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Old 15-12-2013, 06:59 PM
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multiweb (Marc)
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Question G11 clutches

Just want to ask if anybody has ever thought of modifying a G11 in order to lock the RA clutch. The nylon discs tend to slip with bigger loads and moment of inertia. My though is that the clutch is not needed while imaging and I'm quite happy to move the mount to the initial CWD position with the motors then reboot the Gemini.

Not knowing on how other mounts do it I'd be interested in any ideas. So here's what I have in mind.

Drill and tap the front face of the RA face next to the DEC tube to be able to set a locking bolt that would go inside the opposing aluminium face by maybe 5mm. This way I can lock the whole assembly. By unscrewing I can release the clutch again and it'll work as normal. I'd glue the nylon disc to the upper part and have a corresponding hole for the bolt.

It's an easy enough mod and doesn't stop the mount from working the way it was originally designed.

Any thoughts?
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Old 15-12-2013, 07:16 PM
stevous67 (Steve M)
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I hate my G11 clutches.

Good luck Marc,

Steve
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Old 15-12-2013, 07:55 PM
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mill (Martin)
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Pm'd Marc
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Old 15-12-2013, 08:46 PM
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mill (Martin)
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Here is a crude drawing Marc.
Attached Thumbnails
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Old 16-12-2013, 08:07 AM
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multiweb (Marc)
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Quote:
Originally Posted by stevous67 View Post
I hate my G11 clutches.

Good luck Marc,

Steve
Hi Steve, I thought you had moved up with mounts and got a PME or AP by now?

Quote:
Originally Posted by mill View Post
Here is a crude drawing Marc.
Thanks for the PM and the iput Martin. I see what you are saying. I thought about it again last night. Maybe a couple of counter sunk nylon screws on each side of the DEC tube would do it. That would be enough to stop slipage but would shear if anything catches.
I want to get away from relying on the compression system. If I push against the disc or use any spring loaded system to some extent I'm still relying on the RA spring at the back. Ideally I'd like to take that out of the equation. So I'd just tighten it to have proper compression in the bearings, no more no less.
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Old 17-12-2013, 02:20 AM
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The clutches slip due the eventual separation of the bearing grease on the shaft.

Cleaning the pads solves the problem, ( or you could send it in for servicing with your local dealer ; )

If you really do need them to hold tighter, one surface can be secured to the thrust face with contact adhesive. Locking them up to the point of being being rigid is not a good idea, as you are likely to damage the worm gear.
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Old 17-12-2013, 08:02 AM
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multiweb (Marc)
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Quote:
Originally Posted by Peter Ward View Post
The clutches slip due the eventual separation of the bearing grease on the shaft.

Cleaning the pads solves the problem, ( or you could send it in for servicing with your local dealer ; )
Hi Peter, I'm aware of the greasy pads problem and I often wipe them and the alu surface with a bit of degreaser.

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If you really do need them to hold tighter, one surface can be secured to the thrust face with contact adhesive. Locking them up to the point of being being rigid is not a good idea, as you are likely to damage the worm gear.
Understood. That's what I was a little worried about. Thanks for the input.
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Old 18-12-2013, 08:51 PM
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Hi Peter, I'm aware of the greasy pads problem and I often wipe them and the alu surface with a bit of degreaser.
I wouldn't use degreaser ....try isopropyl
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Old 18-12-2013, 09:42 PM
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I wouldn't use degreaser ....try isopropyl
I used acetone. You reckon alcohol is better?
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Old 18-12-2013, 10:11 PM
stevous67 (Steve M)
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Quote:
Originally Posted by multiweb View Post
Hi Steve, I thought you had moved up with mounts and got a PME or AP by now?
You have an excellent memory, but I've kept the G11 for the wide field scope. It's a great mount apart from three things:

1. Those clutches,
2. The way the motors hang out, ready to be ripped off, and lastly,
3. No meridian flip command for autopilot.

I just found out about #3, not very happy about that one.

Ok, back to the threads topic...

Bye Marc!
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Old 20-12-2013, 08:40 AM
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Yes that motor is really asking for it. There are other things in astro that have a blatant bad design. Like the mini USB plug at the back of the lodestar for example. I lost count of people who broke it. It's and expensive exercise for a $700.00 guider. To the point that some third party jmob made an adapter for the back to protect the connection.
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Old 20-12-2013, 04:11 PM
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Quote:
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I used acetone. You reckon alcohol is better?
Either/or. Acetone is fine.... It was the fact that you mentioned de-greaser (i.e. strong automotive detergent + solvents) ...that would not be good.

As you know, I also use a G-11. I haven't had a problem with the clutches by giving it a service (strip down/clean/re-grease) once a year....also I'd recommend the clutch knob set (think you have these already) as it makes the mount decidedly more user friendly.

Cheers
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Old 20-12-2013, 05:39 PM
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Quote:
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Like the mini USB plug at the back of the lodestar for example.
I think astro equipment makers could learn a few things from Apples Magsafe power connection plug/socket....
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