This is a easy rock tumbler. The motor can be any type as long as it has a smooth speed and enough strength to rotate the jar. The tumbler will turn any rough rocks smooth and is very fun to use and make. it doesn't need very many materials and can be made very easily.

Supplies

Materials:

A motor - can be any motor as long as it is not to fast and has a smooth constant speed. I used a fan motor.
Jar - The jar can also be any size but it must be large enough for rocks to fit in. Must also be waterproof.
PVC tubing - there is 2 sizes of tubing needed for this, one 2 cm and one 2.5 cm. 2 pieces or 2 cm and 1 piece of 2.5 cm, all longer than the jar.
Side wood - This is the side supports for the PVC and the motor.
Base wood - This wood is the base and can be plywood, MDF or any other type.
Rubber bands - These add grip and help the jar roll.
Screws or Nails - screws or nails are used to hold everything together.

Equipment

Drill and drill bits
handsaw, electric saw or other method of cutting wood
handsaw, electric saw or other method of cutting PVC
Screwdriver

Step 1: Cutting the Wood

Both the side and base wood must be cut to length. The side wood should be the diameter of the jar you are using. it should be 10cm tall and 3cm wide. This gives enough room for the jar to roll and the PVC tubing. 2 piece are needed for each end.

The base wood needs to be the same width as the side supports. The length of the jar should be the size of the jar plus and space needed for attaching the motor plus another 7 - 10 cm so that the jar can fit and the motor doesn't overheat.

Step 2: Cutting the PVC

The PVC can be cut in any way that you want. I used a hacksaw but any hand saw, electric saw or other method will do as long as a straight side can be made. Remember to sand the PVC after so it is smooth.

The 2 cm pieces must be cut to 4 cm longer than the length of the jar you are using.

The 2.5 cm piece must be cut so that it is 2 cm longer than the length of the jar you are using.

Step 3: Drill the Hole for the First Axle and Motor

This shaft will connect to the motor and so the motor will be mounted to connected to this shaft. The motor will be connected in another step.

This hole should be drilled in a top corner of both pieces of side wood. They must be in the same places so I recommend clamping them together and drilling together. These holes need to go all the way through the wood.

Remember to sand after.

Step 4: Drilling the Second Hole for the Second Axle

This hole must be drilled equal heigh as the other hole. The distance should be roughly 2/3 the diameter of your chosen jar. These holes should be drilled with a 2 cm drill bit as well. This hole must not be drilled all the way through as this axle doesn't need to spin freely. This hole will hold the second piece of 2 cm PVC.

Remember to sand after.

Step 5: Attaching the Motor.

The attachment of the motor is different for every motor as they have different attachment places. Look for any existing holes that can be used to attach. These are the easiest as they already are secure.

If there is no holes and attachment points that some must be made. Holes can be drilled in thin sheet metal. These can also be glued using a strong epoxy.

The motor that I had already had screw holes and so I could simply drill into them and they were securely attached. Screws went into the base and side walls to secure the 2 pieces together.

All types work, just remember that it needs to be secure and so Try and shake it lightly to se if it moves. If it moves, reinforce with more glue, screws or bolts.

The motor must also be attached to the axle and for this glue is the best option. Gears can be added if needed to assist in the speed.

Step 6: Assembly

This is the final step!

Pre-drill and screw the screws through the base wood and into the side pieces. 2 should be enough for each pieces but more can be added if it is not secure enough.

Before screwing the second piece on wrap the rubber bands around the outside PVC tubing every inch. Then insert then into their designated holes. Now the final side can be attached.

The jar can be added on top and you are ready to start tumbling rocks.

Step 7: How to Tumble Rocks

Tumbling is very easy but take time for the rocks to become smooth.

Grits can be purchased online from large stores such as Amazon or Ebay.

For more information visit rock tumbling websites that are specific for the type of rock you are using as it can vary between rock types.

Introduction: Super Easy DIY Rock Tumber