friction on AZ EQ6 (balancing)

[cdh79]

Hello,

 

I have a Skywatcher AZ EQ6 and I have the feeling that I  have too much friction in both the RA, as well as the DEC axis.

The RA axis is constantly having some friction, even when the clutch is fully open.

See this video for the RA axis: https://www.youtube.com/watch?v=rDpEASMqjQA

 

 

When it comes to the DEC axis it rotates much more freely when I turn it counter-clockwise, however when I rotate it clockwise then after a turn or so it locks up and has much more friction.

See this video for the DEC axis: https://www.youtube.com/watch?v=EfgFb1mXpWQ

 

 

Can anyone with an AZ Eq6 confirm (or deny) that it is the same with them?

Does anyone have an idea how to "loosen" this up? 

This makes balancing the mount well a bit problematic.

 

thanks!

Chris

[Owmuchonomy]

I don't see anything wrong with those. If anything, the Dec axis appears too loose. Spinning it at high speed like in your video doesn't really serve a useful purpose. Load the mount up with your kit then check it slowly for binding or even free play. That is more representative of the mount's purpose.

[alacant]

Hi

On mine, the DEC cone bearing -the one at the counterweight end- was tight: Unscrew the counterweight holder and the bearng falls out. Tap the DEC lightly and wiggle and rotate it. Clean and grease the bearing then tighten until the first sign of resistance. Lock it in that position. I think that even when new you have to dismantle, clean and re-lubricate. HTH.

[cdh79]

thanks for your responses!

 

@Chris I normally of course don't spin it, this was just a means of showing the friction..

 

@alacant: Thanks, I will have a look at these bearings

[cdh79]

alacant, do  you mean this here?

 

This fits pretty tight and has rough edges (and the grease had some big metal shavings inside).

I don't know if you can see it well, but the edge on the lower right has been roughed up a bit

 

[alacant]

Yes, that's it. Mine had no oil and the rollers were corroded. In the end, the only way was to replace it:

http://www.aliexpress.com/item/1pc-NEW-Taper-Tapered-Roller-Bearing-30206-Single-Row-30-62-17-25mm/32391547527.html

Oh, BTW, mine's and EQ6 withot the AZ.

[cdh79]

thanks... i think these bearings are different on the AZ.. unless they are so stuck, that i can't even move the outer housing a little bit (the "rollers" do fine, but the ring next to it that i would assume is the housing doesn't move at all..)

 

edit: same on the top where the worm is..

[alacant]

Sorry, I missed the AZ bit. On the eq6, the centre of the bearing you picture falls out. The collar it runs in needs to be knocked out from the other side but best to ignore what I've described in light of different mount. Sorry.

[cdh79]

5 minutes ago, alacant said:

Sorry, I missed the AZ bit. On the eq6, the centre of the bearing you picture falls out. The collar it runs in needs to be knocked out from the other side but best to ignore what I've described in light of different mount. Sorry.

no worries, thank you anyways!

looking at some of the metal shavings that i pulled out it i think it was a good idea to open it up and re-grease it  

[ajk]

I bought a brand new AZ EQ6 GT last week from FLO. I'm a little inspired to open it up and "service it" but it does seem odd to have to do that to a brand new mount. However, sticking to the "do not fix what is not broken" rule of thumb I probably won't open it just yet. Although I have engineering skills so not worried about actually dismantling it I don't see the point just yet. Don't know enough about it yet.

[alacant]

11 minutes ago, ajk said:

 it does seem odd to have to do that to a brand new mount

I think for visual astronomy with a short tlescope you'll be fine. I too was surprised that a €2000 bit of kit needs to be pulled apart to work as expected. Not sure whether this is poor quality control, bad luck or that we expect too much!  

[ajk]

Just now, alacant said:

I think for visual astronomy with a short tlescope you'll be fine. I too was surprised that a €2000 bit of kit needs to be pulled apart to work as expected. Not sure whether this is poor quality control, bad luck or that we expect too much!  

I'm not doing visual, it'll be for imaging. Big learning curve ahead for me.

[alacant]

Ah, OK. In that case you'll be having it in bits several times over. May as well start now!

[jambouk]

It's a balance of having things tight enough, vs there being too much backlash. I can't watch the video as on holiday and have the worlds slowest internet connection. But neither the RA nor the Dec on my AZEQ6 would spin freely like a well oiled bike wheel, but they rotate by hand easily but stop as soon as i let go. There is no grinding and using the motors to rotate either axis a full 180 with the kit attached there is no grinding and no change in tone of the motors at any point, which to me suggests things are fine. There was a fair amount of backlash when both axes when I first got it, but this has been adjusted and now there is minimal. I suspect my mount is a bit "tiughter" than most, but it seems to function well.

James

 

[cdh79]

thanks James, I guess it is just a bit different than what I had expected initially.. 

 

thanks,

Chris