Mike Shade

My question had to do with the DEC top plate on the 1600, not the dovetail that the OTA connects to. It doesn't seem to make much of a difference actually.

Mike J. Shade:

Mike J. Shade Photography:

In War: Resolution

In Defeat: Defiance

In Victory: Magnanimity

In Peace: Goodwill

Sir Winston Churchill

Already, in the gathering dusk, a few of the stars are turning on their lights.

Vega, the brightest one, is now dropping towards the west. Can it be half

a year since I watched her April rising in the east? Low in the southwest

Antares blinks a sad farwell to fall...

Leslie Peltier, Starlight Nights

International Dark Sky Association: <>

From: ap-gto@... [mailto:ap-gto@...]
Sent: Sunday, January 17, 2016 5:06 PM
To: ap-gto@...
Subject: Re: [ap-gto] NEW 1600, DEC AXIS LOCKED

Hi Mike,

Please clarify your second question – just curious.

If the OTA is pointed NORTH (straight up ?), then the saddle tightening knobs would b either on the east or west side of the mount. Can’t see them “pointed south”.

I suppose different folks have their own preference about where the tightening knobs should be when dropping the dovetail plate into the saddle. I find it convenient to tilt the dovetail plate into the saddle’s fixed channel while the OTA is in PARK-2, I prefer to drop the OTA in its horizontal position, to avoid any potential “slide back down” if it were being installed into the saddle if this were done in PARK-3.

That said, I prefer the saddle dovetail tightening knobs to be on the top side, rather than below the saddle. Many years ago, when I first set up my new AP-900, I figured that it would be easier to drop the dovetail plate into a “fixed channel”, and then screw-down the knobs form the top.

If I were to have the tightening knobs “under the saddle”, and then dropped the plate into the sections of saddle attached to the tightening knobs, I would then “effectively” be trying to use the knobs themselves to “LIFT” the heavy OTA upward, into the saddle’s fixed channel. Using the knobs to lift such a weight seemed more difficult than needed, and potentially dangerous if you misjudge the plate top edge actually being sufficiently latched-in, after turning the knobs somewhat.

My way, even if the jaws are initially fully open, the OTA is safely sitting in the fixed channel, and I only need to push one hand against the OTA (horizontally balanced in its saddle), to keep it resting safely, while I reach around the OTA with my free hand, to tighten the knobs, one at a time.

Avoiding mounting the OTA with the mount in PARK-3, lessens my fears of the OTA sliding back down, and slamming hard on the dovetail plate’s DEAD-STOP safety screw (if there is one at the top end), or spearing me in the chest if it isn’t there.

Hope I was clear on this.

Joe Z.

From: mailto:ap-gto@...

Sent: Sunday, January 17, 2016 5:54 PM

To: ap-gto@...

Subject: RE: [ap-gto] NEW 1600, DEC AXIS LOCKED


another question, on the DEC top plate, the one that you attach a dovetail
to. What is the proper orientation of that? WE have it set to that when
the OTA is pointed north, the two dovetail tightening knobs are pointed
south. Is this correct? There is nothing in the documentation we saw that
showed this.

Mike J. Shade:

Mike J. Shade Photography:

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