I'm pretty sure that gas springs are constant force. That's the whole point of them. Fixed force means that you cannot adjust the pressure. You buy a 30lb spring and that is what you get. The adjustable allows you to (one time) remove pressure down till you get it right. If you go too far, you are out of luck.
For a Z axis counterbalance, you don't need a perfect floating counterbalance, maybe 90%. The stroke would be the main thing, make sure you specify a spring with adequate stroke. |