Kreepy Krauly- How does that hammer thing work?

[schurtj]

So I just bought a used Kreepy Krauly Classic, hooked it up an the thing works awesome.

I haven't really opened the insides yet (hope I don't have to for awhile)...can someone explain how the mechanism works? I know the hammer is the only moving part, but I don't understand how the suction from the skimmer translates into the hammer pulsation. Is it like a water wheel that moves from the water being sucked in?

 

[Casey]

Welcome to TFP.

I'm not sure how it works but maybe someone can explain.

 

[SunnyOptimism]

So I just bought a used Kreepy Krauly Classic, hooked it up an the thing works awesome.

I haven't really opened the insides yet (hope I don't have to for awhile)...can someone explain how the mechanism works? I know the hammer is the only moving part, but I don't understand how the suction from the skimmer translates into the hammer pulsation. Is it like a water wheel that moves from the water being sucked in?

It's somewhat complicated but here's the best way I can describe it - water flow at the speeds and pressures at the inlet of the oscillator are not laminar and smooth. There's a fair bit of turbulence across the oscillator plate. That oscillator has a curvature to it that causes a lateral motion when water flows along it. Now, if the water flow was perfectly laminar, then the oscillator plate would move and stop as soon as it hits the edge. If you look at the oscillator plate, you will see that they added four plastic sliding seals. When the oscillator plate moves and closes in one position, those seal slide and then open up a new path for the water to flow through, that then causes the oscillator plate to move in the opposite direction as the flow and pressure on the plate changes.

As that oscillator plate shakes back and forth, the vibration causes the KK to move forward. There's a kids toy called HexBugs if you ever seen them. Essentially they look like little plastic bugs with rubber legs. There's a motor in it that spins an off-axis weighted cam that causes vibration like what you cell phone does on silent mode. That vibration travels along to the rubber legs and the curvature of those legs causes the HexBug to move. They're actually really creepy because they move a lot like a real scurrying bug. Kreepy Krauly operates on the same principle.

The oscillator plate on the KK also drives a small ratchet mechanism that causes the tube connector at top to rotate when the KK is stalled on something (hits the wall but doesn't climb up it or hits a drain plate at the bottom of the deep end) which is why the KK can execute turns and get all over your pool.

Sorry, if the above is not too clear, but without pictures it's kind of hard to explain in words....

 

[schurtj]

Thank you so much for explaining this. It stills seems WAY complicated for just the one moving part!