Re: Tool for saddle clamping

Christopher Erickson

It wouldn't be too hard to CAD-up and 3D-print a slip-over knob that would allow for some additional hand force to remove a stuck knob that doesn't have the Allen key socket.

AP's dovetail lock design is the best of any I have ever seen. Angled brass pin with force being applied to a small area on the dovetail bar. Allowing enough targeted force to really clamp down, but without damaging or distorting the dovetail bar. Dovetail brackets that spread the force out along a longer clamp area or worst-of-all, along the entire length of the side of the bracket, aren't nearly as secure and are at much greater risk of a dovetail bar sliding unexpectedly in the bracket, and inviting disaster.

"Slip Sliding Away..."

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii

On Sat, Jul 24, 2021 at 12:53 PM Woody Schlom <woody_is@...> wrote:

A small strap-wrench would probably also work.  They have lots of leverage and the rubber/plastic parts don’t mar the aluminum.


But I’m confused.  All my AP knobs have a hex socket in the middle of the knob.  That said, all mine are at least 6 years old.  So maybe AP has recently changed to the solid knobs with no hex socket in the middle.  Too bad.  Although I’ve NEVER needed to tighten anything that tight.  But I can see perhaps needing the hex key to loosen a stuck or seized knob.




From: [] On Behalf Of M Hambrick
Sent: Saturday, July 24, 2021 11:56 AM
Subject: Re: [ap-gto] Tool for saddle clamping


Hi Gert

Out of curiosity what is the part number of your dovetail plate ? The knobs look like those on my DOVE15 which has no hex head bolts in the clamping knobs either.

I have had pretty good luck using a jar lid gripper on these knobs. They are simple, cheap, and effective. You can find them in the kitchen section of most department stores (e.g. Wal-Mart). I have noticed something interesting about these grippers though. It seems that after a period of time they will lose their "grippiness" and you will have to replace it.


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