Here we have a set of drywasher plans. It is of the bellows type also known as a "puffer". This machine is designed to be powered by a gas engine but it could also be hand cranked.

The copy of the plans I have doesn't show an author or copyright so I guess it's OK to put them here.

This thing has too many parts for me to consider building it but here are some thoughts based on my drywashing experience.

The plans don't show any bearings on the crankshaft. I would add sealed ball bearings at the three points on the crankshaft. Drywashers create a very unfriendly enviroment for bearings. Ditto for engines - I have seen photos of the engine separated from the drywasher (and the dust) by 6 feet or more using a looooong belt. Dust is not good for humans either - Wear a dust mask!!

I have a small sampling drywasher that uses a different bellows arrangement. The front, back & sides are made of sheet metal. Here are some photos showing how it works:

This view shows the sheet metal back and side of the bellows. Also shown is the movable plywood bottom and the valves. While not very obvious, the back is slightly curved to match the radius of the moving bottom.

Note the weather stripping seal around the plywood bottom and around the top where the riffle box sits.

This photo shows the other end of the plywood bottom showing the use of a piano hinge that runs across the bellows. I think this is better than the two hinges shown in the plans.

I have been told by at least three guys that know about these things that you can wash the cloth which will go under the riffles before you attach it to the tray. After the dry washer is used, never, ever let the cloth get even damp. I usually put mine in the truck at night to prvent dew from getting to it.

Here is a little trick I learned. To see if you are getting any gold, remove the riffle tray, hold the tail end of the tray in one hand and tap on the head end with your other hand. This will move the dirt away from the riffles and expose some of the gold. I found that if I see some gold, there is quite a bit more I can't see. Usually, if I don't see any, I'll still have some gold but I will be disappointed in the amount.

Right click here and choose "save to disk" or "save as" or something like that to download the 328K Zip file

The scans aren't all that great so I'll rescan the plans. I should be able to get at least as good as the illustration at the top of the page.

Go to Tom Ashworth's site for a leaf blower powered, aluminum drywasher - It looks great.