Monday, April 13, 2015

Crappy machining job - Making a new stop for a sink valve stem

I broke the stop one of our bidet valve stems.  It was made out of pot metal, and I turned the handle too hard (I was trying to figure out how to get it apart).  It broke in half and I had to find some way to make a new one.  My wife found a large nylon spacer at lowes, so I used that.
First, I ground a steel bar down to fit in the hole of the stop washer from the other handle.  I used that as a die, because it was easier than trying to cut out the center hole.  I may have been able to drill the corners, but then cutting the straight part would have been hard on something that small.  Plus, using a die, I can try again later if I have to.
I heated it up with a butane mini-torch until it was hot enough to melt the nylon, and then pushed it through.

Then I used the band saw to cut the washer down to the right thickness.  I lined the two up on the die and scratched an outline on the nylon, then used the bandsaw to trim the outside down.  Then I cut a notch in the middle from two sides at the thickness of the main ring, then cut inward at the edges of that to remove the extra.

Here's a picture of it finally installed, with the remaining metal one in the foreground.  It's pretty rough, and my cuts in from the face weren't quite perfect.  It was a little short on one "wing", so I can only install it one way.  It currently turns just a bit passed full on, which is fine.  But if I turn the stop the other way (they're made to allow you to set the stem to turn "on" either clockwise or counter clockwise) then it turns just a little passed full off, which leaves a trickle.  It may wear out fairly fast, I don't know.  Especially if someone has a habit of turning the handle a bit hard, it could flatten the wings and let the stem turn too far.  If that happens, I'll try to make another one out of metal.  Maybe I can heat a piece of aluminum just hot enough with my propane or acetylene torch to pound my die through it.  Otherwise, I may have to try the drill and cut method.

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