Originally Posted by dennyrowland@mac
The Arm reinforcement that I have done looks like this....
It's great to see all of these ideas to improve those arms with a little more rigidity. But FWIW I decided that anything hung below the arms i.e. tubes etc. can only stiffen the arm in the direction of lift. What we need is to stop the torsional movement. Torsionals are what can move the motor shaft off-axis which will amplify the vibration. So, the stresses that occur during a torsional movement are focussed around the outer surface of the arm, so my solution was to fill the webbings with Loctite 9462 mixed with carbon nano tube fibers. The webbs are only filled about half way from the top surface which is sanded to a smooth surface finish that provides the outer skin which increases the torsional strength quite dramatically without gaining much more than about 10 - 14 grams per arm.
I would say that anyone doing a CFD analysis on the stock arms would find that it focusses most of the torsionals around that waisted area in the middle so that is were most of the strength has been added.
This is a great idea. I had thought about filling in those little voids too for the reasons you mentioned but was not sure what material to use so I just tried it with the 16mm tubes and silicone as I explained earlier. I just came in from a brief real estate shoot (video only this time) and while I do see a huge improvement over the original setup it could certainly be better. I am using an AV200 and Sony Nex5N 16MM and I think that unless a person has a Zenmuse this S800 is not delivering very smooth video at all. I have agonized over ways to improve it but I'm far from satisfied with it. Fortunately the Warp Stabilizer feature of Adobe Premiere Pro goes a long way to help out in this area.