dikman
05-15-2014, 08:45 PM
When I bought my Lee pot I was convinced that this potential dripping would not be a problem. The first time I used it I had to rethink things. I cast roundballs, max size .490, so I need a slow stream from the nozzle (otherwise it just goes everywhere!). When I tried to set it to a suitable pour rate it kept running/dripping when I released the knob [smilie=b:. I had to wriggle it or knock it down to get it to stop. Figuring more weight on top would help, I made a knob from round steel stock, tapped a hole and screwed it to the top of the metering rod. Didn't make much difference, and at this point I was beginning to regret buying it.
So I drained the pot to see why it wasn't closing. I noticed that the bottom of the rod wasn't centred and was touching the left side of the nozzle. This constant friction, coupled with the small up/down movement of the rod was obviously stopping it from closing. As the rod is rigidly attached to the handle bracket there was nothing to adjust to centre the rod. The extra weight on top made no difference, because due to the design of the heavy handle weight being attached halfway down the bracket all that weight is transferred sideways and pushes the rod to the side.
The RCBS handle design has a pivot at the top of the metering rod and another at the end of the handle, so the rod can "hang" with a little bit of free-play thus allowing it to centre itself. So I duplicated the RCBS handle, and for good measure fitted a spring on the side to put extra constant downward pressure on the metering rod.
Of course, after I did all this it occurred to me that if I had simply replaced the steel handle knob on the side with one made from a piece of dowel, while keeping the heavy steel knob on top of the metering rod, it may have worked adequately without building a new handle assembly!! By adding extra weight directly on top of the rod, and reducing the side weight to as little as possible it should allow the rod to centre itself more easily and also reduce the side friction.
Oh well, it was an interesting project.......
105019
So I drained the pot to see why it wasn't closing. I noticed that the bottom of the rod wasn't centred and was touching the left side of the nozzle. This constant friction, coupled with the small up/down movement of the rod was obviously stopping it from closing. As the rod is rigidly attached to the handle bracket there was nothing to adjust to centre the rod. The extra weight on top made no difference, because due to the design of the heavy handle weight being attached halfway down the bracket all that weight is transferred sideways and pushes the rod to the side.
The RCBS handle design has a pivot at the top of the metering rod and another at the end of the handle, so the rod can "hang" with a little bit of free-play thus allowing it to centre itself. So I duplicated the RCBS handle, and for good measure fitted a spring on the side to put extra constant downward pressure on the metering rod.
Of course, after I did all this it occurred to me that if I had simply replaced the steel handle knob on the side with one made from a piece of dowel, while keeping the heavy steel knob on top of the metering rod, it may have worked adequately without building a new handle assembly!! By adding extra weight directly on top of the rod, and reducing the side weight to as little as possible it should allow the rod to centre itself more easily and also reduce the side friction.
Oh well, it was an interesting project.......
105019