Hi,

A stepper does not have a feedback system, unlike for example a servo. You can only tell the stepper to move a certain amount of steps, not to go to a certain position. So you need to tell YourDyno when the system is in 0 position (fully open, 0% brake) and how many steps it is to fully closed (100% brake). You do this in the Options-Brake setup. Then YourDyno keeps track of the position, assuming no lost steps. You can lose steps if you set it to move too fast or too high acceleration or the load is too high. That's why some work is needed when setting up the system first time so you ensure the stepper settings are good.

Next time you power up the system, you need to make sure it starts with the brake in 0 position. I normally just by hand check the 0 position and move it to 0 if it is not there upon starting the system. 

Thanks for the fast reply, I had assumed that's why the land and sea one has the big hand wheel on it. I may put a stop and light return spring on mine to ensure zero position on power up. cheers

Yes, the land and sea valve is quite practical with that wheel. I would drop the spring, just check at startup that it is at 0 that's all. This is the valve we use, it works fine.