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Is it OK to rotate the head by hand?

PostPosted: Wed Sep 25, 2013 6:48 am
by deedee7
I just got a used panogear head and while mounting the camera (D700 +16mm fe) on the straight rail (the rail in horizontalposition), I rested my hand on the rail and it gave in and rotated downwards. I've noticed that it's relatively easy to rotate the head on both axis(upper and base rotator) using external force. How much resistance should there be? Should I be worried or is it normal behavior?

PostPosted: Wed Sep 25, 2013 7:57 am
by fma38
There is a friction mecanism, to avoid braking the gears in case the head is stopped by something. It is good to let the friction as soft as you can.

On the yaw axis, there is no problem, even if it is very soft. On the pitch axis, it should no slip by itself under the load, that's all. So, if your camera is well balanced, it is like the yaw axis. If not (which is often the case, because of NPP position), you may have to tighten a little bit. If it does not move, do not touch anything ;o)

PostPosted: Wed Sep 25, 2013 9:16 am
by a a gruntpuddock
Sometimes getting the camera position correct means that it is not balanced, my Fuji had to be entirely in front of the horizontal axis at full zoom.

I don't have a Panogear but would expect that the head should be able to move (albeit reluctantly) when the unit is inactive.

Once it is switched on, the power of the motors is probably being applied to hold the head in position so any attempt to move it manually could damage the gears.

PostPosted: Wed Sep 25, 2013 9:37 am
by fma38
In fact, you can't move the gears by hands from the camera side, because of the tool high ratio. Doing this, you may apply a too high tork on the last gear stage, and brake teeth... This also means that the camera, even unbalanced, does not fall when you switch off the head.

So, you *have* to adjust the friction to be able to manually move the camera (this is sometime easier/faster than moving with the motors), without damaging the gears. It is very easy to do: you just need to remove the bracket, and use the correct key to turn the nut, until you can slip the friction by hand.

PostPosted: Wed Sep 25, 2013 1:30 pm
by a a gruntpuddock
As a general principal, I don't like the idea of messing about with friction adjustments.

If you set them too high the motors have to work harder and this will probably increase the battery drain as well as slowing the rig down (and possibly stripping gears).

PostPosted: Wed Sep 25, 2013 3:07 pm
by fma38
No, the friction is between the output gear and the plate where you mount the camera. It does not increase the tork needed to turn the plate.

PostPosted: Wed Sep 25, 2013 3:18 pm
by a a gruntpuddock
Ah, a 'clutch' in effect.

Thank you.

Update - but, if you set the friction too low, is there not a risk that the camera will slip down when you release it, banging the lens on the mount?

PostPosted: Wed Sep 25, 2013 5:38 pm
by fma38
When you release what? Not sur to understand... As said, the friction needs to be adjusted so the camera stays in place, and does not slip. The large gearbox ratio maintain the camera, even when the motor is off.

PostPosted: Wed Sep 25, 2013 6:35 pm
by Artisan New
Well, one thing is to remember....a motor in reverse is called a dynamo....now, some motordrivers don't like that at all, the currents and voltages are all over the place and since not all motor drivers are protected (by diodes I guess), this can mean idios muchachos.

Greets, Ed

PostPosted: Wed Sep 25, 2013 9:44 pm
by fma38
Again, it is nearly impossible to turn the motor from the camera side, due to high gearbox ratio. And don't do it, as it can brake the output gear. This is why there is a friction, there.