i'm just getting back into AutoCAD after about 5 years layoff and i'm
having some trouble.  i made a solid model of a gear (a large cylinder
with a taller cylinder protuding through the middle).  where the 2
cylinders meet there is suppose to be a filleted edge but i can't get
the fillet command to work correctly.  when the command does do
something, it fillets the wrong way (the fillet curves in towards the
center instead of feathering into the other cylinder).

to work around this, i made a profile of the filleted edge and tried to
revolve it. however, after doing that, i couldn't union all the pieces
together.

any suggestions?  thanks in advance for the help!

 
 Create a fillet edge for everyone cylinder and then join them.
how do you think.