"Position Scale" Pot....

[300EVIL]

Hi Everyone,
I have SacnEco 20 galvo's with matching amps. The gain, LF and HF dampening pots I understand however their is a pot labeled "position scale" on each amp. I assumed they were the zero point for each axis. However, when attempting to adjust them they don't seem to do anything. What are they for?
Thanks!
Adam

[dave]

position scale is image size

[300EVIL]

position scale is image size

Thanks Dave,
How is that different from gain then?
Thanks Again!
Adam

[buffo]

Adam;

Servo Gain controls how hard the amps accelerate the mirrors and is one of the main adjustments involved in tuning the performance of the scanners. Think of it as a "speed" setting. If you adjust the servo gain (up or down) you will see changes in certain parts of the scanned image (especially if you're displaying one of the test patterns), but the *size* of the scanned image will remain the same.

Input Scale is like a pre-amp stage that compensates for differences in the input signal to the amp. Adjusting the scale setting normally will not change your tuning at all, though if you adjust it too high you can force the scanners to move beyond their normal range, which will distort the scanned image.

I think most of the confusion comes from the term "Servo Gain". When people hear "gain" they assume that something gets bigger (or louder). It would make more sense to call it "Servo Speed" or something, but we're stuck with the terminology.

Bottom line, you shouldn't need to adjust your input scale setting unless you have one of the following problems:

1) the scanned image is too small even when you have your software set to output the maximum size image. In this case you would increase the input scale to make the scanned image larger.

2) the scanned image is too large, and you have to drastically reduce the size setting in your software to prevent over-driving the scanners. In this case you would decrease the input scale setting to make the scanned image smaller.

Adam

[300EVIL]

Hi Adam,
Ah, okay. Yeah I thought "gain" meant volume. Mow it makes sense why you have to adjust gain LF and HF together.
Thanks Again!
Adam