It is some time since I was able to contribute anything to this thread but I think what I have here should be of interest to those who have a willingness to take the bull by the horns and make their own gimbal. First a little history. Before the brushless gimbal there was the servo driven gimbal and then I came up with the brushed indirect drive gimbal. Eureka It looked a bit messy but at last the technology was there to produce cineflex performance at a sensible price. Well whilst contemplating how could I produce it in this part of the world along comes DJI with another solution based on different electronics and motors. Just as we all thought that was it, along comes Alex with something really clever and so cheap. I'm so glad I did not invest in my production Indirect drive brushed solution. which worked on a similar principle.
So what is next ?Well IMHO this is it. THE BRUSHLESS INDIRECT DRIVE GIMBAL
Basically it is a brushless 3 axis board with a 4-1 and a 5-1 reduction gear on the motors. This is what I used with my Brushed gimbals and it has a few advantages over direct drive. The main one being that it is much more powerful and is less effected by balance and other issues that can knock it out os sync. So, direct drive for your GoPro's but if you want to move a heavy DSLR or Red Epic then this is better.
The images below are of a prototype drive unit for the pan axis. Powerful and accurate with the alexmos board but the Martinez just didn't cut the mustard as it just does not yet have the refinement of the Alexmos software to adjust for the different parameters. I am running 5-1 on the roll and the pan and 4-1 on the tilt. Don't worry about the speed of response, it is still blisteringly fast. Gain values can be doubled.
One aspect that I thought the likes of DJI and indeed just about everybody else would pick up on is the pan axis function as a means to rotate the image through 90 deg. so that a portrait shot can be tilted downwards. When I hear people banging on about the relative pixel counts of Canon Vs. Nikon etc. These are the same guys that have to crop the sides out of a landscape image. Why is this important, well that is simple as most publications are sold in portrait format. I got around the electronics problem by having an imu on each axis, What you have to consider is that what you see from the cameras point of view is still the same. In terms of movements. For example a pan movement on a Zenmuse will track a curve on the ground when it is pointed down at 45Deg. but with my system it will be a straight line.
View attachment 12212View attachment 12213View attachment 12214 but now with 6 and 9 DoF imu's it is no problem
If you have the pan axis on the camera base plate as opposed to the first motion axis then all that is possible and for less weight gain.