Flint Hills Dude's blog View Details
Posted by Flint Hills Dude | Aug 08, 2014 @ 03:00 PM | 5,428 Views
I switched back from the experimental Sony mount to Mike's original Sony mount. The Sony is now very well balanced in the gimbal, but the whole gimbal weight is still throwing the Phantom's COG a bit far forward, just not as much as before. It's livable for the present. Made some basic PWD and PID adjustments. Trimmed about 1/8th inch from each of the four silicon tubes to stiffen their action. Also hooked up the pitch control to the NAZA. Bench testing was good.

I was going to shoot some basic test footage at a western Kansas location, but neglected to snug down a crucial bolt (on the clamp that hold the camera) before I left and during transit it disappeared, never to be seen again. And, being in western Kansas, I had no way to replace it.

So, lesson learned about long-distance travel with your bird; snug down loose bolts and screws before travel AND carry extra parts if possible. I had a pack of DJI Phantom spare screws along, but that didn't include the gimbal bolts. That was stupid, because I did have spares, just not in my travel kit.

The replacement I chose for the lost bolt is a bit longer and now has, in addition to the snug-down nut, a NyLoc nut. I've screwed the NyLoc on the end far enough to engage the polymer insert and hopefully keep everything together when the Action Cam isn't mounted. AND, I've added a spare set to my travel kit.
Posted by Flint Hills Dude | Jul 11, 2014 @ 03:52 PM | 5,625 Views
Weight of gimbal and camera is throwing the P1 COG too far forward. Getting serious airframe vibrations. I wasn't having a problem with than before when using just an anti-vibe mount. It was better with Vision props than with the original 8" ones, but still unacceptable.

I'll go back to the original gimbal design in hopes of getting it closer to a balanced state. Probably will need to shorten the anti-vibe tubes as well.

I also think DJI should have included more and/or better-spaced attachment sockets on the bottom of the Phantom. For example, a triangle of attachment points would have been much more stable than the two provided which can allow significant side-to-side wobble depending on the mount material.
Posted by Flint Hills Dude | Jun 27, 2014 @ 09:34 AM | 5,953 Views
After assembly, I apparently had connected the roll and pitch motors backwards, which led to a very unstable gimbal!

I switched the motor leads and now it's acting like it's supposed too.

I'm sure I can tune things better, but at this point, I think I'll take it off the test stand and mount it to my Phantom. I'd like to see how it films with just basic power and PID settings. I'll also connect the Pitch control while I'm at it and test it too.
Posted by Flint Hills Dude | Jun 16, 2014 @ 02:45 PM | 6,001 Views
My current project is putting together an experimental gimbal that allows my Sony Action cam (AS30) to be easily mounted and un-mounted using the lightweight Sony Skeleton Frame (AKASF1). The skeleton frame has a standard 1/4 inch tripod socket. It also allows full access to the side buttons and LCD screen. This build will be used on a Phantom v1.1.1.

Mike Klinker of KlinkAir LLC designed a gimbal for me similar to his Mobius version. We were guessing on balance points.

After assembly, it was obvious that the roll motor balance point needed to move to the left. Unfortunately, it couldn't move far enough to achieve good balance and still allow the pitch motor's bell to turn freely.

Mike suggested that I might be able to ream a bit off of the inside of the pitch motor mount. That would allow the motor to move to the left enough to balance.

So I measured the amount of distance to the left that I would need and dremelled out the pitch motor mount socket about 2mm more in diameter to a depth of 4mm using masking tape as guides.

When I remounted the pitch motor, the modification allowed me to achieve good roll motor balance without binding the pitch motor bell.

For both motors, I'm using the iFlight GBM2212-80 No Shaft Extension.

I've finished all of the assembly and wiring. I'm using the RTF V4 Brushless Gimbal Controller with SimpleBGC 2.2b2 from Witespy. I've built a test stand out of an acrylic riser, so I can tune the gimbal without having to have it on my Phantom. I also made an adapter to connect from one of my Phantom batteries (XT60) to a standard JST plug that mates with the JST leads I soldered to the board's power connections.

My first tests have been satisfactory. I will next permanently attach the IMU to the camera platform. Then I will begin the PWD and PID tuning...