Arca Swiss Primer (1 Viewer)

The subject comes up now and then as to how to keep spotting scopes from loosening from either a tripod head platform or from a plate that attaches to a tripod head.
The ED50 cannot tolerate the brute force method as it will eventually damage the insert in the foot.
Larger scopes have enough weight to often overcome the screw and friction pad attachment on many plates causing them to rotate.
The Manfrotto plates that use a pin in addition to a screw help quite a bit if your scope's foot has a hole for a pin, though even they can loosen eventually.

The answer, I find, is just use Arca Swiss compatible clamps and plates.

Pic 1 shows an Arca type clamp in it's native habitat, in this case a Markins ballhead.

Pic 2 shows an Arca type clamp mounted on a Manfrotto 3130 (128 now) using a plastic spacer.

Pic 3 shows an Arca plate in it's more common setting, mounted to a long lens. Notice how the lip catches the back edge of the foot. This prevents any movment.

Pic 4 shows the same type plate on an ED50.

Pic 5 shows an Arca plate on an ED82.

There are many manufacturers of Arca compatible components and while they aren't inexpensive, they work better than anything else. The better manufacturers as Really Right Stuff, Markins, and Kirk makes specific plates for SLR camera bodies as well

Here's a detail of how I mounted the Arca clamp to the 3130 head.
I drilled one hole through the recess of the head and plastic spacer to utilize a 1/4-20 bolt to thread into the existing threaded mount hole in the clamp.

In addition to the above, I also drilled and tapped another 1/4-20 hole into the clamp. I drilled another clearance hole in the head's recess and spacer to use another bolt for extra security and anti-twist.

This assembly can be taken apart and revert back with no damage or reduced function to the head for use with Manfrotto plates, if desired.