EQ6 problems (again)

[pmrid]

Hi folks. my trusty EQ6 is playing up. Last night, 4 hours of flawless guiding. Tonight, a distinct click and big dec jump (seen on the PHD graph as well as in the images). There is a sort of period - about 100 seconds but it does vary a bit up to 120 seconds. I can hear the click. Is it time to bite the bullet and open it up? I dread the thought but it seems the way to go.
Peter

[Tandum]

Peter, can you feel any slop in the dec axis if you wiggle it by hand? Does the dec axis rotate freely with the clutches off? Are you balanced. It might be the worm mesh if it's got a click to it.

[pmrid]

The wierd thing is that the dec axis moves well, seems not to have any high spots and has no slop. So it must be in the worm or the gear. My guess is that there's a bit of swarf floating around in there that has got caught up in the worm/gear train somewhere.
The RA axis on the other hand is getting stiffer and has a few definite 'sticky' spots. Plus it has a little slop as well. So it's worm needs adjusting but also, it needs a good clean and regrease as well, I am thinking. But I've never opened an EQ6 or HEQ5 before so I'm just a bit jumpy about it.

Peter.

[Tandum]

Here is a strip down guide (http://www.astro-baby.com/EQ6%20rebuild%20guide/EQ6%20Strip%20Down%20Home.htm). I don't see why you'd drive out / remove sealed bearings though.
There is a round nut on the back of the RA shaft which is a real pain to get off.

[pjphilli]

Hi Peter

I had a similar problem with myHEQ5Pro, ie it would guide ok but often I could here a loud click and the guiding would jump up to six or more pixels and and slowly pulled down to normal. I too suspected the mount mechanicals and stripped it down. I found that the mount mechanicals were perfect in every respect, well greased and no rubbish to be cleaned out. Putting it together is also easy EXCEPT when you come to readjust the worm/wheel. The rather crude way of doing this can mean quite a few interative trials at adjustment and test before getting it right.
HOWEVER, by chance I saw a comment from Craig Stark that if some mounts are operated in with the PHD Brain Dec Algorithm in the Low Pass Filter setting you can get the above problem with DEC guiding and he recommended using the Resist Switching mode. I made this change and
my DEC guiding has been perfect ever since. So Peter, please check this out before you strip down your mount.
Cheers Peter

[bmitchell82]

Im about to rip mine apart tonight, not that theres much wrong in the guiding section, as im achiving a 10.2 Pk-Pk PE curve. but the problem is that when i release the clutches the mount doesn't freely rotate :( so i have a feeling its like clag glue in there. supa lube+ a few hours = smooth again. :) ill let you know how i go and what little things i had to do that isn't mentioned.

[pmrid]

Thanks for that hint. Will check it out first.
Peter.

[hotspur]

I see a lot of these mounts along with their smaller brothers heq 5s

They are rather ubiqitious-like a late model commodore out side a centre link

office.I owned a eq 6 for twelve months,best thing I ever did was get rid off it.

Absolute rubbish-poorly made,extremely ugly to look at.the materials and machining very rough,I could see it starting to go down hill in the twelve months I owned,the paint work and finish-very poor.Just my opinion from the observations on my one,others like them.

best advice-get rid of it and buy a proper mount!

cheers Chris

[danielsun]

Peter, I had a similar problem and found that (behind the black cover nuts with the two little holes on them) there is a lock nut that keeps the backlash of the worm gear bearing, well that nut must be just right. Basically just nipped up to the bearing and not overtightened. I found mine was too tight and pressing on the bearing which caused my dec to lock and then jump, but yet too loose and you will have too much backlash.
The worm meshing to the main gears are also critical. They are adjusted by the two small grub screws.Too tight and it will bind too loose and you will have backlash.
If you have to pull it apart don't worry it is actually a very basic dasign and you will learn how it all operates.
I also found that making the adustments with the main locking bolts loosened to a slight grab helps give you a feel for how much you are adjusting.

Cheers Daniel.

