NEQ6 Declination getting looser

[neil phillips]

I have noticed recently  that when locked down, if I mess with the scope. meaning balancing or whatever. The scope can move a bit. It feels like the declination axis has over tIme got looser. How easy is it to correct this ?

Is it possible when this gets looser, that planetary imaging can become a bit more jittery. Poor seeing aside I thought, but cant be sure, that the videos are a bit more jittery when capturing. I am a bit uncertain about this though, because even slight wind causes a similar appearance. And its been like that lately.

 I am not particularly hands on with these kind of things. But could likely do it, if it is not too difficult. Any advice guys. Much appreciated for any help

[Chris]

Hi, I'm always tweaking my dec axis backlash, it will take you 10 minutes max I promise

1) Slightly loosen the 4 Allen key bolts on the worm carrier casing.

2) There are two little grub screws on the same casing 90 degrees to the 4 bolts, these control the slight adjustments to the spur gear meshing with the worm gear. It is slack in the spur gear meeting the worm gear which is causing the 'wobble' in Dec.

Slacken one of these grub screws and tighten the other whilst at the same time wobbling the dec axis until the play in dec goes away.

If you go too tight the dec axis will bind so when you have adjusted the grub screws so there is zero play, just loosen back very slightly, maybe 1/8th a turn.

3) re-tighten the 4 larger bolts.

Finished

[neil phillips]

Cheers Chris does it matter which  grub srcrew is slackened and tightened.

if there is slack couldn't I try just a small tightening of one of the grub screws .

As you can see, I am new to this. cheers for the advice

[gajjer]

Hi Neil

See Astro baby's guide to stripping down the mount. It will help you understand what is going on.

At the end she describes how to do the adjustment.

http://www.astro-baby.com/EQ6%20rebuild%20guide/EQ6-declination%20strip%20down.htm

http://www.astro-baby.com/EQ6%20rebuild%20guide/EQ6%20declination%20rebuild.htm

hope that helps

cheers

gaj

[neil phillips]

Cheers for the link Gaj

[Chris]

Cheers Chris does it matter which  grub srcrew is slackened and tightened.

if there is slack couldn't I try just a small tightening of one of the grub screws .

As you can see, I am new to this. cheers for the advice

Hi, I wouldn't risk it, I would slacken one side a touch first before tightening the other side. This is because slackening one side makes room for adjustment of the other side. If you don't slacken one side first you could be pushing against a tightened grub screw the other side which could damage/strip the thread on the grub screw or worse perhaps.

Remember the little grub screws are purely for pushing the worm carrier casing in one direction or the other, the spur gear gets pushed closer or further from the worm gear as a result (I can't remember which grub screw tightens or loosens?). The 4 larger bolts are for securing the whole casing in position once adjusted. Once the 4 bolts are re-tightened it doesn't matter if the grub screws are loose but it matters if they are over tight. 

I'm probably not the best at explaining it so as above, check our Astrobaby's EQ6 strip down guide, It's what I used when I started fiddling with my eq6. I did mean to link it myself so sorry about that

[Peter Drew]

Before doing any worm adjustments it's worth checking if the puck is loose, this can give the same effect as backlash and I've seen this problem before. There are three grubscrews round the periphery of the DEC casting holding the puck in place. 

[sbooder]

STOP!  before diving in and adjusting the worm, check the worm retaining nut,  This is more likely to become loose before the worm mesh (presuming you get to use your scope as little as the rest of us with such rubbish weather?), and cause to much float.

[Chris]

STOP!  before diving in and adjusting the worm, check the worm retaining nut,  This is more likely to become loose before the worm mesh (presuming you get to use your scope as little as the rest of us with such rubbish weather?), and cause to much float.

Good Point! YES TRY THIS FIRST!

Yes, if you undo the little black cap and turn the retaining clip clockwise, if it turns freely it was loose. Don't go too tight or it will make the worm very stiff to turn and the stepper motors will struggle to turn it.

[neil phillips]

Ho Guys I am not the sort to jump in feet first luckily I haven't done anything yet

  The Declination clutch,  I checked the Phillips screw that holds it in place. And indeed it was a little loose So I tightened that, It felt like it was locking down better once this was done I will wait until I do planetary imaging again, before I decide if it has cured the problem or not.

There is a very slight rattle from side to side about 2 or 3 mill when I grab the telescope tube rings, and feel if the declination has any play. Infact when I balance the scope I have to set it slightly off balance, or this 2  or 3  mill, becomes 12" At F20

I can see on the declination housing 3 straight head screws and directly above them what looks like 3 allen key type screws, its a been a long while but I think I remember these being for changing the saddles,

I am not sure what this meant

---------

Good Point! YES TRY THIS FIRST!

Yes, if you undo the little black cap and turn the retaining clip clockwise, if it turns freely it was loose. Don't go too tight or it will make the worm very stiff to turn and the stepper motors will struggle to turn it.

---------

Cheers for the feedback, as you can see imaging is my thing not engineering

[Chris]

Hi, what it means is the 2-3mm of play could be due to the retaining clip at the end of the worm gear being loose. If you look at your mount you should see a couple of round black circular caps on each side of the mount casing. Undo the caps on the west side of the mount by turning them anti clockwise. You will then see the retaining clips which look like thin washers with two grooves 180 degrees apart. Use the groove to turn them a touch clockwise. If they were loose they will indeed turn freely clockwise. If they don't turn freely clockwise they are not loose. Don't tighten them too much else the worm becomes still to turn by the steeper motors.

hope this is a little clearer

[Chris]

Another thing that can cause this 2-3mm of backlash is the thing I first mentioned.

[neil phillips]

Hi, what it means is the 2-3mm of play could be due to the retaining clip at the end of the worm gear being loose. If you look at your mount you should see a couple of round black circular caps on each side of the mount casing. Undo the caps on the west side of the mount by turning them anti clockwise. You will then see the retaining clips which look like thin washers with two grooves 180 degrees apart. Use the groove to turn them a touch clockwise. If they were loose they will indeed turn freely clockwise. If they don't turn freely clockwise they are not loose. Don't tighten them too much else the worm becomes still to turn by the steeper motors.

hope this is a little clearer

Ok cheers Chris I will check