# U R invited to an Inertia Ball (wear your thinking cap)

Joined: September 25th, 2006, 2:19 pm
Here is an inertia dependent HDD w/steel ball and drilled holes.

Hammer moves forward to fire gun, inertia moves the ball from A to B overcomming gravity. Connection with valve stem is complete.

Hammer rebounds so inertia plus gravity moves ball from B to A.

The sixty-four dollar question:
Now the hammer moves forward again. Might the hammer's velocity at this point impart enough inertia to the ball to move the ball back to B whilst fighting gravity?

Last edited by oo7fuzz on November 23rd, 2011, 3:47 am, edited 1 time in total.

Joined: April 28th, 2010, 12:23 am
i think that might work , but as it stands in not sure that ball would travel to position B unless you are depending on spring torque

Joined: September 25th, 2006, 2:19 pm
That could be done. Then the valve stem would need more extension. The stem really needs to be extended as is so a little more might not hurt. Sad that the stem has to be extended at all, but I saw no other way around it. Got any ideas?

Joined: November 28th, 2002, 6:26 pm
Here is an inertia dependent HDD w/steel ball and drilled holes.

Hammer moves forward to fire gun, inertia moves the ball from A to B overcomming gravity. Connection with valve stem is complete.

Hammer rebounds so inertia plus gravity moves ball from B to A.

The sixty-four dollar question:
Now the hammer moves forward again. Might the hammer's velocity at this point impart enough inertia to the ball to move the ball back to B whilst fighting gravity?

...that actually makes contact with the valve stem, then the ball will be held in place by the force from the stem until the stem has stopped and reversed the hammer's direction.

That is to say - until the hammer's reverse acceleration is complete, the ball is held at A by the stem.

At which point, when the hammer disconnects from the valve stem, the hammerspring starts accelerating the hammer forward again - generating g-force that continues to hold the ball at B until it hits the stem again.

Conclusion: I don't think the ball will fall back to A until the gun is cocked.

Steve
Last edited by pneuguy on November 23rd, 2011, 4:09 am, edited 1 time in total.

Joined: September 25th, 2006, 2:19 pm
..on the rebound from valve closure, does the hammer usually leave contact with the stem?

I guess I was looking for some inertia imparted to the ball via some amount over travel plus gravity on that part of the cycle.
The angle of the ball race should be favorable at that point to help propel the ball. But as you say, maybe not.

The Ball needs to only get a little over half way out of the way. Nicking the stem would easily send the ball to position A.
Last edited by oo7fuzz on November 23rd, 2011, 4:26 am, edited 1 time in total.

Joined: April 28th, 2010, 12:23 am
...that actually makes contact with the valve stem, then the ball will be held in place by the force from the stem until the stem has stopped and reversed the hammer's direction.

That is to say - until the hammer's reverse acceleration is complete, the ball is held at A by the stem.

At which point, when the hammer disconnects from the valve stem, the hammerspring starts accelerating the hammer forward again - generating g-force that continues to hold the ball at B until it hits the stem again.

Conclusion: I don't think the ball will fall back to A until the gun is cocked.

Steve
thats a lot of G's on the rebound too.Cool design though

Joined: April 28th, 2010, 12:23 am
i think that might work , but as it stands in not sure that ball would travel to position B unless you are depending on spring torque
and have a mild reduction toward the stem entrance so the ball cannot escape of lock itself..cool design , me likey

Joined: April 1st, 2009, 3:18 am
Here is an inertia dependent HDD w/steel ball and drilled holes.

Hammer moves forward to fire gun, inertia moves the ball from A to B overcomming gravity. Connection with valve stem is complete.

Hammer rebounds so inertia plus gravity moves ball from B to A.

The sixty-four dollar question:
Now the hammer moves forward again. Might the hammer's velocity at this point impart enough inertia to the ball to move the ball back to B whilst fighting gravity?

...is to use a one way roller bearing. The bearing would be placed inside the striker with the bearing outer most surface radius riding along the top surface of the tube. The bearing will function in the forward motion freely. On bounceback the bering applies locking force as it is not designed to rotate that given direction. This device would require very close tolerances to work properly.

One schematic thought up, to minimize tolerance issues: Slot the striker on the top along the axis, drill and tap two holes on either side of the slot, drop a spring in each hole, then the bearing with an axle, two set screws in the holes. The set screws not only hold things in place, they also control ride height of said bearing and control frictional force. To prevent galling, a steel tube used with a brass bearing should do the trick; softer material than the tube.

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Joined: November 28th, 2002, 6:26 pm
..on the rebound from valve closure, does the hammer usually leave contact with the stem?

I guess I was looking for some inertia imparted to the ball via some amount over travel plus gravity on that part of the cycle.
The angle of the ball race should be favorable at that point to help propel the ball. But as you say, maybe not.

The Ball needs to only get a little over half way out of the way. Nicking the stem would easily send the ball to position A.
...the instant when the hammer is at maximum backward velocity, and backward acceleration therefore ceases.

I think you're confusing velocity with acceleration. It's hammer acceleration that can push the ball around. Not hammer velocity. For the ball to be pushed from B to A, the hammer has to be pushed backward. But the only force available to do that, comes from contact with the valve.

Once the ball and stem disconnect, backward acceleration has to cease.

Steve

Joined: November 28th, 2002, 6:26 pm
...is to use a one way roller bearing. The bearing would be placed inside the striker with the bearing outer most surface radius riding along the top surface of the tube. The bearing will function in the forward motion freely. On bounceback the bering applies locking force as it is not designed to rotate that given direction. This device would require very close tolerances to work properly.

One schematic thought up, to minimize tolerance issues: Slot the striker on the top along the axis, drill and tap two holes on either side of the slot, drop a spring in each hole, then the bearing with an axle, two set screws in the holes. The set screws not only hold things in place, they also control ride height of said bearing and control frictional force. To prevent galling, a steel tube used with a brass bearing should do the trick; softer material than the tube.