The first thing you need to know about making Ricin is that it is very deadly.
Ricin is a poison found naturally in castor beans. If castor beans are chewed and swallowed, the released ricin can cause injury. 

Ricin can be made from the waste material left over from processing castor beans. It can be made in the form of a powder, a mist, or a pellet, or it can be dissolved in water or weak acid. Ricin is just about the easiest, and at the same time, most toxic poison that a criminal can

This is how to make a home made ricin :
1.      Place 2 oz of hot water in a glass jar and add one teaspoon of lye, mix thoroughly.
2.      Wait for the lye mixture to cool.
3.      Place 2 oz of castor beans into the liquid and let them soak for an hour.
4.      Pour the liquid out taking care not to get any on your skin.
5.      Rinse the beans off with cool water and remove outside layer of bean with tweezers.
6.      Place the bean in a blender with 4 oz of acetone for every 1 oz of beans.
7.      Blend until completely mixed or a milky substance.
8.      Place in air tight jar for approximately 3 days.
9.      After three days shake jar to mix thoroughly and drain through a coffee filter.
10.  Throw away the liquid portion.
11.  Make sure to squeeze the bean portion so that all the acetone is out of the mixture.
12.  Spread on pan covered with newspaper and let it dry.
13.  The final Ricin should be free of acetone and contaminants.
14.  The product should look like a powder when complete.
15.  Remember thi is a very dangerous substance, extreme caution should be taken.