Subtract Error

I have been trying to write a lisp to create a 3D plate with a center hole in it and i can not get the "Subtract" command to work in lisp. I create a "box" then a "cylinder" after each of them i us the "entlast" function to identify them. However when i put in the command in the lisp, it does not except the entity that the "entlast" gives it. Below is how i have tried it and i can not get it to work. What am i doing wrong?

(command "BOX" P6 P7 BPT)
(setq E1 entlast)
(command "CYLINDER" P5 PBR BPT)
(setq E2 entlast)
(command "Subtract" E1 "" E2 "")

 

Change
(setq E1 entlast)
to
(setq E1 (entget (entlast)))

in it and i can not get the "Subtract" command to work in lisp. I create a
"box" then a "cylinder" after each of them i us the "entlast" function to
identify them. However when i put in the command in the lisp, it does not
except the entity that the "entlast" gives it. Below is how i have tried it
and i can not get it to work. What am i doing wrong?

 

actually he needs...
(setq E1 (entlast))

 

Eliminate the entget and you've got it.
E2 has to be an entity, not an association
list (or whatever you call the issue of an entget).

(command "BOX" P6 P7 BPT)
(setq E1 (entlast))
(command "CYLINDER" P5 PBR BPT)
(setq E2 (entlast))
(command "Subtract" E1 "" E2 "")

-doug

 

Glad we're in agreement there!

It's actually a pretty neat way of creating a 'complex' solid.
I can't see it going much further than this, but maybe...

Not quite as versatile as a true solid, but easier than putting the pieces
together manually.
-doug