Hi David, although I don't have one of these myself, it's on my "To Buy" list - it seems like it might do the trick and is rated at 5KG/11lbs horizontal weight. There's a picture or two here. $99 incl shipping seems to be the best deal you'll get on it.

http://www. ------.com/new-strong-articulating-arm-support-max-5kg-horizontally-with-15mm-rod-clamp_p861.html

So are the pictures etc. in the ad propaganda? What would you recommend V.K.?

There is a mini version of the original Manfrotto Magic Arm, its is VERY sturdy, but you will need to twist the knob several times to change between "moveable" and "fixed" state. This makes it quite unhandy if you need to move the screens often. If you just want to keep them in position its fine.

http://www.gimahhot.de/m900-748931-0-0-0/manfrotto-830-hydro-kit-mini-814-1-386b.html?utm_source=product_feeds&utm_medium=google_products&ia-pmtrack=153316565

VFGadgets has provided an excellent solution. It's a very solid arm with clamps at all articulation points.

I HAVE to take a minute to sing some praises for VFGadgets. These guys ask for a picture of my rig and ask for the bolt pattern of the displays I'm needing to mount. Then they put the solution together for me and FedEx'ed it to me to try (without payment or even giving them a credit card). And I'm nobody!!

I just came across this post. My friction arms constantly unscrew themselves from the 1/4" and 3/8" threads on my rig and it drives me up the wall. This looks like it could be a good solution ( http://www.vfgadgets.com/monitor-mounts/fluid-head-monitor-mount ) but has anyone tried it? Of course the only problem with this design is that I don't have rosettes on my shoulder rig, so I couldn't used it to mount my EVF...

@kavadni These look very good. Thanks for sharing.

But rather than using them a superclamp to attach this to my tripod, what I'd really like is to have the option to mount this to a rod system (with a piece of hardware that fits over both rods to keep it in place) so that I can also use it with my shoulder rig. Do you know of a rod-mountable accessory with a lockable hole for a stud?

My Digital Juice arm is very sturdy. I use it often. It's rated to 5lbs and it comes with a nice clamp-

http://www.bhphotovideo.com/c/product/838303-REG/Digital_Juice_111004_ARM_CLAMP_BUN_Articulating_Arm_and_Mini.html

some hairspray of something else that is slightly sticky sprayed on the friction surfaces can help keep the joints from sagging.

@kavadni The video on the Manfrotto site says that each end is a 5/8" stud. One is threaded for a 1/4" screw, and the other is threaded for a 3/8" screw. I was trying to bypass the screws entirely and find something lockable that would grasp the 5/8" stud because I find that the screws tend to unscrew themselves and then the arm just swings freely. That's why I liked the Cinevate Universal Rail Block: http://www.bhphotovideo.com/c/product/552599-REG/Cinevate_Inc_CI_RA_AS_000002_CI_RA_AS_000002_Universal_Rails_Block.html

I agree on hardware that attaches to both rails.

@kavadni You may be right about the rotation, but I plan to find a screw that screws through the center hole and applies pressure against the bolt to keep it in place. Since it won't be fighting gravity this may be able to provide enough resistance to hold it still.

The manfrotto mini-hydrostat arm is bomb-proof. 5/8" stud one end, 1/4" screw the other. Expensive though