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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

High quality but economical gyrostabilized gimbal for Epic/Scarlet

holy thers alot of ppl in here that are way smarter than me.....
 
I may have a Tyler Mini Gyro unit soon that will be available for rental, I am shooting a project for a client and the client is wanting to buy one for his use. It will be available and I'm thinking for reasonable rates as I'm going to oversee the unit, rent it out for him.

Most rates for the Tyler are $375 per day, But I'm thinking $200 to $250 per day, we want to keep the unit working to recoup the investment.

Anyone interested?

Frazier
 
I fly a Bell 47 J-2 and use a true gimbal mount with two Kenyon KS-8. They work great. Not expensive at all. The mount could easily be put on other vehicles. The last time I was involved with a Tyler mount was on a Warner Bros picture in 1993. Too much to go through with those large inertial mount systems. Old school.
 
Like laurie i am waiting for the epic to proceed. Coming very soon but the wait has been painful. Still on track otherwise. I am really focusing on a universal camera head and once i get the mechanics built outside of the 3d environment, look forward to sharing with Laurie on the stabalization phase.
 
It's a pleasure to discover several people are looking for a good and affordable stailizer.

What I'm thinking of is a system without any mechanical gyros, such as those manufactured by Kenyon. The Kenyon gyros are wonderful, but my need is different.

To give an update, I've been waiting for some feedback from a certain site.

In short, the challenge of stabilizers is this: There is no way to distinct gravitation from other forces acting on an object. Just think yourself sitting in an airplane without seeing the ground. When the plane accelerates and deacclerates in different directions, it's very difficult, or in fact impossible, to say which direction is vertical. But this is also a necessity condition to hold a camera horizontal during a shot.

The solution to this is, one needs to detect the vertical/horizontal axis while the camera is in rest, and then measure the angular velocities while the camera moves to pass the information of the direction of the vertical/horizontal axis from one moment to the next one. This kind of system is sensitive to cumulative errors and thus, high quality gyros to measure the angular velocity are needed. In addition, one needs to detect when the camera is not accelerating/deaccelerating to reset at such situations the information of the vertical/horizontal axis.

The magnetic field of the earth can be employed to assists such a process and the standard approach to adapt different kind of measurements to each other relies on so called Kalman filters. However, there are also cases when the magnetic field is of little or even no use: To understand why, think first of modern smart phones such as the iPhone (or as a Finn should perhaps add a Nokia phone ;-) ). The choice between landscape and portrait is detected with inclination sensors. But, when the phone is put on a table and rotated, the inclination angle does not change at all and therefore the phone does not react on the rotation. Just tested this with my iPhone and Nokia E7, and neither one swicthes the orientation of the dsiplay when rotated on a table.

In the same manner there is no change in the reading of magnetic sensors when the rotation is on the plane perperdicular to the magnetic field. In other words, when the magnetic field line is locally parallel to the rotation axis. (Compare, the inclination of a phone does not change when the rotation axis is parallel to the gravitation field lines, i.e., to vertical lines.) Unfortunately, since the magnetic field lines are often rather tangential to the surface of the earth, in many case the magnetic field is not that helpful in stabilizing the yaw angle. However, this is perhaps the most critical angle. For, the eye recognizes quickly if the horizontal line is tilted or if it swings back and forth.

Now, my goal is to come up with an affordable stabilizer, and what just described suggests rather fine and precise mechanics, high quality (optical) gyros and so on. And that means also high costs. But, have an idea how to compensate for such challenges in order to keep the expenses down, and as hinted already, waiting for some feedback from a site to whom suggested to co-operate on this. We'll see what happens. Unfortunately, not able to predict the outcome yet.
 
I'm no mathematician but i believe the following is true.

All we need is a line between the centre of gravity of the earth and the centre of gravity of what we want to stabilize. Once we have that line established we can find a horizon (90 degrees to that line) and all other angles in relationship.

The problem we face is that this line is referenced by a gyro which tilts outside of a 90 degree angle. Once this occurs the relationships between all other axis on the gimble totally changes. In other words they are all no longer 90 degrees to each other (in reference to the COG of earth). All other data coming in from the other gyros therefore will be off (exponentially as the angle variation increases towards "gimbal lock") I believe this explains drift. You cannot fix this problem with better gyros. It is the reality of geometry.

You fix this by adding a fourth axis giving you a trig equation which is usable. As long as the relationship between the first two children is fixed in terms of axis. From that you can always determine the angle to the cog of earth while maintaining move-ability and reference of the other axis .
 
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