RE: [PSUBS-MAILIST] elliptical heads

In a message dated 10/25/2009 10:16:29 A.M. Pacific Daylight Time, bottomgun@mindspring.com writes:

The Germans found that the screw-advanced moveable trim weight couldn’t react quick enough to trim issues and that could not be operated at all when experiencing up or down angles (the weight jammed against the screw threads). Hopefully you can engineer out these issues in some manner for your moveable mass.

R/Jay

Hi Jay. Yes, we were gonna talk about that.

My sliding weight mechanism is pretty simple and won't jam. It will be moved by an electric actuator and is basically a wheeled sled between the two main ribs across the floor.

I'm not sure how much weight will need to be shifted yet, but hopefully not that much.

It's not my intention to actually rely on it to change dive angle. It's main function is to re-balance the sub from submerged balance to surface balance as the rear ballast tank is considerably larger than the front ballast tank. This is to hold up the heavier back end when surfaced.

Submerged, the front and back sections need to be equal in weight so shifting a little weight forward will level off the sub once the ballast tanks are flooded.

For dive angle changes, I plan on shifting my weight inside the sub as it's easy to move around inside. I have a sliding seat mount planned and I can always move a couple of the lead bricks around too.

The sliding seat will recline so I can lay down or sit up, depending on if I'm cruising along submerged or moving slowly peering at something close up to the main 20 inch window.

Frank D.