The Homemade Heat Pump Manifesto

[AC_Hacker]

Daox,

Sure, the water swivel is used to transfer water (or drilling mud) down a rotating drilling pipe. The purpose of this is to lubricate and cool the drill bit, and to flush cuttings up and out of the hole.

They can be purchased on ebay currently at this link:

water well swivel, great deals on Business Industrial on eBay!

I've been trying to reduce cost on this project at every step, so I made my own.

I don't currently have a lathe, so I tried to find off the shelf parts to do the trick. I made two different kinds, here's the best...

Against all advice I decided to use 3/4 inch drill pipe. I now realize that for really serious drilling 3/4 is too narrow and constrictive to transfer the amount of water required to drill deep. However, for depths such as I'm undertaking, it works just fine.

Here's a drawing:

I forgot to label the holes that are drilled in staggered positions (for strength) on opposite sides of the pipe.

Here's a photo of the drilling in process:

...so you'll want to stagger the holes and both holes should have a combined area a bit bigger than the ID of your drill pipe.

Now the trick is to find a shell and a bearing that require minimum machining to fit up properly.

Here's what I came up with:

The white shell and screw-on end caps are from Ace Hardware and are called a 'PVC 1 1/4 inch compression T'. Throw the rubber compression thingies away, you won't need them.

Here was the real breakthrough: The bearings are not measured in millimeters as bearings usually are, but are inch bearings. Get one that has an ID of 1 inch. The bearing OD must be specified to be the same as or just slightly smaller than the ID of the compression T. I found one (sorry, I forget the exact OD of the bearing) that was a perfect snug fit inside the PVC plastic compression fitting.

The 3/4 pipe OD will have to be skimmed down a few thousandths to be a proper press-on fit to the inside of the sealed bearing. This will take off the tops of the threads, but not enough to affect strength.

I stuck some bread dough about an inch down into the top end pipe and filled it up with J.B. Weld to form a plug so the water wouldn't get out.

If you want to use the rotary mud drilling technique, your rotating motor doesn't do much of the work, the water and mud become the real tool.

If you need to drill through sand/clay, mud drilling progress is really fast. However, the mud does obscure the soil you're going through. I really learned a lot about the soil characteristics, sand characteristics & soil moisture zones etc, by digging dry.

Hope this helps...

Regards,

-AC_Hacker