7" Articulated Magic Arm with Single Rod Clamp - 15mm (4 1/4"thread) for Dslr Rig Support System

Just received this arm and tried to use it on a shoot today with the Lilliput 7" 5D field video monitor. The swivel joints all lock tight with the knob. However. the threaded post into the 15mm rod clamp, is impossible to get tight enough. The weight of the monitor keeps causing it to loosen, allowing the monitor to swing like a barn door. I'm going to try some Loctite on the threads, but if that doesn't work, I'll probably have to get a stronger arm. If I had something lighter to mount, I'd probably give it four or five stars, but with the 7" monitor it just doesn't quite do the job.

ADDED Feb 8, 2013:

I ordered a Cowboy Studio super clamp and have attached the monitor to the tripod on several days of shooting. This works great. It is pretty east to position the arm so the weight is pushing down against the 1/4" threads to keep it from loosening. Also the whole setup is much more sturdy on the tripod. For moving around I adjust the monitor arm & monitor to hang straight down with the monitor facing toward the folded legs. This works pretty well for re-positioning the camera without removing everything. Since mounting the arm to the tripod, I could bump it to four stars.

ADDED Feb 11, 2013:

I just received a double 15mm adapter-it goes onto both rails and has the 1/4" threads for mounting the magic arm. This is much more stable that the original single 15mm clamp. I still haven't had to do any actual hand-held production, but with the Loc-Tite on the threads, this seems a lot more stable in just testing it out in the office. I'm not sure why this part is currently not available-hopefully they will get more in stock, as it is really useful. http://www.amazon.com/gp/product/B007GWFN8E/ref=oh_details_o01_s00_i00