[RobF]

This isn't your NEQ6 is it Peter? Surely under warranty still?

[pmrid]

Thanks Daniel. It seems there are several possible reasons/causes for these dec jumps. Not all are mechanical, which I found surprising. I appreciate your help and will give special attention to the worm, as you have suggested.
cheers
Peter.

[bmitchell82]

Well i pulled the EQ6 apart, and there was only "scant" bits of lube, no black lube which was a pleasure, and all of the bearing surfaces where nice. Now its so damn silent i cant even hear it moving apart from the whine of the motors.! and if it wast for stars moving on my auto guider i would have a hard time believing it had moved. Hopefully next week i can get it out and do a PE run to see if i have made it better worse or indifferent.!

Chris, i do have to say about your EQ6, its fine that you don't like em because you had a poor experience BUT... they are a very cheap mount. its like going to bunnings and buying a 14 dollar jig saw and saying this jigsaw is absolute A55 and the best thing i did was chuck it out and go buy a makita... You knew when you purchased the mount that it was the cheap chines rip off of a mount.

But within saying that all you have to do is look at the images i take, and im tracking perfectly holding above what the mount is intended to carry. and i know a lot of people who are doing the same sure i have polished the turd to within a inch of its life but... its all good! And if you have the money to go buy a Tak EM400 or losmandy titan or AP GTO 900, then you get a pre polished turd of exceptional engineering!

[pmrid]

Well done.
I am seeing my EQ6 in an entirely new light courtesy of your colourful description of them as a polished t%^d. Somehow, my EQ6 will never be quite the same.
Peter.

[DavidTrap]

All this talk of polishing turds reminds me of a great quote:

"You can't polish a turd, but you can roll it in glitter and put a hat on it!"

DT

[bmitchell82]

Ahhh :) sorry bout that peter :D, i have this problem for calling it as i see it no matter how politically correct it is. Good luck with ya turd :) polish it well! :lol:

[Moon]

I enjoy pulling my EQ6 apart, polishing it, and putting it back together again. I could never build it from scratch, so I guess this is the next best thing.
It's old and scratched and battle weary - a genuine workhorse. Selling it would be like selling my first car. I hope I never have to do it.
James

PS I had some loose stuff in mine that caused all sorts of problems: clean the inside and it will be happy again, and you will feel satisfied that you fixed it.

[bmitchell82]

just a question james, what was your proceedure to adjusting the worms to rid of backlash ect ect.

[Moon]

The main 'trick' is to try to turn the gear with your finger when the stepper motors are removed. Trial and error, it's very sensitive to get it right - no binding + no backlash.
Also have a looksee through the peep holes when putting the stepper motor back in. It's easy to get it misaligned and not realise at the time.

While we are on the topic, I think the older version is a bit better in this regard - there is less backlash in my old EQ6 compared to my NEQ6 - the redesign to the stepper motor transfer gear was a step backwards I think. I have never seen anyone else report this... maybe becuase not too many people out there who have owned both?
James

[bmitchell82]

cools. i think tonight im going to have to spend a few minutes playing around with it because like you say, a quater turn and she's all up the creek!

I guess what i was asking is do you set the worm carrier bearings first then the worm meshing? or is it a push here pull there kind of setup. as i was dissapointed that the drive end of the worm there was no seating for the roller ball bearing to seat into. it just floats, is that what that little black cap is used for, to hold the bearing at a set distance?

[AdrianF]

Sounds like my current boss :P.

Adrian

[bmitchell82]

finished up last night tuning the eq6, hopefully i have done the PEMpro stuff right. 1 hr 3 worm cycles though i had alot of drift in the mount :( quick setup due to clouds rolling in.

taken though the ed80+dsi image scale at 1.74 arc per pixel

I want to do another run with the scopes next week, and see if i can get the PE down a bit lower. but at the moment with less than +-8 arc sec thats not bad at all. the oscollations are smaller than before. there is no backlash now in any of the drives and its quiet :) for 10 bucks worth of super lube + 4hrs of my time im very happy!