Friday, September 25, 2009

Pottery Classes

The Potters Place runs pottery classes for the Juvenile Assistance Corporation, who is in connection with the Clackamas County Social Services. We run these classes free of charge in hopes to help children build confidence, learn a new hobby and have a creative outlet. If you have any questions, or know of a child that could benefit from these classes please feel free to contact us.

Monday, September 7, 2009

How to make a home made electric potters / pottery wheel

Here is a potters wheel plan that uses an AC electric motor.
Now, there are two different basic kinds of motors you can use for a potters wheel (actually, there are technically several different kinds of electric motors, but these two are the most common) an AC motor or a DC motor.
The difference between the two (as pertaining to potters wheels) is that an AC motor is cheap but hard to control the speed. A DC motor is more expensive and harder to find (cheaply) but easy to control the speed.
We chose to use an AC motor at this point, we picked on up off of craigs list for $15.00. It is 3/4 horse power and 1750 rpm. Now, if you can find one with the same horse power with a lower rpm range, that is great! But if it is higher (something around 3000) this is way too fast, and will be hard to use on a potters wheel.

Once we have the motor here is a list of other things you will need;

Three pillow bearings.
One block bearing.

One 12 inch shaft (all the parts we used were 1/2 inch in bore).

One 6 inch shaft.

One dual pulley (this pulley will contain two pulleys in one, you will want them to measure any where from 3-4 inches).

One large pulley (8-9 inches).

Two hinges (we used v-shaped hinges, instead of door hinges).

One 1 inch deep and 0.5 cm thick and about four feet long, stick of aluminum. This will be used to make the pulley system for the wheel.

A desk top (or a desk, if you can find one that measures 15-20 inches high. Any higher then that, and it is difficult to use as a potters wheel.

You will need a wheel head. Either you can buy one (which they run about $45-65 on Brent's web site or you can build one out of plastic like we did). We picked up a piece of cheap plastic at the Portland Rebuilding Center that was used at one time for a counter top. We cut this piece with a normal saw and jig saw, making sure it measured 12 inches in width.

For a splash pan like ours (which is made of wood) you will want to also get a 1x8 that is about 10 feet tall.

A couple of 2x4's (you will need at least 2, 8 feet tall 2x4's).

An a series of screws (a couple 3 inches, 2 inches and 1 1/4).

3 feet of nylon rope or you can use metal cable (which is always a good alternative).

You will need caulk for sealing the splash pan area. You will also want to get some wood treatment of some kind, either a stain or a polyurethane.

Now your ready to build!

Build yourself a desk. Remember these things, it has to be very stable! No tipping or tilting of any kind, all legs must be the same length. On average the desks used are about 2 feet (sometimes smaller) in width and up to 3-4 feet in length (four feet is a stretch but at least 3.5.. this gives you room to put a bucket of water and tools).

If you are building the splash pan out of wood, you can build that next. Use the 1x8 and surround the front of the desk area with a box shape. Make sure that this box is screwed into the desk and is sturdy. You will also want to make sure your measuring is right on, because the gaps of the splash pan will need to be filled with caulk. Also one other thing to remember, is the wheel head is 12 inches wide and your splash pan will have to fit over the wheel head. So make sure it is larger then 12 inches!! Give yourself some room, maybe 3-4 inches all the way around..
There are other ways of making a splash pan, you can use a trash can lid (just turn it over, drill a hole and put under the wheel head) or if you find a good Tupperware piece that will fit, that too would work.

Once the desk is built and the splash pan in place (if you decided to build one) find out where the center of the wheel head will sit and drill a hole. Since we used 1/2 inch bore on all our pulley/shaft pieces we drilled a 1/2 inch hole.

You will be bolting down the block bearing on the top of this hole...

Right below the hole you will need to make a support for the pillow bearing. In the picture bellow it illustrates what will need to go bellow the hole you've created in the desk top

The shaft will go threw the block bearing on the top of the desk and down threw to the bottom of the desk and connect to the pillow bearing that will hold it into place at the bottom. The pulley on this shaft is the 8 inch pulley. This pulley also sits on the opposite side of the motor.

Once this pulley, shaft and the bearings are in place, you will want to work on the opposite side, where you will mount the motor.

At this point, you will want to put together the pulley system that will be on the hinges. The purpose of the hinges, is to give yourself speed control of the motor. The tighter the belts get, the more speed you will get. You tighten the belts by putting one of the pulleys on a hinge system that will swing and tighten the belt.

We created an open on one side, box out of aluminum and bolted it together. On the open side you will want to drill some holes and bolt in the hinges. Next to the hinges, drill a few more holes to fit the two other pillow bearings.

This swinging arm is pictured bellow;

As you can see from the photo's, there are two pillow bearings on either side of the aluminum box and in between is the shaft and dual pulley. One of these pulleys will be connected to the wheel head and the other pulley connected to the motor.
Now, the pulley on the motor will need to be verily small, the smaller on the motor side, the slower the speed and the large on the pulley system side the slower the speed. Any motor that you pick up that is over 1000 rpm's you will want to slow down (and actually, most potters wheels that come stock from a factory max out at 250 rmps).

In the picture above, it illistrates the two pulley systems that are put together and who the belts are connected to them.

Once you have the pulley systems together, you will want to make a foot petal of some kind that will pull on the hinged pulley system.
We bolted an eye bolt in the aluminum hinge system, so that rope or cable could pull on the hinge. Once the rope was in place we added a self contained pulley (that can be purchased at any home improvement store, such a Lowes or Home Depot and most are found in the cable/dog cage areas) this kind of a pulley can be bolted down or to the leg of the potters wheel where the cable/rope will go threw it.

Once this is done, get out the 2x4's and create a foot petal station. Cut two 2x4's a foot long and screw them together side by side (this is going to be used for the base, which is located under the petal) the petal it's self can be 7-8 inches in length, so cut two 2x4's into 7-8 inches in length. Screw these two together side by side.
Cut two more 2x4's about 4-5 inches tall. Screw these two pieces together ontop of one another. This will be a stand for the base, which will hold the other self containing pulley needed. Cut two more 2x4's, these will need to be 5-6 inches tall and do not do any thing more to these. Leave them single.
Take the base and take the stand and screw the stand in the center of the base at the top (so on either end, which ever you deem the top end) the stand should be standing on the base. On the top of the stand, screw in the self containing pulley.
Now, from the base of the base, measure 1-2 inches in and screw in the two single pieces on each side. Make sure they are directly across from each other.
With a 1/2 inch drill bit, drill a hole threw the petal (you will need to drill one side and then the other, most bits will not go threw 8 inches of wood, which is what the petal will measure when it's screwed together, side by side).
Also drill a hole in each of the single pieces you just attached to either side of the base. These holes have to line up with one another.

Get a 10 inches tall and 1/2 inches in width bolt (and a nut that fits this bolt) you might also want to get a few washers that fit this bolt also.
Force this bolt threw the holes you've made in the side stands and in the petal. Make sure it goes all the way threw and once it's out on the other side, go ahead and put the nut on it and tighten it. The tighter you make it, the harder it will be to force the petal down (or make it move at all). This is the point!!!
When you're throwing a piece on the potters wheel you will want to be able to press down on the petal and just adjust the speed once and then throw. Instead of having to constantly having to press down on the petal.

Using some L brackets you can screw the foot petal into the frame of the potters wheel, or you can leave it loose. I screwed in the petal to the frame, so that the petal would not be moving around.

And that is it!! You should have a working potter wheel.

If you have problems with the belt falling off of the pulley when it has too much slack, grab some nails and nail them near the pulley, to block the belt from falling out.