There are many factors that dictate the
quality of final quality of homemade biodiesel fuel

There are many factors that dictate the
quality of final quality of homemade biodiesel fuel  

You don't need a really fancy biodiesel processor to make your own     
high quality diesel fuel.  There are many factors that dictate the
quality of final quality of homemade biodiesel fuel.  The number one
most important consideration is the quality of the oil. If your
oil is good then a second hand blender could be the best biodiesel
processor for you, and an excellent investment.

It is the quality of the oil that you put in your biodiesel
processor that is the most important.  The best way to save
a lot of headaches is to try and choose clean sources of
waste oil in.  Dirty, contaminated oil is a
lot harder to filter. It can contain water, food debris,
salt, used condoms, old filters that the restaurant accidentally dropped in, dead animals and lots of other strange things.  Be prepared for some surprises! 
 
Your first step will be to find a good source of relatively clean
oil as well as something to store it in. The most common sources of
free cooking oil are restaurants.  MacDonald's, KFC or similar
fast food outlets are a good place to start.  I have found that small “Maw and Pa” type of restaurants are good because they have not got a contract with a reduction company to pick up their waste oil.  They are some times a lot easier to deal with than a company or franchise store.

It is probably easiest to get your waste oil from a restaurant but
it is also the dirtiest oil in terms of how much you will
end up having to filter it before you can put it in your biodiesel
processor.  However, waste oil from restaurants is plentiful and one
restaurant can produce anywhere from 5 to over 50 gallons a week.