A great way to separate rock from dirt. It's perfect for gardens or in my case landscape rock!

I needed to install a french drain to redirect the rain from the front of my house. The problem was that my house is surrounded by rock beds! I ended up building a powered wheelbarrow trommel to save me from separating the river rock from the good dirt by hand. The trommel will also come in handy for getting all those pesky rocks from my wife's garden. The most novel thing about it is that the trommel sits on top of my wheel barrel so that dirt is dispensed right in the wheelbarrow for easy transportation. Oh, and I built the thing for less than 90.00.

Step 1: Building the Frame and Track

Dimensions
If you'd like to build one for yourself, you'll have to make up the dimensions as you custom fit the frame for your wheelbarrow. Rather than describing whats in the pictures, I tried to just take good descriptive pictures so that you could copy the design from them.

Specs for the basic parts

Gear reduction motor (125 rpm, 1/10hp, 12v, 12 amp)
3/4 inch pulley with 5/8 inch bore, but any size pulley will work
10 amp manual battery charger
1/4 or 1/2 inch wire mesh screen fencing from any hardware store
The tops of three 5 gallon buckets (two for wheel tracks and one for pulley)
8 castor wheals that fit in the track of the bucket rims
(optional) Rubber floor mat to use for funneling the load into the trommel drum

Tips

If you are going to use a garbage can to catch the rocks as they come out of the trommel, you'll find that the wheelbarrow will tip backwards. I shifted my wheelbarrow's legs back 6 inches. The easiest way to keep the cross plate that gives the legs their stability is to turn the legs around before remounting them. If you'd like to save 15 or so dollars you could forgo the mesh screen and bolt two 5 gallon buckets together and then drill "a lot* of 5/16 in holes in buckets to simulate a screen. It works. I tried it, but it won't perform as well as the mess screen. Get a wheelbarrow with two wheels! I overloaded the wheelbarrow a few times and almost it.

Step 2: Creating the Drum

I moved to a new house with lava rock and found myself wishing the wire drum was 1/2 mesh than 1/4. The orange drum's 1/4 square mesh worked really well for separating river rock from dirt. This blue drum with 1/2 inch mesh is more aggressive. It will let more dirt through, but if you are confident that you don't have any pebbles in your pile you are good.

Shopping list

3 five gallon buckets
1 five foot role of wire weld fencing
28 half inch pan head screws (the fatter the head the better.)
Depending on how fat the heads of your pan head screws are and how big of holes your fence has you may need to get 28 washers to help hold down the wire.

Steps

Cut two of the buckets about 1.5 inches below the bottom most channel. I used a sawzall, but a hacksaw works too.
Cut the third bucket just below the bottom most channel. Use this one for the middle of the drum.
Slide the middle bucket rim onto the drum. Then slide the two other bucket rims onto the ends of the fencing.
Starting with the outside bucket rims, screw the fencing down to the inside of the first rim.
Once you have one rim on, dry fit the drum on the trommel and line up the other end rim with the track wheels. Then screw the fencing down to the second rim.
NOTE : Remember this thing has to turn. Make sure that you screw the rims on straight so that your wheels run smoothly in the channels. Use washers with the screws if the heads of your screws are not wide enough to grab a hold of the fence.
Once you are confident in how the drum turns, line up the middle rim with the pulley from the motor.
Attach the belt to the pulley.
Screw down the fencing to the middle rim with just four screws. Then give it turn using the belt. Adjust the positioning of the rim until the drum turns with ease using the belt. It should not seam like it struggles. If the drum turns like it's an off balance egg then you've got some more tuning to do.
Once the drum turns like a dream, screw fence down to the middle rim with the remaining screws.