Hey guys, So lately my team has been experiencing a very strange "flopping" with both of our Movi m5's. Our current set up includes a A7s, MetaBones, Canon 16-35mm f4 and SmallHD 501. The Issue we are running into only happens around very specific cars. Mainly Vintage cars or any older muscle cars. The flop occurs when you are with 10-15 feet of the car. If the car fly's by it's not a issue but if the car is near the Movi Op at all during Idle or a slower shot the Movi will freak out and start flipping around rapidly. We spoke with the guys over at Freefly about the issue and they don't seem to have a solution for us. We understand that the issue is most likely caused by a RF interference put out by the cars but we would love some input from anyone else out there experiencing the same issue. There has to be a gimbal solution that can handle what we throw at the Movi on each shoot. Hopefully someone else out there has experienced similar issues and if so is there a solution to the problem aside from just not shooting cars? Will the same issue happen with a m10 or m15? Does the Ronin have the same issue? We use the Movi on every shoot and love it minus these few issues we have had. Last weekend on top of Angeles Crest in Los Angeles, Ca near all the radio towers (not sure what all those antenna's are) the movi would clearly be working fine and all of a sudden I took one step to the left and it would flop and flip around. I would move back to the right a little and the Movi would be totally fine. It was almost like it would hit a wall. Not sure if that's caused by a similar issue I just figured I would share that in case it helps get to the bottom of this issue. Attached is a link to a video showing the Movi m5 working properly and as soon as I walk close to the car (Vintage Street legal Sprint Car) the Movi "flops" and freaks out until you reset it.
I have a question for you: When the MōVI "flops" in your video, it clearly looks as though it's quite out of balance. Can you show a video of what the MōVI looks like on its stand not powered up? Are you familiar with the 3-axis balancing techniques? The reason this could be important is that the M5 has limited horsepower, and if the camera isn't properly balanced, it will work quite a bit harder, and if it does, it can easily reach its limits, and if it does so, it'll power down like you are experiencing. And one of the things you could check (assuming you're running the latest 4.01 software is the "Heading Assist" mode, and see what it's set to. If it's "compass" or "GPS", you could try setting it to another setting. The car could be throwing off copious amounts of interference that could be confusing the MōVI.
Based on the video I would agree with Steve. You aren't moving very radically when it stops providing power to the motors yet the camera pretty violently flops. Also can't see how many lights were on while you were walking. If not balanced really well there is more amps being pulled from the battery. At some point there isn't enough juice to handle the loads. Could happen even with a perfectly balanced camera in high maneuvering load movements. Finally even if the battery shows that it is full if it is an older battery with lots of charges it may simply be nearing end of life.
It would be very interesting to have the MōVI Configurator open while this is going on to see what the charts look like. I wonder if the sound of that motor (what a sound!) might be interfering with the IMU in some way and convincing the MōVI that the gimbal is oscillating uncontrollably. Many possibilities.
Hey Steve and Gary, Thanks for the replies. I'm very confident in my ability to properly balance the movi. I have gone through the cinestar/movi training with quadrocopter and have never had any issue of not being able to properly balance a camera on the Movi. The Movi in the video (and I repeated this issue 3 times after having to fully power down the Movi) would throw itself forward. The motors didn't completely shut off during the "flop" but it almost looked as if the Movi would randomly power to the motors throwing the Movi to its end points rapidly. Everytime this has happened its been the same results. Movi is working great until you "hit that wall" and then the Movi freaks out and throws itself every direction possible. Also I have been flying model aircraft for some time now and I'm very religious about constantly checking batteries and maintaining them. The battery in the video was fully charged and a fairly new battery. This issue of flopping was near the beginning of that days shoot (maybe second or third shot). So three lights on the Movi were on when it was working properly. Next time this happens I will make sure to take a video with the Movi config up!
I would look to rfi coming from an engine with a distributor as opposed to a modern fuel injected engine. The test to do is with the car motor running and not running.
Mark, We have done that test with the car not running and then running and the issue only happens when the engine is running. We first thought it had something to do with the magneto's on the vintage cars (Miller Race cars) but we have found the same issue happen with a much more modern engine. A few weeks ago we were shooting a restored Plymouth Duster and the same issue happened. Properly balanced, Fresh fully charged battery. Hyper thin HDMi cable. The Movi was performing perfectly and we came to a stop in our rental truck (2014 Dodge Ram 1500 with a 5.7L Hemi) with the Duster parked 15 feet in front of the rental truck. With both cars running I jumped out the back of the truck and went to sent the Movi down in its stand on the tailgate and the Movi started to "flop" again. I tried to reset the Movi by fully powering down and back up and the problem still continued. I tried 3 times before asking the driver of our rental truck to turn off the motor thinking maybe the rental truck is causing this issue? The Movi fired up when the rental truck was shut off and the Duster was still running. Very confused at this point I took the Movi near the Duster and again it flopped. This issue is so frustrating! Something to mention: this issue (minus the issue last week on Angeles Crest in LA) seems to only happen when you are behind the exhaust of the vehicle. We have experienced this issue about 10 times now on 10 different cars usually during a wrap around shot of the rear of the car while it's running.