Hollow cylinder

X -> R len ( 0.3 0.3 ) R height ( 0.1 1.3 ) R radius ( 0.5 1.75 ) R* tex ( 1 12 ) R* count ( 10 63 ) A ( 90 0 ) S ( 1 1 1 ) [ MAIN ]
MAIN 1 count len radius height -> Y 
Y 30  ->   A ( 10 2 )  [ YB ] 
YB ->  [ T ( 1.5 0 0 ) [ YB2 ] ] 


YB2 ->  {   S ( 1 1 1 ) A ( 90 2 ) D ( 0.3 3 1.0 ) [ S ( 0.3 0.3 height )  I ( Cube tex 0 1 ) ]  }

X -> R len ( 0.3 0.3 ) R height ( 0.1 1.3 ) R sx ( 1 3 ) R sy ( 1 3 ) R radius ( 0.5 1.75 ) R* tex ( 1 12 ) R* count ( 10 63 ) A ( 90 0 ) S ( 1 1 1 ) [ MAIN ]


MAIN 1 count len radius height -> Y T ( 1 2 0 ) S ( 0.2 0.2 4 ) Y1 T ( 0 -12 0 ) Y1


Y 30  height tex sx sy ->   A ( 10 2 )  [ YB ] 

Y1 40 height tex sx sy -> A ( 10 2 ) [ YB ]



YB ->  [ T ( sx 0 0 ) [ YB2 ] ] 


YB2 ->  {   S ( 1 1 1 ) A ( 90 2 ) D ( 0.3 3 1.0 ) [ S ( 0.3 0.3 height )  I ( Cube tex 0 1 ) ]  }