Skywatcher AZ-EQ6 saddle issue.... warning

[IanH]

Hi everyone,

Just thought I would log my experience with a loosening saddle on this otherwise excellent mount. 

I am currently visual only in Alt-Az with a C11 SCT - so that's quite a weight, but it seems nicely balanced thanks to the long counterweight shaft and a Baader handle on the OTA to balance the Alt axis.  This is still supposedly well under the limit of this mount for visual use.

Anyway, recently the saddle became a bit loose, I didn't worry too much as I don't image with it, then the other day I was picking up the mount head and the saddle dropped off  !   Fortunately nothing was attached at the time... 

Surprisingly the saddle only attaches to the mount by 3 tiny recessed allen type grub screws which bite against the circular metal rim (softer metal than the screws).  There is a tapered overlap to the rim which the screws go up against, which (in theory) prevents the head dropping off if the screws are extended sufficiently.  But, as the saddle rim is smooth all the way round, if the screws are slightly loose the saddle can still rotate independently.

The mount came with an allen key c. 4mm, so I tried using this to tighten it and it seemed to work.  However, I noticed it could loosen again very easily and go from apparently secure to yank-off-able with a bit of manual wobbleing.   It seems  the amount of the overlap for the screws to hold against is fairly small so they don't have to loosen much in order for it to completely come away.   In addition as the three screws are all that is applying the Alt rotational force against the saddle - there is the possibility of continuous loosening especially if it is not sufficiemtly balanced (thankyou Newton for your 3rd law).

I have to say I don't understand why there is not some sort of screw hole on the saddle itself, as that would surely be more secure and stop the chance of rotation which would spoil an image etc.

Anyway, how to solve this:  by trial and error, I have now found the correct allen key size needed to properly tighten the screws is 3mm - so not the one that it came with.

This key allows me to tighten the saddle back on such that the screws must really be biting into the metal.

Obviously I will be re-tightening every time I set up (and checking during the sessions), and making sure the Alt balance is perfect.  I suggest other owners do the same.

If this is obvious to all, then I apologise for being thick and wonder if there is anything else I need to worry about?

All the best,

Ian

[Helen]

Thanks for the heads up Ian, I want to use my C11 on mine too.  I had a word with FLO at Kelling and Steve thinks that ADM will be starting doing aftermarket upgrades for the saddles.  I suggested one for the counterweight bar that allowed easy integration of a guidescope mount which would allow easy adjustment to allow accurate set up of two scopes.

Helen

[IanH]

I would go for an upgraded saddle if someone made it.   I even wondered about drilling holes in the existing one, for a more secure connection.  I would feel safer knowing it can't drop off again.   That probably means sourcing replacement screws too.

The guidescope on the countereight bar is an interesting idea.  There seems to be a lot of untapped potential in the design of this mount.

Ian

[Sleepy Kiki]

Hi Ian

thanks for the heads up, I just got an AZ-EQ6 so will double check the screws tonight. Glad to hear you spotted it before any damage was done. I hope ADM do a saddle that fits into the AZ-EQ6. I still have my ADM dual saddle from my HEQ5 but it just needs a new puck to fit into it

[66mikeg]

Try a couple of drops of Locktite 290 (NOT superglue) I've been around all the little grub screws on my HEQ5 with this, it doesn't stop you from undoing with an allen key etc but it does stop them from loosening accidentally 

[IanH]

Re: Loctite 290 - that looks very interesting, I've not heard of it before.  I will definitely give it a go.

Thanks,

Ian

[mikeoates]

Does anyone know if a repacement saddle is being made. I find that the saddle does not grip the losmandy bar very well giving a degree or two cone error! I use the ADM side-by-side system.

Thanks,

Mike

[laser_jock99]

Does anyone know if a repacement saddle is being made. I find that the saddle does not grip the losmandy bar very well giving a degree or two cone error! I use the ADM side-by-side system.

 

Thanks,

 

Mike

Altair do a nice heavy duty saddle clamp

http://www.altairastro.com/product.php?productid=16536&cat=308&page=1

I have 35kg of scope hanging off one.

[mikeoates]

Altair do a nice heavy duty saddle clamp

http://www.altairastro.com/product.php?productid=16536&cat=308&page=1

I have 35kg of scope hanging off one.

Altair do a nice heavy duty saddle clamp

http://www.altairastro.com/product.php?productid=16536&cat=308&page=1

I have 35kg of scope hanging off one.

That does look good, but does it fit the AZ-EQ6 GT, I have emailed Altair Astro to find out.

