Pocket Scan :Circular Mirror Movement?

Its tuff because the up/down movement (Y) is faster than the left/right movement (X). Here's what I do to make it look like a circle. I set the movement rate of the scans kinda slow (that would be a lower value for channel 6), then make, say 4 points like a square that you will have it move through. Set the chase speed to be a bit faster than how long it will take the scan to actaully get to the next point, so part way to location one, the timer expires and it starts to move to location 2, before it gets to 2, its changes direction to go to 3... If you add more points it looks more like a circle. You can test it by just clicking though the scenes before the scan is done moving. Im not sure if there is a better way, other than to have a computer calculate it for you and send the right DMX values to actually make a circle.

--Kevin

I had Compu 2000 generate the right dmx values (for an 8 point circle), but it's still pretty choppy. I've tried playing with the speed and fade control on the controller, and that helps some.

I guess I need to figure out exactly how the mirror movement speed (on DMX channel 6) relates to the speed and fade sliders on the controller.

This requires tons of math and a nice drawing or two. To find the positions of where the beams go, i graphed a Sin graph and Cos graph. I wrote PAN next to the sin and TILT next to cos. I then proceeded to label the Y axis of each graph with the top most part of the curve being 100% and the bottom most part of the curve being 0%. I took 8 values in even incremends on both graphs and labeled them 1-8 (these are the chase steps) I then calculated the percent that each point had. I used those to make a table that showed the X and Y pan and tilt values for an 8 step circle chase. Lastly, I programmed this on my operator and set the speed to a decently high rate and viola, it looked like a circle. This may seem complex but it is how a more expensive controller with an FX engine works. It simply maps the pan and tilt channels of a light to various mathematical functions that allow it to pan tilt etc in a regular manner.
PS I was quite bored
-Michael, Lighting Designer
Also, to account for the diferences in pan and tilt I pretended that the pan was the same as the tilt and adjusted all of my pan values so that 100 % was at say 90 and 0 % was say 10