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Clutch Tightness

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#1 chuckscap

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Posted 30 March 2014 - 10:33 PM

I have a Parallax Mount (very vintage) with the original Losmandy stepper motors. Since I've had fork mounted alt/az mounts pretty much for the 15 years I've had telescopes I'm really a noob with EQ mounts.

First question: How tight should my clutches be with the stepper motors, if they're too tight can I burn out my motors?

Second question: I have the Gemini 2 upgrade with the Maxon Servo motors. I plan to install them after I have a good drift equatorial alignment (and it gets a little warmer). How tight should my clutches be with these motors?

Thanks!

#2 Dave Lee

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Posted 31 March 2014 - 10:08 AM

I have never used a Parallax Mount, but after a glance at their webpage and description of the current models, these sound similar to Losmandy mount mechanics.

In the Losmandy case the clutch does not affect how hard the motor has to work to turn the shaft(s). When you REALLY tighten down the clutches on the G11 mount, all that you have really done is to 'lock' the scope movement with the gear/motor rotation (which because of the very high gearing makes the scope hard to push-to move in that case). Unless the clutches are so loose that the clutches slip when the motor/gears are driving it, tighter vs. looser does not affect the load on the motors.

I don't know if that is how the old Parallax scopes work or not, but it might be since 'push to' with tracking was how the mounts worked in 'vintage times' and this is a nice model for purposes of push-to operation. It is kind of like an equitorially aligned Dobsonian (kinda').

dave

#3 chuckscap

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Posted 01 April 2014 - 04:00 AM

Thanks! Here's is picture of my my mount, it is kind of massive. I should have the Gemini 2 kit installed and my C14 on it in a few weeks. Weather has not been conducive of course. Selling the Mewlon, with the tree pollen, and fires we've had in Colorado, the Mewlon hasn't been out of it's case in 4 years. I needed a sealed OTA with Goto.

Thanks again.

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#4 schluterdude

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Posted 01 April 2014 - 01:18 PM

Clutches are there to save the gears in the event of a collision between the OTA and mount. That way it can slip rather than ding a gear or burn up a motor. Same is true from people bumping the scope accidentally.

If I am photographing an object, I lock it down pretty snug. If I am doing outreach, it's set pretty loose. I'd rather have to realign it than replace gears and motors!

#5 chuckscap

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Posted 02 April 2014 - 08:00 PM

Thanks again






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