Polariser Filter

DanWeston · Jan 5, 2018

I've fitted a polariser to my E90. Results are great and I'd recommend it to anyone.

However, it does seem to unbalance the gimbal a bit. It's not causing any notable problem... but I'm worried it might be stressing the motors.

Can anyone advise?

Ty Pilot · Jan 5, 2018

In the past when I have added a filter and it un-balanced the gimbal on a different aircraft, the fix was to simply add a counter weight to bring it back into balance. The trick is to get counter weight correctly oriented opposite the filter in all 3 axis'. In my case it was on a P2 using a Gopro and the lens (due to the offset built into the camera) was not directly in the front center but off to the side as well. The counter weight needed to be at the rear and offset to the other side to balance in both the X and Y axis. There was no need for any vertical displacement as the lens was center on to the gimbal.

I used a quarter as the weight and placed velcro with one sticky sided tape onto it and the body of the camera so I could remove the counter balance when not using the filter.

DanWeston · Jan 6, 2018

Thanks Ty Pilot. I'm actually having a bit of trouble with the gimbal in that the camera sometimes locks on a horizontal angle. The gimbal still operates but it seems to think that, when at an angle, it's horizontal... if that makes sense. Result is that I get video/photos on the 'wonk' - albeit stable.

I've removed the filter for now and will see if the problem persists. Anyone else had this and do you think it's a result of the filter? Strange thing is that it's a horizontal 'wonk' when the filter unbalances it on the vertical.

Ty Pilot · Jan 6, 2018

You're welcome, I don't have a 520/E90 but could it be that you need to do an accelerometer calibration? In my experience when the gimbal is out of balance it will usually do one of two things. If it is strong enough to overcome the weight, it will do so and operate normally, or as in my case with Zenmuse; it would hum and buzz loudly while shaking. I would think if it is off angle and not straining then perhaps it is a calibration issue but I'm just guessing at that.

DanWeston · Jan 6, 2018

I'm just looking up how to calibrate it now funnily enough so will give that a try for sure. It's strange because it's not permanent - just happens now and again and needs the old off/on to resolve. Shame because the polariser really does make a difference.