Thanks for the pointer.

Mike

[paulastro]

I have to say, it seems rather sad to me that having paid a good chunk of money for a mount, people then either have to do a mod or spend yet more money on a third party fix to ensure the mount works as well as it should have done in the first place!

This seems to happen rather too often to me with astronomical equipment.  People don't buy cars and then expect to spend more money so that they run properly and are safe, so why should we astronomers have to do it?

Come on SW, fix the problem, save your  customers some cash and give them peace of mind!

(Just to say, I have a high regard for SW, and they are certainly not the only culprits!)

[mikeoates]

Just as an update, I now have an Altair heavy duty saddle clamp as above and the later EQ6 puck is the same as the AZ-EQ6 GT and fits a treat. Very well made, a quality product.

Mike

[johnpd]

Can someone post a picture of where these screws are located?

Thanks,

  JohnD

[mikeoates]

Here you go...

That image is a cropped stock image from Skywatcher, I just added the details.

Mike

[jambouk]

Is it just a case of tightening these to make sure it's safe?

[mikeoates]

Is it just a case of tightening these to make sure it's safe?

Yes it is, there are three equally spaced around the section, only one visible in that photo. Those are the screws that you loosen to remove the puck if you are replacing it.

Mike

[jambouk]

Is there a risk of de-centring the puck and introducing some error to the subsequent position / rotation of the OTA? Does it need to be centred like the polar scope reticle?

Jd

[mikeoates]

Is there a risk of de-centring the puck and introducing some error to the subsequent position / rotation of the OTA? Does it need to be centred like the polar scope reticle?

Jd

All you do is lossen those screws so that the puck can be removed, and re-fit the new one, just gently nip up the screws a little to make sure the puck in centered, then tighten.

What I did before removing the original puck is level the saddle clamp horizontally with a bubble level. Remove the original puck and replace the new one making sure it's level before tightening up.

Mike

[Zakalwe]

Is there a risk of de-centring the puck and introducing some error to the subsequent position / rotation of the OTA? Does it need to be centred like the polar scope reticle?

Jd

No.

You might have to re-specify the Home position in the handset if you've drastically altered the position. Or, if using EQMOD, point the OTA at the normal Park position (but don't park it) and hit Re-Sync Encoders.

[johnpd]

Here you go...

That image is a cropped stock image from Skywatcher, I just added the details.

Mike

Gracias,

  And thanks for giving the key size. I thought that was the case but had  a problem finding the proper allen key. The screws are really embedded in there.

JohnD

[Sleepy Kiki]

Just as an update, I now have an Altair heavy duty saddle clamp as above and the later EQ6 puck is the same as the AZ-EQ6 GT and fits a treat. Very well made, a quality product.

Mike

Thanks for the heads up Mike  , I have the an old ADM dual saddle for the HEQ5 so will pick up a new puck so I can re-use this on the AZ-EQ6!

[Dubhar]

Has anyone else actually had this problem? I was considering this mount but I'm tempted to shy away from it if things could potentially fall off from what would seam to be a potentially major fault with the mount.

[jambouk]

I checked the tension in the theee screws last night and they were all as tight as a tight thing.

The C11 hasn't fallen of the mount yet.

Jd

[fondofchips]

Thanks for the heads up Ian, I bought one of these yesterday so I'II check all the fasteners.  At the end of the day motors & movement will tend to loosen the fixings, especially if they haven't been tightened up properly when the mount was made.

[IanH]

It was me that orginally found this issue. It was a bit of a shock, at the time. I am new to this, so did not know the puck needed to be tight. I was surprised that keeping the screws tight was not mentioned in the manual, but maybe it's supposed to be obvious. Anyway I'm really happy with the mount now.

I think after the Heq6, Synta/Skywatcher made some significant improvements to construction - the Az bolts, the altitude adjuster etc. The puck screws maybe should have had attention, the different angle in Az mode means they are under a slightly higher load with a heavy OTA. I just check mine now every time I go out - the same as checking the tripod legs and joints are tight etc. I've only had to tigthen them maybe 1 in 5 times.

So, don't let this put you off, it is an excellent mount for the money. I'm not aware of another Alt Az mount with encoders, motors and tracking that can take 2 scopes upto 20kg each for less than several thousands of pounds, and this can do Eq mode too.

Ian

[nucleardwarf]

No issues with mine.  I have checked the torsion on the allen screws and they are very secure, wouldn't hurt though to check every once in a while.

Great mount, love it to bits.