Francis' Junction: DIY Potter's Wheel or Turntable For Ferro-cement Projects

I borrowed this idea from pottery where a potter's wheel is used to shape round ceramic ware. Modern potter's wheel uses a motor or crankshaft and flywheel to turn the platform. Traditional pottery wheel uses a pivot system usually in the shape of an inverted cone and attached to the platform. It's hand-powered. My potter's wheel uses glass marbles as the pivot and ferro-cement for the platform and base.

I created this potter's wheel or turntable especially for my ferro-cement projects. It helps me turn the project assembly around as I work on it rather than walk over the other side.

Hand-powered Potter's wheel or turntable made of ferro-cement

A ferro-cement project assembly on top of the potter's wheel

Construction of The Potter's Wheel

This is a cross-section diagram of the potter's wheel which is constructed from cut-outs of a large plastic container, some glass marbles and ferro-cement.

Cross-section of turntable consisting of a base unit and top unit with glass marbles in between

My potter's wheel consists of a top unit which acts as a platform where I place my project assembly. The lower section of this top unit acts like a pivot and rides freely over glass marbles placed in a hole in the bottom unit.

The glass marbles act as ball-bearings to enable the top unit (pivot and platform) turn around easily when you move the platform with your hand.

The bottom unit is the container for the marbles.

Materials Needed

A large cylindrical plastic container (the size depends on how big you want to make the potter's wheel). Some glass marbles. Portland cement, sand and water for making the mortar. Iron rods and wire mesh.

Large plastic container (6 liters) used to hold ice-cream

Cut out the two pieces (top and bottom) with a pair of sharp scissors. See diagram below:

Cut-outs from the plastic container

Description

The pivot or base of the top unit sits on the marbles and the walls of the pivot kept in place by the walls of the bottom unit. Only the top of the marbles and the bottom of the top unit are in full contact. There should be a small gap in between the concrete shoulders of the top and base units so that they do not touch each other.

Notice the small gap between the top and bottom units

The bottom unit has a circular hole with plastic part as the side walls. This hole is filled completely with a layer of glass marbles of the same size. The amount of marbles used depends on the size of the hole. If the hole is packed too loosely with only a few marbles, the top unit or wheel resting on the marbles would wobbled because of uneven distribution of weight. On the other hand, if too many marbles are packed in tightly, they would restrict free movement and the wheel becomes difficult to turn around with your hand. You can add some lubricant such as grease or motor oil for better motion.

Construction of The Bottom Unit

Start off by making the bottom unit. The diameter of the plastic mold should be 2 or 3 cm larger than your plastic container. Reinforced the base with some iron rods and wire mesh.

Cut-out plastic mold for the base

Pour enough mortar containing 1 part cement and 3 parts sand (the basic ferro-cement mixture) to cover the wired grid.


Basic frame-work of iron rods, wire mesh and mortar

Place plastic part in center and filled the sides with mortar

Then, place the cylindrical shaped plastic cut-out directly over the center of the mold. The inside section of plastic now becomes the mold for the hole where the marbles are placed. The outside section of this mold is filled with mortar and becomes the walls of the bottom or base unit.

Fill the empty space outside the circular plastic with mortar until it reaches the brim or top edge of the plastic. The height of this wall is critical as the hole you are creating should be deep enough to hold a layer of marbles plus about two centimeters of the pivot when the top unit is placed over the bottom unit.

The bottom unit of the potter's wheel is now completed and left to harden.

This is how the bottom unit looks like when completed. It's a container for the marbles.

Construction of The Top Unit - Pivot and Platform

The making of the top unit of the potter's wheel follows almost the same steps above except that the plastic part came from the bottom section of the original plastic container and you make a pivot instead of a hole.

Start off by making the platform. The diameter of the plastic mold should be 2 or 3 cm larger than your plastic container. Reinforced the bottom with some iron rods and wire mesh.

Pour enough mortar containing 1 part cement and 3 parts sand (the basic ferro-cement mixture) to cover the wired grid in the mold. Now, take the cut-out plastic which is the cut-off bottom portion of the plastic container and filled it tightly with mortar. You would want this unit to be solid hard when completed as this is the pivot which rides on top of the marbles.

Construction of the top unit

The next step is a bit tricky. You have to invert the plastic part containing the wet mortar and place it directly over the center of the mortar in the base mold. I did it by covering the mortar in the plastic with a piece of hard cardboard. Then, I inverted the plastic part without any mortar falling off and placed the covered part over the center of the base mold.

Once it's in place, I removed the hard cardboard and the plastic part is now firmly embedded in the center of the mortar in the base mold. Next, I checked that the protruding plastic part has the height and alignment I needed. You may have to add or remove some mortar around the plastic part for this fine adjustment.