.com/group/EQMOD/files/Hardware%20Tinkerers/)
The docs are at the bottom of the page)

It is my personal belief that all those kits are not really necessary in most cases.. waste of money, until you are really sure if you have a problem (and what it is, of course).
What may be necessary is cleaning, and adjustment...

[Damian Couzoff]

Most likely the mount needs to be cleaned and regreased.If the mount has been overloaded,the bearings will eventually wear out.Like the polar scope,the setting circles are second rate,and l dont use both.

[bojan]

Damian, those bearings are bigger than those used on some car wheels (the weight of the car is +1 tonne, the speed of the car is 100km/h.. the scope weights 25kg, and the speed is .... well, VERY slow) . And in most cases they are still useable even after 100,000km.
It is totally impossible for them to wear out in EQ6.
But, they may be tightened too much (in which case they may behave like Stephen described, if they are of lower quality, not made to tighter tolerances) - tapered bearing at the counterweight side must be tightened.. but not too tight, just enough to eliminate backlash.
And of course, they may be dirty.

[bmitchell82]

Damien just like bojan said, if you can ware those bearings out you are a absolute machine they are huge! and carrying such a small load is almost impossible.

Its the same thing that makes me laugh when people think because the bearing has a fancy name it must be better :P hahhaha some good sales ploy around there.

Look at the little link about how does your EQ6 behave. My EQ6pro works within Losmandy G11 standard specs! No it is completely standard all i have done is tuned it and regreased it!

[coldlegs]

Update

Decided to put my 6' newt on the mount and see what the pec looked like with significantly less weight on it and it behaved perfectly. If you compare the attached screen shot with the one one this thread

http://www.iceinspace.com.au/forum/showthread.php?t=83678

It sure doesn't like a weighty 10” meade sct on it. The meade's about 12.7kgs plus 9.5kgs on an extender bar. People have run heavier I'm told but I'm probably pushing the limit. What do you guys think? As for the bearings, I was thinking maybe one of the rollers had failed and that gave me the jerky feeling and with my luck when I opened it I wouldn't have the bit I needed to fix it on hand so I bought everything in sight!!
Cheers
Stephen

[RobF]

I was reminded last Sun night just how critical balance is for my Heq5. My tracking was ok, but only so-so on M33 for a 30mins. Then I realised I hadn't adjusted counter-wts to make the rig East heavy. Did so, and the FWHM of all the subsequent subs (and roundness too) was about 70% of those beforehand and tracking smoothed in RA a lot (also quite a bit in DEC).

Bottom line, weight and how it's distributed can greatly affect your performance on a given night.

Fascinating to read what the bojan and Brendan had to say on EQ6 bearings too. I'd thought about it in those terms, but make sense they'd be hard to wear out...

[Ausrock]

Is there a comprehensive "how to" on stripping and "tuning" an EQ6? I thought I'd seen something somewhere on the www but I'll be damned if I can remember where.

BTW, Brendan.........I d/loaded your "setting up an EQ6" on (in desparation), two different PC's but the files show as XML documents and make absolutely no sense.........any suggestions please mate.

[bmitchell82]

there are heaps of guides google will reveal them! Tuning a EQ6 is a totally different matter its more about feel and there is no... absolute method :(

as for the guide its a word document not a excel document? click the link and it should download many people have done it so far so i know it works.

As for my balance I have mine perfect :) I don't bias because that puts load on motors which isn't that flash. If you have actually adjusted it properly then you don't have those issues of major back lash which is why you would load the motors up so to speak.

As for your PEC graph that isn't that grand the PE pk to pk isn't bad but the rate of change is a bit too rapid and will cause your guider issues to try and hold onto the star

here (http://brendanmitchell.net/?page_id=10&wppa-album=15&wppa-photo=157&wppa-occur=1) is my PE graph and its holding the 10" with all the fruit for imaging. each one of those major grid lines is 1 minute so that should give you a idea on the speed and amount of error happening.

Brendan

[Ausrock]

That's what I thought but regardless of whether I use the home PC or work's I end up with XML files :shrug:. The screen shots show the lower "screen bar" when the cursor is over the link displaying it as a "docx" and what shows when I actually "click" on the link, the zip folder contains the XML files. Buggered if I can figure it out.

[bojan]

It's a sticky in DIY section..
http://www.iceinspace.com.au/forum/showthread.php?t=55025